Can social policy influence socioeconomic disparities? Korean War GI Bill eligibility and markers of depression

Opportunities and challenges in using instrumental variables to study causal effects in nonrandomized stress and trauma research

OBJECTIVE

Researchers are often interested in assessing the causal effect of an exposure on an outcome when randomization is not ethical or feasible. Estimating causal effects by controlling for confounders can be unconvincing because important potential confounders remain unmeasured. Study designs leveraging instrumental variables (IVs) offer alternatives to confounder-control methods but are rarely used in stress and trauma research.

METHOD

We review the conceptual foundations and implementation of IV methods. We discuss strengths and limitations of IV approaches, contrasting with confounder-control methods, and illustrate the relevance of IVs for stress and trauma research.

RESULTS

IV approaches leverage an external or exogenous source of variation in the exposure. Instruments are variables that meet three conditions: relevance (variation in the IV is associated with variation in the chance of exposure), exclusion (the IV only affects the outcome through the exposure), and exchangeability (no unmeasured confounding of the IV-outcome relationship). Interpreting estimates from IV analyses requires an additional assumption, such as monotonicity (the instrument does not change the chance of exposure in different directions for any two individuals). Valid IVs circumvent the need to correctly identify, measure, and control for all confounders of the exposure-outcome relationship. The primary challenge is identifying a valid instrument.

CONCLUSIONS

IV approaches have strengths and weaknesses compared with confounder-control approaches. IVs offers a promising complementary study design to improve evidence about the causal effects of exposures on outcomes relevant to stress and trauma. Collaboration with scientists who are experienced with identifying and analyzing IVs will support this work. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A quantitative assessment of the frequency and magnitude of heterogeneous treatment effects in studies of the health effects of social policies

Substantial heterogeneity in effects of social policies on health across subgroups may be common, but has not been systematically characterized. Using a sample of 55 contemporary studies on health effects of social policies, we recorded how often heterogeneous treatment effects (HTEs) were assessed, for what subgroups (e.g., male, female), and the subgroup-specific effect estimates expressed as Standardized Mean Differences (SMDs). For each study, outcome, and dimension (e.g., gender), we fit a random-effects meta-analysis. We characterized the magnitude of heterogeneity in policy effects using the standard deviation of the subgroup-specific effect estimates (τ). Among the 44% of studies reporting subgroup-specific estimates, policy effects were generally small (<0.1 SMDs) with mixed impacts on health (67% beneficial) and disparities (50% implied narrowing of disparities). Across study-outcome-dimensions, 54% indicated any heterogeneity in effects, and 20% had τ > 0.1 SMDs. For 26% of study-outcome-dimensions, the magnitude of τ indicated that effects of opposite signs were plausible across subgroups. Heterogeneity was more common in policy effects not specified a priori. Our findings suggest social policies commonly have heterogeneous effects on health of different populations; these HTEs may substantially impact disparities. Studies of social policies and health should routinely evaluate HTEs.

Heterogeneous treatment effects in social policy studies: An assessment of contemporary articles in the health and social sciences

PURPOSE

. Social policies are important determinants of population health but may have varying effects on subgroups of people. Evaluating heterogeneous treatment effects (HTEs) of social policies is critical to determine how social policies will affect health inequities. Methods for evaluating HTEs are not standardized. Little is known about how often and by what methods HTEs are assessed in social policy and health research.

METHODS

. A sample of 55 articles from 2019 on the health effects of social policies were evaluated for frequency of reporting HTEs; for what subgroupings HTEs were reported; frequency of a priori specification of intent to assess HTEs; and methods used for assessing HTEs.

RESULTS

. 24 (44%) studies described some form of HTE assessment, including by age, gender, education, race/ethnicity, and/or geography. Among studies assessing HTEs, 63% specified HTE assessment a priori, and most (71%) used descriptive methods such as stratification; 21% used statistical tests (e.g., interaction terms in a regression); and no studies used data-driven algorithms.

CONCLUSIONS

. Although understanding HTEs could enhance policy and practice-based efforts to reduce inequities, it is not routine research practice. Increased evaluation of HTEs across relevant subgroups is needed.

Understanding the benefits of different types and timing of education for mental health: A sequence analysis approach

OBJECTIVES

Individuals increasingly experience delays or interruptions in schooling; we evaluate the association between these non-traditional education trajectories and mental health.

METHODS

Using year-by-year education data for 7,501 National Longitudinal Survey of Youth 1979 participants, ages 14-48 (262,535 person-years of education data), we applied sequence analysis and a clustering algorithm to identify educational trajectory groups, incorporating both type and timing to credential. Linear regression models, adjusted for early-life confounders, evaluated relationships between educational trajectories and mental health component scores (MCS) from the 12-item short form instrument at age 50. We evaluated effect modification by race, gender, and race by gender.

RESULTS

We identified 24 distinct educational trajectories based on highest credential and educational timing. Compared to high school (HS) diplomas, < HS (beta=-3.41, 95%CI:-4.74,-2.07) and general educational development credentials (GEDs) predicted poorer MCS (beta=-2.07,95%CI:-3.16,-0.98). The following educational trajectories predicted better MCS: some college immediately after High School (beta=1.52, 95%CI:0.68,2.37), Associate degrees after long interruptions (beta=1.73, 95%CI:0.27,3.19), and graduate school soon after Bachelor's completion (beta=1.13, 95%CI:0.21,2.06). Compared to White men, Black women especially benefited from educational credentials higher than HS in predicting MCS.

CONCLUSIONS

Both type and timing of educational credential predicted mental health. Black women's mental higher especially benefited from higher educational credentials.

Does the Type and Timing of Educational Attainment Influence Physical Health? A Novel Application of Sequence Analysis

Nontraditional education trajectories are common, but their influence on physical health is understudied. We constructed year-by-year education trajectories for 7,501 National Longitudinal Survey of Youth 1979 participants aged 14 to 48 years (262,535 person-years of education data from 1979 to 2014). We characterized trajectory similarity using sequence analysis and used hierarchical clustering to group similar educational trajectories. Using linear regression, we predicted physical health summary scores of the participants at age 50 years from the 12-item Short-Form Survey, adjusting for available confounders, and evaluated effect modification by sex, race/ethnicity, and childhood socioeconomic status. We identified 24 unique educational sequence clusters on the basis of highest level of schooling and attendance timing. General education development credentials predicted poorer health than did high school diplomas (β = -3.07, 95% confidence interval: -4.07, -2.07), and bachelor's degrees attained at earlier ages predicted better health than the same degree attained at later ages (β = 1.66, 95% confidence interval: 0.05, 3.28). Structurally marginalized groups benefited more from some educational trajectories than did advantaged groups (e.g., Black vs. White Americans with some college; those of low vs. high childhood socioeconomic status who received an associate's or bachelor's degree). Both type and timing of educational credentials may influence physical health. Literature to date has likely underestimated the impact of educational trajectories on health.

Is it possible to overcome the 'long arm' of childhood socioeconomic disadvantage through upward socioeconomic mobility?

OBJECTIVES

Socioeconomically disadvantaged children have worse adult health; we test if this 'long arm' of childhood disadvantage can be overcome through upward socioeconomic mobility in adulthood.

METHODS

Four SES trajectories (stable low, upwardly mobile, downwardly mobile and stable high) were created from median dichotomized childhood socioeconomic status (SES; childhood human and financial capital) and adult SES (wealth at age 67) from Health and Retirement Study respondents (N = 6669). Healthy ageing markers, in tertiles, were walking speed, peak expiratory flow (PEF), and grip strength measured in 2008 and 2010. Multinomial logistic regression models, weighted to be nationally representative, controlled for age, gender, race, birthplace, outcome year and childhood health and social capital.

RESULTS

Upwardly mobile individuals were as likely as the stable high SES group to be in the best health tertile for walking speed (OR = 0.81; 95% CI: 0.63, 1.05; P = 0.114), PEF (OR = 0.97; 95% CI: 0.78, 1.21; P = 0.810) and grip strength (OR = 0.97; 95%CI: 0.74, 1.27; P = 0.980).

DISCUSSION

Findings suggest the 'long arm' of childhood socioeconomic disadvantage can be overcome for these markers of healthy ageing through upward socioeconomic mobility.

Differential associations between state-level educational quality and cardiovascular health by race: Early-life exposures and late-life health

Cardiovascular diseases (CVD) are patterned by educational attainment but educational quality is rarely examined. Educational quality differences may help explain racial disparities. Health and Retirement Study respondent data (1992-2014; born 1900-1951) were linked to state- and year-specific educational quality measures when the respondent was 6 years old. State-level educational quality was a composite of state-level school term length, student-to-teacher ratio, and per-pupil expenditure. CVD-related outcomes were self-reported (N = 24,339) obesity, heart disease, stroke, ever-smoking, high blood pressure, diabetes and objectively measured (N = 10,704) uncontrolled blood pressure, uncontrolled blood sugar, total cholesterol, high-density lipoprotein cholesterol (HDL), and C-reactive protein. Race/ethnicity was classified as White, Black, or Latino. Cox models fit for dichotomous time-to-event outcomes and generalized estimating equations for continuous outcomes were adjusted for individual and state-level confounders. Heterogeneities by race were evaluated using state-level educational quality by race interaction terms; race-pooled, race by educational quality interaction, and race-specific estimates were calculated. In race-pooled analyses, higher state-level educational quality was protective for obesity (HR = 0.92; 95%CI(0.87,0.98)). In race-specific estimates for White Americans, state-level educational quality was protective for high blood pressure (HR = 0.95; 95%CI(0.91,0.99). Differential relationships among Black compared to White Americans were observed for obesity, heart disease, stroke, smoking, high blood pressure, and HDL cholesterol. In race-specific estimates for Black Americans, higher state-level educational quality was protective for obesity (HR = 0.88; 95%CI(0.84,0.93)), but predictive of heart disease (HR = 1.07; 95%CI(1.01,1.12)), stroke (HR = 1.20; 95%CI(1.08,1.32)), and smoking (HR = 1.05; 95%CI(1.02,1.08)). Race-specific hazard ratios for Latino and Black Americans were similar for obesity, stroke, and smoking. Better state-level educational quality had differential associations with CVD by race. Among minorities, better state-level educational quality was predominately associated with poorer CVD outcomes. Results evaluate the 1900-1951 birth cohorts; secular changes in the racial integration of schools since the 1950s, means results may not generalize to younger cohorts.

Performance of Matching Methods as Compared With Unmatched Ordinary Least Squares Regression Under Constant Effects

Matching methods are assumed to reduce the likelihood of a biased inference compared with ordinary least squares (OLS) regression. Using simulations, we compared inferences from propensity score matching, coarsened exact matching, and unmatched covariate-adjusted OLS regression to identify which methods, in which scenarios, produced unbiased inferences at the expected type I error rate of 5%. We simulated multiple data sets and systematically varied common support, discontinuities in the exposure and/or outcome, exposure prevalence, and analytical model misspecification. Matching inferences were often biased in comparison with OLS, particularly when common support was poor; when analysis models were correctly specified and common support was poor, the type I error rate was 1.6% for propensity score matching (statistically inefficient), 18.2% for coarsened exact matching (high), and 4.8% for OLS (expected). Our results suggest that when estimates from matching and OLS are similar (i.e., confidence intervals overlap), OLS inferences are unbiased more often than matching inferences; however, when estimates from matching and OLS are dissimilar (i.e., confidence intervals do not overlap), matching inferences are unbiased more often than OLS inferences. This empirical "rule of thumb" may help applied researchers identify situations in which OLS inferences may be unbiased as compared with matching inferences.

Mother's education and late-life disparities in memory and dementia risk among US military veterans and non-veterans

BACKGROUND

Adverse childhood socioeconomic status (cSES) predicts higher late-life risk of memory loss and dementia. Veterans of U.S. wars are eligible for educational and economic benefits that may offset cSES disadvantage. We test whether cSES disparities in late-life memory and dementia are smaller among veterans than non-veterans.

METHODS

Data came from US-born men in the 1995-2014 biennial surveys of the Health and Retirement Study (n=7916 born 1928-1956, contributing n=38 381 cognitive assessments). Childhood SES was represented by maternal education. Memory and dementia risk were assessed with brief neuropsychological assessments and proxy reports. Military service (veteran/non-veteran) was evaluated as a modifier of the effect of maternal education on memory and dementia risk. We employed linear or logistic regression models to test whether military service modified the effect of maternal education on memory or dementia risk, adjusted for age, race, birthplace and childhood health.

RESULTS

Low maternal education was associated with worse memory than high maternal education (β = -0.07 SD, 95% CI -0.08 to -0.05), while veterans had better memory than non-veterans (β = 0.03 SD, 95% CI 0.02 to 0.04). In interaction analyses, maternal education disparities in memory were smaller among veterans than non-veterans (difference in disparities = 0.04 SD, 95% CI 0.01 to 0.08, p = 0.006). Patterns were similar for dementia risk.

CONCLUSIONS

Disparities in memory by maternal education were smaller among veterans than non-veterans, suggesting military service and benefits partially offset the deleterious effects of low maternal education on late-life cognitive outcomes.

Do the health benefits of education vary by sociodemographic subgroup? Differential returns to education and implications for health inequities

PURPOSE

Evidence suggests education is an important life course determinant of health, but few studies examine differential returns to education by sociodemographic subgroup.

METHODS

Using National Longitudinal Survey of Youth 1979 (n = 6158) cohort data, we evaluate education attained by age 25 years and physical health (PCS) and mental health component summary scores (MCS) at age 50 years. Race / ethnicity, sex, geography, immigration status, and childhood socioeconomic status (cSES) were evaluated as effect modifiers in birth year adjusted linear regression models.

RESULTS

The association between education and PCS was large among high cSES respondents (β = 0.81 per year of education, 95% CI: 0.67, 0.94), and larger among low cSES respondents (interaction β = 0.39, 95% CI: 0.06, 0.72). The association between education and MCS was imprecisely estimated among White men (β = 0.44; 95% CI: -0.03, 0.90), while, Black women benefited more from each year of education (interaction β = 0.91; 95% CI: 0.19, 1.64). Similarly, compared to socially advantaged groups, low cSES Blacks, and low and high cSES women benefited more from each year of education, while immigrants benefited less from each year of education.

CONCLUSIONS

If causal, increases in educational attainment may reduce some social inequities in health.

Military Service, Childhood Socio-Economic Status, and Late-Life Lung Function: Korean War Era Military Service Associated with Smaller Disparities

BACKGROUND

Military service is associated with smoking initiation, but U.S. veterans are also eligible for special social, financial, and healthcare benefits, which are associated with smoking cessation. A key public health question is how these offsetting pathways affect health disparities; we assessed the net effects of military service on later life pulmonary function among Korean War era veterans by childhood socio-economic status (cSES).

METHODS

Data came from U.S.-born male Korean War era veteran (service: 1950-1954) and non-veteran participants in the observational U.S. Health and Retirement Study who were alive in 2010 (average age = 78). Veterans (N = 203) and non-veterans (N = 195) were exactly matched using coarsened exact matching on birth year, race, coarsened height, birthplace, childhood health, and parental and childhood smoking. Results were evaluated by cSES (defined as maternal education <8 yr/unknown or ≥8 yr), in predicting lung function, as assessed by peak expiratory flow (PEF), measured in 2008 or 2010.

FINDINGS

While there was little overall association between veterans and PEF [β = 12.8 L/min; 95% confidence interval (CI): (-12.1, 37.7); p = 0.314; average non-veteran PEF = 379 L/min], low-cSES veterans had higher PEF than similar non-veterans [β = 81.9 L/min; 95% CI: (25.2, 138.5); p = 0.005], resulting in smaller socio-economic disparities among veterans compared to non-veterans [difference in disparities: β = -85.0 L/min; 95% CI: (-147.9, -22.2); p = 0.008].

DISCUSSION

Korean War era military service appears to disproportionately benefit low-cSES veteran lung functioning, resulting in smaller socio-economic disparities among veterans compared with non-veterans.

Depression: point-prevalence and risk factors in a North Cyprus household adult cross-sectional study

BACKGROUND

Depression is one of the most common diagnosed psychiatric disorders in the world. Besides individual risk factors, it is also found that environment and socio-cultural factors are the other main risk factors for depression. In this article, the results of the 2016 national household survey of depression in North Cyprus (NC) are presented. The aim of the study is to determine the prevalence and possible risk factors of depression in NC households.

METHODS

The study was conducted between April and June 2016, the sample consisting of Turkish-speaking individuals between 18 and 88 years of age living permanently in NC. A multi-stage stratified (randomized) quota was used in the survey, and 978 people were selected according to the 2011 census. A 21 item questionnaire prepared by the researchers and a Turkish version of the Beck Depression Inventory scales were used for obtaining data.

RESULTS

This cross-sectional study found a point prevalence of 23.4% for relatively high BDI scores (≥17) suggesting clinical depression. Being female, a widow, unemployed, having a limited education and low income level, having a physical illness, living alone, and using illicit substances were defined as possible risk factors for depression.

CONCLUSIONS

When we consider the world prevalence, NC has one of the higher depression prevalence. NC has environmental and socio-cultural characteristics such as a history of war, migration and colonization, high unemployment rates, socioeconomic problems, similar to other extremely high prevalence depression countries and regions, which give a strong indication of the importance of socio-cultural factors on depression.

Are There Spillover Effects from the GI Bill? The Mental Health of Wives of Korean War Veterans

Background

The Korean War GI Bill provided economic benefits for veterans, thereby potentially improving their health outcomes. However potential spillover effects on veteran wives have not been evaluated.

Methods

Data from wives of veterans eligible for the Korean War GI Bill (N = 128) and wives of non-veterans (N = 224) from the Health and Retirement Study were matched on race and coarsened birth year and childhood health using coarsened exact matching. Number of depressive symptoms in 2010 (average age = 78) were assessed using a modified, validated Center for Epidemiologic Studies-Depression Scale. Regression analyses were stratified into low (mother < 8 years schooling / missing data, N = 95) or high (mother ≥ 8 years schooling, N = 257) childhood socio-economic status (cSES) groups, and were adjusted for birth year and childhood health, as well as respondent’s educational attainment in a subset of analyses.

Results

Husband’s Korean War GI Bill eligibility did not predict depressive symptoms among veteran wives in pooled analysis or cSES stratified analyses; analyses in the low cSES subgroup were underpowered (N = 95, β = -0.50, 95% Confidence Interval: (-1.35, 0.35), p = 0.248, power = 0.28).

Conclusions

We found no evidence of a relationship between husband’s Korean War GI Bill eligibility and wives’ mental health in these data, however there may be a true effect that our analysis was underpowered to detect.