Abstract 15140: Older Participant Perspectives on Permanent Study Drug Discontinuation in an Ongoing Primary Prevention Trial of Statins: A Qualitative Study

Introduction: Study drug discontinuation is commonplace in clinical trials of older populations and poses a major challenge to trial investigators. Little is known about why older participants discontinue the study drug. This study aimed to understand factors contributing to permanent study drug discontinuation among participants aged ≥70 years within an ongoing primary prevention trial of statins by tapping into their experiences and perceptions. Methods: Trial participants who had permanently discontinued the study drug within 2 years of randomization were purposively sampled based on age (<75 and ≥75 years) and sex to participate in semi-structured phone interviews between March 2019 and February 2020. Interviews were audio-recorded, transcribed and analyzed thematically. Results: Thirty participants took part (21 females; mean age, 77 years) and three themes were identified from the data. Perceived adverse events (AEs) and their impact on daily living (mobility, functional capacity, quality of life, etc.) were identified as the major factors leading to the participants permanently discontinuing their study drug. Muscle symptoms were the most commonly reported AE. Selected participant quotes which describe symptoms and their impact are presented in Table. For some, a challenging life circumstance further lowered their tolerance to the perceived AEs thus making discontinuation more likely. A few discontinuations were attributed to other factors (e.g. concerns about possible side effects, GP advice, unrelated illness). Conclusion: Among healthy older participants enrolled in a statin trial, perceived AEs and their related impact were key factors contributing to the permanent study drug discontinuation. Addressing anticipated participant-reported AEs and their concerns about drug-related side effects at trial entry and offering timely medical assistance and support when AEs occur may be useful to reduce drug discontinuation rates.

Vitamin B12 and risk of diabetes: new insight from cross-sectional and longitudinal analyses of the China Stroke Primary Prevention Trial (CSPPT)

IntroductionPrevious studies in mostly Western populations have yielded conflicting findings on the association of vitamin B12 with diabetes risk, in part due to differences in study design and population characteristics. This study sought to examine the vitamin B12–diabetes association in Chinese adults with hypertension by both cross-sectional and longitudinal analyses.Research design and methodsThis report included a total of 16 699 participants from the China Stroke Primary Prevention Trial, with pertinent baseline and follow-up data. Diabetes mellitus was defined as either physician-diagnosed diabetes, use of glucose-lowering drugs, or fasting blood glucose (FBG) ≥7.0 mmol/L. New-onset diabetes was defined as any new case of onset diabetes during the follow-up period or FBG ≥7.0 mmol/L at the exit visit.ResultsAt baseline, there were 1872 (11.2%) patients with diabetes; less than 1.5% had clinical vitamin B12 deficiency (<148.0 pmol/L). Over a median follow-up period of 4.5 years, there were 1589 (10.7%) cases of new-onset diabetes. Cross-sectional analyses showed a positive association between baseline vitamin B12 levels and FBG levels (β=0.18, 95% CI 0.15 to 0.21) and diabetes (OR=1.16, 95% CI 1.10 to 1.21). However, longitudinal analyses showed no association between baseline vitamin B12 and new-onset diabetes or changes in FBG levels. Among a subset of the sample (n=4366) with both baseline and exit vitamin B12 measurements, we found a positive association between an increase in vitamin B12 and an increase in FBG.ConclusionsIn this large Chinese population of patients with hypertension mostly sufficient with vitamin B12, parallel cross-sectional and longitudinal analyses provided new insight into the conflicting findings of previous studies, and these results underscore the need for future studies to consider both baseline vitamin B12 and its longitudinal trajectory in order to better elucidate the role of vitamin B12 in the development of diabetes. Such findings would have important clinical and public health implications.