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Neighborhood socioeconomic conditions (NSECs) are associated with resident diet, but most research has been cross-sectional. We capitalized on a natural experiment in Pittsburgh, Pennsylvania, in which 1 neighborhood experienced substantial investments and a sociodemographically similar neighborhood that did not, to examine pathways from neighborhood investments to changed NSECs and changed dietary behavior. We examined differences between renters and homeowners. Data were from a random sample of households (n = 831) in each of these low-income Pittsburgh neighborhoods that were surveyed in 2011 and 2014. Structural equation modeling tested direct and indirect pathways from neighborhood to resident dietary quality, adjusting for individual-level sociodemographics, with multigroup testing by homeowners versus renters. Neighborhood investments were directly associated with improved dietary quality for renters (β = 0.27, 95% confidence interval (CI): 0.05, 0.50) and homeowners (β = 0.51, 95% CI: 0.10, 0.92). Among renters, investments also were associated with dietary quality through a positive association with commercial prices (β = 0.34, 95% CI: 0.15, 0.54) and a negative association with residential prices (β = −0.30, 95% CI: −0.59, −0.004). Among homeowners, we did not observe any indirect pathways from investments to dietary quality through tested mediators. Investing in neighborhoods may support resident diet through improvements in neighborhood commercial environments for renters, but mechanisms appear to differ for homeowners.

Among 626 participants of the Men’s Lifestyle Validation Study (2011–2013), we evaluated the validity and reproducibility of a self-administered 152-item semiquantitative food frequency questionnaire (SFFQ) using two 7-day dietary records (7DDRs), 4 Automated Self-Administered 24-hour dietary recalls (ASA24s), four 24-hour urine samples, 1 doubly labeled water measurement (repeated in 104 participants), and 2 fasting blood samples, collected over 15 months. Compared with 7DDRs, SFFQs underestimated energy intake, macronutrients, and sodium intake but overestimated some micronutrients. The mean of the Spearman correlation coefficients was 0.66 (range, 0.38–0.88) between 46 energy-adjusted nutrients estimated from 7DDRs and the final SFFQ, deattenuated for within-person variation in the 7DDRs. These deattenuated correlations were similar using ASA24s as the comparison. Relative to biomarkers, SFFQs underestimated energy, sodium, and protein intakes, as well as the sodium:potassium ratio. The energy-adjusted correlations between the final SFFQ and the biomarkers were slightly lower than the correlations between the SFFQ and 7DDRs. Using the method of triads to calculate validity coefficients, the median validity coefficient between SFFQ and true intake was 0.65 and 0.69 using 7DDRs and ASA24s, respectively, as the third method. These data indicate that this SFFQ provided reasonably valid estimates for a wide range of nutrients when evaluated by multiple comparison methods.

There is no consensus on the most reliable method of ascertaining falls among the elderly. Therefore, we investigated which method captured the most falls among prefrail and frail seniors from 2 randomized controlled trials conducted in Zurich, Switzerland: an 18-month trial (2009-2010) including 200 community-dwelling prefrail seniors with a prior fall and a 12-month trial (2005-2008) including 173 frail seniors with acute hip fracture. Both trials included the same methods of fall ascertainment: monthly active asking, daily self-report diary entries, and a call-in hotline. We compared numbers of falls reported and estimated overall and positive percent agreement between methods. Prefrail seniors reported 499 falls (fall rate = 2.5/year) and frail seniors reported 205 falls (fall rate = 1.4/year). Most falls (81% of falls in prefrail seniors and 78% in frail seniors) were reported via active asking. Among prefrail seniors, diaries captured an additional 19% of falls, while the hotline added none. Among frail seniors, the hotline added 16% of falls, while diaries added 6%. The positive percent agreement between active asking and diary entries was 100% among prefrail seniors and 88% among frail seniors. While monthly active asking captures most falls in both groups, this method alone missed 19% of falls in prefrail seniors and 22% in frail seniors. Thus, a combination of active asking and diaries for prefrail seniors and a combination of active asking and a hotline for frail seniors is warranted.

Calibrating dietary self-report instruments is recommended as a way to adjust for measurement error when estimating diet-disease associations. Because biomarkers available for calibration are limited, most investigators use self-reports (e.g., 24-hour recalls (24HRs)) as the reference instrument. We evaluated the performance of 24HRs as reference instruments for calibrating food frequency questionnaires (FFQs), using data from the Validation Studies Pooling Project, comprising 5 large validation studies using recovery biomarkers. Using 24HRs as reference instruments, we estimated attenuation factors, correlations with truth, and calibration equations for FFQ-reported intakes of energy and for protein, potassium, and sodium and their densities, and we compared them with values derived using biomarkers. Based on 24HRs, FFQ attenuation factors were substantially overestimated for energy and sodium intakes, less for protein and potassium, and minimally for nutrient densities. FFQ correlations with truth, based on 24HRs, were substantially overestimated for all dietary components. Calibration equations did not capture dependencies on body mass index. We also compared predicted bias in estimated relative risks adjusted using 24HRs as reference instruments with bias when making no adjustment. In disease models with energy and 1 or more nutrient intakes, predicted bias in estimated nutrient relative risks was reduced on average, but bias in the energy risk coefficient was unchanged.

The authors evaluated the validity of a 152-item semiquantitative food frequency questionnaire (SFFQ) by comparing it with two 7-day dietary records (7DDRs) or up to 4 automated self-administered 24-hour recalls (ASA24s) over a 1-year period in the women's Lifestyle Validation Study (2010-2012), conducted among subgroups of the Nurses' Health Studies. Intakes of energy and 44 nutrients were assessed using the 3 methods among 632 US women. Compared with the 7DDRs, SFFQ responses tended to underestimate sodium intake but overestimate intakes of energy, macronutrients, and several nutrients in fruits and vegetables, such as carotenoids. Spearman correlation coefficients between energy-adjusted intakes from 7DDRs and the SFFQ completed at the end of the data-collection period ranged from 0.36 for lauric acid to 0.77 for alcohol (mean r = 0.53). Correlations of the end-period SFFQ were weaker when ASA24s were used as the comparison method (mean r = 0.43). After adjustment for within-person variation in the comparison method, the correlations of the final SFFQ were similar with 7DDRs (mean r = 0.63) and ASA24s (mean r = 0.62). These data indicate that this SFFQ provided reasonably valid estimates for intakes of a wide variety of dietary variables and that use of multiple 24-hour recalls or 7DDRs as a comparison method provided similar conclusions if day-to-day variation was taken into account.

The Oxford WebQ is an online 24-hour dietary questionnaire that is appropriate for repeated administration in large-scale prospective studies, including the UK Biobank study and the Million Women Study. We compared the performance of the Oxford WebQ and a traditional interviewer-administered multiple-pass 24-hour dietary recall against biomarkers for protein, potassium, and total sugar intake and total energy expenditure estimated by accelerometry. We recruited 160 participants in London, United Kingdom, between 2014 and 2016 and measured their biomarker levels at 3 nonconsecutive time points. The measurement error model simultaneously compared all 3 methods. Attenuation factors for protein, potassium, total sugar, and total energy intakes estimated as the mean of 2 applications of the Oxford WebQ were 0.37, 0.42, 0.45, and 0.31, respectively, with performance improving incrementally for the mean of more measures. Correlation between the mean value from 2 Oxford WebQs and estimated true intakes, reflecting attenuation when intake is categorized or ranked, was 0.47, 0.39, 0.40, and 0.38, respectively, also improving with repeated administration. These correlations were similar to those of the more administratively burdensome interviewer-based recall. Using objective biomarkers as the standard, the Oxford WebQ performs well across key nutrients in comparison with more administratively burdensome interviewer-based 24-hour recalls. Attenuation improves when the average value is taken over repeated administrations, reducing measurement error bias in assessment of diet-disease associations.

Improving estimates of individuals' dietary intakes is key to obtaining more reliable evidence for diet-health relationships from nutritional cohort studies. One approach to improvement is combining information from different self-report instruments. Previous work evaluated the gains obtained from combining information from a food frequency questionnaire (FFQ) and multiple 24-hour recalls (24HRs), based on assuming that 24HRs provide unbiased measures of individual intakes. Here we evaluate the same approach of combining instruments but base it on the better assumption that recovery biomarkers provide unbiased measures of individual intakes. Our analysis uses data from the 5 large validation studies included in the Validation Studies Pooling Project: the Observing Protein and Energy Nutrition Study (1999-2000), the Automated Multiple-Pass Method validation study (2002-2004), the Energetics Study (2006-2009), the Nutrition Biomarker Study (2004-2005), and the Nutrition and Physical Activity Assessment Study (2007-2009). The data included intakes of energy, protein, potassium, and sodium. Under a time-varying usual-intake model analysis, the combination of an FFQ with 4 24HRs improved correlations with true intake for predicted protein density, potassium density, and sodium density (range, 0.39-0.61) in comparison with use of a single FFQ (range, 0.34-0.50). Absolute increases in correlation ranged from 0.02 to 0.26, depending on nutrient and sex, with an average increase of 0.14. Based on unbiased recovery biomarker evaluation for these nutrients, we confirm that combining an FFQ with multiple 24HRs modestly improves the accuracy of estimates of individual intakes.

Twenty-four-hour dietary recalls provide high-quality intake data but have been prohibitively expensive for large epidemiologic studies. This study's goal was to assess whether the web-based Automated Self-Administered 24-Hour Recall (ASA24) performs similarly enough to the standard interviewer-administered, Automated Multiple-Pass Method (AMPM) 24-hour dietary recall to be considered a viable alternative. In 2010–2011, 1,081 adults from 3 integrated health systems in Detroit, Michigan; Marshfield, Wisconsin; and Kaiser-Permanente Northern California participated in a field trial. A quota design ensured a diverse sample by sex, age, and race/ethnicity. Each participant was asked to complete 2 recalls and was randomly assigned to 1 of 4 protocols differing by type of recall and administration order. For energy, the mean intakes were 2,425 versus 2,374 kcal for men and 1,876 versus 1,906 kcal for women by AMPM and ASA24, respectively. Of 20 nutrients/food groups analyzed and controlling for false discovery rate, 87% were judged equivalent at the 20% bound. ASA24 was preferred over AMPM by 70% of the respondents. Attrition was lower in the ASA24/AMPM study group than in the AMPM/ASA24 group, and it was lower in the ASA24/ASA24 group than in the AMPM/AMPM group. ASA24 offers the potential to collect high-quality dietary intake information at low cost with less attrition.

We pooled data from 5 large validation studies (1999-2009) of dietary self-report instruments that used recovery biomarkers as referents, to assess food frequency questionnaires (FFQs) and 24-hour recalls (24HRs). Here we report on total potassium and sodium intakes, their densities, and their ratio. Results were similar by sex but were heterogeneous across studies. For potassium, potassium density, sodium, sodium density, and sodium:potassium ratio, average correlation coefficients for the correlation of reported intake with true intake on the FFQs were 0.37, 0.47, 0.16, 0.32, and 0.49, respectively. For the same nutrients measured with a single 24HR, they were 0.47, 0.46, 0.32, 0.31, and 0.46, respectively, rising to 0.56, 0.53, 0.41, 0.38, and 0.60 for the average of three 24HRs. Average underreporting was 5%-6% with an FFQ and 0%-4% with a single 24HR for potassium but was 28%-39% and 4%-13%, respectively, for sodium. Higher body mass index was related to underreporting of sodium. Calibration equations for true intake that included personal characteristics provided improved prediction, except for sodium density. In summary, self-reports capture potassium intake quite well but sodium intake less well. Using densities improves the measurement of potassium and sodium on an FFQ. Sodium:potassium ratio is measured much better than sodium itself on both FFQs and 24HRs.

The semiquantitative food frequency questionnaire (FFQ) has been the primary source of dietary exposure data in epidemiology for decades. Although frequency instruments had been evaluated before the 1985 publication "Reproducibility and Validity of a Semiquantitative Food Frequency Questionnaire" by Willett et al. (Am J Epidemiol. 1985;122(1):51-65), that paper was the prototype for the development and validation of what was then a highly innovative method for collecting dietary data. This approach was adopted in nearly all subsequent cohort studies of diet and disease. The paper also catalyzed an extended scientific discourse regarding methods for validation, energy adjustment, and measurement error. It is now well established that data from FFQs and other self-reported dietary assessment instruments have both value and error and that this error should be considered in the analysis and interpretation of findings, including sensitivity analyses in which adjustment for measurement error is explored. Advances in technology make it feasible to consider collecting multiple granular short-term instruments such as recalls or records over time in addition to FFQs among all participants in large cohort studies; both provide valuable information. Without a doubt, the 1985 publication by Willett et al. provided the foundation that propelled the field of nutritional epidemiology forward, and it continues to be relevant today.

We used a biomarker of activity-related energy expenditure (AREE) to assess measurement properties of self-reported physical activity and to determine the usefulness of AREE regression calibration equations in the Women's Health Initiative. Biomarker AREE, calculated as the total energy expenditure from doubly labeled water minus the resting energy expenditure from indirect calorimetry, was assessed in 450 Women's Health Initiative participants (2007-2009). Self-reported AREE was obtained from the Arizona Activity Frequency Questionnaire (AAFQ), the 7-Day Physical Activity Recall (PAR), and the Women's Health Initiative Personal Habits Questionnaire (PHQ). Eighty-eight participants repeated the protocol 6 months later. Reporting error, measured as log(self-report AREE) minus log(biomarker AREE), was regressed on participant characteristics for each instrument. Body mass index was associated with underreporting on the AAFQ and PHQ but overreporting on PAR. Blacks and Hispanics underreported physical activity levels on the AAFQ and PAR, respectively. Underreporting decreased with age for the PAR and PHQ. Regressing logbiomarker AREE on logself-reported AREE revealed that self-report alone explained minimal biomarker variance (R(2) = 7.6, 4.8, and 3.4 for AAFQ, PAR, and PHQ, respectively). R(2) increased to 25.2, 21.5, and 21.8, respectively, when participant characteristics were included. Six-month repeatability data adjusted for temporal biomarker variation, improving R(2) to 79.4, 67.8, and 68.7 for AAFQ, PAR, and PHQ, respectively. Calibration equations "recover" substantial variation in average AREE and valuably enhance AREE self-assessment.

To date, Web-based 24-hour recalls have not been validated using objective biomarkers. From 2006 to 2009, the validity of 6 Web-based DietDay 24-hour recalls was tested among 115 black and 118 white healthy adults from Los Angeles, California, by using the doubly labeled water method, and the results were compared with the results of the Diet History Questionnaire, a food frequency questionnaire developed by the National Cancer Institute. The authors performed repeated measurements in a subset of 53 subjects approximately 6 months later to estimate the stability of the doubly labeled water measurement. The attenuation factors for the DietDay recall were 0.30 for blacks and 0.26 for whites. For the Diet History Questionnaire, the attenuation factors were 0.15 and 0.17 for blacks and whites, respectively. Adjusted correlations between true energy intake and the recalls were 0.50 and 0.47 for blacks and whites, respectively, for the DietDay recall. For the Diet History Questionnaire, they were 0.34 and 0.36 for blacks and whites, respectively. The rate of underreporting of more than 30% of calories was lower with the recalls than with the questionnaire (25% and 41% vs. 34% and 52% for blacks and whites, respectively). These findings suggest that Web-based DietDay dietary recalls offer an inexpensive and widely accessible dietary assessment alternative, the validity of which is equally strong among black and white adults. The validity of the Web-administered recall was superior to that of the paper food frequency questionnaire.

Public health strategies to estimate tobacco use, its precursors, its correlates, and its sequelae are of considerable concern not only because of adverse effects of tobacco use, but also because tobacco use is intertwined with other health-related behaviors (1). Accurate tobacco use history is necessary for developing biomarkers of harm and exposure critical in clinical and regulatory research. Tobacco research often uses systematic measures (2) to facilitate understanding of the natural history of usage trends, to identify research and treatment needs, and to evaluate prevention and control programs. Another example of heavy reliance on recall of smoking lies in recent genome-wide association studies of measures of nicotine dependence (3–6). While engaging in high-level quality control of genomic data, all of the studies relied on retrospective self-report of nicotine dependence or smoking quantity without reference to the reliability, validity, or recall interval of these phenotypes. Questions remain regarding whether the reported association between variation in the nicotinic acetylcholine receptor gene cluster on chromosome 15q25.1 and measures of nicotine dependence are independent of the locus’ association with diseases such as lung cancer. Variation in unreported measurement properties of methods of assessing these phenotypes may partly explain the difficulty in teasing apart the underlying causal model. Tobacco use is one of many health-related behaviors for which epidemiologic research often relies on self-report and recall, with or without biologic verification. Surveillance surveys often include questions about ever use of common forms of tobacco (cigarettes, smokeless, cigars, pipe), age at first tobacco use or first cigarette (initiation), extent of current use, number of quit attempts, and related health behaviors (7). Most research in tobacco use history relies on recall of experiences. Although the quality of self-reports may depend on strategies to reduce reporting error and optimize recall, retrospective research can overcome some of the limitations of prospective research, in part because perceptions of privacy and confidentiality can affect prospective reporting (8). Underreporting of tobacco use can be related to interaction with an interviewer (e.g., social desirability bias). Even the standard of biochemical testing, which remains the most common method of validating tobacco self-report, is useful only for validating or quantifying exposure for a specific duration. Thus, a repeated-measures prospective study with biologic testing might not capture episodic use of tobacco (8). The purpose of this project was to examine the validity of questions in the authors’ Lifetime Tobacco Use Questionnaire (LTUQ). To accomplish this, the investigators examined convergent validity of separate measures of the same events, studied first in adolescence and later in young adulthood or adulthood. Specifically, the present analyses examined the convergent validity of a) tobacco use measures administered initially in two separate prospective, repeated-measures cohort studies, compared with b) similar measures administered to the same cohorts with the LTUQ between 2005 and 2008. Because of limitations inherent in self-report, neither the prospective data nor the recent interview data were considered a “gold standard.” Only a small portion of the prospective data reported real-time measures and in most cases involved near-term retrospective recall of events occurring within a period ranging from a week to several years. This study builds on earlier psychometric work (9, 10) that identified moderate to high test-retest reliability of self-administration of earlier and later versions of the study questionnaire in separate Web samples. The present analyses addressed the following research questions: a) What is the convergent validity of tobacco use responses when original prospective responses are compared with later LTUQ responses? and b) What question-related factors appear to moderate the validity of recall? A related goal was to explore characteristics of the instrument.

Tracking falls among elders is challenging. In this reliability study, which took place between October 2007 and February 2008, the authors compared participants’ daily recordings of falls on calendars with a telephone survey of recall of falls over the previous 3 months within the population-based MOBILIZE Boston Study cohort, a cohort of 765 elders. From the cohort, 218 participants were randomly selected. Falls were tracked prospectively on daily calendars (mailed back monthly). Telephone recalls of falls over the previous 3 months were conducted in January and February 2008. Agreement, sensitivity, and specificity were calculated to compare the occurrence of falls as determined by 3-month recall with falls recorded by daily calendar (gold standard) during the same 3-month period. Results showed good agreement between recall and calendars: 27 persons reported a fall by both methods. However, while the 3-month recall correctly classified persons who did not fall (164 persons by both methods), it missed 25% of participants who fell (of 36 participants with a calendar-reported fall, 9 did not report a fall by telephone recall). Kappa was 0.74 (95% confidence interval: 0.68, 0.80), sensitivity was 75%, and specificity was 96%. Retrospective 3-month recall of falls resulted in underreporting of falls by as much as 25% compared with daily calendars. Calendars should be considered the preferred method of ascertaining falls in longitudinal studies.

Few studies have evaluated the validity of adolescent diet recall after many decades. Between 1943 and 1970, yearly diet records were completed by parents of adolescents participating in an ongoing US study. In 2005-2006, study participants who had been 13-18 years of age when the diet records were collected were asked to complete a food frequency questionnaire regarding their adolescent diet. Food frequency questionnaires and diet records were available for 72 participants. The authors calculated Spearman correlation coefficients between food, food group, and nutrient intakes from the diet records and food frequency questionnaire and deattenuated them to account for the effects of within-person variation measured in the diet records on the association. The median deattenuated correlation for foods was 0.30, ranging from -0.53 for a beef, pork, or lamb sandwich to 0.99 for diet soda. The median deattenuated correlation for food groups was 0.31 (range: -0.48 for breads to 0.70 for hot beverages); for nutrient intakes, it was 0.25 (range: -0.08 for iron to 0.82 for vitamin B(12)). Some dietary factors were reasonably recalled 3-6 decades later. However, this food frequency questionnaire did not validly measure overall adolescent diet when completed by middle-aged and older adults on average 48 years after adolescence.

Epidemiologic research shows that pets influence human health, demonstrating both protective and deleterious health risks; therefore, valid definitions of pet exposure would enhance research. The authors determined how well young adults aged 18 years report their early childhood pets. Subjects in an established birth cohort from Detroit, Michigan, born in 1987–1989 (n = 820) were asked a series of questions about pets in the home during their first 6 years of life. Pet recall was compared with annual prospectively collected parental report from 12–18 years prior. Exposure to cats was correctly reported on average 86.3% of the time (95% confidence interval: 85.0, 87.5) and dogs 79.2% (95% confidence interval: 77.7, 80.6) of the time (P

Validation of early childhood diet recalls by surrogate responders decades later has not been possible because of a lack of diet records from the distant past. Between 1948 and 1970, parents of children participating in the Fels Longitudinal Study (Kettering, Ohio) completed a 7-day diet record for their children every year from birth to age 18 years. In 2005–2006, all surviving women (n = 59) with a child aged 3–5 years when diet records had been collected were asked to complete a 42-item food frequency questionnaire (FFQ) pertaining to 1 of their children's diets at age 3–5 years. One or more diet records were available for 48 children. The authors calculated Spearman correlation coefficients for correlations between food, food-group, and nutrient intakes from the diet records and the FFQ and deattenuated them to account for the effects of within-person variation in the diet records on the association. For foods, the median deattenuated correlation coefficient was 0.19 (range, −0.31 to 0.85); moderate-to-high correlations were found for some specific foods. Correlations for food groups were slightly higher (median, 0.27; range, −0.14 to 0.85). Correlations for nutrient intakes were consistently low (median, 0.06; range, −0.35 to 0.27). Overall, the FFQ did not validly reflect overall preschool diet when completed by mothers 4 decades later.

Large-bowel endoscopy with removal of polyps strongly reduces colorectal cancer risk. In epidemiologic studies, ascertainment of large-bowel endoscopies often relies on self-reports and might be prone to imperfect recall. In 2003-2004, the authors assessed the validity of self-reported colorectal endoscopies in a population-based case-control study including 540 cases and 614 controls from southwest Germany and calculated odds ratios of colorectal cancer risk according to self-reports and medical records. They sought to obtain all medical records for the last self-reported endoscopy and for a subsample of 100 subjects reporting no previous endoscopy. In total, 377 of 483 records could be obtained (78%). Sensitivity of self-reports was 100%, and specificity ranged from 93% to 98% among subgroups defined by age, gender, education, family history of colorectal cancer, and case-control status. The odds ratios for colorectal cancer risk after previous colonoscopy were 0.31 (95% confidence interval: 0.21, 0.45) using self-reports and 0.31 (95% confidence interval: 0.20, 0.47) using medical records. However, agreement between self-reports and medical records was poor regarding type of endoscopy (colonoscopy, sigmoidoscopy, or rectoscopy; kappa = 0.22), moderate concerning polypectomy (kappa = 0.58), and reasonable for year of examination (kappa = 0.70). Self-reports of previous colorectal endoscopies agreed well with medical records, but validation appears to be essential with respect to details of the examination.

Vegetables and fruits are rich in carotenoids, a group of compounds thought to protect against cancer. Studies of diet-disease associations need valid and reliable instruments for measuring dietary intake. The authors present a measurement error model to estimate the validity (defined as correlation between self-reported intake and “true” intake), systematic error, and reliability of two self-report dietary assessment methods. Carotenoid exposure is measured by repeated 24-hour recalls, a food frequency questionnaire (FFQ), and a plasma marker. The model is applied to 1,013 participants assigned between 1995 and 2000 to the nonintervention arm of the Women’s Healthy Eating and Living Study, a randomized trial assessing the impact of a low-fat, high-vegetable/fruit/fiber diet on preventing new breast cancer events. Diagnostics including graphs are used to assess the goodness of fit. The validity of the instruments was 0.44 for the 24-hour recalls and 0.39 for the FFQ. Systematic error accounted for over 22% and 50% of measurement error variance for the 24-hour recalls and FFQ, respectively. The use of either self-report method alone in diet-disease studies could lead to substantial bias and error. Multiple methods of dietary assessment may provide more accurate estimates of true dietary intake.

Use of self-reported confidence ratings may be an efficient method for assessing recall bias. In this exploratory application of the method, the authors examined the relation between case-control status and self-reported confidence ratings. In 2002 and 2003, melanoma cases (n = 141) and controls (n = 143) aged 20-44 years residing in Ontario, Canada, estimated the amounts of time they had spent outdoors in summer activities when they were 6-18 years of age and indicated their confidence in the accuracy of each estimate. The generalized estimating equations extension of logistic regression was used to examine dichotomized confidence ratings (more confident vs. less confident) for activities reported for ages 6-11 years and 12-18 years. Types of activity were associated with more confident reporting for both age strata; as the number of stable outdoor activity periods (total number of similar outdoor periods within each activity) reported by respondents increased, confidence decreased. Cumulative time spent outdoors was also associated with more confidence but reached statistical significance only for the age stratum 12-18 years. There was no statistically significant association between case-control status and self-reported confidence for either age stratum (6-11 years: odds ratio = 0.91; 12-18 years: odds ratio = 1.32), which suggests an absence of recall bias for reported time spent outdoors.

Studies of long-term effects of breastfeeding on the health of both infants and mothers often rely on maternal recall of breastfeeding duration after several decades. The authors evaluated this recall by 140 college-educated, US women 69–79 years of age who breastfed a child in 1940–1956 and recorded the duration both prospectively in a diary for the Menstruation and Reproductive History Study and retrospectively in a questionnaire in 1990– 1991. Mean prospective breastfeeding duration was 5.6 months (range, 1–12 months). Mean reporting difference, questionnaire minus diary duration, was 0.0 months, with a standard deviation of 2.7 months; women who recorded short durations tended to overreport, while women who noted long durations underreported. The weighted kappa statistic for reporting agreement was 0.55 (95% confidence interval: 0.42, 0.67), with better recall observed for women in the youngest quintile at recall, firstborns, and infants with more siblings. Ever having breastfed was recalled by 94% of women. For categories of 1–3, 4–6, 7–9, and 10–12 months, recalled breastfeeding duration was correctly classified by 54% of women and was classified within ±1 category by 89%. The observed misclassification, if nondifferential with respect to outcome, would appreciably attenuate estimates of dose-response associations between breastfeeding duration and later health. bias (epidemiology); breast feeding; epidemiologic methods; mental recall; reproductive history; validation studies

The authors assessed the accuracy of cause(s) of subfertility as reported by women in a self-administered questionnaire in comparison with medical record information, in a nationwide cohort study of women receiving in vitro fertilization treatment in the Netherlands (n = 9,164) between 1983 and 1995. Validity was expressed as sensitivity and specificity, and reliability was expressed by the kappa statistic and overall agreement between self-reports and medical records for various subfertility categories. The sensitivity for subfertility attributed to tubal, male, hormonal, cervical, uterine, and idiopathic factors and for endometriosis was 84%, 78%, 65%, 40%, 46%, 59%, and 83%, respectively. The corresponding kappas were 0.79, 0.71, 0.38, 0.34, 0.13, 0.50, and 0.52, respectively. For 54% of all women who reported two or more causes of subfertility, the medical record revealed only one major factor. Conversely, for 43% of all women whose subfertility was attributed to two or more major factors in the record, only one factor was reported by the women. Older age at the time of filling out the questionnaire, low educational level, long duration of subfertility, and pre-in vitro fertilization treatment were associated with less accurate reporting. The results indicate that the validity of self-reports for tubal and male subfertility is satisfactory. For unexplained subfertility, the validity is moderate; for other causes of subfertility and when two causes of subfertility play a role, the validity is low. Copyright

Screening by whole-body clinical skin examination may improve early diagnosis of melanoma and reduce mortality, but objective scientific evidence of this is lacking. As part of a randomized controlled trial of population screening for melanoma in Queensland, Australia, the authors assessed the validity of self-reported history of whole-body skin examination and factors associated with accuracy of recall among 2,704 participants in 2001. Approximately half of the participants were known to have undergone whole-body skin examination within the past 3 years at skin screening clinics conducted as part of the randomized trial. All positive and negative self-reports were compared with screening clinic records. Where possible, reports of skin examinations conducted outside the clinics were compared with private medical records. The validity of self-reports of whole-body skin examination in the past 3 years was high: Concordance between self-reports and medical records was 93.7%, sensitivity was 92.0%, and specificity was 96.3%. Concordance was lower (74.3%) for self-reports of examinations conducted in the past 12 months, and there was evidence of "telescoping" in recall for this more recent time frame. In multivariate analysis, women and younger participants more accurately recalled their history of skin examinations. Participants with a history of melanoma did not differ from other participants in their accuracy of recall.

A validation study evaluated the accuracy of self-reported use of commonly used medications among older women. Within a case-control study of breast cancer, drug information was ascertained by interview. Pharmacy records from 1990 to 1999 were obtained from a Washington State health maintenance organization (66% of subjects) and retail pharmacies (34% of subjects) on a sample of subjects (212 cases, 191 controls) and used as the "gold standard." Recall accuracy was assessed for 6-month, 2-year, and 8-year time windows. Sensitivity of antihypertensive use was 92% (95% confidence interval (CI): 85, 96) for cases and controls in the 6-month period and slightly lower for the 2-year (90% (95% CI: 82, 94) and 87% (95% CI: 78, 92)) and 8-year (80% (95% CI: 69, 88) and 79% (95% CI: 68, 88)) periods. For statins, sensitivity was 83% (95% CI: 64, 93) for cases and 93% (95% CI: 69, 99) for controls in the 6-month period, 75% (95% CI: 55, 88) and 86% (95% CI: 60, 96) in the 2-year period, and 67% (95% CI: 42, 85) and 75% (95% CI: 41, 93) in the 8-year period. For self-report of antidepressants, sensitivities ranged from 66% (95% CI: 47, 80) in the 6-month period to 44% (95% CI: 30, 60) in the 8-year period. Specificity was high among all drug classes, ranging from 91% to 100%. Recall did not differ by case-control status. Trivial changes in estimates were observed when health maintenance organization records alone were used as the gold standard. Self-reported use of antihypertensives and statins appears to be relatively accurate among older women.

Most information concerning possible cancer risks attributable to lifetime exposure to diagnostic x-rays comes from studies in which x-ray history was ascertained by interview or questionnaire, but little is known about the accuracy of such information. The authors assessed agreement between medical x-ray histories obtained through interview and by review of medical records from thyroid cancer case-control studies conducted in Sweden (1985-1992; 123 cases and 123 controls) and from members of a prepaid health plan in the United States (1986-1991; 50 cases and 50 controls). In both studies, substantial disagreement was found between the numbers of x-ray examinations reported in the interview and in the medical records. There was an indication of relatively poorer reporting among controls, particularly for certain types of x-ray examinations and for large numbers of such examinations. Estimates of the risk associated with exposure to diagnostic x-rays were similar, regardless of whether interview or medical record data were used, even though ordinal dose classifications based on the two sources differed considerably. In populations with a high frequency of exposure, spurious associations with numbers of x-ray examinations or estimated thyroid dose might arise because of differences in recall. However, in the present data, reporting errors by cases and controls seemed to be largely nondifferential.

Estimated associations between self-reported age at menopause and health may be attenuated if self-report is inaccurate. In a cross-sectional study, it is not possible to assess validity or reproducibility. Instead, one can examine digit preference, e.g., overreporting of numbers ending in zero or five. Typically, analyses use equal proportions-10% probability for each digit-as the reference distribution. Depending on the age distribution of the sample and on the underlying distribution of age at the event, however, an alternative reference distribution may be more appropriate. As an illustration, the authors examined digit preference in the self-reported calendar year at the final menstrual period in cross-sectional data from 2,151 naturally postmenopausal women in the Study of Women's Health Across the Nation (1995-1997), a multisite, multiethnic study of women aged 40-55 years. With chi-square tests, the distribution of terminal digit for self-reported year at the final menstrual period was compared with several reference distributions. The observed distribution was much closer to a reference distribution based on previously published data than it was to equal proportions. Future assessments of digit preference in cross-sectional studies should consider alternatives to equal proportions, particularly for samples with small age ranges and events with a restricted underlying age distribution.

Although methods of collecting food intake data have been studied intensively, there have been fewer investigations into the collection of supplement intake data. Use of eight types of vitamin and mineral supplements was reported between 1994 and 1997 by 2,377 subjects participating in a calibration substudy of the Hawaii-Los Angeles Multiethnic Cohort Study. Subjects gave information on supplement use as part of a dietary questionnaire (administered twice) and during three 24-hour dietary recalls. Multivitamins were the most commonly used supplements (55% of the subjects), followed by vitamin C (40%), vitamin E (33%), and calcium (29%). Vitamin A, beta-carotene, selenium, and iron supplements were each used by fewer than 10% of the subjects. Weighted kappa statistics for agreement between the recalls and the questionnaire across six categories of frequency of use ranged from 0.74 for vitamin E to 0.16 for vitamin A and were generally higher for frequently used supplements. The reproducibility of questionnaire responses at two time points varied from 0.64 to 0.39. In comparison with three recalls, a brief questionnaire can accurately and reproducibly capture data on supplement use for frequently consumed products, but it may perform less well for products used less often or more intermittently.

Associations have been found between birth weight and many diseases in adult life. In most countries, few birth records exist for older adults; therefore, birth weight is usually obtained by maternal recall or self-report. This study examined determinants of the availability and accuracy of self-report in middle-aged and elderly women. Birth weights, recorded at the time of birth, were found in 1999 for a subset of 363 women participating in a long-running cancer research study in the United Kingdom. Questionnaires were sent to the surviving 286 women requesting information on their birth weight and other factors related to their birth family. Twenty-five percent of the 244 respondents were able to report their birth weight to within 4 ounces (113.4 g) of that listed in birth records, 28% reported it inaccurately, and 47% did not know their birth weight. The most important factors determining the availability of self-reported birth weight were having a living mother and a low birth weight (< or = 6 pounds (2,722 g)). The most important determinants of accuracy, for those who provided a report, were being younger and the eldest child. Research studies relying on self-reported birth weight should take these factors into account.

This study examined the relations between food patterns and five components of the metabolic syndrome in a sample of Swedish men (n = 2,040) and women (n = 2,959) aged 45-68 years who joined the Malmö Diet and Cancer study from November 1991 to February 1994. Baseline examinations included an interview-administered diet history, a self-administered questionnaire, blood pressure and anthropologic measurements, and blood samples donated after an overnight fast. Cluster analysis identified six food patterns for which 43 food group variables were used. Logistic regression analysis was used to examine the risk of each component (hyperinsulinemia, hyperglycemia, hypertension, dyslipidemia, and central obesity) and food patterns, controlling for potential confounders. The study demonstrated relations, independent of specific nutrients, between food patterns and hyperglycemia and central obesity in men and hyperinsulinemia in women. Food patterns dominated by fiber bread provided favorable effects, while food patterns high in refined bread or in cheese, cake, and alcoholic beverages contributed adverse effects. In women, food patterns dominated by milk-fat-based spread showed protective relations with hyperinsulinemia. Relations between risk factors and food patterns may partly depend on gender differences in metabolism or food consumption and on variations in confounders across food patterns.