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Introduction As the rate of obesity increases, so does the incidence of obesity-related comorbidities. Metabolic and bariatric surgery (MBS) is the most effective treatment for obesity, yet this treatment is severely underused. MBS can improve, resolve, and prevent the development of obesity-related comorbidities; this improvement in health also results in lower healthcare costs. The studies that have examined these outcomes are often limited by small sample sizes, reliance on outdated data, inconsistent definitions of outcomes, and the use of simulated data. Using recent real-world data, we will identify characteristics of individuals who qualify for MBS but have not had MBS and address the gaps in knowledge around the impact of MBS on health outcomes and healthcare costs.Methods and analysis Using a large US employer-based retrospective claims database (Merative), we will identify all obese adults (21+) who have had a primary MBS from 2016 to 2021 and compare their characteristics and outcomes with obese adults who did not have an MBS from 2016 to 2021. Baseline demographics, health outcomes, and costs will be examined in the year before the index date, remission and new-onset comorbidities, and healthcare costs will be examined at 1 and 3 years after the index date.Ethics and dissemination As this was an observational study of deidentified patients in the Merative database, Institutional Review Board approval and consent were exempt (in accordance with the Health Insurance Portability and Accountability Act Privacy Rule). An IRB exemption was approved by the wcg IRB (#13931684). Knowledge dissemination will include presenting results at national and international conferences, sharing findings with specialty societies, and publishing results in peer-reviewed journals. All data management and analytic code will be made available publicly to enable others to leverage our methods to verify and extend our findings.

Abstract Background Understanding the relationship between adolescent pregnancy and adult education and employment outcomes is complicated due to the endogeneity of fertility behaviors and socio-economic functioning. Studies exploring adolescent pregnancy have often relied on limited data to measure adolescent pregnancy (i.e. birth during adolescence or self-reports) and lack access to objective measures of school performance during childhood. Methods We use rich administrative data from Manitoba, Canada, to assess women’s functioning during childhood (including pre-pregnancy academic performance), fertility behaviors during adolescence (live birth, abortion, pregnancy loss, or no history of pregnancy), and adult outcomes of high school completion and receipt of income assistance. This rich set of covariates allows calculating propensity score weights to help adjust for characteristics possibly predictive of adolescent pregnancy. We also explore which risk factors are associated with the study outcomes. Results We assessed a cohort of 65,732 women, of whom 93.5% had no teen pregnancy, 3.8% had a live birth, 2.6% had abortion, and

Abstract Background Perinatal risk factors can vary by immigration status. We examined psychosocial and behavioral perinatal health indicators according to immigration status and immigrant characteristics. Methods We conducted a population-based cross-sectional study of 33,754 immigrant and 172,342 non-immigrant childbearing women residents in Manitoba, Canada, aged 15–55 years, who had a live birth and available data from the universal newborn screen completed within 2 weeks postpartum, between January 2000 and December 2017. Immigration characteristics were from the Canadian federal government immigration database. Logistic regressions models were used to obtain Odds Ratios (OR) with 95% confidence intervals (CI) for the associations between immigration characteristics and perinatal health indicators, such as social isolation, relationship distress, partner violence, depression, alcohol, smoking, substance use, and late initiation of prenatal care. Results More immigrant women reported being socially isolated (12.3%) than non-immigrants (3.0%) (Adjusted Odds Ratio (aOR): 6.95, 95% CI: 6.57 to 7.36) but exhibited lower odds of depression, relationship distress, partner violence, smoking, alcohol, substance use, and late initiation of prenatal care. In analyses restricted to immigrants, recent immigrants (

Summary: Background: Population-based longitudinal studies on bereaved children and youth's mental health care use are scarce and few have assessed the role of surviving parents' mental health status. Methods: Using register data of individuals born in Sweden in 1992–1999, we performed a matched cohort study (n = 117,518) on the association between parental death and subsequent initiation of antidepressant treatment among individuals bereaved at ages 7–24 years. We used flexible parametric survival models to estimate the hazard ratios (HRs) over time after bereavement, adjusting for individual and parental factors. We further examined if the association varied by age at loss, sex, parental sociodemographic factors, cause of death, and the surviving parents' psychiatric care. Findings: The bereaved were more likely to initiate antidepressants treatment than the nonbereaved matched individuals during follow-up (incidence rate per 1000 person years 27.5 [26.5–28.5] vs. 18.2 [17.9–18.6]). The HRs peaked in the first year after bereavement and remained higher than the nonbereaved individuals until the end of the follow-up. The average HR over the 12 years of follow-up was 1.48 (95% confidence interval [1.39–1.58]) for father's death and 1.33 [1.22–1.46] for mother's death. The HRs were particularly high when the surviving parents received psychiatric care before bereavement (2.11 [1.89–2.56] for father's death; 2.14 [1.79–2.56] for mother's death) or treated for anxiety or depression after bereavement (1.80 [1.67–1.94]; 1.82 [1.59–2.07]). Interpretation: The risk of initiating antidepressant treatment was the highest in the first year after parental death and remained elevated over the next decade. The risk was particularly high among individuals with surviving parents affected by psychiatric morbidity. Funding: The Swedish Research Council.

Abstract Background Diagnosis codes in administrative health data are routinely used to monitor trends in disease prevalence and incidence. The International Classification of Diseases (ICD), which is used to record these diagnoses, have been updated multiple times to reflect advances in health and medical research. Our objective was to examine the impact of transitions between ICD versions on the prevalence of chronic health conditions estimated from administrative health data. Methods Study data (i.e., physician billing claims, hospital records) were from the province of Manitoba, Canada, which has a universal healthcare system. ICDA-8 (with adaptations), ICD-9-CM (clinical modification), and ICD-10-CA (Canadian adaptation; hospital records only) codes are captured in the data. Annual study cohorts included all individuals 18 + years of age for 45 years from 1974 to 2018. Negative binomial regression was used to estimate annual age- and sex-adjusted prevalence and model parameters (i.e., slopes and intercepts) for 16 chronic health conditions. Statistical control charts were used to assess the impact of changes in ICD version on model parameter estimates. Hotelling’s T2 statistic was used to combine the parameter estimates and provide an out-of-control signal when its value was above a pre-specified control limit. Results The annual cohort sizes ranged from 360,341 to 824,816. Hypertension and skin cancer were among the most and least diagnosed health conditions, respectively; their prevalence per 1,000 population increased from 40.5 to 223.6 and from 0.3 to 2.1, respectively, within the study period. The average annual rate of change in prevalence ranged from -1.6% (95% confidence interval [CI]: -1.8, -1.4) for acute myocardial infarction to 14.6% (95% CI: 13.9, 15.2) for hypertension. The control chart indicated out-of-control observations when transitioning from ICDA-8 to ICD-9-CM for 75% of the investigated chronic health conditions but no out-of-control observations when transitioning from ICD-9-CM to ICD-10-CA. Conclusions The prevalence of most of the investigated chronic health conditions changed significantly in the transition from ICDA-8 to ICD-9-CM. These results point to the importance of considering changes in ICD coding as a factor that may influence the interpretation of trend estimates for chronic health conditions derived from administrative health data.

Background It is well established that maternal mental illness is associated with an increased risk of poor development for children. However, inconsistencies in findings regarding the nature of the difficulties children experience may be explained by methodological or geographical differences. Aims We used a common methodological approach to compare developmental vulnerability for children whose mothers did and did not have a psychiatric hospital admission between conception and school entry in Manitoba, Canada, and Western Australia, Australia. We aimed to determine if there are common patterns to the type and timing of developmental difficulties across the two settings. Method Participants included children who were assessed with the Early Development Instrument in Manitoba, Canada (n = 69 785), and Western Australia, Australia (n = 19 529). We examined any maternal psychiatric hospital admission (obtained from administrative data) between conception and child's school entry, as well as at specific time points (pregnancy and each year until school entry). Results Log-binomial regressions modelled the risk of children of mothers with psychiatric hospital admissions being developmentally vulnerable. In both Manitoba and Western Australia, an increased risk of developmental vulnerability on all domains was found. Children had an increased risk of developmental vulnerability regardless of their age at the time their mother was admitted to hospital. Conclusions This cross-national comparison provides further evidence of an increased risk of developmental vulnerability for children whose mothers experience severe mental health difficulties. Provision of preventative services during early childhood to children whose mothers experience mental ill health may help to mitigate developmental difficulties at school entry.

Objectives Over three decades ago, the Aboriginal Justice Inquiry identified structural racism in Canada’s justice system. Although rates of youth criminal charges and incarcerations have declined substantially since then, it is unclear whether First Nations youth are treated differently than non-First Nations youth for similar offences. Our study addressed this question. Approach This retrospective cohort study of youth born 1991-2001 and living in Manitoba between ages 12-17 used whole-population linked administrative data to identify youth charged with a crime (N=13,543). First Nations youth (n=7,081) were compared with all other Manitoba (AOM) youth (n=6,462) on whether their criminal charge proceeded or was dropped, deferred or diverted. The study applied an intersectionality theoretical framework. Individual (age, type and severity of charge, ever in child protection care, youth and/or mother diagnosed mental disorder, maternal incarceration, number of siblings, urban/rural residence) and social strata (First Nations identity, income, sex) factors were adjusted for using multi-level models. Results After accounting for other factors, First Nations youth had a higher risk of a charge proceeding than AOM (adjusted Relative Risk (aRR) 1.16, 95% CI 1.12-1.20). There was no difference in charges proceeding for male First Nations youth compared with male AOM, whereas among females, the risk was greater for First Nations (aRR 1.31, 95% CI 1.26-1.36). Low income and a history of being in the care of the child protection system increased the risk of charges proceeding for AOM only (aRR 1.16, 95% CI 1.13-1.18; aRR 1.13, 95% CI 1.07-1.20); for First Nations, there was no increased risk of charges proceeding associated with these intersecting factors. Conclusion These findings provide quantitative evidence of the intersecting structural racism in the youth criminal justice system previously identified by First Nations leaders. Future research will follow this cohort to determine whether more judicial sanctions are applied to First Nations youth throughout the justice process, including within criminal courts and corrections.

Objectives Perinatal risk factors can vary by immigration status. To advance knowledge on sociobehavioral health risks among pregnant and childbearing immigrant women, we compared perinatal health indicators between immigrant and non-immigrants, overall, and according to key immigrant characteristics (refugee status, secondary migration, birth region, and duration of residence). Approach We conducted a population-based cross-sectional study of 33,754 immigrant and 172,342 non-immigrant childbearing women in Manitoba, Canada, aged 15-55 years, who had newborn screening data completed by public health nurses within two weeks postpartum from 2000 to 2017. The screening data was linked to a Canadian national immigration database. Additional databases were linked to collect demographic and perinatal clinical information. Logistic regression models were used to examine the associations between immigration characteristics and perinatal health indicators, such as social isolation, relationship distress, partner violence, depression, alcohol, smoking, substance use and late prenatal care initiation. Results More immigrant women reported being socially isolated (12.3%) than non-immigrants (3.0%) (Adjusted Odds Ratio (aOR): 6.90, 95% Confidence Interval (CI): 6.53, 7.28) but exhibited lower odds of other outcomes. In the analysis restricted to immigrants, recent immigrants (< 5 years of stay) had higher odds of being socially isolated (aOR: 9.29, 95% CI: 7.80, 11.06) and late prenatal care (aOR: 1.73, 95% CI: 1.23, 2.42) compared to long-term immigrants, but lower odds relationship distress, depression, alcohol, smoking and substance use. Refugee status was positively associated with social isolation, relationship distress, depression, and late prenatal care whereas secondary migration was protective for social isolation, relationship distress, and smoking. Relationship distress and behavioral health indicators varied by maternal birth region. Conclusion The novel linkage of birth screening data with the immigration data advances knowledge on immigrant perinatal health by identifying risk patterns for multiple psychosocial and behavioral health indicators, highlighting subgroups at higher and lower risk of exposures that may contribute to adverse perinatal health outcomes.

Objectives Indigenous children in Canada, including Metis children, are taken into care by the child welfare system at a disproportionately high rate. The objective of this study was to explore factors related to having a child taken into care from Metis families in Manitoba, and specifically from Metis mothers experiencing incarceration. Approach The cohort comprised all mother-child dyads in Manitoba, Canada with live births between Jan 1, 2004-Dec 31, 2014. The factors we examined included the mother experiencing incarceration after the birth of a child, having prior interaction with the legal system, socioeconomic status, maternal age, and mother’s mental health disorder diagnoses. Using the Cox proportional hazards model, unadjusted and adjusted hazard ratios describing the risk of a child being taken into care by five years of age were generated for three exposure groups: no incarceration, prenatal incarceration, and postnatal incarceration. Results Before adjustment, mothers experiencing incarceration after the birth of a child had greater risk of having a child taken into care (HR 9.3; 95% CI 7.7-11.3) compared with women who did not experience incarceration; after adjusting for measured confounders, their elevated risk dropped to aHR 6.1 (5.0-7.4). After further adjustment for prior custody in the prenatal period, mothers experiencing incarceration had 3.8 times the risk (3.0-5.0), and after adjusting for maternal mental health disorders, this dropped to 2.6 times the risk (2.0-3.4). In fully adjusted models, other factors associated with having a child taken into care included receiving diagnoses for a substance use disorder (aHR 2.6; 2.1-3.2) and for psychosis (aHR 2.4; 1.4-4.1) during the five years prior to the child’s birth. Conclusion Due to colonialism, Metis women experience high levels of social and mental health complexity, placing their children at increased risk of being taken into care. Responding to the Truth and Reconciliation Commission’s Calls to Action to redress the harms of colonialism is necessary to support Metis children’s health and well-being.

Objective The objective is to examine the association between trajectories of childhood residential and school mobility and academic achievement (literacy, numeracy) in Grade 3 using linked whole-population administrative data in Manitoba, Canada. Secondarily, we assessed childhood residential/school mobility based on neighbourhood income levels (moving in/out of low- or mid-/high-income neighbourhoods). Approach This retrospective cohort study used linkable, de-identified administrative data (health, education, national census, provincial survey) from the provincial Population Research Data Repository housed at the Manitoba Centre for Health Policy (MCHP). Among kindergarteners from 2005 to 2014 (n = 83,894), those not having continuous residency in Manitoba, valid education assessments, and relevant family-level covariates were excluded. We followed this eligible cohort from kindergarten to Grade 3 based on various neighbourhood income trajectories of residential and school mobility. To assess Grade 3 literacy and numeracy scores based on trajectories, log-binomial regression models were conducted using SAS® version 9.4. Results The total cohort included 36,754 children; at the end of kindergarten, 14.2% resided in low-income neighbourhoods, and 84.8% lived in mid-/high-income neighbourhoods. Moving between two low-income neighborhoods between kindergarten to Grade 3 was associated with an increased risk of poor Grade 3 numeracy and literacy scores (numeracy aRR=1.39 [1.16,1.67]; literacy aRR=1.31 [1.08,1.59]). When moving between neighborhood income levels, the association was stronger for children moving into low-income neighbourhoods (e.g., mid-/high-income to low-income: numeracy aRR=1.41 [1.19,1.67]) than children moving into mid/high-income neighbourhoods (e.g., low-income to mid-/high-income: numeracy aRR=1.31 [1.08,1.59]). Changing schools between kindergarten and Grade 3 was also associated with poorer numeracy and literacy scores in Grade 3 (numeracy aRR=1.31 [1.22,1.40]; literacy aRR=1.34 [1.24,1.44]); however, the strength varied based on residential mobility patterns. Conclusion Moving homes/schools can differentially impact children’s educational attainment depending upon the income level of residing neighborhood(s). Stakeholders should recognize different levels of risks related to mobility and provide support accordingly to reduce the adverse impact. Support systems should be tailored to not only children but also families and neighbourhoods.

Objective A family history of a chronic disease often predicts disease risk, with predictive value determined by heritability, the proportion of variation in risk explained by inherited genetic factors. Our objective was to assess the validity of disease heritability estimates from electronic healthcare records (EHRs) that capture family relationships and disease diagnoses. Approach A population-based investigation was conducted using healthcare records from Manitoba, Canada for 1970 to 2021. We constructed family relationships for up to four generations using health insurance registration information containing unique family and individual identifiers. Health histories for family members were created using diagnosis codes in hospital and physician visit records. Linear mixed-effects models were used to estimate heritability (h) for 130 chronic health conditions using open-source Clinical Classifications Software that defines clinically-meaningful disease categories. Comparisons between EHR-derived estimates and genetically-derived estimates from published studies were used to assess validity of the methodology. Results Health insurance registration data were used to construct 10,000 families that included 116,879 individuals. Median family size was 9 (interquartile range: 8). Median observation time was 39.6 years (interquartile range: 25.7). Males comprised half (51.0%) of family members. A total of 272,114 familial relationships were identified; slightly more than half (53%) were first degree (i.e., child and parent) relationships. One-third (33.2%) of families were comprised of four generations; only 15.3% were comprised of two generations. Heritability estimates were consistent with published genetically-derived estimates for several conditions, including diabetes (EHR h = 0.29 vs. 0.22), anemia (EHR h = 0.21 vs. 0.20), and asthma (EHR h = 0.34 vs. 0.33). However, inconsistencies were identified for pancreatic disorders, gastrointestinal conditions, some mental health conditions, and heart disease. Conclusion EHRs provide a promising approach to explore heritability of selected health conditions in large, diverse populations. Inconsistencies between EHR-derived and genetically-derived estimates are indicative of the limitations of diagnoses recorded for administrative purposes. Future research will explore sex-specific heritability estimates and effects of change in disease diagnosis coding over time.

Family health history is a well-established risk factor for many health conditions but the systematic collection of health histories, particularly for multiple generations and multiple family members, can be challenging. Routinely-collected electronic databases in a select number of sites worldwide offer a powerful tool to conduct multigenerational health research for entire populations. At these sites, administrative and healthcare records are used to construct familial relationships and objectively-measured health histories. We review and synthesize published literature to compare the attributes of routinely-collected, linked databases for three European sites (Denmark, Norway, Sweden) and three non-European sites (Canadian province of Manitoba, Taiwan, Australian state of Western Australia) with the capability to conduct population-based multigenerational health research. Our review found that European sites primarily identified family structures using population registries, whereas non-European sites used health insurance registries (Manitoba and Taiwan) or linked data from multiple sources (Western Australia). Information on familial status was reported to be available as early as 1947 (Sweden); Taiwan had the fewest years of data available (1995 onwards). All centres reported near complete coverage of familial relationships for their population catchment regions. Challenges in working with these data include differentiating biological and legal relationships, establishing accurate familial linkages over time, and accurately identifying health conditions. This review provides important insights about the benefits and challenges of using routinely-collected, population-based linked databases for conducting population-based multigenerational health research, and identifies opportunities for future research within and across the data-intensive environments at these six sites.

Abstract Background Previous studies have reported an intergenerational association between maternal and offspring preterm birth (PTB) but the nature of the association remains unclear. We assessed the association between maternal and offspring preterm birth using a quasi-experimental sibling design and distinguishing between preterm birth types. Methods We conducted a retrospective intergenerational cohort study of 39,573 women born singleton in Manitoba, Canada (1980–2002) who gave birth to 79,198 singleton infants (1995–2016). To account for familial confounding we defined a subcohort of 1033 sisters with discordant PTB status who subsequently gave birth and compared offspring PTB rates between 2499 differentially exposed cousins using log-binomial fixed-effects generalized estimating equation models. PTB was defined as a delivery

Introduction Administrative health data capture diagnoses using the International Classification of Diseases (ICD), which has multiple versions over time. To facilitate longitudinal investigations using these data, we aimed to map diagnoses identified in three ICD versions – ICD-8 with adaptations (ICDA-8), ICD-9 with clinical modifications (ICD-9-CM), and ICD-10 with Canadian adaptations (ICD-10-CA) – to mutually exclusive chronic health condition categories adapted from the open source Clinical Classifications Software (CCS). Methods We adapted the CCS crosswalk to 3-digit ICD-9-CM codes for chronic conditions and resolved the one-to-many mappings in ICD-9-CM codes. Using this adapted CCS crosswalk as the reference and referring to existing crosswalks between ICD versions, we extended the mapping to ICDA-8 and ICD-10-CA. Each mapping step was conducted independently by two reviewers and discrepancies were resolved by consensus through deliberation and reference to prior research. We report the frequencies, agreement percentages and 95% confidence intervals (CI) from each step. Results We identified 354 3-digit ICD-9-CM codes for chronic conditions. Of those, 77 (22%) codes had one-to-many mappings; 36 (10%) codes were mapped to a single CCS category and 41 (12%) codes were mapped to combined CCS categories. In total, the codes were mapped to 130 adapted CCS categories with an agreement percentage of 92% (95% CI: 86%–98%). Then, 321 3-digit ICDA-8 codes were mapped to CCS categories with an agreement percentage of 92% (95% CI: 89%–95%). Finally, 3583 ICD-10-CA codes were mapped to CCS categories; 111 (3%) had a fair or poor mapping quality; these were reviewed to keep or move to another category (agreement percentage=77% [95% CI: 69%–85%]). Conclusions We developed crosswalks for three ICD versions (ICDA-8, ICD-9-CM, and ICD-10-CA) to 130 clinically meaningful categories of chronic health conditions by adapting the CCS classification. These crosswalks will benefit chronic disease studies spanning multiple decades of administrative health data.

Introduction Ectopic pregnancy occurs in 1% to 2% of the all recognized pregnancies, yet half of women who have an ectopic pregnancy do not have any known risk factors. A potential but unstudied risk factor for ectopic pregnancy is benzodiazepine use, which could affect muscle contraction in the fallopian tube. Objectives and Approach We compared the risk of ectopic pregnancy among women with and women without benzodiazepine prescriptions before conception. using data from United States commercial insurance claims (IBM® MarketScan® Databases). We performed a cohort study of 1,691,366 pregnancies between November 1, 2008 and September 30, 2015, and used unadjusted and inverse probability of treatment (IPT) weighted log-binomial models to calculate relative risks (RR) of ectopic pregnancy for pregnant women who did and did not fill any prescriptions for benzodiazepines in the 90 days before conception. Sub-group analysis was conducted on women who had anxiety and women who had insomnia diagnoses in the year before conception. Results Of the 1,691,366 pregnant women, 1.06% filled at least two benzodiazepine prescriptions in the 90 days before conception. Among women with a benzodiazepine prescription, there was an excess of 80 ectopic pregnancies per 10,000 pregnancies, and their IPT-weighted risk of ectopic pregnancies was 1.47 (95% CI 1.32 to 1.63) times greater relative to women without benzodiazepine prescriptions before conception. The IPT-weighted RR between ectopic pregnancy and benzodiazepine use was 1.34 (95% CI 1.18 to 1.53) among women with anxiety disorder diagnoses and 1.28 (95% CI 0.99 to 1.68) among women with an insomnia diagnosis. Conclusion / Implications This study found that women who have a benzodiazepine prescription before conception are at an increased risk of ectopic pregnancy. This information can help women and their health care providers make more fully informed decisions about benzodiazepine use in their reproductive years.

Introduction Studies on the relationship between exposure to maternal depression in early childhood and childhood development have been limited by small samples, lack of information on timing of maternal depression, and use of a composite measure of childhood development. Objectives and Approach We linked multiple Manitoba datasets to examine the relationship between exposure to maternal depression in early childhood and childhood development at school entry across five domains, and age at exposure to maternal depression on developmental outcomes using a population-based cohort (n = 52,103). Maternal depression was defined using physician visits, hospitalizations, and pharmaceutical data, while developmental vulnerability was assessed using the well-validated Early Development Instrument. Relative risk of developmental vulnerability was assessed using log-binomial regression models, adjusted for maternal and childhood characteristics at the birth of the child. Results Children exposed to maternal depression before age 5 had a 17% higher risk of having at least one developmental vulnerability at school entry than children not exposed to such depression before age 5. Exposure to maternal depression before age 5 was most strongly associated with social competence (aRR = 1.28, 95% CI 1.20, 1.38), physical health and well-being (aRR = 1.28, 95% CI 1.20, 1.36), and emotional maturity (aRR = 1.27, 95% CI 1.18, 1.37). For most developmental domains, exposure to maternal depression before age 1 and between ages 4 and 5 had the greatest association with developmental vulnerability. Conclusion / Implications Our findings that children exposed to maternal depression were at higher risk of developmental vulnerability at school entry is consistent with previous studies. However, we found that the association between exposure to maternal depression and development varied across developmental domains, and the relationship varied depending on the age of exposure to maternal depression. Ongoing analyses of discordant cousins will shed more light on the causal nature of this relationship.

Introduction: When designing prospective and retrospective longitudinal cohort studies, investigators must make decisions about study duration (i.e. length of follow-up) and frequency of outcome measurement. The impact of these decisions have been previously investigated in the prospective setting, but have not been described for retrospective cohort studies. Objectives: To examine the impact and potential challenges of longitudinal design decisions in retrospective cohort studies and illustrate the effects of varying study duration and frequency of outcome measurement in the retrospective setting using a numeric example. Methods: Linked administrative data from Manitoba was used. The cohort included all mothers who experienced the death of an infant between April 1, 1999 and March 31, 2012 and a matched (3:1) group of mothers who did not experience death. A generalized linear mixed model was used to model differences in the trend in the number of healthcare contacts for the two groups. Holding sample size constant, the model was fit to the data for combinations of duration and frequency. Estimated standard errors and regression coefficients were compared. Results: A total of 2576 mothers were included; 644 experienced death of an infant and 1932 were matched to this group. Thirteen combinations of frequency (1, 2, 3, 4 periods/year) and duration (1, 2, 3, 4 years) were compared. As frequency increased from 1 to 4 periods/year, the standard error of the group-time-time interaction decreased up to 98.9%. As duration increased from 1 to 4 years, the standard error of the interaction decreased up to 96.9%. As frequency and duration increased, the coefficients trended toward zero. Conclusions: Retrospective designs using administrative data offer greater flexibility to select time-related design elements than prospective designs, but present potential new challenges. Recommendations about how to select and report time-related design decisions in retrospective cohort studies should be included in reporting guidelines.

Introduction Children who have a history of involvement in child protection services (CPS) are over-represented in the youth and adult criminal justice systems. There are significant health and socioeconomic implications for individuals involved in either or both CPS and the justice system. Understanding the ‘overlap’ between these two systems would provide insight into the health and social needs of this population. This protocol describes a research programme on the relationship between the child welfare and the youth justice systems, looking specifically at the population involved in both CPS and the youth justice system. We will examine the characteristics associated with involvement in these systems, justice system trajectories of individuals with a history of CPS involvement and early adult outcomes of children involved in both systems.Methods and analysis Administrative data sets will be linked at the individual level for three cohorts born 1991, 1994 and 1998 in Manitoba, Canada. Involvement in CPS will be categorised as ‘placed in out-of-home care’, ‘received in-home services, but was not placed in care’ or ‘no involvement’. Involvement in the youth justice system will be examined through contacts with police between ages 12 and 17 that either led to charges or did not proceed. Individual, maternal and neighbourhood characteristics will be examined to identify individuals at greatest risk of involvement in one or both systems.Ethics and dissemination The study was approved by the University of Manitoba Health Research Ethics Board and permission to access data sets has been granted by all data providers. We also received approval for the study from the First Nations Health and Social Secretariat of Manitoba’s Health Information Research Governance Committee and the Manitoba Metis Federation. Strategies to disseminate study results will include engagement of stakeholders and policymakers through meetings and workshops, scientific publications and presentations, and social media.

Background: Migrants with insecure residency status (i.e., undocumented migrants and asylum-seekers, who are denied or waiting for authorized residency) often experience social and psychosocial adversities and limited access to health care. Nonetheless, they have not been profiled on the risk of severe maternal morbidity (SMM), a sentinel measure of maternal health and maternity care. Methods: A cohort study on all births recorded in the Swedish Medical Birth Register from 2000–2014 (N = 1,570,472). Lacking a maternal personal identification number was used as an indicator for insecure residency status (1.3% of all births). We used Poisson regression models to estimate risk ratios of SMM in migrant women with insecure residency status compared to the Swedish-born or migrant women with long-term residency, adjusting for the calendar year of birth, maternal age, and parity. Results: Overall SMM rate among migrant women with insecure residency status was 21.5/1000 and 14.7/1000 among Swedish-born women. Compared to Swedish-born, migrants with insecure residency status had 50% higher risk of overall SMM (adjusted risk ratio (aRR)=1.54 [1.37–1.74]) and over 80% higher risk of SMM excluding transfusion-only cases (aRR=1.88 [1.37–2.57]). When compared to migrant women with long-term residency, migrant women with insecure residency also had a higher risk of SMM (overall SMM aRR=1.42 [1.26,1.61]; SMM excluding transfusion only cases aRR=1.43 [1.04,1.97]), suggesting that insecure residency conferred additional risks of SMM beyond migration. Conclusion: Migrant women with insecure residency status had increased risk of severe maternal morbidity.

BACKGROUND:Children born to adolescent mothers generally perform more poorly on school readiness assessments than their peers born to adult mothers. It is unknown, however, whether this relationship extends to the grandchildren of these adolescent mothers. This paper examines the multi-generational outcomes associated with adolescent motherhood by testing whether the grandchildren of adolescent mothers also have lower school readiness scores than their peers; we further assessed if this relationship was moderated by whether the child's mother was an adolescent mother. METHODS:We used population-based data to conduct the retrospective cohort study of children born in Manitoba, Canada, 2000-2009, whose mothers were born 1979-1997 (n = 11,326). Overall school readiness and readiness on five domains of development were analyzed using logistic regression models. RESULTS:Compared with children whose mothers and grandmothers were both ≥ 20 at the birth of their first child, those born to grandmothers who were < 20 and mothers who were ≥ 20 years old at the birth of their first child had 39% greater odds of being not ready for school (95% CI: 1.22-1.60). Children whose grandmothers were ≥ 20 and mothers were < 20 at the birth of their first child had 25% greater odds of being not ready for school (95% CI: 1.11-1.41), and children born to grandmothers and mothers who were both

Introduction Fetal Alcohol Spectrum Disorder (FASD) is a significant public health concern. Prenatal care (PNC) settings are integral to preventing prenatal alcohol exposure as physicians delivering PNC services are in a unique position to reduce alcohol consumption during pregnancy. However, few studies have investigated PNC use among women who drink during Objectives and Approach Analysis was conducted of women with children born in Manitoba between April 1, 1984 and Mach 31, 2012, with follow up till 2013 using linkable administrative and novel clinic data. Study group included women whose child(ren) were diagnosed with FASD from 1999 to 2012 (n=702) at a centralised FASD diagnostic clinic. Comparison group included women from the general population whose children who did not have an FASD diagnosis (n=2097), matched on the index child’s birthdate, postal code, and SES. Adequacy of PNC utilization was defined using the revised Graduated Index of Prenatal Care Utilization. Results This is the first population-based study to investigate rates of PNC usage of women who have given birth to children with FASD. Rates of inadequate PNC were higher among the study group (adjusted RR 2.47, 95% CI 2.08 to 2.94), as well as no PNC (adjusted RR 3.55, CI 2.42 to 5.22). Among the study group 63% accessed PNC, with 59% receiving intermediate, adequate, or intensive PNC. Conclusion/Implications Results represent opportunity for screening and brief intervention programs to be delivered in PNC health care settings, as well as outreach programs to facilitate the uptake of PNC among high risk women.

Introduction Many studies demonstrating an association between in utero exposure to serotonergic antidepressants and higher risk of neurodevelopmental disorders in children are confounded by history of maternal depression and disease severity. We conducted a population-based analysis of women diagnosed with mood/anxiety disorder, a patient population for whom pharmacotherapy is clearly indicated. Objectives and Approach Using linked population-based administrative data, we identified all mother-newborn pairs in Manitoba (born 1996 to 2009, with follow-up through 2014). High dimensional propensity scores and inverse probability treatment weighting were used to address confounding by indication and disease severity. The final trimmed cohort consisted of mothers who were diagnosed with a mood/anxiety disorder from 90 days prior to conception until delivery (n=4995). Cox Proportional Hazard Regression models were used to estimate risk of Autism Spectrum Disorder, epilepsy and attention deficit hyperactivity disorder (ADHD) in offspring. In addition to clinical data, we used novel education data to define outcomes in children. Results Among the cohort of mothers diagnosed with a mood/anxiety disorder during pregnancy or up to 90 days before, 16.8% received at least two dispensations of an SSRI or SNRI during pregnancy. We did not observe an association between use of SSRIs/SNRIs during pregnancy and increased risk of Autism Spectrum Disorder (hazard ratio 0.92; 95% CI 0.42 to 2.03), epilepsy (hazard ratio 1.21; 95% CI 0.48 to 3.05), or ADHD (hazard ratio 1.13, 95% CI 0.78 to 1.64) among offspring. Conclusion/Implications In the absence of randomized control trials, large observation studies using sophisticated data analysis are the gold standard of evidence to help patients and clinicians making the decision to continue antidepressant use during pregnancy. Results of this study reassure women for whom the medication is clinically indicated.

Introduction Few studies are capable of investigating the impact of untreated maternal depression versus in-utero antidepressant exposure on long-term effects on children. Previous studies are limited by confounding by indication and are unable to follow children over time to accurately investigate long term outcomes present in childhood and adolescence. Objectives and Approach We utilize linkable administrative data to facilitate longitudinal analysis to investigate mental and educational outcomes in children exposed to in utero antidepressants. Using population-level linked administrative data from a universal health system, this study included all mother-newborn dyads in Manitoba (born 1996 to 2009, with follow-up through 2014). High Dimensional Propensity Scores and inverse probability treatment weighting were used to address confounding by indication and disease severity.Cox Proportional Hazard Regression models were used to estimate risk of mood and anxiety disorder in children and educational outcomes. Results Asymmetric trimming of the study cohort resulted in a total of 4998 mother-child dyads; 4159 children whose mothers did not use SSRIs/SNRIs during pregnancy and 839 children who were exposed to 2+ prescriptions in-utero. Use of SSRIs/SNRIs during pregnancy was not associated with an increased risk of mood/anxiety disorder in children HR 1.32 (95% CI 0.67 to 2.62). Initial results on the association between in-utero antidepressant use and early childhood development index (EDI) scores indicate no impact on school readiness (31.9% vs 29.3%), or scores on standardized tests of literacy and numeracy in Grade 3 (28.4% meeting expectation versus 31.4%) and in Grade 7 (68.8% versus 70.0%). Conclusion/Implications Administrative data facilitate investigation into an important clinical concern. These data provide robust evidence demonstrating in a large population based sample, in utero exposure to serotonergic antidepressants compared with no exposure does not increase risk of the onset of mood and anxiety disorders and adverse educational outcomes in children .

Introduction Separation from one’s child can have significant consequences for parental health and well-being. Objectives and Approach We aimed to investigate whether parents whose children were placed in care had higher rates of avoidable (amenable and preventable) mortality. Data were obtained from the Swedish national registers. Mortality rates among parents whose children were placed in care between 1990 and 2012 (17 505 mothers, 18 286 fathers) were compared with a 5:1 matched cohort of parents whose children were not placed. We computed rate differences and hazard ratios of all-cause and avoidable mortality. Results When compared with parents who did not have a child placed in care, there were an additional 21 avoidable deaths per 10 000-person years among mothers and an additional 27 avoidable deaths per 10 000-person years among fathers whose children were placed in care. Among mothers, death due to preventable causes were 3·83 times greater (95% CI 2·82-5·21) and deaths due to amenable causes were 3·12 times greater (95% CI 2·07-4·69) for those whose children were placed in care. Among fathers, death due to preventable causes was 1·75 times greater (95% CI 1·41-2·16) and deaths due to amenable causes were 1·52 times greater (95% CI 1·08- 2·13) for those whose children were placed in care. Avoidable mortality rates were higher among mothers whose children were young when placed in care and parents whose children were all placed in care. Conclusion/Implications Mothers who had a young child placed and parents whose children were all placed in care are at much higher risk of avoidable mortality than parents whose children were not placed in care. Targeted public health interventions and more attentive health care could reduce risk of avoidable mortality in this group of parents.

Introduction Mothers have increased mental illness such as anxiety and depression after the death of a child. Objectives and Approach The mental health of all mothers who experience the death of an infant (< 1 years old) in Manitoba, Canada between April 1, 1999, and March 31, 2011 (n = 534) is examined in the four years leading up to, and the four years following, the death of their child to determine how long increased levels of mental-health realted outcomes remain elevated after the death of an infant. Mental health-related outcomes of these mothers are compared with a matched (3:1) cohort of mothers who did not experience the death of a child (n = 1,602). Results Compared with mothers who did not experience the death of a child, mothers experiencing this event had higher rates of anxiety diagnoses and psychotropic prescriptions starting 6 months before the death. Elevated rates of anxiety continued for the first year and elevated rates of psychotropic prescriptions continued for six months after the death of the child. Mothers who experienced the death of a child had higher rates of depression diagnoses in the year after the death. Relative rates (RR) of depression (RR = 4.94), anxiety (RR = 2.21), and psychotropic medication use (RR = 3.18) were highest in the six months after the child’s death. Conclusion/Implications Elevated rates of depression, anxiety, and psychotropic medication use after the death of a child end within one year of the child’s death.

Introduction Adolescent girls in care of child protection services are more likely to become pregnant than adolescent girls not in care, and mothers who were in care are more likely to have their children placed in care. Objectives and Approach Linkable administrative data were used to determine whether adolescent mothers in care are at greater risk of having their child placed in care before age two. A population-based cohort of adolescent mothers whose first child was born in Manitoba, Canada between April 1, 1998, and March 31, 2013 (n = 5,942) was used. Adjusted odds ratios (AOR) of having that first child taken into care before their second birthday were compared between mothers who were in care (n = 576) and mothers who were not in care (n = 5, 366) at the birth of their child using logistic regression models. Results Adolescent mothers who were in care had greater odds of having their child taken into care before the child’s second birthday (AOR = 7.53; 95% CI = 6.19-9.14). Specifically, their children had higher odds of being taken into care in their first week of life (AOR = 11.64; 95% CI = 8.83-15.34), between one week and their first birthday (AOR = 3.63; 95% CI = 2.79-4.71)., and between their first and second birthday (AOR = 2.21; 95% CI = 1.53-3.19). Conclusion/Implications Findings support an intergenerational cycle of involvement with child protection services. More and better services are required for adolescent mothers who give birth while in care of child protection services.

Introduction Large population-based data sets present similar analytic issues across such fields as: population health, clinical epidemiology, education, justice, and children’s services. Step-wise approaches and generalized tools can bring together several pillars: big (typically administrative) data, programming, and study design/analysis. How can we improve efficiency and explore alternative designs? Objectives and Approach Linked data sets typically contain: 1) files presenting longitudinal histories 2) substantive files noting various events (concussions, burns, loss of a loved one, public housing entry) and several possible covariates and outcomes. Step-wise approaches enable automating tasks by developing general tools (decreasing programmer input) and facilitating alternative designs. Macros improve upon the classic ‘one design, one data set’ perspective. Two case studies highlight tradeoffs in retrospective cohort studies (quasi-experiments) among sample size, length of follow-up, and the number of time periods. Results Study 1: Step 1 calculated the number of mothers with a child placed in care during various index years. Taking 1 year before and after placement generated 5,991 eligible mothers; selecting 5 years before/after decreased the N to 2,281. Step 2 selected appropriate in-province residents. Step 3 handled missing covariates and outcomes, while Step 4 ran alternative designs. One example (of several) compared maternal mental health outcomes using 8 time periods (in 2 years) before/after the event with outcomes using 16 time periods (in 4 years) before/after. Besides showing increasing maternal problems, the 4-year follow-up sometimes produced different statistically significant periods than the 2-year follow-up. Study 2. Swedish/Canadian comparisons of mothers with children placed in foster care highlighted growing differences in maternal pharmaceutical use. Conclusion/Implications Presenting design alternatives is straightforward and applicable across disciplines. Ongoing work is facilitating comparisons of ‘experimental’ and control groups. Literature-derived guidelines and simulation-based techniques should lead to better design decisions. Automated model assessment can help analyze robustness, statistical power, residuals, and bias, suggesting artificial intelligence approaches.

Introduction Educational attainment is known to be related to family size, birth order, and the educational achievement of an older sibling. Objective This study examines younger siblings in large families, exploring the extent to which each older sibling’s educational attainment is associated with attainment of the younger sibling. Methods Linkable administrative data were used to create a population-based cohort of third children in three child families born in Manitoba, Canada between April 1, 1984 and March 31, 1994, who stayed in the province until at least age 20 (n = 5,771). Logistic regression models were used to examine the relationship between the youngest siblings’ educational achievement and that of their older two siblings, adjusting for a series of confounders. Results Youngest siblings have the greatest odds of graduating from high school if both older siblings graduated. Females also had greater odds of graduating if only one of those older siblings had graduated; this did not increase the odds for males. Associations in educational attainment were stronger when siblings were born close together. For siblings born further apart, these associations were stronger if those siblings were of the same sex as the youngest sibling. Conclusions In large families, the educational attainment of each older sibling is associated with the educational attainment of the younger sibling; associations differ depending on the birth order and sex of the older siblings. Families in which older siblings do not graduate from high school may be experiencing numerous challenges. Children with older siblings who fail to graduate may benefit from additional supports to increase their likelihood of graduation.

ABSTRACT Objective Failing to graduate high school is linked to many risk factors, including family history academic achievement. This research examines how important an older sibling’s academic achievement is in predicting whether a younger sibling will graduate high school. Method This study used linkable administrative databases housed at the Manitoba Centre for Health Policy (MCHP). The cohort consists of 33,843 individuals born in Manitoba between April 1, 1983 and March 31, 1994, who stayed in the province until at least their 20th birthday, had at least one older sibling, and had no missing values on key variables. Logistic regression, controlling for a variety of confounders, is used to determine how much having an older sibling who didn’t graduate high school impacts the odds of a younger sibling not graduating high school. Results The adjusted odds of not graduating high school within 6 years of entering grade nine for individuals who had at least one older sibling who did not graduate high school was 4.81 (p < 0.0001, 95% CI 4.4-5.2) times higher than for individuals whose older sibling(s) graduated high school. Individuals living in low income neighborhoods at birth or age 18, individuals living in rural northern Manitoba at birth or age 18, and individuals who moved before age 18 were significantly less likely to finish high school. High school graduation rates for those living in the lowest income quintile at age 18 whose older siblings graduated high school were higher than those living in the highest income quintile at age 18 and had at least one older sibling who did not graduate high school. Conclusion The influence of an older sibling’s educational achievement has significant implications for younger siblings’ odds of high school graduation. This is likely due to social learning (younger sibling modeling actions of older sibling), and the shared parental influence and social risk experienced by both siblings.

ABSTRACT Background Risk factors for teenage pregnancy are linked to many factors, including a family history of teenage pregnancy. This research examines whether a mother’s teenage childbearing or an older sister’s teenage pregnancy more strongly predicts teenage pregnancy in a younger sister. Methods This study used linkable administrative databases housed at the Manitoba Centre for Health Policy (MCHP). The original cohort consisted of 17,115 women born in Manitoba between April 1, 1979 and March 31, 1994, who stayed in the province until at least their 20th birthday, had at least one older sister, and had no missing values on key variables. Propensity score matching (1:2) was used to create balanced cohorts for two logistic regression models; one examining the impact of an older sister’s teenage pregnancy on a younger sister's teenage pregnancy and the other analyzing the effect of the mother’s teenage childbearing on a younger sister's teenage pregnancy odds. Results The adjusted odds of becoming pregnant between ages 14 and 19 for teens with at least one older sister having a teenage pregnancy were 3.06 (99% CI 2.53 - 3.64) times higher than for women whose older sister(s) did not have a teenage pregnancy. Teenage daughters of mothers who had their first child before age 20 had 1.51 (99% CI 1.29 - 1.78) times higher odds of pregnancy than those whose mothers had their first child after age 19. Educational achievement was adjusted for in a sub-population examining the odds of pregnancy between ages 16 and 19. After this adjustment, the odds of teenage pregnancy for teens with at least one older sister who had a teenage pregnancy were reduced to 2.34 (99% CI 1.92-2.86) and the odds of pregnancy for teen daughters of teenage mothers were reduced to 1.35 (99% CI 1.15-1.59). Conclusion Given that an older sister’s teenage pregnancy has a much stronger impact than a mother’s teenage pregnancy, this study suggests social modeling to be a stronger risk factor for teenage pregnancy than living in an adverse environment created by a mother's adolescent childbearing. This study contributes to understanding of the broader topic “who is influential about what” within the family.

Understanding the processes across childhood and adolescence that affect later life inequalities depends on many variables for a large number of individuals measured over substantial time periods. Linkable administrative data were used to generate birth cohorts and to study pathways of inequity in childhood and early adolescence leading to differences in educational attainment. Advantages and disadvantages of using large administrative data bases for such research were highlighted.Children born in Manitoba, Canada between 1982 and 1995 were followed until age 19 (N = 89,763), with many time-invariant measures serving as controls. Five time-varying predictors of high school graduation-three social and two health-were modelled using logistic regression and a framework for examining predictors across the life course. For each time-varying predictor, six temporal patterns were tested: full, accumulation of risk, sensitive period, and three critical period models.Predictors measured in early adolescence generated the highest odds ratios, suggesting the importance of adolescence. Full models provided the best fit for the three time-varying social measures. Residence in a low-income neighborhood was a particularly influential predictor of not graduating from high school. The transmission of risk across developmental periods was also highlighted; exposure in one period had significant implications for subsequent life stages.This study advances life course epidemiology, using administrative data to clarify the relationships among several measures of social behavior, cognitive development, and health. Analyses of temporal patterns can be useful in studying such other outcomes as educational achievement, teen pregnancy, and workforce participation.