Design considerations for hypertension chronotherapy trials: insights from experience and modelling

Abstract Chronotherapy aims to maximise treatment efficacy while minimising side effects by scheduling treatment according to personal biological rhythms. In recent years, randomised clinical trials (RCTs) have been conducted to evaluate whether scheduled blood pressure interventions can improve patient outcomes. However, reports of time-of-day effects have attracted rebuttals and engendered methodological debate. A perfectly controlled chronotherapy trial (i.e., a trial that assesses the effect of assigning time of intervention) will never be feasible in the real world; yet some factors may be more critical to consider and control for than others. To advance the conversation about how best to evaluate the effects of antihypertensive chronotherapeutic interventions in RCTs, we discuss critical considerations for clinical trials of chronotherapy for hypertension and apply mathematical modelling to provide quantitative insights into the extent to which such factors may influence the detected effect size.