Designing Pre-Screening Questionnaires That Actually Pre-Screen

Online pre-screening is one of the highest-leverage tools a site has: it filters obvious non-qualifiers before a human spends a minute on the phone. But questionnaire design is a balancing act — every extra question costs completions.

Principles that hold up

Ask only what disqualifies. The pre-screener's job is not to collect a medical history; it's to catch the handful of criteria that rule out most people. Age range, diagnosis, one or two key medications, and a deal-breaker comorbidity usually cover it.

Front-load the essentials. Put the most-disqualifying question first. If 60% of applicants are excluded by age, ask age first and let people exit early rather than after ten questions.

Write like a human. "Have you been told by a doctor that you have type 2 diabetes?" beats "Do you meet ADA diagnostic criteria for T2DM?" Every acronym costs you respondents.

Keep it under three minutes. Completion rates fall off sharply beyond 8–10 questions. If the protocol truly demands more, split it: a short public screener, then a deeper phone screen.

Don't reveal the answer key. Phrase questions so the "right" answer isn't obvious, or motivated applicants will tell you what you want to hear — and you'll pay for it at the screening visit.

Score, don't just pass/fail

A weighted score lets coordinators triage: call the 95s first, the 60s when there's time. Borderline responders often turn out to be eligible once a human clarifies a question they misread.

Close the loop

Track pre-screen scores against actual screening outcomes. If people who score well keep failing on the same criterion at the visit, that criterion needs a better question — or needs to move into the screener at all. The questionnaire is never finished; it's tuned.