Research Attitudes Questionnaire scores predict Alzheimer's disease clinical trial dropout.

BACKGROUND: Missing data are a notable problem in Alzheimer's disease clinical trials. One cause of missing data is participant dropout. The Research Attitudes Questionnaire is a 7-item instrument that measures an individual's attitudes toward biomedical research, with higher scores indicating more favorable attitudes. The objective of this study was to describe the performance of the Research Attitudes Questionnaire over time and to examine whether Research Attitudes Questionnaire scores predict study dropout and other participant behaviors that affect trial integrity. METHODS: The Research Attitudes Questionnaire was collected at baseline and weeks 26 and 52 from each member of 119 participant/study partner dyads enrolled in a Phase 2, randomized, double-blind, placebo-controlled mild-to-moderate Alzheimer's disease clinical trial. Within-subject longitudinal analyses examined change in Research Attitudes Questionnaire scores over time in each population. Logistic regression analyses that controlled for trial arm and clustering in trial sites were used to assess whether baseline Research Attitudes Questionnaire scores predicted trial completion, study medication compliance, and enrollment in optional substudies. RESULTS: Participants and study partners endorsed statistically similar ratings on the Research Attitudes Questionnaire that were stable over time. Participants with baseline Research Attitudes Questionnaire scores above 28.5 were 4.7 (95% confidence interval = 1.01 to 21.95) times as likely to complete the trial compared to those with lower scores. Applying the same cutoff, baseline study partner Research Attitudes Questionnaire scores were similarly able to predict study completion (odds ratio = 4.2, 95% confidence interval = 1.71 to 10.32). Using a score cutoff of 27.5, higher participant Research Attitudes Questionnaire scores predicted study medication compliance (odds ratio = 5.85, 95% confidence interval = 1.34 to 25.54). No relationship was observed between Research Attitudes Questionnaire score and participation in optional substudies. CONCLUSION: This brief instrument that measures research attitudes may identify participants at risk for behaviors that cause missing data.

Gender of Study Partners and Research Participants Associated With Differences in Study Partner Ratings of Cognition and Activity Level.

OBJECTIVES: Studies of Alzheimer's disease typically include "study partners" (SPs) who report on participants' cognition and function. Prior studies show SP reports differ depending on the relationship between the SP and participant, that is, spouse or adult child. Adult children SPs are typically female. Could differing reports be due to gender? Knowing this may help explain variability in measurement. METHODS: The Aging, Demographics, and Memory Study enrolled a subset of participants from the Health and Retirement Study. Each participant had an SP. Bivariate and multivariable regression models compared 718 SP-participant dyads. RESULTS: In analyses of 4 groups defined by SP and participant gender, dyads composed of 2 women were less likely to identify as White (75.8%, 95% confidence interval [CI], 70.4-80.5) than dyads composed of 2 men (93.3%, 95% CI, 81.2-97.8). In analyses adjusted for the severity of cognitive and functional impairment, women SPs rated women participants as more active than they rated men, mean 2.15 (95% CI, 2.07-2.22) versus mean 2.30 (95% CI, 2.24-2.37), respectively, on a 4-point scale. Similarly, men SPs rated women participants as more active than they rated men, mean 2.1 (95% CI, 2.0-2.2) and mean 2.4 (95% CI, 2.3-2.5), respectively. In an analysis of cognitively unimpaired participants, women SPs rated participants' memory worse than men SPs did (p < .05). DISCUSSION: SP and participant gender influence SPs' reports of another person's cognition and activity level. Our findings expand what is understood about how nondisease factors influence measures of disease severity.

Predictors of who Serves as an Alzheimer's Disease Research Participant's Study Partner and the Impact of their Relationship on Study Partners' Reports on Participants.

Background: Alzheimer's disease and Alzheimer's disease related dementias (AD/ADRD) research typically requires participants to enroll with a "study partner" (SP). Little is known about what predicts who steps into the SP role or whether the SP's relationship to the participant affects their reports of disease severity.Methods: Health and Retirement Study data (HRS), collected prior to the Aging, Demographics and Memory Study (ADAMS), was used to identify sociocultural factors that predict who serves as a SP in ADAMS. SP-reported outcomes were compared between three types of participant-SP relationships: spousal, adult child, and other.Results: Spouses (35%) and adult children (39%) were similarly likely to serve as SPs. Factors predicting who served differed. In multivariable analyses, adult children rated participants less impaired than spouses on measures of memory, judgment, and organizational abilities (p < .05). Conclusions: The participant-SP relationship has independent effects on the SP's reports of the severity of cognitive impairments.