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Background: From an evolutionary biology perspective, where growth and reproduction trade‐off against longevity, we assessed the associations of growth from birth to puberty by phase with later glycemic indicators and any differences by sex. Methods: In the population‐representative Hong Kong Chinese "Children of 1997" birth cohort (n = 8327), the relation of initial size (weight‐for‐age z score (WAZ) at birth, length/height‐for‐age z score (LAZ) at 3 months or body‐mass‐index‐for‐age z score (BAZ) at 3 months based on the World Health Organization growth standards/references) and growth at different phases (WAZ gains from 0 to 2 and 2 to 8 years, LAZ or BAZ gains from 3 months to 3 years, 3 to 8 years and 8 to 14 years) with fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) at ~17.5 years, was assessed using adjusted partial least squares regression. Additional analyses further considered growth in late and early infancy. Results: This study included 3276 of the cohort participants. Higher WAZ gain from 2 to 8 years, LAZ and BAZ gains from 3 to 8 years were consistently associated with higher FPG, adjusted for maternal and infant characteristics, family history of diabetes and household income. Also, higher BAZ gain from 3 to 8 years was associated with higher HbA1c. These associations did not differ by sex. Conclusions: Our findings suggest different mechanisms could underlie the pathogenesis of glucose intolerance. Factors that drive specific growth at different phases need to be evaluated to better inform child growth management for long‐term health outcomes. [ABSTRACT FROM AUTHOR]

Abstract Background Glucose-6-phosphate dehydrogenase (G6PD) deficiency affects 6.0% of the global population. G6PD deficiency has been associated with lower risk of cardiovascular disease and higher risk of diabetes, which could be etiologically informative, but these relations are uncertain. To clarify, we assessed the associations of G6PD deficiency with serum metabolite profiles in late adolescence. Methods In a nested case-control study of 50 G6PD-deficient late adolescents (~17.5 years) and 150 sex-matched non-G6PD-deficient controls from a Chinese birth cohort: "Children of 1997", we compared 80 serum metabolites analyzed by nuclear magnetic resonance spectrometry using adjusted linear regression with Bonferroni correction for testing 12 traits (p < 0.0042). Results G6PD-deficiency was inversely associated with serum levels of total cholesterol (−0.27 mmol, 95% confidence interval (CI) −0.46, −0.09, p = 0.004), free cholesterol (−0.08 mmol, 95% CI −0.13, −0.03, p = 0.003) and creatinine (−0.004 mmol, 95% CI −0.007, −0.001, p = 0.003), adjusted for sex and parental education. G6PD deficiency was not associated with fatty acids, amino acids, glucose or related metabolites, ketone bodies or glycoprotein. Conclusions G6PD deficiency is associated with lower serum levels of cholesterol and creatinine, but not other serum metabolites. Whether such differences are transient or become more evident in adulthood warrant further investigations. Highlights • G6PD deficiency was associated with lower serum levels of total and free cholesterol, and creatinine. • G6PD was unrelated to serum fatty acids, amino acids, glucose, ketone bodies or glycoprotein. • Such differences in serum metabolites at ~17.5 years by G6PD status warrant further investigations. [ABSTRACT FROM AUTHOR]

Purpose: Prospectively childhood behavioral problems and low self-esteem are associated with depression. However, these mental health changes over time have never been examined. This study assessed the association of childhood behavioral trajectories and self-esteem changes over time with adolescent depressive symptoms.Methods: Parent-reported Rutter behavioral assessments and self-reported Culture-Free Self-Esteem Inventories (SEI) were obtained via record linkage from the Student Health Service, Department of Health (Hong Kong), and the Patient Health Questionnaire-9 (PHQ-9) depressive symptom scores were obtained via active follow-up of the Hong Kong's Children of 1997" Chinese birth cohort. Partitional clustering was used to generate homogenous trajectories between ~ 7 and ~ 11 years for Rutter scores. Changes in low self-esteem between ~ 10 and ~ 12 years were obtained from the SEI. Multiple linear regression was used to estimate their associations with depressive symptom scores at ~ 13 years.Results: Four trajectories/groups (stable low, declining, rising, and stable high) of Rutter score and self-esteem groups were created. The stable low behavioral trajectory was associated with the fewest depressive symptoms while the stable high trajectory had 1.23 more depressive symptoms [95% confidence interval (CI) 0.84 to 1.61] than the stable low trajectory. Consistently low self-esteem (stable low) was associated with 2.96 more depressive symptoms (95% CI 2.35-3.57) compared to consistently high self-esteem (stable high).Conclusions: Sustained or worsening childhood behavioral problems and low self-esteem were precursors of adolescent depressive symptoms, and as such could be an early indicator of the need for intervention. [ABSTRACT FROM AUTHOR]

Breastfeeding has many benefits for mother and infant. Whether breastfeeding also protects against type 2 diabetes is unclear. To clarify the role of breastfeeding in type 2 diabetes, we assessed the association of breastfeeding with insulin resistance in late adolescence in a birth cohort from a non-Western setting where breastfeeding was not associated with higher socio-economic position. We used multivariable linear regression, with multiple imputation and inverse probability weighting, to examine the adjusted associations of contemporaneously reported feeding in the first 3 months of life (exclusively breastfed, mixed feeding, or always formula-fed) with fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) at 17 years in a subset ( n = 710, 8.6% of entire cohort) of the Hong Kong Chinese birth cohort 'Children of 1997.' We found a graded association of breastfeeding exclusivity in the first 3 months of life with lower fasting insulin and HOMA-IR ( p-for-trend < .05), but not fasting glucose, at 17 years. Exclusively breastfed adolescents (7%) had nonsignificantly lowest fasting insulin and HOMA-IR, adjusted for sex, birth weight, parity, length of gestation, pregnancy characteristics, parents' education, and mother's place of birth. Exclusively breastfeeding for 3 months may be causally associated with lower insulin resistance in late adolescence. Further follow-up studies into adulthood are required to clarify the long-term protection of breastfeeding from type 2 diabetes. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Within populations, height is positively associated with economic success and in economically developed populations inversely associated with health. Recent studies also suggest air pollution may result in higher bone turnover markers among children, which may affect growth. However, few studies have investigated the effect of air pollution on height or growth rate. We therefore assessed the associations of several air pollutants with height at different ages. Methods: We simultaneously assessed associations of particulate matter with a diameter of 10 micrometers or less (PM10), sulfur dioxide (SO2), nitric oxide (NO), and nitrogen dioxide (NO2) in utero, in infancy, and in childhood with height at different ages (∼9, ∼11, ∼13, and ∼15 years), in a population‐representative birth cohort “Children of 1997” (n = 8327) from the developed non‐Western setting of Hong Kong with relatively high air pollution and short children, using partial least square regression. Results: After considering multiple comparison, higher SO2 in childhood was associated with shorter height at ∼13 years (–0.20 cm, 99% CI −0.32 to −0.06). This difference was not evident at ∼15 years. Conclusions: These observations suggest that air pollution may affect the trajectory of growth and development rather than final height, with corresponding implications for health in later life. [ABSTRACT FROM AUTHOR]

Objectives A warning from Health Canada suggests that testosterone increases blood pressure (BP). No evidence from large randomized controlled trials is available, and observational studies are confounded by ill-health lowering serum testosterone. To address the evidence gap, we assessed the association of pubertal testicular volume, as a reflection of testosterone production, with BP. Methods We examined whether testicular volume was associated with sex-, age-, and height-standardized BP z-score at ∼13 years in a population-representative Chinese birth cohort ( n = 5195, 63% follow-up). We used age at pubertal onset, determined as the earliest age when Tanner stage II for genitalia, breast, or pubic hair, or testicular volume of 4 mL occurred, as control exposures. These exposures were expected to produce findings different from testicular volume because they are not direct measures of testosterone. They were used to ascertain specificity of exposure and to detect residual confounding. Results Greater testicular volume was associated with higher systolic BP by 0.03 z-score, which is equivalent to 1.40 mm Hg per standard deviation of testicular volume (95% CI 0.02-0.04), adjusted for infant characteristics, socioeconomic position, and childhood body mass index. Similarly adjusted, earlier pubertal onset was not associated with higher systolic BP z-score in boys or girls. Conclusions Greater pubertal testicular volume is related to higher BP, consistent with a potential role of androgens in the higher BP in boys than girls that emerges during puberty. Our finding provides preliminary evidence supportive of more definitive studies to clarify the warning on testosterone from Health Canada. [ABSTRACT FROM AUTHOR]

Many pollutants are endocrine disruptors with impacts on reproduction and health in animals, but evidence in humans, of which sex-specific effects on pubertal development may be an indicator, is less clear. We examined the association of air pollution in utero and during early life with pubertal development in Hong Kong, China, an area with a high level of air pollution compared with other similarly developed cities. We assessed sex-specific associations of particulate matter less than or equal to 10 µm in diameter (PM10), nitric oxide, sulfur dioxide, and nitrogen dioxide in different growth phases with clinically assessed pubertal stage at approximately age 11 years (as indicated by Tanner stage) in a large population-representative birth cohort, the "Children of 1997." We used partial least squares regression to account for colinearity between air pollutants. Among 1,938 girls, PM10 exposure in utero and during infancy was negatively associated with pubertal stage and breast development, whereas among 2,136 boys, sulfur dioxide and nitrogen dioxide exposure in utero, during infancy, and in childhood were negatively associated with pubertal stage. These sex-specific associations with pubertal development are consistent with endocrine-disrupting effects. Given the health impact of altered pubertal timing, further investigation across the life course may help quantify the full effects and the corresponding need for preventive measures. [ABSTRACT FROM AUTHOR]

The FAMILY Cohort is a longitudinal study of health, happiness and family harmony (the '3Hs') at individual, household and neighbourhood levels in Hong Kong. Using a family living in the same household as the sampling unit, the study (n = 20 279 households and 46 001 participants) consists of a composite sample from several sources, including: a population-representative random core sample (n = 8115 households and 19 533 participants); the first-degree relatives of this sample (n = 4658 households and 11 063 participants); and oversampling in three new towns (n = 2891 households and 7645 participants) and in three population subgroups with anticipated changes in family dynamics (n = 909 households and 2160 participants). Two household visits and five telephone- or web-based follow-ups were conducted over 2009-14. Data collected include socio-demographics, anthropometrics, lifestyle and behavioural factors, measures of social capital, and standardized instruments assessing the 3Hs. We also intend to collect biomaterials in future. The analytical plan includes multilevel inter-relations of the 3Hs for individuals, households, extended families and neighbourhoods. With Hong Kong's recent history of socioeconomic development, the FAMILY Cohort is therefore relevant to global urban populations currently experiencing similarly rapid economic growth. The FAMILY Cohort is currently set up as a supported access resource. [ABSTRACT FROM AUTHOR]

Background: The ongoing yellow fever epidemic in Angola strains the global vaccine supply, prompting WHO to adopt dose sparing for its vaccination campaign in Kinshasa, Democratic Republic of the Congo, in July-August, 2016. Although a 5-fold fractional-dose vaccine is similar to standard-dose vaccine in safety and immunogenicity, efficacy is untested. There is an urgent need to ensure the robustness of fractional-dose vaccination by elucidation of the conditions under which dose fractionation would reduce transmission.Methods: We estimate the effective reproductive number for yellow fever in Angola using disease natural history and case report data. With simple mathematical models of yellow fever transmission, we calculate the infection attack rate (the proportion of population infected over the course of an epidemic) with various levels of transmissibility and 5-fold fractional-dose vaccine efficacy for two vaccination scenarios, ie, random vaccination in a hypothetical population that is completely susceptible, and the Kinshasa vaccination campaign in July-August, 2016, with different age cutoff for fractional-dose vaccines.Findings: We estimate the effective reproductive number early in the Angola outbreak was between 5·2 and 7·1. If vaccine action is all-or-nothing (ie, a proportion of vaccine recipients receive complete protection [VE] and the remainder receive no protection), n-fold fractionation can greatly reduce infection attack rate as long as VE exceeds 1/n. This benefit threshold becomes more stringent if vaccine action is leaky (ie, the susceptibility of each vaccine recipient is reduced by a factor that is equal to the vaccine efficacy). The age cutoff for fractional-dose vaccines chosen by WHO for the Kinshasa vaccination campaign (2 years) provides the largest reduction in infection attack rate if the efficacy of 5-fold fractional-dose vaccines exceeds 20%.Interpretation: Dose fractionation is an effective strategy for reduction of the infection attack rate that would be robust with a large margin for error in case fractional-dose VE is lower than expected.Funding: NIH-MIDAS, HMRF-Hong Kong. [ABSTRACT FROM AUTHOR]

Background: To examine the association of glucose-6-phosphate dehydrogenase (G6PD) deficiency with adolescent physical and mental health, as effects of G6PD deficiency on health are rarely reported. Methods: In a population-representative Chinese birth cohort: “Children of 1997” (n = 8,327), we estimated the adjusted associations of G6PD deficiency with growth using generalized estimating equations, with pubertal onset using interval censored regression, with hospitalization using Cox proportional hazards regression and with size, blood pressure, pubertal maturation and mental health using linear regression with multiple imputation and inverse probability weighting. Results: Among 5,520 screened adolescents (66% follow-up), 4.8% boys and 0.5% girls had G6PD deficiency. G6PD-deficiency was not associated with birth weight-for-gestational age or length/height gain into adolescence, but was associated with lower childhood body mass index (BMI) gain (-0.38 z-score, 95% confidence interval (CI) -0.57, -0.20), adjusted for sex and parental education, and later onset of pubic hair development (time ratio = 1.029, 95% CI 1.007, 1.050). G6PD deficiency was not associated with blood pressure, height, BMI or mental health in adolescence, nor with serious infectious morbidity until adolescence. Conclusions: G6PD deficient adolescents had broadly similar physical and mental health indicators, but transiently lower BMI gain and later pubic hair development, whose long-term implications warrant investigation. [ABSTRACT FROM AUTHOR]

Background: Birth order has been proposed as a cardiovascular risk factor, because the lower birth weight and greater infant weight gain typical of firstborns could programme metabolism detrimentally. Methods: We examined the associations of birth order (firstborn or laterborn) with birth weight-for-gestational age, length/height and body mass index (BMI) z-scores during infancy, childhood, and puberty using generalized estimating equations, with age at pubertal onset using interval-censored regression and with age-, sex- and height-standardized blood pressure, height and BMI z-scores at 13 years using linear regression in a population-representative Chinese birth cohort: “Children of 1997” (n = 8,327). Results: Compared with laterborns, firstborns had lower birth weight-for-gestational age (mean difference = -0.18 z-score, 95% confidence interval (CI) -0.23, -0.14), lower infant BMI (-0.09 z-score, 95% CI -0.14, -0.04), greater childhood height (0.10 z-score, 95% CI 0.05, 0.14) and BMI (0.08 z-score, 95% CI 0.03, 0.14), but not greater pubertal BMI (0.05 z-score, 95% CI -0.02, 0.11), adjusted for sex, parental age, birthplace, education and income. Firstborns had earlier onset of pubic hair (time ratio = 0.988, 95% CI 0.980, 0.996), but not breast or genitalia, development. Firstborns had greater BMI (0.07 z-score, 95% CI 0.002, 0.15), but not height (0.05 z-score, 95% CI -0.01, 0.11), at 13 years, but similar blood pressure. Conclusions: Differences by birth order continue into early adolescence with firstborns being heavier with earlier pubic hair development, which could indicate long-term cardiovascular risk. [ABSTRACT FROM AUTHOR]

Introduction: Low early life socio-economic position is more strongly associated with adiposity among women than men. We examined whether the sex difference of social patterning in general and central adiposity exists before adulthood. Methods: In Hong Kong’s “Children of 1997” birth cohort, we used multivariable regression to examine the association of parental education, a marker of early life socio-economic position, with body mass index (BMI) (n = 7252, 88% follow-up) and waist-height ratio (n = 5636, 68% follow-up), at 14 years. Results: Parental education of Grade 9 or below, compared to Grade 12 or above, was associated with higher waist-height ratio z-score particularly in girls (0.30, 95% confidence interval (CI) 0.19, 0.41) compared to boys (0.12, 95% CI 0.02, 0.22) (p for sex interaction = 0.02). Lower parental education was associated with greater BMI z-score in adolescents of locally born mothers, but not adolescents of migrant mothers, with no difference by sex. Conclusions: Different social patterning in different markers of adiposity may imply different sociological and biological mediating pathways. A stronger association between low early life socio-economic position and waist-height ratio in adolescent girls may indicate sex-specific influences of SEP related early life exposures on central adiposity. [ABSTRACT FROM AUTHOR]

Background and Aims Second-hand smoke (SHS) exposure is associated negatively with childhood behavioural problems in western settings. In a developed non-western setting, we estimated the associations of early SHS exposure during the prenatal and postnatal periods with several aspects of adolescent mental health. Design Multivariable linear regression was used to estimate the adjusted associations of pre- and postnatal SHS exposure with adolescent mental health. Setting Hong Kong. Participants Population-representative 'Children of 1997' birth cohort. Behavioural problems at ~11 years were available for 5598, self-esteem at ~11 years for 6937 and depressive symptoms at ~13 years for 5797. Measurements SHS was categorized as no SHS exposure, occasional prenatal SHS exposure from non-parental sources, daily prenatal SHS exposure from non-parental sources, postnatal SHS exposure from non-parental sources, prenatal and postnatal SHS exposure from non-parental sources, occasional paternal smoking, daily paternal smoking and any maternal smoking. Behavioural problems were assessed from parent-reported Rutter score, self-esteem from self-reported Culture-Free Self-Esteem Inventory score and depressive symptoms from self-reported Patient Health Questionnaire-9 score. Findings Prenatal SHS exposure from non-parental sources was associated with behavioural problems at ~11 years (1.24, 95% confidence interval 0.20-2.28) adjusted for sex, age of assessment, survey mode (for depressive symptoms only), socio-economic position (SEP), mother's birthplace, gestational age and parity; paternal smoking and maternal smoking were associated with more mental health problems but also with lower SEP. Conclusions In Hong Kong, prenatal second-hand tobacco smoke exposure appears to be a risk factor for behavioural problems at age 11 years independent of socio-economic position. [ABSTRACT FROM AUTHOR]

Background Preterm, and more recently early term, birth has been identified as a risk factor for poor health. Whether the sequelae of late preterm or early term birth extends to poor mental health and well-being in adolescence is unclear and has not been systematically assessed. Method Linear regression was used to assess the adjusted associations of gestational age (very/moderate preterm (<34 weeks, n=85), late preterm (34-36 weeks, n=305), early term (37-38 weeks, n=2228), full term (39-40 weeks, n=4018), late term (41 weeks, n=809), post-term (=42 weeks, n=213)) with self-reported selfesteem at ~11 years (n=6935), parent-reported Rutter score assessing the common emotional and behavioural problems at ~7 years (n=6292) and ~11 years (n=5596) and self-reported depressive symptoms at ~13 years (n=5795) in a population-representative Hong Kong Chinese birth cohort 'Children of 1997' where gestational age has little social patterning. Results: Very/moderate preterm birth was associated with higher Rutter subscore for hyperactivity (ß coefficients 0.5, 95% CI 0.01 to 1.00) at ~7 years but not at ~11 years, adjusted for sex, age, socioeconomic position, parents' age at birth, birth order and secondhand smoke exposure. Similarly adjusted, late preterm, early term, late term and post-term birth were not associated with self-esteem or depressive symptoms. Conclusions: In a population-representative birth cohort from a non-Western-developed setting, gestational age had few associations with mental health and well-being in adolescence, whereas very preterm birth was specifically associated with hyperactivity in childhood. Inconsistencies with studies from Western settings suggest setting specific unmeasured confounding may underlie any observed associations. [ABSTRACT FROM AUTHOR]

Background: Informal child care (child care by untrained family members, relatives or employees in the home) in Western populations is often associated with poorer psychological well-being, which may be confounded by socioeconomic position. We examined the association of informal child care, common in non-Western settings, with adolescent psychological well-being, using Hong Kong’s Chinese “Children of 1997” birth cohort. Methods: Multivariable linear regression was used to examine the adjusted associations of informal child care (at 0.5, 3, 5 and 11 years) with parent-reported Rutter score for child behavior at 11 years, self-reported Culture-Free Self-Esteem Inventories score at 11 years and self-reported Patient Health Questionnaire-9 depressive symptom score at 13 years. Model comparisons were used to identify the best representation of child care, in terms of a critical period of exposure to informal child care (independent variable) at a specific age, combination of exposures to informal child care at several ages or an accumulation of exposures to informal child care. Results: Child care was not associated with behavioral problems. A model considering child care at 3 years best represented the association of child care with self-esteem while a model considering child care at 5 years best represented the association of child care with depressive symptoms. Informal child care at 3 years was associated with lower self-esteem (-0.70, 95% confidence interval (CI) -1.26 to -0.14). Informal child care at 5 years was associated with more depressive symptoms (0.45, 95% CI 0.17 to 0.73). Conclusion: In a developed non-Western setting, informal child care was associated with lower self-esteem and more depressive symptoms. [ABSTRACT FROM AUTHOR]

Background: In Western settings, migration is associated with psychological well-being, but studies inevitably focus on culturally distinct ethnic minorities, making it difficult to distinguish migration from cultural assimilation. Many children in Hong Kong, a developed non-Western setting, have migrant parents with the same Chinese ethnicity. This study examined the association of migration with the child’s psychological well-being in Hong Kong. Methods: Multivariable linear regression was used in Hong Kong’s ‘Children of 1997’ Chinese birth cohort to examine the adjusted associations of migration (both parents Hong Kong born n=4285, both parents migrant n=1921, mother-only migrant n=462, father-only migrant n=1110) with a parent-reported Rutter score for child behaviour at ∼7 (n=6294, 80% follow-up) and ∼11 years (n=5598, 71% follow-up), self-reported Culture-Free Self-Esteem Inventory score at ∼11 years (n=6937, 88% follow-up) and self-reported Patient Health Questionnaire-9 (PHQ-9) depressive symptom score at ∼13 years (n=5797, 73% follow-up), adjusted for sex, highest parental education and occupation, household income, maternal and paternal age at birth, age of assessment and survey mode (PHQ-9 only). Results: Migration was unrelated to the overall self-esteem or depressive symptoms, but both parents migrant was associated with better behaviour (lower Rutter scores) at ∼7 years (β-coefficient (β) −1.07, 95% CI –1.48 to −0.66) and ∼11 years (−0.89, 95% CI −1.33 to −0.45). Conclusions: In a non-Western context, migration appeared to be protective for childhood behaviour. [ABSTRACT FROM AUTHOR]

Highlights: [•] We did a representative assessment of HPV vaccine acceptability in Hong Kong. [•] We found that while acceptability was moderate, the actual uptake was markedly lower. [•] Female adolescent HPV vaccine acceptability increased from 2008 to 2012. [•] The willingness to pay of HPV vaccination was largely lower than the market price. [•] Cost of vaccination was a barrier against HPV vaccine acceptability. [ABSTRACT FROM AUTHOR]

PURPOSE: To examine whether mode of delivery was associated with childhood adiposity in a developed non-Western context. METHODS: We used generalized estimating equations to estimate the association of mode of delivery (vaginal or cesarean) with body mass index (BMI) z-score and overweight (including obesity) from 3 months to 13 years, in 7809 term birth (94% follow-up) from a population-representative Chinese birth cohort, 'Children of 1997.' We used multiple imputation for missing data. RESULTS: The cesarean section rate (26%) was higher for children born in private hospitals, with lower gestational age, lower birth order, higher maternal age, higher maternal BMI, and higher family socioeconomic position. Cesarean section was not associated with BMI z-score from 3 months to 13 years (mean difference, 0.03; 95% confidence interval, -0.02 to 0.09) or overweight from 3 years to 13 years (odds ratio, 0.98; 95% confidence interval, 0.77 to 1.25) after adjusting for infant and maternal characteristics and family socioeconomic position. CONCLUSIONS: In a non-Western developed setting, mode of delivery was not clearly associated with BMI or overweight (including obesity) into late childhood. From a public health perspective, the role of mode of delivery and its mechanistic pathway in the current burgeoning epidemic of obesity needs to be clarified. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To examine whether mode of delivery was associated with childhood adiposity in a developed non-Western context. Methods: We used generalized estimating equations to estimate the association of mode of delivery (vaginal or cesarean) with body mass index (BMI) z-score and overweight (including obesity) from 3 months to 13 years, in 7809 term birth (94% follow-up) from a population-representative Chinese birth cohort, “Children of 1997.” We used multiple imputation for missing data. Results: The cesarean section rate (26%) was higher for children born in private hospitals, with lower gestational age, lower birth order, higher maternal age, higher maternal BMI, and higher family socioeconomic position. Cesarean section was not associated with BMI z-score from 3 months to 13 years (mean difference, 0.03; 95% confidence interval, −0.02 to 0.09) or overweight from 3 years to 13 years (odds ratio, 0.98; 95% confidence interval, 0.77 to 1.25) after adjusting for infant and maternal characteristics and family socioeconomic position. Conclusions: In a non-Western developed setting, mode of delivery was not clearly associated with BMI or overweight (including obesity) into late childhood. From a public health perspective, the role of mode of delivery and its mechanistic pathway in the current burgeoning epidemic of obesity needs to be clarified. [Copyright &y& Elsevier]

Observationally, breastfeeding is associated with lower blood pressure in Western developed settings, whereas little association exists in developing settings. However, postnatal characteristics (e.g., breast milk substitutes, infection rates, underweight, and pubertal timing) differ between these settings. We examined the association of breastfeeding with blood pressure at ~13 years, using multivariable linear regression, in 5,247 term births in 1997 from a population-representative Hong Kong Chinese birth cohort where socioeconomic patterning of breastfeeding differs from that of Western and developing settings but standard of living, social infrastructure, and postnatal characteristics are similar to those of Western settings. Higher education is associated with short-term breastfeeding but recent migration with longer-term breastfeeding. Compared with never breastfeeding, exclusive breastfeeding for >3 months was not associated with blood pressure (systolic mean difference = 0.82 mm Hg, 95% confidence interval (Cl): -0.46, 2.11 and diastolic mean difference = 0.49 mm Hg, 95% Cl: -0.22, 1.21), nor was partial breastfeeding for any length of time or exclusive breastfeeding for <3 months (systolic mean difference = 0.01 mm Hg, 95% Cl: -0.64, 0.66 and diastolic mean difference = 0.16 mm Hg, 95% Cl: -0.20, 0.52), adjusted for socioeconomic position and infant characteristics. Lack of association in a non-Western developed setting further suggests that observations concerning breastfeeding and blood pressure vary with setting, thereby casting doubt on causality. [ABSTRACT FROM AUTHOR]

PURPOSE: Adult height is the sum of growth during fetal, infancy, childhood, and puberty, controlled by different biological factors. In long-term developed Western populations, height is positively associated with socioeconomic position, but less clearly so in recently developing populations. We aimed to elucidate socioeconomic influences on height at different growth phases. METHODS: We examined the associations of parents' education and grandparents' education with birth weight and height gain z-scores during infancy (birth to <2 years), childhood (2 to <8 years), and puberty (8 to <14 years) adjusted for parents' height using generalized estimating equations in Hong Kong's 'Children of 1997' birth cohort (n = 8264). RESULTS: Parents' education, but not grandparents', was positively associated with birth weight (z-score, 0.07; 95% confidence interval [CI] 0.01-0.12 for grade >=12 compared with grade <=9) and height gain during infancy (0.11; 95% CI, 0.05-0.18), adjusted for gender, gestational age, initial size, parity, parents' age, parents' birthplace, and parents' height. Conversely, similarly adjusted, grandparents' education, but not parents', was associated with height gain during childhood (0.11; 95% CI, 0.04-0.18). CONCLUSIONS: Parental education was associated with fetal and infant, but not childhood, linear growth, suggesting the mechanism underlying socioeconomic influences on height at different growth phases may be contextually specific. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: Adult height is the sum of growth during fetal, infancy, childhood, and puberty, controlled by different biological factors. In long-term developed Western populations, height is positively associated with socioeconomic position, but less clearly so in recently developing populations. We aimed to elucidate socioeconomic influences on height at different growth phases. Methods: We examined the associations of parents' education and grandparents' education with birth weight and height gain z-scores during infancy (birth to <2 years), childhood (2 to <8 years), and puberty (8 to <14 years) adjusted for parents' height using generalized estimating equations in Hong Kong's “Children of 1997” birth cohort (n = 8264). Results: Parents' education, but not grandparents', was positively associated with birth weight (z-score, 0.07; 95% confidence interval [CI] 0.01–0.12 for grade ≥12 compared with grade ≤9) and height gain during infancy (0.11; 95% CI, 0.05–0.18), adjusted for gender, gestational age, initial size, parity, parents' age, parents' birthplace, and parents' height. Conversely, similarly adjusted, grandparents' education, but not parents', was associated with height gain during childhood (0.11; 95% CI, 0.04–0.18). Conclusions: Parental education was associated with fetal and infant, but not childhood, linear growth, suggesting the mechanism underlying socioeconomic influences on height at different growth phases may be contextually specific. [Copyright &y& Elsevier]

The predictive-adaptive response paradigm postulates that slow fetal growth advances puberty as a life-history strategy for reproductive success, when constraints on postnatal growth are minimal. The authors examined the association of birth weight for gestational age and small for gestational age (SGA) status (birth weight for gestational age <10th percentile, 6.9%) with clinically assessed age at onset of Tanner stage II in a non-Western developed population using interval-censored regression in 7,366 children (89% follow-up) from a population-representative Chinese birth cohort, “Children of 1997” in Hong Kong. Neither SGA status nor birth weight z score for gestational age was associated with age at onset of puberty, adjusted for sex, mother's place of birth, parental height, income, and parental education. Greater childhood height and linear growth were associated with younger age at onset of puberty. SGA status was associated with earlier puberty after adjustment for childhood height (time ratio = 0.984, 95% confidence interval: 0.972, 0.995) but later puberty after adjustment for linear growth (time ratio = 1.017, 95% confidence interval: 1.005, 1.030). In this developed city of China, SGA status was not associated with timing of puberty. However, the observation may be contextually specific depending on how other attributes, such as childhood growth, differ between SGA and other children. [ABSTRACT FROM PUBLISHER]

Background Early puberty often occurs in migrants from less to more economically developed locations, particularly among girls, perhaps because of mismatched inter-generational conditions. However, migrants may differ from their host population in many ways.Objective In an ethnically homogenous Chinese population in a developed environment, we examined the association of mother's growth environment (proxied by migration status) with age at onset of puberty. We assessed differences by sex and whether associations were independent of intra-uterine growth.Methods We used interval-censored survival analyses in 3832 boys and 3279 girls (follow-up rate of 92%) from the ‘Children of 1997’ birth cohort, comprising 88% of births in Hong Kong in April and May 1997, to examine the adjusted association of mother's migration status (born and raised in mainland China or in comparatively more developed Hong Kong), with clinically assessed age at onset of puberty (Tanner stage II for breast/genital and pubic hair development).Results Children with mothers from a less developed environment had earlier onset of breast/genital [time ratio (TR) 0.987, 95% confidence intervals (CIs) 0.980–0.993] and pubic hair (TR 0.993, 95% CI 0.986–1.000) development, independent of birth size for gestational age and socio-economic position, possibly with a more marked association in girls.Conclusion Mismatch of growth conditions between mothers and children was associated with younger age at onset of puberty. Given the association of early puberty with chronic diseases, inter-generational influences may be relevant to the emerging epidemics of these diseases in rapidly developing populations where age of puberty is declining sharply. [ABSTRACT FROM PUBLISHER]

Background In Western populations, informal child care is associated with childhood obesity. However, informal child care and obesity share social patterning making evidence from other settings valuable.Methods We used multivariable linear and logistic regression models to estimate the association of child care at 6 months and at 3, 5 and 11 years with body mass index (BMI) z-score and overweight (including obesity) at 11 years in a Hong Kong Chinese birth cohort. We assessed whether associations varied with sex or socio-economic position (SEP). We used multiple imputation for missing exposures and confounders.Results Of the original 8327 cohort members, 7933 are alive, participating and living in Hong Kong. At ~11 years, 6796 had their BMI clinically assessed. Higher SEP was associated with informal care. After imputation, informal care at each of 3, 5 or 11 years was separately associated with higher BMI z-score [3 years 0.10, 95% confidence interval (CI) 0.03–0.18, 5 years 0.12, 95% CI 0.04–0.21, 11 years 0.17, 95% CI 0.04–0.31] and with the presence of overweight [odds ratio (OR) 3 years 1.19, 95% CI 1.03–1.37, 5 years OR 1.20, 95% CI 1.03–1.40, 11 years OR 1.21, 95% CI 1.02–1.45], adjusted for sex, SEP and birth weight z-score. Current informal care had the strongest association. However, informal child care at 5 years also contributed. There was no evidence of differences by sex or SEP.Conclusions In a developed, non-Western setting, informal child care was associated with childhood obesity. Modifiable attributes of informal child care warrant investigation for obesity prevention. [ABSTRACT FROM AUTHOR]

Background: The key epidemiological difference between pandemic and seasonal influenza is that the population is largely susceptible during a pandemic, whereas, during non-pandemic seasons a level of immunity exists. The population-level efficacy of household-based mitigation strategies depends on the proportion of infections that occur within households. In general, mitigation measures such as isolation and quarantine are more effective at the population level if the proportion of household transmission is low. Methods/Results: We calculated the proportion of infections within households during pandemic years compared with non-pandemic years using a deterministic model of household transmission in which all combinations of household size and individual infection states were enumerated explicitly. We found that the proportion of infections that occur within households was only partially influenced by the hazard h of infection within household relative to the hazard of infection outside the household, especially for small basic reproductive numbers. During pandemics, the number of withinhousehold infections was lower than one might expect for a given h because many of the susceptible individuals were infected from the community and the number of susceptible individuals within household was thus depleted rapidly. In addition, we found that for the value of h at which 30% of infections occur within households during non-pandemic years, a similar 31% of infections occur within households during pandemic years. Interpretation: We suggest that a trade off between the community force of infection and the number of susceptible individuals in a household explains an apparent invariance in the proportion of infections that occur in households in our model. During a pandemic, although there are more susceptible individuals in a household, the community force of infection is very high. However, during non-pandemic years, the force of infection is much lower but there are fewer susceptible individuals within the household. [ABSTRACT FROM AUTHOR]

As economic development increases, puberty occurs at younger ages, and this could contribute to an increase in the incidence of cardiovascular diseases and hormone-related cancers. The factors that determine pubertal timing are poorly understood. The growth axis that is active during puberty is active in the first 6 months of life and interacts with the immune system. The authors examined whether prior infections, proxied by number of hospital admissions for infections at different ages, were associated with age at pubertal onset (Tanner stage II) using interval-censored regression in the Children of 1997 cohort, which is a population-representative Chinese birth cohort (n = 7,527). Mediation by growth was also examined. Girls, but not boys, who were hospitalized for infections at least twice in the first 6 months of life experienced pubertal onset about 8 months later (mean = 10.3 years, time ratio = 1.08, 95% confidence interval: 1.04, 1.12) than did those without such hospitalizations (mean = 9.6 years) after adjustment for infant characteristics and socioeconomic position (sex interaction: P = 0.02). There were no such associations for infections at 6 months to ≤8 years of age. Growth did not mediate the association. Early infectious morbidity in girls may be associated with later puberty, perhaps via suppression of the gonadotropic axis. The lowering of the number of infections in early life that accompanies economic development could be an additional factor that contributes to earlier puberty. [ABSTRACT FROM PUBLISHER]

Purpose: A high rate of infant growth may be associated with adult cardiovascular disease. We investigated factors associated with infant weight growth in a large sample from the recently transitioned population of Hong Kong. Methods: We used a nonlinear shape invariant model with random effects among 5949 term, singletons (77% follow-up) from a population-representative Hong Kong Chinese birth cohort “Children of 1997” to investigate factors associated with weight growth in the first year of life. Results: Overall birth weight was lower but infant growth was more rapid than the 2006 WHO standards. Shorter gestation and lower birth order were associated with lower birth weight and faster infant growth. Female sex, maternal smoking in pregnancy, and a mother born in Hong Kong were associated with lower birth weight, but not with faster growth. Higher maternal education was associated with faster infant growth, grades 10–11 (1.03, 95% confidence interval [CI] = 1.03–1.05), greater than or equal to grade12 (1.07, CI = 1.04–1.09) compared with less than or equal to grade 9. Conclusions: Infant growth may respond more rapidly to socio-economic development than birth weight. Whether mother’s education is associated with rapid infant growth via current conditions or her own “constitution” is unclear, nevertheless we believe this study illustrates the importance of contextually specific research for understanding the determinants of population health. [ABSTRACT FROM AUTHOR]

An essay is presented on the 2009 H1N1 pandemic and the implementation of initial responses to mitigate its effects. It says that the responses to H1N1, which is more widespread compared to SARS, went well including its early detection in North America, integration of clinical laboratory for disease severity, and nonpharmaceutical interventions. It adds that there are still lessons to be learned for future H1N1 planning and timely access to influenza vaccines and antivirals remains a challenge.

Purpose: To identify factors associated with variability in anatomical and functional response of diabetic macular oedema (DMO) after 4 mg of intravitreal triamcinolone acetonide (ivTA), and for recurrence of macular oedema. Design: Pooled analysis of individual data from two randomized controlled trials. Methods: This was a multicentre study involving 107 eyes with DMO administered 4 mg ivTA. Predictive factors for response to treatment were evaluated with linear regression analysis. Factors associated with time to recurrence of oedema were studied with Cox proportional hazards modelling. Main outcome measures were maximum improvement in optical coherence tomography (OCT)-measured central foveal thickness (CFT) and best-corrected visual acuity (BCVA), final CFT and BCVA at 12 months and time to oedema recurrence. Results: Greater reduction of retinal thickening occurred in eyes with worse baseline thickening ( P < 0.001). There was also greater improvement of visual acuity in eyes with poorer preoperative BCVA levels ( P < 0.001). Age, duration of oedema and previous macular laser treatment had no significant effect on maximal BCVA or CFT improvement. Eyes given 4 mg triamcinolone alone were more likely to develop recurrence of oedema at 12 months than those given a combination of 4 mg triamcinolone plus sequential laser (hazard ratio 2.60 [95% confidence interval: 1.45–4.67]). Conclusion: Baseline OCT-measured retinal thickening and BCVA are important predictors of maximal anatomical and functional response of DMO to ivTA, respectively. Combination treatment strategy using sequential laser therapy may have a role in delaying recurrence of oedema after triamcinolone. [ABSTRACT FROM AUTHOR]

Background: The effectiveness of single-drug antiviral interventions to reduce morbidity and mortality during the next influenza pandemic will be substantially weakened if transmissible strains emerge which are resistant to the stockpiled antiviral drugs. We developed a mathematical model to test the hypothesis that a small stockpile of a secondary antiviral drug could be used to mitigate the adverse consequences of the emergence of resistant strains. Methods and Findings: We used a multistrain stochastic transmission model of influenza to show that the spread of antiviral resistance can be significantly reduced by deploying a small stockpile (1% population coverage) of a secondary drug during the early phase of local epidemics. We considered two strategies for the use of the secondary stockpile: early combination chemotherapy (ECC; individuals are treated with both drugs in combination while both are available); and sequential multidrug chemotherapy (SMC; individuals are treated only with the secondary drug until it is exhausted, then treated with the primary drug). We investigated all potentially important regions of unknown parameter space and found that both ECC and SMC reduced the cumulative attack rate (AR) and the resistant attack rate (RAR) unless the probability of emergence of resistance to the primary drug ρA was so low (less than 1 in 10,000) that resistance was unlikely to be a problem or so high (more than 1 in 20) that resistance emerged as soon as primary drug monotherapy began. For example, when the basic reproductive number was 1.8 and 40% of symptomatic individuals were treated with antivirals, AR and RAR were 67% and 38% under monotherapy if ρA = 0.01. If the probability of resistance emergence for the secondary drug was also 0.01, then SMC reduced AR and RAR to 57% and 2%. The effectiveness of ECC was similar if combination chemotherapy reduced the probabilities of resistance emergence by at least ten times. We extended our model using travel data between 105 large cities to investigate the robustness of these resistance-limiting strategies at a global scale. We found that as long as populations that were the main source of resistant strains employed these strategies (SMC or ECC), then those same strategies were also effective for populations far from the source even when some intermediate populations failed to control resistance. In essence, through the existence of many wild-type epidemics, the interconnectedness of the global network dampened the international spread of resistant strains. Conclusions: Our results indicate that the augmentation of existing stockpiles of a single anti-influenza drug with smaller stockpiles of a second drug could be an effective and inexpensive epidemiological hedge against antiviral resistance if either SMC or ECC were used. Choosing between these strategies will require additional empirical studies. Specifically, the choice will depend on the safety of combination therapy and the synergistic effect of one antiviral in suppressing the emergence of resistance to the other antiviral when both are taken in combination. [ABSTRACT FROM AUTHOR]

Purpose. Assess the effectiveness of a two-step health education program by nurses delivered through nonsmoking mothers to help fathers of sick children quit smoking. Design. Randomized, controlled trial. Setting. General pediatric wards of four major hospitals in Hong Kong. Subjects. Nonsmoking mothers who had a live-in smoking spouse were recruited when they brought sick children to the hospital. A total of 752 mothers were randomized into the intervention arm and 731 into the control arm. Intervention. The intervention group received standardized health advice, behavior modification booklets, and a 1-week telephone reminder. The control group received usual care. Measurements. The main outcome measure was the quit rate (7-day point prevalence) of smoking fathers as determined by telephone follow-up with mothers at 3 and 12 months. Quit attempts and smoking reduction were secondary outcome measures. Results. At 3 months, more fathers in the intervention group had quit smoking (7.4% vs. 4.8%; p = .03), reduced daily cigarette consumption by 50% or more (30.6% vs. 22.6%; p < .001), and reported quit attempts (6.5% vs. 3.6%; p = .01). The differences were not statistically significant by 12 months. Conclusion. A simple health education intervention provided by nurses to mothers of sick children has a short-term effect in helping smoking fathers quit, reduce consumption, and trigger quit attempts. Future studies should confirm the longer-term sustainability of the effect. [ABSTRACT FROM AUTHOR]

The article cites a study that examines the effectiveness of an elderly smoking cessation counseling training program for social workers. The researchers evaluated the effectiveness of the 9-hour smoking cessation counseling training program. The findings of the study reveal that the smoking cessation training program achieved sustained effectiveness in the first year after training in enhancing knowledge, positively shifting attitudes and boosting self-perceived competence.

Abstract: This paper compares the extent to which the principle of “equal treatment for equal need”(ETEN) is maintained in the health care delivery systems of Hong Kong, South Korea and Taiwan. Deviations in the degree to which health care is distributed according to need are measured by an index of horizontal inequity. Income-related inequality in utilization is split into four major sources: (i) direct effect of income; (ii) need indicators (self-assessed health status, activity limitation, and age and gender interaction terms); (iii) non-need variables (education, work status, private health insurance coverage, employer-provided medical benefits, Medicaid status (low-income medical assistance), geographic region and urban/rural residency and (iv) a residual term. Service types studied include western doctor, licensed traditional medicine practitioner (LTMP), dental and emergency room (ER) visits, as well as inpatient admissions. Violations of the ETEN principle are observed for physician and dental services in Hong Kong . There is pro-rich inequity in western doctor visits. Unusually, this inequity exists for general practitioner but not specialist care. In contrast, South Korea appears to have almost comprehensively maintained ETEN although the better-off have preferential access to higher levels of outpatient care. Taiwan shows intermediate results in that the rich are marginally more likely to use outpatient services, but quantities of western doctor and dental visits are evenly distributed while there is modest pro-rich bias in the number of LTMP episodes. ER visits and inpatient admissions in Taiwan are either proportional or slightly pro-poor. Future work should focus on the evaluation of policy interventions aimed at reducing the observed unequal distributions. [Copyright &y& Elsevier]

Objective: To examine the secular effects of opportunistic screening for cervical cancer in a rich, developed community where most other such populations have long adopted organised screening. Design, setting, and participants: The analysis was based on 15 140 cases of invasive cervical cancer from 1972 to 2001. The effects of chronological age, time period, and birth cohort were decomposed using both maximum likelihood and Bayesian methods. Results: The overall age adjusted incidence decreased from 24.9 in 1972-74 to 9.5 per 100,000 in 1999-2001, in a log-linear fashion, yielding an average annual reduction of 4.0% (p<0.001) during! the 30 year period. There were two second order and thus identifiable changes: (1) around the mid-1920s cohort curve representing an age-period interaction masquerading as a cohort change that denotes the first availability of Pap testing during the 1960s concentrated among women in their 40s; (2) a hook around the calendar years 1982-83 when cervical cytology became a standard screening test for pregnant women. Conclusions: Hong Kong's cervical cancer rates have declined since Pap tests first became available in the 1960s, most probably because of increasing population coverage over time and in successive generations in a haphazard fashion and punctuated by the systematic introduction of routine cytology as part of antenatal care in the 1980s. [ABSTRACT FROM AUTHOR]

The evidence base for most educational initiatives, at least until very recently, is largely composed of low-level evidence. Four major barriers underlie this historical observation, namely: (1) perceived ethical and acceptability problems arising from the unequal treatment of learners in experimental designs; (2) limited choice of outcome measures and validated instruments; (3) time and resource constraints; and (4) methodological issues concerning contextual confounding and small sample sizes. We advocate the adoption of a ‘balanced scorecard’ approach in the evaluation of education interventions that brings together a comprehensive panel of outcomes under one framework. We require a diversity of rigorously applied methods to generate these outcomes, drawing from the quantitative and qualitative disciplines of epidemiology, psychology and economics. We further suggest that the research community discuss and agree on a standardized set of common metrics or benchmarks. We conclude with a case study examining whether a hand-held computer clinical decision support tool improves clerkship learning of evidence-based medicine. The era of Brownian motion in health education research is over. What we demand in terms of burden of proof for educational effectiveness should be no less rigorous than our call for an ever escalating threshold concerning evidence of clinical care. [ABSTRACT FROM AUTHOR]

To better understand the distribution of resources and health care consumption patterns in different geo-ethnic and socio-economic settings, we sought to describe the patterns of illness, care-seeking behavior and health services utilization in Hong Kong compared to the US and UK. Data were derived from the 2002 Hong Kong Thematic Household Survey covering 31,762 non-institutional and institutional residents, representing 6,504,255 persons after applying population weights. Of 1000 individuals during a 1-month period, 567 reported symptoms, 512 of whom considered seeking health care. Four hundred and forty persons visited western allopathic medical practitioners, with 372 (84.5%) in primary care and 68 (15.5%) in specialty care. There were 54 visits to traditional Chinese medical practitioners and 16 emergency room episodes. Seven individuals were hospitalized in community hospitals and on average one in 1000 were admitted to a tertiary medical center. Ninety out of the 567 who experienced symptoms undertook self-management strategies, which included over-the-counter western allopathic medications (n = 54) or traditional Chinese remedies (n = 14) or both (n = 2), dietary modification (n = 1) and rest (n = 15). We have mapped the ecology of health care in Hong Kong. Monthly prevalence estimates were remarkably similar to US figures for hospital-based events, whereas there was evidence of apparent, substantial "over-consumption" of ambulatory, community-based care. Our results also indicate that the local community's care-seeking orientation still very much favors western allopathic medicine over traditional Chinese therapy, at least for acute illness episodes. [ABSTRACT FROM AUTHOR]

Background: Recognising that household interviews may produce biased estimates of health services utilisation, we examined for under- and over-reporting of hospitalisation episodes in three recent, consecutive population-based household surveys in Hong Kong. Methods: Territory-wide inpatient service utilisation volumes as estimated from the 1999, 2001 and 2002 Thematic Household Surveys (THS) were benchmarked against corresponding statistics derived from routine administrative databases. Between-year differences on net under-reporting were quantified by Cohen's d effect size. To assess the potential for systematic biases in underreporting, age- and sex-specific net under-reporting rates within each survey year were computed and the F-test was performed to evaluate differences between demographic subgroups. We modelled the effects of age and sex on the likelihood of ever hospitalisation through logistic regression to compare the odds ratios respectively derived from survey and administrative data. Results: The extent of net under-reporting was moderately large in all three years amounting to about one-third of all inpatient episodes. However, there did not appear to be significant systematic biases in the degree of under-reporting by age or sex on stratified analyses and logistic regression modelling. Conclusion: Under-reporting was substantial in Hong Kong's THS. Recall bias was likely most responsible for such reporting inaccuracies. A proper full-design record-check study should be carried out to confirm the present findings. [ABSTRACT FROM AUTHOR]

Background: As yet, no one has written a comprehensive epidemiologic account of a severe acute respiratory syndrome (SARS) outbreak from an affected country. Objective: To provide a comprehensive epidemiologic account of a SARS outbreak from an affected territory. Design: Epidemiologic analysis. Setting: The 2003 Hong Kong SARS outbreak. Participants: All 1755 cases and 302 deaths. Measurements: Sociodemographic characteristics; infection clusters by time, occupation, setting, and workplace; and geospatial relationships were determined. The mean and variance in the time from infection to onset (incubation period) were estimated in a small group of patients with known exposure. The mean and variance in time from onset to admission, from admission to discharge, or from admission to death were calculated. Logistic regression was used to identify important predictors of case fatality. Results: 49.3% of patients were infected in clinics, hospitals, or elderly or nursing homes, and the Amoy Gardens cluster accounted for 18.8% of cases. The ratio of women to men among infected individuals was 5:4. Health care workers accounted for 23.1% of all reported cases. The estimated mean incubation period was 4.6 days (95% CI, 3.8 to 5.8 days). Mean time from symptom onset to hospitalization varied between 2 and 8 days, decreasing over the course of the epidemic. Mean time from onset to death was 23.7 days (CI, 22.0 to 25.3 days), and mean time from onset to discharge was 26.5 days (CI, 25.8 to 27.2 days). Increasing age, male sex, atypical presenting symptoms, presence of comorbid conditions, and high lactate dehydrogenase level on admission were associated with a greater risk for death. Limitations: Estimates of the incubation period relied on statistical assumptions because few patients had known exposure times. Temporal changes in case management as the epidemic progressed, unavailable treatment information, and several potentially important factors that could not be thoroughly analyzed because of the limited sample size complicate interpretation of factors related to case fatality. Conclusions: This analysis of the complete data on the 2003 SARS epidemic in Hong Kong has revealed key epidemiologic features of the epidemic as it evolved. [ABSTRACT FROM AUTHOR]

Background: Accurate, objective models of triage for patients with suspected severe acute respiratory syndrome (SARS) could assess risks and improve decisions about isolation and inpatient treatment. Objective: To develop and validate a clinical prediction rule for identifying patients with SARS in an emergency department set- ting. Design: Retrospective analysis using a 2-step coefficient-based multivariable logistic regression scoring method with internal validation by bootstrapping. Setting: 2 hospitals in Hong Kong. Participants: 1274 consecutive patients from 1 hospital and 1375 consecutive patients from another hospital. Measurements: Points were assigned on the basis of history, physical examination, and simple investigations obtained at presentation. The outcome measure was a final diagnosis of SARS, as confirmed by World Health Organization laboratory criteria. Results: Predictors for SARS on the basis of history (step 1) included previous contact with a patient with SARS and the presence of fever, myalgia, and malaise. Age 65 years and older and younger than 18 years and the presence of sputum, abdominal pain, sore throat, and rhinorrhea were inversely related to having SARS. In step 2, haziness or pneumonic consolidation on chest radiographs and low lymphocyte and platelet counts, in addition to a positive contact history and fever were associated with a higher probability of SARS. A high neutrophil count the extremes of age, and sputum production were associated with a lower probability of SARS. In the derivation sample, the observed incidence of SARS was 4.4% for those assigned to the low-risk group (in steps 1 or 2); in the high-risk group, incidence of SARS was 21.0% for quartile 1, 39.5% for quartile 2, 61.2% for quartile 3, and 79.7% for quartile 4. This prediction rule achieved an optimism-corrected sensitivity of 0.90, a specificity of 0.62, and an area under the receiver-operating characteristic curve of 0.85. Limitations: The prediction rule may not apply to isolated cases occurring during an interepidemic period. Generalizability of the findings should be confirmed in other SARS-affected countries and should be prospectively validated if SARS returns. Conclusions: Our findings suggest that a simple model that uses clinical data at the time of presentation to an emergency department during an acute outbreak predicted the incidence of SARS and provided good diagnostic utility. [ABSTRACT FROM AUTHOR]

A total of 1,068 asymptomatic close contacts of patients with severe acute respiratory (SARS) from the 2003 epidemic in Hong Kong were serologically tested, and 2 (0.19%) were positive for SARS coronavirus immunoglobulin G antibody. SARS rarely manifests as a subclinical infection, and at present, wild animal species are the only important natural reservoirs of the virus. [ABSTRACT FROM AUTHOR]

Objective: Improving response rates, particularly among physicians, is important to minimize nonresponder bias and increase the effective sample size in epidemiologic research. We conducted a randomized trial to examine the impact of prepayment vs. postpayment incentives on response rates.Study design and setting: Self-completion postal questionnaires were mailed to 949 physicians who were respondents to an earlier survey and representative of the general physician population in Hong Kong. These physicians were randomly allocated to receive a HK$20 cash prepayment incentive that accompanied the survey (n = 474) or a postpayment reward of the same amount on receipt of the completed questionnaire (n = 475).Results: The final prepayment response rate was 82.9%, compared with 72.5% in the postpayment arm (P < .001). Of the eight alternative incentive and follow-up strategies evaluated, three lie on the efficiency frontier (i.e., not dominated), including postpayment with three mailings at HK$42.7, prepayment with three mailings at HK$66.5 and prepayment with three mailings and telephone follow-up at HK$112.1 per responder recruited (US$1 = HK$7.8).Conclusion: The findings demonstrate that prepayment cash incentives are superior to postpayment of the equivalent amount in improving response rates among a representative sample of Hong Kong physicians. Further research should concentrate on confirming the generalizability of these findings in other health care occupation groups and settings. [Copyright &y& Elsevier]

Background and objectives: We performed a follow-up survey to document changes in the level of computerization among physicians in Hong Kong between 2000 and 2001, specifically examining whether their self-reported intention to computerize various clinical or administrative tasks actually translated into computerization of these tasks 1 year later. Determining such a relationship will indicate the reliability, and thus the utility of questions regarding self-reported intention to computerize clinical practice. Methods: A self-completed follow-up postal questionnaire was sent to all 949 physicians who responded to the original questionnaire. Pairwise repeated dichotomous responses from 2000 and 2001 on the computerization of specific functions were compared using McNemar test. Wilcoxon sign-ranked test was employed to compare the total number of tasks computerized in the 2 years. Multivariate logistic regression modeling was carried out to determine predictors for the translation of intention to computerize into actual computerization. Results: The response rate was 77.0%. There was a significant increase in the number of tasks computerized for both “corporate” and “individual” practices between 2000 and 2001. The proportion of physicians who intended to computerize and actually computerized ranged from 7.7 to 51.0% for different tasks. For five clinical tasks, more than 50% respondents in corporate practices translated the intention to implementation, compared to fewer than 20% in individual practices. Predictors found to be associated with the translation of intention to computerize into actual computerization included higher number of tasks intended to computerize, higher number of tasks already computerized, and more positive physicians’ attitudes on the impact of computerization to clinical practice. Conclusions: We conclude that physicians’ self-reported intention to computerize the clinical practice 12 months previously was moderately associated with actual implementation, with varying degrees of concordance for different clinical and administrative tasks. The identified predictors for the translation of intention to actual computerization may be useful in targeting specific strategies to promote computerization of clinical practice. [Copyright &y& Elsevier]