Kendra Rothert’s research while affiliated with Kaiser Permanente and other places

Attrition, or dropout, is a problem faced by many online health interventions, potentially threatening the inferential value of online randomized controlled trials. In the context of a randomized controlled trial of an online weight management intervention, where 85% of the baseline participants were lost to follow-up at the 12-month measurement, the objective was to examine the effect of nonresponse on key outcomes and explore ways to reduce attrition in follow-up surveys. A sample of 700 non-respondents to the 12-month online follow-up survey was randomly assigned to a mail or telephone nonresponse follow-up survey. We examined response rates in the two groups, costs of follow-up, reasons for nonresponse, and mode effects. We ran several logistic regression models, predicting response or nonresponse to the 12-month online survey as well as predicting response or nonresponse to the follow-up survey. We analyzed 210 follow-up respondents in the mail and 170 in the telephone group. Response rates of 59% and 55% were obtained for the telephone and mail nonresponse follow-up surveys, respectively. A total of 197 respondents (51.8%) gave reasons related to technical issues or email as a means of communication, with older people more likely to give technical reasons for non-completion; 144 (37.9%) gave reasons related to the intervention or the survey itself. Mail follow-up was substantially cheaper: We estimate that the telephone survey cost about US $34 per sampled case, compared to US$15 for the mail survey. The telephone responses were subject to possible social desirability effects, with the telephone respondents reporting significantly greater weight loss than the mail respondents. The respondents to the nonresponse follow-up did not differ significantly from the 12-month online respondents on key outcome variables. Mail is an effective way to reduce attrition to online surveys, while telephone follow-up might lead to overestimating the weight loss for both the treatment and control groups. Nonresponse bias does not appear to be a significant factor in the conclusions drawn from the randomized controlled trial.

To assess the efficacy of a Web-based tailored behavioral weight management program compared with Web-based information-only weight management materials. Participants, 2862 eligible overweight and obese (BMI = 27 to 40 kg/m2) members from four regions of Kaiser Permanente's integrated health care delivery system, were randomized to receive either a tailored expert system or information-only Web-based weight management materials. Weight change and program satisfaction were assessed by self-report through an Internet-based survey at 3- and 6-month follow-up periods. Significantly greater weight loss at follow-up was found among participants assigned to the tailored expert system than among those assigned to the information-only condition. Subjects in the tailored expert system lost a mean of 3 +/- 0.3% of their baseline weight, whereas subjects in the information-only condition lost a mean of 1.2 +/- 0.4% (p < 0.0004). Participants were also more likely to report that the tailored expert system was personally relevant, helpful, and easy to understand. Notably, 36% of enrollees were African-American, with enrollment rates higher than the general proportion of African Americans in any of the study regions. The results of this large, randomized control trial show the potential benefit of the Web-based tailored expert system for weight management compared with a Web-based information-only weight management program.

Objective: To describe a comprehensive, population-based weight management program. • Setting: A large, not-for-profit integrated health care delivery system. • Program: The initiative focuses efforts in 5 areas: (1) clinical management, (2) community partner-ships, (3) legislation/public policy, (4) successful practices dissemination, and (5) research. Imple-mentation of guidelines and programs is local, allow-ing regions to maximize impact by leveraging tools, services, and new technologies in ways that best suit their unique operational structures. • Results: Initiative-based interventions have been implemented in the areas of prevention and treat-ment of obesity in children and adolescents, pre-venting overweight and obesity in adults, identifying and managing adults at high risk of an adverse medical event, and treating severe obesity. • Conclusion: Weight management is a complex and rapidly evolving field that requires key partnerships and a multidisciplinary team approach to target interventions effectively.

Over 3,000 subjects were recruited in 3 U.S. regions for a randomized experiment of an online weight management intervention. Participants were sent invitations to web survey reassessments after 3, 6, and 12 months. High and increasing nonresponse to the three follow- up surveys created the potential for nonresponse bias in key program outcomes. A subsample of the nonrespondents at the one-year follow-up was selected for a nonresponse study. This subsample was then randomly assigned to a short telephone or mail survey. This was done in order to evaluate cost efficiency, differential effectiveness of mode combinations in reducing nonresponse bias, and measurement differences by mode. The responses from the nonresponse study were then to be added to the baseline measures and used in an imputation model. Differences between the telephone and mail survey reports posed an added methodological problem, allowing further exploration of sensitivity of the results not just to nonresponse, but also to the mode used in the second stage through comparison of different imputation models. Implications are discussed for cost, nonresponse bias, measurement differences, and post-imputation variance estimates.

The relationship between women's employment and the risk of divorce is both complex and controversial. The role specialization (or interdependence) view of marriage argues that the gains to marriage for both partners decrease when both are in the labor force, and hence women's employment destabilizes marriage. In contrast, the economic opportunity hypothesis asserts that female labor force participation does not intrinsically weaken marriage, but gives women resources that they can use to leave unsatisfactory marriages. Here we use data from the two waves of the National Survey of Families and Households to conduct the first large-scale empirical test of those conflicting claims. Our results provide clear evidence that, at the individual level, women's employment does not destabilize happy marriages but increases the risk of disruption in unhappy marriages.

This article reports on a study of the schooling careers of a recent cohort of African Americans that found that 44 percent of the women and 34 percent of the men reentered school at least once. There were few differences in educational credentials at age 27 between those who attained their education in one spell or two spells of enrollment, although more than two school reentries were not associated with high levels of educational credentials. Using recent models of educational decision making to study the determinants of school reentry and applying discrete time hazards regression, the authors found that, as in models of school persistence, a reentry to school is a function of the costs of enrollment, the probability of success, and the utility of schooling to the individual. Familial resources are not important predictors of a decision for schooling, whereas such factors as military service and engagement with the labor force are. On the basis of these findings, the authors argue that models of educational attainment that emphasize the importance of continuous enrollment need to be updated. These models seem to be particularly inappropriate for the study of groups that experience systemically limited opportunities during childhood.