Missing Data in Longitudinal Surveys: A Comparison of Performance of Modern Techniques

Using a simulation study, the performance of complete case analysis, full information maximum likelihood, multivariate normal imputation, multiple imputation by chained equations and two-fold fully conditional specification to handle missing data were compared in longitudinal surveys with continuous and binary outcomes, missing covariates, and an interaction term

Associations between active commuting, body fat, and body mass index: population based, cross sectional study in the United Kingdom.

OBJECTIVE: To determine if promotion of active modes of travel is an effective strategy for obesity prevention by assessing whether active commuting (walking or cycling for all or part of the journey to work) is independently associated with objectively assessed biological markers of obesity. DESIGN: Cross sectional study of data from the wave 2 Health Assessment subsample of Understanding Society, the UK Household Longitudinal Study (UKHLS). The exposure of interest, commuting mode, was self reported and categorised as three categories: private transport, public transport, and active transport. PARTICIPANTS: The analytic samples (7534 for body mass index (BMI) analysis, 7424 for percentage body fat analysis) were drawn from the representative subsample of wave 2 respondents of UKHLS who provided health assessment data (n = 15,777). MAIN OUTCOME MEASURES: Body mass index (weight (kg)/height (m)(2)); percentage body fat (measured by electrical impedance). RESULTS: Results from multivariate linear regression analyses suggest that, compared with using private transport, commuting by public or active transport modes was significantly and independently predictive of lower BMI for both men and women. In fully adjusted models, men who commuted via public or active modes had BMI scores 1.10 (95% CI 0.53 to 1.67) and 0.97 (0.40 to 1.55) points lower, respectively, than those who used private transport. Women who commuted via public or active modes had BMI scores 0.72 (0.06 to 1.37) and 0.87 (0.36 to 0.87) points lower, respectively, than those using private transport. Results for percentage body fat were similar in terms of magnitude, significance, and direction of effects. CONCLUSIONS: Men and women who commuted to work by active and public modes of transport had significantly lower BMI and percentage body fat than their counterparts who used private transport. These associations were not attenuated by adjustment for a range of hypothesised confounding factors

Welfare Regimes and Social Inequalities in Health Dynamics: A Comparative Analysis of Panel Data from Britain, Denmark, Germany and the US

Objective: To describe average national trajectories of self-rated health over a 7-year period, identify social determinants of cross-sectional and longitudinal health; and compare cross-national patterns. Design: Prospective nationally representative household panel studies (the US Panel Study of Income Dynamics; British Household Panel Survey; the German Socio-Economic Panel Survey; the Danish panel from the European Community Household Panel Survey). Setting: The US, Britain, Germany and Denmark Participants: Household heads and their partners of working age throughout follow-up (US: 4855; Britain: 4365; Germany: 4694; Denmark: 3252). Main Outcome Measure: Repeated measures of self-rated health (1995 – 2001). Social indicators include education, occupational class, employment status, income, age, gender, minority status and marital status, all measured in 1994. Methods: Latent growth curve models describe average national trajectories of self-rated health and individual differences in these trajectories. Latent factors representing intercept and slope components are extracted from seven annual observations across time for self-rated health, and are conditioned on predictors measured one year prior to baseline. Aging-vector graphs are used to visualize trajectories of self-rated health. Results: The vector graphs for the US and Germany show that self-rated health remained relatively stable for young adults, declined as adults became middle aged and then became more stable again. The graphs for Britain and Denmark indicate a steady decline throughout working life. The Danish model indicates an unfavourable trend in self-rated health during a period that experienced a move to monetarism: ratings were lower for persons of a given age in 2001 than for persons of the same age in 1995. Social covariates predicted baseline health in all four countries, with the strength of association consistent with Esping-Andersen’s welfare regime type. The strongest social gradients were seen in the US, while the weakest were seen in Germany and Denmark. Britain occupied a position between these two extremes. Once inequalities in baseline health had been accounted for, there were few determinants of mean health decline. When these did occur, they were in countries classified as liberal welfare states. There was little difference in the aging trajectories for those with advantaged and average social profiles. By contrast, disadvantage has a strong effect on aging trajectories. Differences were already apparent at 25 years of age in the US and Britain and gaps widened with age in all four countries. Conclusion: National differences in self-rated health trajectories and their social correlates may be attributed, in part, to welfare policies. The paper is forthcoming in the Journal of Community Health and Epidemiology (JECH). Peggy McDonough is an Associate Professor in the Dalla Lana School of Public Health at the University of Toronto. Her research interests in social inequalities in health and women’s health have led her recently to incorporate a comparative welfare state dimension in her studies

Individualization, opportunity and jeopardy in American women's work and family lives: A multi-state sequence analysis

AbstractLife course sociologists are increasingly concerned with how the general character of biographies is transformed over historical time – and with what this means for individual life chances. The individualization thesis, which contends that contemporary biographies are less predictable, less orderly and less collectively determined than were those lived before the middle of the 20th century, suggests that life courses have become both more internally dynamic and more diverse across individuals. Whether these changes reflect expanding opportunities or increasing jeopardy is a matter of some debate. We examine these questions using data on the employment, marital and parental histories, over the ages of 25–49, for five birth cohorts of American women (N=7150). Our results show that biographical change has been characterized more by growing differences between women than by increasing complexity within individual women's lives. Whether the mounting diversity of work and family life paths reflects, on balance, expanding opportunities or increasing jeopardy depends very much on the social advantages and disadvantages women possessed as they entered their prime working and childrearing years

Bi-directional relationships between body mass index and height from three to seven years of age: an analysis of children in the United Kingdom Millennium Cohort Study

Adiposity and height are known to correlate in childhood but it is less clear whether height and weight gain occur in synergy. We investigate the bidirectional relationships between measures of height and body mass index (BMI) – an indicator of adiposity – and their rates of change. The sample comprises singleton children in the Millennium Cohort Study (N = 11,357). Child anthropometrics measured by trained interviewers at ages three, five and seven years (2003-2009) were transformed to standardised scores based on 1990 British Growth Reference data from which piecewise linear models for height and BMI were jointly fitted. At three years of age, zHeight was positively related to subsequent zBMI velocities, whereas zBMI at three years was positively related to zHeight velocity to age five but inversely related to zHeight velocity from five to seven years of age. Age three zBMI predicted zHeight velocity from three to five years more strongly than age three zHeight predicted zBMI velocity over the same period. The rate of change in zHeight was positively correlated with subsequent zBMI velocity and vice versa. This new evidence on the bidirectional relationships between height and BMI velocities sheds light on the early childhood origins of obesity in adulthood and the need to monitor growth as well as weight gain

Is foster caring associated with an earlier transition to adulthood for caregivers’ own children? ONS Longitudinal Study

This study investigates whether the existing children in a fostering household differ from young people in non-caregiving households in the timing of their transitions to key adult roles, known to affect later health and life chances. Using data from the ONS Longitudinal Study, we pooled records from census years 1971-2001 and linked them to follow-up records from 1981-2011. We identified 2656 children living with a foster child and compared their profiles on the “big five” transitions to roles of adulthood — finishing school; leaving home; finding work and becoming financially independent; getting married; and having children — with those of other children without a foster child in the household (N=209,453). We fitted logistic and multinomial models that controlled for childhood socioeconomic and demographic confounders to estimate the proportion achieving the five roles measured in early adulthood. We found a modest but reliably higher proportion of caregivers’ children having achieved the transition to adulthood. There was some evidence that caregivers’ children might cope better with the transition to adulthood if they were older than the foster child or were female. The findings suggest that supporting foster parents with delaying their children’s transition to adulthood could become part of the role of supervising social workers

The lifelong health and wellbeing trajectories of people who have been in care: Findings from the Looked-after Children Grown up Project

The overarching aim of the Looked-after Children Grown Up Project (LACGro) was to use the unique data in the Office for National Statistics Longitudinal Study to build a comprehensive picture up to mid-life of the health and social functioning of care experienced members of the study. To achieve that, we set ourselves a number of objectives: • To determine whether children in residential care, kinship care and in foster care have different health and social experiences 10 to 40 years later compared to children in parental homes. • To explore if children cared for in residential settings do better or worse than children in kinship or foster care, and if children in kinship care fare better than children in foster care. • To understand if any differences in health and social difficulties vary by gender or ethnicity/migration status for those who have been looked after in childhood. • To investigate if care experiences and their outcomes differ by the census in which children are observed. • To find out what evidence there is for later resilience. Are there continuities or discontinuities in outcomes? • To explore if there is evidence that a long-term experience of care predicts better or worse outcomes than a short-term experience. • To consider if caregivers’ children are affected in the long-term by living with a child in care. Through the research, our goal was to describe the scale of inequalities in outcomes for children cared for in different places, of different ages and d identities, and to begin to understand how these factors interact to produce inequalities

Light drinking versus abstinence in pregnancy : behavioural and cognitive outcomes in 7-year-old children : a longitudinal cohort study

To assess whether light drinking in pregnancy is linked to unfavourable developmental outcomes in children. Design Prospective population-based cohort. Setting UK. Population Ten thousand five hundred and thirty-four 7-year-olds. Methods Quasi-experimental using propensity score matching (PSM) to compare children born to light (up to 2 units per week) and non-drinkers. Main outcome measures Behavioural difficulties rated by parents and teachers; cognitive test scores for reading, maths and spatial skills. Results Ordinary least squares (OLS) regression and PSM analyses are presented. For behavioural difficulties, unadjusted estimates for percentage standard deviation (SD) score differences ranged from 2 to 14%. On adjustment for potential confounders, differences were attenuated, with a loss of statistical significance, except for teacher-rated boys' difficulties. For boys, parent-rated behavioural difficulties: unadjusted, −11.5; OLS, −4.3; PSM, −6.8; teacher-rated behavioural difficulties: unadjusted, −13.9; OLS, −9.6; PSM, −10.8. For girls, parent-rated behavioural difficulties: unadjusted, −9.6; OLS, −2.9; PSM, −4.5; teacher-rated behavioural difficulties: unadjusted, −2.4; OLS, 4.9; PSM, 3.9. For cognitive test scores, unadjusted estimates for differences ranged between 12 and 21% of an SD score for reading, maths and spatial skills. After adjustment for potential confounders, estimates were reduced, but remained statistically significantly different for reading and for spatial skills in boys. For boys, reading: unadjusted, 20.9; OLS, 8.3; PSM, 7.3; maths: unadjusted, 14.7; OLS, 5.0; PSM, 6.5; spatial skills: unadjusted, 16.2; OLS, 7.6; PSM, 8.1. For girls, reading: unadjusted, 11.6; OLS, −0.3; PSM, −0.5; maths: unadjusted, 12.9; OLS, 4.3; PSM, 3.9; spatial skills: unadjusted, 16.2; OLS, 7.7; PSM, 6.4. Conclusion The findings suggest that light drinking during pregnancy is not linked to developmental problems in mid-childhood. These findings support current UK Department of Health guidelines on drinking during pregnancy