Equity in bariatric surgery use: a cohort study.

BACKGROUND: Metabolic and bariatric surgery (MBS) is the most effective and durable treatment for obesity; however, access to MBS is not equitable. OBJECTIVE: To determine the rate of MBS among eligible adults with obesity by demographics, health characteristics, and geography to better define populations that would benefit from resources to reduce barriers to access for this treatment. SETTING: Adults with obesity were identified in the US employer-based retrospective claims database (Merative™). METHODS: Rates of MBS were examined across demographics (age, sex, region, year, health plan type) health characteristics (obesity-related comorbidities, healthcare costs, inpatient admissions), and by state. Given differences in coverage requirements, rates are examined for 2 populations: Class 2 (BMI 35-39.9 kg/m2) and Class 3 (BMI 40+ kg/m2) obesity. RESULTS: Of the 777,565 eligible adults, 49,371 (6.4%) had MBS; 3.2% of those with Class 2 and 8.3% of those with Class 3 obesity had MBS. MBS rates varied substantially by demographic and health characteristics, ranging from 1% to 14%, and from 2% to 41% among those with Class 2 and Class 3 obesity, respectively. Geographically, rates ranged from 0% (Hawaii) to 7.4% (New Mexico) for those with Class 2 Obesity and from 4.2% (Hawaii) to 15.3% (Mississippi) among those with Class 3 Obesity. CONCLUSIONS: Use of MBS among eligible adults with obesity varies substantially across characteristics, indicating inequity in access to this treatment. To ensure greater access to the most effective treatment for obesity, policies should be implemented to reduce or eliminate barriers to care.

Identifying newborn discharge to child protective services: Comparing discharge codes from birth hospitalization records and child protection case files.

PURPOSE: Newborn removal by North America's child protective services (CPS) disproportionately impacts Indigenous and Black families, yet its implications for population health inequities are not well understood. To guide this as a domain for future research, we measured validity of birth hospitalization discharge codes categorizing newborns discharged to CPS. METHODS: Using data from 309,260 births in Manitoba, Canada, we compared data on newborns discharged to CPS from hospital discharge codes with the presumed gold standard of custody status from CPS case reports in overall population and separately by First Nations status (categorization used in Canada for Indigenous peoples who are members of a First Nation). RESULTS: Of 309,260 newborns, 4562 (1.48%) were in CPS custody at hospital discharge according to CPS case reports and 2678 (0.87%) were coded by hospitals as discharged to CPS. Sensitivity of discharge codes was low (47.8%), however codes were highly specific (99.8%) with a positive predictive value (PPV) of 81.4%, and a negative predictive value (NPV) of 99.2%. Sensitivity, PPV and specificity were equal for all newborns but NPV was lower for First Nations newborns. CONCLUSIONS: Canadian hospital discharge records underestimate newborn discharge to CPS, with no difference in misclassication based on First Nations status.

Observational cohort investigating health outcomes and healthcare costs after metabolic and bariatric surgery: a study protocol.

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.

Type 2 Diabetes Remission After Bariatric Surgery and Its Impact on Healthcare Costs.

PURPOSE: Bariatric surgery is the most effective and durable treatment of obesity and can put type 2 diabetes (T2D) into remission. We aimed to examine remission rates after bariatric surgery and the impacts of post-surgical healthcare costs. MATERIALS AND METHODS: Obese adults with T2D were identified in Merative™ (US employer-based retrospective claims database). Individuals who had bariatric surgery were matched 1:1 with those who did not with baseline demographic and health characteristics. Rates of remission and total healthcare costs were compared at 6-12 and 6-36 months after the index date. RESULTS: Remission rates varied substantially by baseline T2D complexity; differences in rates at 1 year ranged from 41% for those with high-complexity T2D to 66% for those with low- to mid-complexity T2D. At 3 years, those who had bariatric surgery had 56% higher remission rates than those who did not have bariatric surgery, with differences of 73%, 59%, and 35% for those with low-, mid-, and high-complexity T2D at baseline. Healthcare costs were $3401 and $20,378 lower among those who had bariatric surgery in the 6 to 12 months and 6 to 36 months after the index date, respectively, than their matched controls. The biggest cost differences were seen among those with high-complexity T2D; those who had bariatric surgery had $26,879 lower healthcare costs in the 6 to 36 months after the index date than those who did not. CONCLUSION: Individuals with T2D undergoing bariatric surgery have substantially higher rates of T2D remission and lower healthcare costs.

Parental death and initiation of antidepressant treatment in surviving children and youth: a national register-based matched cohort study.

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.

Neighborhood disinvestment and severe maternal morbidity in the state of California.

BACKGROUND: Social determinants of health, including neighborhood context, may be a key driver of severe maternal morbidity and its related racial and ethnic inequities; however, investigations remain limited. OBJECTIVE: This study aimed to examine the associations between neighborhood socioeconomic characteristics and severe maternal morbidity, as well as whether the associations between neighborhood socioeconomic characteristics and severe maternal morbidity were modified by race and ethnicity. STUDY DESIGN: This study leveraged a California statewide data resource on all hospital births at ≥20 weeks of gestation (1997-2018). Severe maternal morbidity was defined as having at least 1 of 21 diagnoses and procedures (eg, blood transfusion or hysterectomy) as outlined by the Centers for Disease Control and Prevention. Neighborhoods were defined as residential census tracts (n=8022; an average of 1295 births per neighborhood), and the neighborhood deprivation index was a summary measure of 8 census indicators (eg, percentage of poverty, unemployment, and public assistance). Mixed-effects logistic regression models (individuals nested within neighborhoods) were used to compare odds of severe maternal morbidity across quartiles (quartile 1 [the least deprived] to quartile 4 [the most deprived]) of the neighborhood deprivation index before and after adjustments for maternal sociodemographic and pregnancy-related factors and comorbidities. Moreover, cross-product terms were created to determine whether associations were modified by race and ethnicity. RESULTS: Of 10,384,976 births, the prevalence of severe maternal morbidity was 1.2% (N=120,487). In fully adjusted mixed-effects models, the odds of severe maternal morbidity increased with increasing neighborhood deprivation index (odds ratios: quartile 1, reference; quartile 4, 1.23 [95% confidence interval, 1.20-1.26]; quartile 3, 1.13 [95% confidence interval, 1.10-1.16]; quartile 2, 1.06 [95% confidence interval, 1.03-1.08]). The associations were modified by race and ethnicity such that associations (quartile 4 vs quartile 1) were the strongest among individuals in the "other" racial and ethnic category (1.39; 95% confidence interval, 1.03-1.86) and the weakest among Black individuals (1.07; 95% confidence interval, 0.98-1.16). CONCLUSION: Study findings suggest that neighborhood deprivation contributes to an increased risk of severe maternal morbidity. Future research should examine which aspects of neighborhood environments matter most across racial and ethnic groups.

Unwinding the tangle of adolescent pregnancy and socio-economic functioning: leveraging administrative data from Manitoba, Canada.

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 < 1% had a pregnancy loss. Women with a history of adolescent pregnancy were less likely to complete high school regardless of the outcome of that pregnancy. The probability of dropping out of high school was 7.5% for women with no history of adolescent pregnancy; after adjusting for individual, household, and neighborhood characteristics, the probability of dropping out of high school was 14.2 percentage points (pp) higher (95% CI 12.0-16.5) for women with live birth, 7.6 pp. higher (95% CI 1.5-13.7) for women with a pregnancy loss, and 6.9 pp. higher (95% CI 5.2-8.6) for women who had abortion. They key risk factors for never completing high school are poor or average school performance in 9th grade. Women who had a live births during adolescence were much more likely to receive income assistance than any other group in the sample. Aside from poor school performance, growing up in poor households and in poor neighborhoods were also highly predictive of receiving income assistance during adulthood. DISCUSSION: The administrative data used in this study enabled us to assess the relationship between adolescent pregnancy and adult outcomes after controlling for a rich set of individual-, household-, and neighborhood-level characteristics. Adolescent pregnancy was associated with higher risk of never completing high school regardless of the pregnancy outcome. Receipt of income assistance was significantly higher for women having a live birth, but only marginally higher for those who had a pregnancy that ended in loss or termination, underlining the harsh economic consequences of caring for a child as a young mother. Our data suggest that interventions targeting young women with poor or average school marks may be especially effective public policy priorities.

Examining the relationship between maternal mental health-related hospital admissions and childhood developmental vulnerability at school entry in Canada and Australia.

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.

Use of Medication to Treat Attention-Deficit/Hyperactivity Disorder in Young Children: The Role of Maternal History of Psychotropic Medication Use.

We examine whether, among children diagnosed with ADHD, are those whose mothers have a history of psychotropic medication use more likely to treat their ADHD with medication? Children born in Manitoba, Canada from 2000 to 2010 diagnosed with ADHD between their 4th and 8th birthday. Maternal psychotropic medication use was assessed from one year before the child's birth to the child's fourth birthday. Logistic regression models examine the relationship between maternal history of psychotropic medication use and the use of medication to treat ADHD in children. Among the 2384 children diagnosed with ADHD, the rate of ADHD medication use was higher for those whose mother had a history of psychotropic medication use (76.6%) than for those whose mothers did not (72.5%) (OR 1.24, 95% CI 1.03, 1.49). Children whose mothers have a history of psychotropic medication use are more likely to have their ADHD treated with medication.

Antihypertensive Medication Use before and during Pregnancy and the Risk of Severe Maternal Morbidity in Individuals with Prepregnancy Hypertension.

OBJECTIVE: Our objective is to examine severe maternal morbidity (SMM) and patterns of antihypertensive medication use before and during pregnancy among individuals with chronic hypertension. STUDY DESIGN: We examined 11,759 pregnancies resulting in a live birth or stillbirth to individuals with chronic hypertension and one or more antihypertensive prescription 6 months before pregnancy (Optum, 2007-17). We examined whether study outcomes were associated with the use of medication as compared to no use during pregnancy. In addition, patterns of medication use based on the Food and Drug Administration guidance and literature were evaluated. Medication use was divided into prepregnancy and during pregnancy use and classified as pregnancy recommended (PR) or not pregnancy recommended (nPR) or no medication use. SMM was defined per the Centers for Disease Control and Prevention definition of 21 indicators. Risk ratios (RR) reflecting the association of SMM with the use of antihypertensive medications were computed using modified Poisson regression with robust standard errors and adjusted for maternal age, education, and birth year. RESULTS: Overall, 83% of individuals filled an antihypertensive prescription during pregnancy and 6.3% experienced SMM. The majority of individuals with a prescription prior to pregnancy had a prescription for the same medication in pregnancy. Individuals with any versus no medication use in pregnancy had increased adjusted RR (aRR) of SMM (1.18, 95% confidence interval [CI]: 0.96-1.44). Compared to the use of PR medications before and during pregnancy, aRRs were 1.42 (95% CI: 1.18-1.69, 12.4% of sample) for nPR use before and during pregnancy, 1.52 (1.23-1.86; 12.4%) for nPR (before) and PR (during) use, and 2.67 (1.73-4.15) for PR and nPR use. Patterns with no medication use during pregnancy were not statistically significant. CONCLUSION: Pattern of antihypertensive medication use before and during pregnancy may be associated with an elevated risk of SMM. Further research is required to elucidate whether this association is related to the severity of hypertension, medication effectiveness, or suboptimal quality of care. KEY POINTS: · Individuals with any medication use compared to no medication use in pregnancy had an increased risk of SMM.. · Specific medication use patterns were associated with an elevated risk of SMM.. · Pattern of antihypertensive medication use before and during pregnancy may be associated with an increased risk of SMM..

Recurrent pregnancy loss and incident arthritis in midlife: an exploratory longitudinal analysis of the Study of Women's Health Across the Nation.

PURPOSE: To explore the association between recurrent pregnancy loss (RPL) and incident arthritis in midlife women. METHODS: We analyzed the U.S. Study of Women's Health Across the Nation, a multi-ethnic cohort following pre- or peri­menopausal women, using data from baseline up to the tenth annual follow-up visit. Discrete survival analysis was used to estimate adjusted hazard ratios and 95% confidence intervals for risk of incident arthritis at annual intervals in women with versus without RPL. RESULTS: Of the 2159 participants analyzed, 8.5% reported a history of RPL. Cumulative incidence of arthritis was 43.3% in women with RPL and 40.1% in women without RPL, though differences between groups varied over time. Significant associations were observed only at visits three to seven, with the strongest associations at visits four to six. The adjusted hazard ratios (95% confidence intervals) were 1.80 (1.30-2.50) at visit 4 (median age = 50 years), 1.95 (1.38-2.75) at visit 5 (median age = 51 years), and 1.82 (1.28-2.58) at visit 6 (median age = 52 years). CONCLUSIONS: Women with previous RPL may have elevated risk of arthritis specifically when entering their 50s, on average. Additional research is needed to determine whether women with a history of RPL may benefit from early detection of arthritis in midlife.

Psychosocial and behavioral health indicators among immigrant and non-immigrant recent mothers.

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 (< 5 years) had higher odds of being socially isolated (aOR: 9.04, 95% CI: 7.48 to 10.94) and late initiation of prenatal care (aOR: 1.50, 95% CI: 1.07 to 2.12) compared to long-term immigrants (10 years or more) but lower odds of relationship distress, depression, alcohol, smoking and substance use. Refugee status was positively associated with relationship distress, depression, and late initiation of prenatal care. Secondary immigrants, whose last country of permanent residence differed from their country of birth, had lower odds of social isolation, relationship distress, and smoking than primary migrants. There were also differences by maternal region of birth. CONCLUSION: Immigrant childbearing women had a higher prevalence of social isolation but a lower prevalence of other psychosocial and behavioral perinatal health indicators than non-immigrants. Health care providers may consider the observed heterogeneity in risk to tailor care approaches for immigrant subgroups at higher risk, such as refugees, recent immigrants, and those from certain world regions.

Familial associations in adolescent substance use disorder: a population-based cohort study.

BACKGROUND AND AIMS: Family history of substance use disorder (SUD) affects a child's risk of the disorder through both genetic and shared environmental factors. We aimed to estimate the association between parental or older sibling SUD history with the risk of adolescent SUD diagnosis. DESIGN, SETTING AND PARTICIPANTS: We conducted a population-based cohort study using administrative health-care databases in the Province of Manitoba, Canada, which has a universal and publicly funded health-care system. We included all children born from 1984 to 2000 who have linkages to both parents and were followed until age 18 years. We used generalized estimating equation models to produce unadjusted and adjusted relative risk (RR) estimates of adolescent SUD risk. The study cohort included 134 389 children and 31 307 full sibling pairs; 51.3% were male and 35.4% first-born. MEASUREMENTS: The exposure was SUD diagnosis in a mother or father in either hospitalization or outpatient physician visit records before the children's age of 13 years. The secondary exposure was an adolescent SUD diagnosis in an older full sibling. The outcome was SUD diagnosis during adolescence (13 and 18 years of age) identified in either hospitalization or physician visit records. Children demographics and characteristics associated with SUD diagnosis were included in the models. FINDINGS: Of the 134 389 children, 9.5% had a mother with a history of SUD, 11.3% had a father and 1.3% had an older sibling with a history of SUD diagnosis; 2566 (1.9%) had an adolescent SUD diagnosis. An increased risk of adolescent SUD was observed with SUD history in mothers [adjusted RR (aRR) = 2.50; 95% confidence interval (CI) = 2.26, 2.79], fathers (aRR = 2.15; 95% CI = 1.95, 2.37), both parents (aRR = 3.74; 95% CI = 3.24, 4.31) and older sibling (aRR = 3.85; 95% CI = 2.53, 5.87). CONCLUSIONS: A family history of substance use disorder in parents or older siblings appears to be associated with increased SUD risk in adolescents.

Record linkage and big data-enhancing information and improving design.

BACKGROUND AND OBJECTIVES: To highlight the potential of multiple file record linkage. Linkage increases the value of existing information by supplying missing data or correcting errors in existing data, through generating important covariates, and by using family information to control for unmeasured variables and expand research opportunities. METHODS: Recent Manitoba papers highlight the use of linkage to produce better studies. Specific ways in which linkage helps deal with different substantive issues are described. RESULTS: Wide data files-files containing considerable amounts of information on each individual-generated by linkage improve research by facilitating better design. Nonexperimental work in particular benefits from such linkages. Population registries are especially valuable in supplying family data to facilitate work across different substantive fields. CONCLUSION: Several examples show how record linkage magnifies the value of information from individual projects. The results of observational studies become more defensible through the better designs facilitated by such linkage.

Transitions between versions of the International Classification of Diseases and chronic disease prevalence estimates from administrative health data: a population-based study.

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.

Subsequent risk of stillbirth, preterm birth, and small for gestational age: A cross-outcome analysis of adverse birth outcomes.

BACKGROUND: Stillbirth, preterm birth, and small for gestational age (SGA) birth have an increased recurrence risk. The occurrence of one of these biologically related outcomes could also increase the risk for another one of these outcomes in a subsequent pregnancy. OBJECTIVES: We assessed cross-outcome risks for subsequent stillbirth, preterm birth, and SGA. METHODS: We used live birth and fetal death records to identify singleton, sequential birth pairs in California (1997-2017). Stillbirth was defined as delivery at ≥20 weeks of gestation of a foetus that died in utero; preterm birth as live birth at 20-36 weeks; and small for gestational age as sex-specific birthweight <10th percentile for gestational age. Risk ratios (RR) were computed using modified Poisson regression and adjusted for potential confounders. Sensitivity analyses included analysing a cohort restricted to primiparous index births and using inverse-probability censoring weights. RESULTS: Of 3,108,532 birth pairs, 16,668 (0.5%), 260,596 (8.4%) and 331,109 (10.7%) of index births were stillborn, preterm and SGA, respectively. Among individuals with an index stillbirth, the adjusted RRs were 1.90 (95% confidence interval [CI] 1.83, 1.98) for subsequent preterm and 1.35 (95% CI 1.28, 1.41) for subsequent SGA. Among those with index preterm birth, the adjusted RRs were 2.02 (95% CI 1.92, 2.13) for stillbirth and 1.42 (95% CI 1.41, 1.44) for SGA. Among those with index SGA, the adjusted RRs were 1.54 (95% CI 1.46, 1.63) for stillbirth and 1.45 (95% CI 1.44, 1.47) for preterm birth. Similar results were reported for sensitivity analyses. CONCLUSIONS: Individuals experiencing stillbirth, preterm birth, or SGA in one pregnancy had an increased risk of one of these biologically related outcomes in a subsequent pregnancy. These findings could encourage enhanced surveillance for individuals who experience stillbirth, preterm birth, or SGA and desire a subsequent pregnancy.

Multigenerational health research using population-based linked databases: an international review.

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.