Trial design for ineffectiveness research: a mixed-methods survey.

Area of Science:

• Health Services Research
• Clinical Trial Design
• Evidence-Based Medicine

Background:

• High-quality research demonstrating a lack of effectiveness is crucial for de-adopting ineffective health services.
• Optimal trial designs for ineffectiveness research remain under-debated.
• Ineffectiveness research tests the hypothesis that an intervention is ineffective.

Purpose of the Study:

• To explore principal investigators' preferences for trial designs in ineffectiveness research.
• To understand the rationale behind investigators' choices for superiority versus equivalence trial designs.
• To identify potential barriers to adopting appropriate trial designs for demonstrating ineffectiveness.

Main Methods:

• A mixed-methods online survey was administered to principal investigators identified from clinicaltrials.gov.
• Participants were presented with a vignette of researchers planning an ineffectiveness trial.
• A multiple-choice question assessed preference for superiority or equivalence trial design, followed by a free-response question on reasoning.

Main Results:

• 139 principal investigators completed the survey (37.5% completion rate).
• A majority (56.8%) favored superiority trials, while 27.3% favored equivalence trials.
• Key reasons for favoring superiority trials included familiarity and perceived smaller sample size requirements; reasons for favoring equivalence trials centered on the distinction between lack of effectiveness and ineffectiveness.

Conclusions:

• A minority of experienced researchers favor equivalence trials for ineffectiveness research.
• Misconceptions and lack of familiarity with equivalence trial designs may hinder their adoption.
• Further education on equivalence trial design is needed to optimize ineffectiveness research.