A sequential multi-method approach using focus groups, individual interviews, and quantitative instrument development procedures was used to develop and evaluate a scale to measure patient trust in health care providers (HCPs). The resulting 15-item Health Care Relationship (HCR) Trust Scale was tested for internal consistency, test-retest reliability, and construct validity. The Cronbach alphas were .92 (time 1) and .95 (time 2), respectively. Test-retest reliability was .59 (p < .01). The HCR Trust Scale did not correlate with the Marlowe-Crowne Social Desirability Scale (r = .20, p = .07) or the Rapid Estimate of Adult Literacy in Medicine scale (r = -.21, p = .13). Principal component factor analysis with varimax rotation revealed a three-factor solution that explained 69% of the estimated common variance in the HCR trust scale. Cronbach alphas for the 3 factors ranged from .81 to .89. Findings of this study support the use of the HCR Trust Scale for measuring trust in various HCPs by diverse patient populations. More work is needed to test the usefulness of the scale with a greater number of patients and in other chronic illness populations.

BACKGROUND: Few rigorously designed studies have documented the efficacy of interventions to improve medication adherence among patients prescribed highly active antiretroviral. Data are needed to justify the use of limited resources for these programs. METHODS: A 2-arm, randomized, controlled trial evaluated the efficacy of a community-based, home-visit intervention to improve medication adherence. Participants were 171 HIV-infected adults prescribed a minimum of 3 antiretroviral agents. The majority had a past or current history of substance abuse. Subjects were randomly assigned to receive home visits for 1 year or usual care. Medication adherence was assessed with Medication Event Monitoring stem caps at 3-month intervals from randomization through 3 months after the conclusion of the intervention. RESULTS: A larger proportion of subjects in the intervention group demonstrated adherence greater than 90% compared with the control group at each time point after baseline. The difference over time was statistically significant (Extended Mantel-Haenszel test: 5.80, P = 0.02). A statistically significant intervention effect on HIV-RNA level or CD4 cell count was not seen, but there was a statistically significant association between greater than 90% adherence and an undetectable HIV-RNA over time (P < 0.03). CONCLUSION: Home visits from a nurse and a community worker were associated with medication adherence greater than 90% among a cohort of socially vulnerable people living with HIV/AIDS in northeastern United States.

The purpose of this paper is to describe electronic monitoring device (EMD) (e.g., MEMS caps) use among HIV-infected adults enrolled in a randomized clinical trial and to make explicit some of the benefits and caveats of using electronic monitoring device technology. This is a descriptive, exploratory study of EMD use among 128 HIV-infected adults treated with at least three antiretroviral agents. Thirty-six percent of the sample admitted that they did not use the EMD consistently. Forty-one percent of the subjects reported taking out more than one dose at a time and 26% reported opening the EMD but not taking the medication. Special subject-related issues accounted for only a small percentage of all reported problems with EMD use (e.g., transient housing, incarceration, substance abuse relapse and drug treatment). Results of this study suggest that EMDs may underestimate antiretroviral adherence among HIV-infected adults. Recommendations for improving EMD data quality are presented.

An adaptive approach to Poisson regression modelling is presented for analysing event data from electronic devices monitoring medication-taking. The emphasis is on applying this approach to data for individual subjects although it also applies to data for multiple subjects. This approach provides for visualization of adherence patterns as well as for objective comparison of actual device use with prescribed medication-taking. Example analyses are presented using data on openings of electronic pill bottle caps monitoring adherence of subjects with HIV undergoing highly active antiretroviral therapies. The modelling approach consists of partitioning the observation period, computing grouped event counts/rates for intervals in this partition, and modelling these event counts/rates in terms of elapsed time after entry into the study using Poisson regression. These models are based on adaptively selected sets of power transforms of elapsed time determined by rule-based heuristic search through arbitrary sets of parametric models, thereby effectively generating a smooth non-parametric regression fit to the data. Models are compared using k-fold likelihood cross-validation.