Mediators of Weight Loss Maintenance in the Keep It Off Trial.

Background: An important step toward enhancing the efficacy of weight loss maintenance interventions is identifying the pathways through which successful interventions such as the Keep It Off trial have worked. Purpose: This study aimed to assess the viability of mediated relationships between the Keep It Off Guided intervention, conceptually and empirically grounded potential mediators, and weight. Repeated measurement of mediators and weight enabled documentation of the temporal ordering of intervention delivery and changes in mediators and in weight among participants randomized to the Guided intervention or Self-Directed comparison group. Methods: Total, direct, and indirect effects of the Guided intervention on weight change were calculated and tested for significance. Indirect effects were comprised of the influence of the intervention on three change scores for each mediator and the relationship between mediator changes and weight changes 6 months later. Results: Guided intervention participants regained about 2% less weight over 24 months than Self-Directed participants. Starting daily self-weighing accounted for the largest share of this difference, followed by not stopping self-weighing. Conclusions: Daily self-weighing mediated 24-month weight loss maintenance. Trial Registration Number: The trial is registered with ClinicalTrials.gov (Identifier: NCT00702455 www.clinicaltrials.gov/ct2/show/NCT00702455).

Self-report compared to electronic medical record across eight adult vaccines: do results vary by demographic factors?

Immunizations are crucial to the prevention of disease, thus, having an accurate measure of vaccination status for a population is an important guide in targeting prevention efforts. In order to comprehensively assess the validity of self-reported adult vaccination status for the eight most common adult vaccines we conducted a survey of vaccination receipt and compared it to the electronic medical record (EMR), which was used as the criterion standard, in a population of community-dwelling patients in a large healthcare system. In addition, we assessed whether validity varied by demographic factors. The vaccines included: pneumococcal (PPSV), influenza (Flu), tetanus diphtheria (Td), tetanus diphtheria pertussis (Tdap), Human Papilloma Virus (HPV), hepatitis A (HepA), hepatitis B (HepB) and herpes zoster (shingles). Telephone surveys were conducted with 11,760 individuals, ≥18, half with documented receipt of vaccination and half without. We measured sensitivity, specificity, positive and negative predictive value, net bias and over- and under-reporting of vaccination. Variation was found across vaccines, however, sensitivity and specificity did not vary substantially by either age or race/ethnicity. Sensitivity ranged between 63% for HepA to over 90% (tetanus, HPV, shingles and Flu). Hispanics were 2.7 times more likely to claim receipt of vaccination compared to whites. For PPSV and Flu those 65+ had low specificity compared to patients of younger ages while those in the youngest age group had lowest specificity for HepA and HepB. In addition to racial/ethnic differences, over-reporting was more frequent in those retired and those with household income less than $75,000. Accurate information for vaccination surveillance is important to estimate progress toward vaccination coverage goals and ensure appropriate policy decisions and allocation of resources for public health. It was clear from our findings that EMR and self-report do not always agree. Finding approaches to improve both EMR data capture and patient awareness would be beneficial.

Telephone counseling and home telemonitoring: the Weigh by Day Trial.

OBJECTIVE: To test the effects of telephone counseling and telemonitoring on weight loss. METHODS: A randomized-controlled trial was conducted over 18 months. Participants were assigned to an immediate or delayed-start group. The intervention included a Thin-Link((R)) home telemonitoring scale and biweekly telephone counseling over 6 months. RESULTS: The immediate group lost significantly more weight relative to the delayed group over the first 6 months (-7.5 versus +1.3 pounds) and at subsequent visits. CONCLUSION: Compared to no treatment, the intervention was effective at producing weight loss. Home telemonitoring may enhance standard weight-loss counseling.

Self-weighing promotes weight loss for obese adults.

BACKGROUND: Frequent self-weighing has been proposed as an adjuvant strategy to promote weight loss. Not all experts agree on its utility, and the literature supporting its effectiveness is somewhat limited by methodologic shortcomings related to the subjective assessment of self-weighing frequency. DESIGN: A prospective cohort design was utilized to examine 100 participants enrolled in a weight-loss trial that encouraged frequent, objectively measured self-weighing at home. Measurements were made at pretreatment and at follow-up visits at 6 and 12 months. SETTING/PARTICIPANTS: Participants were employed, obese adults enrolled in the Weigh By Day trial. Study data were collected between October 2005 and May 2007. INTERVENTION: The intervention consisted of a 6-month behavioral weight-loss program that employed telephone counseling, a written manual, and a home telemonitoring scale. MAIN OUTCOME MEASURES: The primary outcomes of interest were body weight and clinically meaningful weight loss (i.e., > or =5%). Analyses were performed in March 2008. RESULTS: Self-weighing was a significant predictor of body weight over time. Participants lost about 1 extra pound for every 11 days they self-weighed during treatment. In addition, participants who self-weighed at least weekly were 11 times more likely to lose at least 5% of their pretreatment weight after 6 months. Improvements attenuated after 12 months. CONCLUSIONS: Self-weighing may be a strategy to enhance behavioral weight-loss programs. Weekly self-weighing seems to be a reasonable, evidence-supported recommendation for successful weight loss, but more research is warranted to determine the independent contribution of self-weighing to successful weight loss, as well as its potential risk of negative psychological impact.