Patients and investigators prefer measures of absolute risk in subgroups for pragmatic randomized trials

Pragmatic randomized trials are important tools for shared decision-making, but no guidance exists on patients' preferences for types of causal information. We aimed to assess preferences of patients and investigators toward causal effects in pragmatic randomized trials.

We (a) held three focus groups with patients (n = 23) in Boston, MA; (b) surveyed (n = 12) and interviewed (n = 5) investigators with experience conducting pragmatic trials; and (c) conducted a systematic literature review of pragmatic trials (n = 63).

Patients were distrustful of new-to-market medications unless substantially more effective than existing choices, preferred stratified absolute risks, and valued adherence-adjusted analyses when they expected to adhere. Investigators wanted both intention-to-treat and per-protocol effects but felt methods for estimating per-protocol effects were lacking. When estimating per-protocol effects, many pragmatic trials used inappropriate methods to adjust for adherence and loss to follow-up.

We made four recommendations for pragmatic trials to improve patient centeredness: (1) focus on superiority in effectiveness or safety, rather than noninferiority; (2) involve patients in specifying a priori subgroups; (3) report absolute measures of risk; and (4) complement intention-to-treat effect estimates with valid per-protocol effect estimates.