J. Michael Oakes

The measurement of SES in health research: current practice and steps toward a new approach

The resurgence of social epidemiology has yet to induce corresponding research into basic measurement issues. This paper aims to motivate investigators to refocus attention on the measurement of socioeconomic status (SES). With a primarily American focus, we document striking paucity of basic research in SES, review the history of SES measurement, highlight the central limitations of current measurement approaches, sketch a new theoretical perspective, present new pilot results, and outline areas for future research. We argue (1) that lack of conceptual clarity and the bypassing of standard psychometric techniques have retarded SES measurement. And (2) social epidemiologists should revisit the measurement of SES and consider whether a richer, psychometrically induced, approach would be more useful. Our pilot study suggests a great deal of uniformity between existing SES measures and that a new approach may be worthy of pursuit.

Effects of calorie labeling and value size pricing on fast food meal choices: results from an experimental trial.

BackgroundAlthough point-of-purchase calorie labeling at restaurants has been proposed as a strategy for improving consumer food choices, a limited number of studies have evaluated this approach. Likewise, little research has been conducted to evaluate the influence of value size pricing on restaurant meal choices.MethodsTo examine the effect of point-of-purchase calorie information and value size pricing on fast food meal choices a randomized 2 × 2 factorial experiment was conducted in which participants ordered a fast food meal from one of four menus that varied with respect to whether calorie information was provided and whether value size pricing was used. Study participants included 594 adolescents and adults who regularly ate at fast food restaurants. Study staff recorded the foods ordered and consumed by each participant. Participants also completed surveys to assess attitudes, beliefs and practices related to fast food and nutrition.ResultsNo significant differences in the energy composition of meals ordered or eaten were found between menu conditions. The average energy content of meals ordered by those randomized to a menu that included calorie information and did not include value size pricing was 842 kcals compared with 827 kcals for those who ordered their meal from a menu that did not include calorie information but had value size pricing (control menu). Results were similar in most analyses conducted stratified by factors such as age, race and education level.ConclusionAdditional research is needed to better evaluate the effects of calorie labeling and value size pricing on fast food meal choices. Studies in which participants are repeatedly exposed to these factors are needed since long term exposure may be required for behavior change.

Does Residential Density Increase Walking and Other Physical Activity

Many agree that increasing physical activity will improve public health. This paper reports on empirical findings on the relationship between the density of the residential environment, walking and total physical activity. Using multiple objective and self-reported measures for 715 participants in the US, and improved techniques for sampling and analysis, it finds that density is associated with the purpose of walking (travel, leisure) but not the amount of overall walking or overall physical activity, although there are sub-group differences by race/ ethnicity. Overall, higher densities have many benefits in terms of efficient use of infrastructure, housing affordability, energy efficiency and possibly vibrant street life. But higher densities alone, like other built environment features, do not appear to be the silver bullet in the public health campaign to increase physical activity.

The effects of neighborhood density and street connectivity on walking behavior: the Twin Cities walking study

A growing body of health and policy research suggests residential neighborhood density and street connectivity affect walking and total physical activity, both of which are important risk factors for obesity and related chronic diseases. The authors report results from their methodologically novel Twin Cities Walking Study; a multilevel study which examined the relationship between built environments, walking behavior and total physical activity. In order to maximize neighborhood-level variation while maintaining the exchangeability of resident-subjects, investigators sampled 716 adult persons nested in 36 randomly selected neighborhoods across four strata defined on density and street-connectivity – a matched sampling design. Outcome measures include two types of self-reported walking (from surveys and diaries) and so-called objective 7-day accelerometry measures. While crude differences are evident across all outcomes, adjusted effects show increased odds of travel walking in higher-density areas and increased odds of leisure walking in low-connectivity areas, but neither density nor street connectivity are meaningfully related to overall mean miles walked per day or increased total physical activity. Contrary to prior research, the authors conclude that the effects of density and block size on total walking and physical activity are modest to non-existent, if not contrapositive to hypotheses. Divergent findings are attributed to this studys sampling design, which tends to mitigate residual confounding by socioeconomic status.

Changing work and work-family conflict: Evidence from the work, family, and health network

Schedule control and supervisor support for family and personal life may help employees manage the work-family interface. Existing data and research designs, however, have made it difficult to conclusively identify the effects of these work resources. This analysis utilizes a group-randomized trial in which some units in an information technology workplace were randomly assigned to participate in an initiative, called STAR, that targeted work practices, interactions, and expectations by (1) training supervisors on the value of demonstrating support for employees’ personal lives and (2) prompting employees to reconsider when and where they work. We find statistically significant, although modest, improvements in employees’ work-family conflict and family time adequacy, and larger changes in schedule control and supervisor support for family and personal life. We find no evidence that this intervention increased work hours or perceived job demands, as might have happened with increased permeability of work across time and space. Subgroup analyses suggest the intervention brought greater benefits to employees more vulnerable to work-family conflict. This study uses a rigorous design to investigate deliberate organizational changes and their effects on work resources and the work-family interface, advancing our understanding of the impact of social structures on individual lives.

Effects of Socioeconomic and Racial Residential Segregation on Preterm Birth: A Cautionary Tale of Structural Confounding

Confounding associated with social stratification or other selection processes has been called structural confounding. In the presence of structural confounding, certain covariate strata will contain only subjects who could never be exposed, a violation of the positivity or experimental treatment effect assumption. Thus, structural confounding can prohibit the exchangeability necessary for meaningful causal contrasts across levels of exposure. The authors explored the presence and magnitude of structural confounding by estimating the independent effects of neighborhood deprivation and neighborhood racial composition (segregation) on rates of preterm birth in Wake and Durham counties, North Carolina (1999-2001). Tabular analyses and random-intercept fixed-slope multilevel logistic models portrayed different structural realities in these counties. The multilevel modeling results suggested some nonsignificant effect of residence in tracts with high levels of socioeconomic deprivation or racial residential segregation on adjusted odds of preterm birth for white and black women living in these counties, and the confidence limit ratios indicated fairly consistent levels of precision around the estimates. The results of the tabular analysis, however, suggested that many of these regression modeling findings were off-support and based on no actual data. The implications for statistical and public health inference, in the presence of no data, are considered.

RISKS AND WRONGS IN SOCIAL SCIENCE RESEARCH An Evaluator's Guide to the IRB

Having an Institutional Review Board (IRB) review and monitor the use of human subjects is now fundamental to ethical research. Yet social scientists appear increasingly frustrated with the process. This article aims to assist evaluators struggling to understand and work with IRBs. The author theorizes why IRBs frustrate and insists there is only one remedy: We must accept the legitimacy of IRB review and (a) learn more about IRB regulations, imperatives, and the new pressures on them; and (b) educate IRBs about social scientific methodologies and empirically demonstrable risks. A research agenda and tips are offered.

Why eat at fast-food restaurants: reported reasons among frequent consumers.

A convenience sample of adolescents and adults who regularly eat at fast-food restaurants were recruited to participate in an experimental trial to examine the effect of nutrition labeling on meal choices. As part of this study, participants were asked to indicate how strongly they agreed or disagreed with 11 statements to assess reasons for eating at fast-food restaurants. Logistic regression was conducted to examine whether responses differed by demographic factors. The most frequently reported reasons for eating at fast-food restaurants were: fast food is quick (92%), restaurants are easy to get to (80%), and food tastes good (69%). The least frequently reported reasons were: eating fast food is a way of socializing with family and friends (33%), restaurants have nutritious foods to offer (21%), and restaurants are fun and entertaining (12%). Some differences were found with respect to the demographic factors examined. It appears that in order to reduce fast-food consumption, food and nutrition professionals need to identify alternative quick and convenient food sources. As motivation for eating at fast-food restaurants appears to differ somewhat by age, sex, education, employment status, and household size, tailored interventions could be considered.

Reducing HIV risk behavior of men who have sex with men through persuasive computing: Results of the Men's INTernet Study-II

Objective:The primary objective of this study was to develop and test a highly interactive Internet-based HIV prevention intervention for men who have sex with men (MSM). MSM remain the group at highest risk for HIV/AIDS in the United States and similar countries. As the Internet becomes popular for seeking sex, online interventions to reduce sexual risk are critical. Given previous studies, a secondary objective was to demonstrate that good retention is possible in online trials. Design:A randomized controlled trial with 3-month, 6-month, 9-month, and 12-month follow-up design was employed. Methods:In 2008, 650 participants were randomized to an online, interactive sexual risk reduction intervention or to a waitlist null control. Results:Retention was 76–89% over 12 months. At 3-month follow-up, results showed a 16% reduction in reported unprotected anal intercourse risk among those in the treatment condition versus control [95% confidence interval (95% CI) of rate ratio: 0.70–1.01]. No meaningful differences were observed at 12-month follow-up. Conclusion:Internet-based, persuasive computing programs hold promise as an effective new approach to HIV prevention for MSM, at least in the short term. Further, online trials can be conducted with acceptable retention provided strong retention protocols are employed. Four directions for future research are identified.

Statistical power for nonequivalent pretest-posttest designs: The impact of change-score versus ANCOVA models

Nonequivalent controlled pretest-posttest designs are central to evaluation science, yet no practical and unified approach for estimating power in the two most widely used analytic approaches to these designs exists. This article fills the gap by presenting and comparing useful, unified power formulas for ANCOVA and change-score analyses, indicating the implications of each on sample-size requirements. The authors close with practical recommendations for evaluators. Mathematical details and a simple spreadsheet approach are included in appendices.