Before you join a clinical study

1. Identify the study and local site

Record the official study title, registry identifier, sponsor, site name, principal investigator when listed, and the person who contacted you. On ClinicalTrials.gov, the registry identifier begins with NCT. Search that identifier yourself instead of relying on a link in a message.

Match the condition, intervention, study type, age range, sponsor, and location. Treat each match as corroborating evidence. A registry entry does not endorse the recruiter, prove that a local location remains open, or show every procedure you may face. ClinicalTrials.gov explains the fields and limits of a study record (opens in a new tab).

2. Check the study groups and assignment

Open the study details and identify the study type, phase when applicable, intervention model, number of groups or arms, allocation method, masking, and primary outcome time frame. These fields reveal facts that a short recruitment description may soften or omit.

If allocation is randomized, ask for the assignment ratio. A two-arm study may use 1:1 assignment, 2:1 assignment, or another ratio. If masking is used, identify who is blinded and when unblinding may occur. If the study uses a placebo or active comparator, ask what standard care remains available and what rescue treatment the protocol allows.

For a crossover study, mark each treatment period and washout. For a dose-escalation study, ask whether cohorts receive different doses and whether sentinel participants are dosed before the rest of a cohort. Use the design to build questions; do not use it to estimate personal medical risk without the consent information and clinical guidance.

3. List visits, home tasks, and restrictions

Find the intervention duration and follow-up period. Then build a workload list. Count clinic visits, remote visits, calls, questionnaires, diary days, home measurements, blood draws, imaging sessions, procedures, overnight stays, device use, specimen shipping, and records requests.

Add constraints that occupy time even when no visit occurs: fasting, medication rules, contraception requirements, limits on alcohol, nicotine, caffeine, exercise, driving, sun exposure, travel, or participation in another study. Ask the study team for the schedule of activities or a visit-by-visit summary. Never change medication, food, fluid, or activity routines from a public listing. Follow written study instructions and involve your clinician when a restriction affects your care.

Open the burden calculator and enter the hours and costs you can estimate. Keep medical risk outside the calculation. A time-and-expense result cannot determine whether a study is medically appropriate.

4. Find consent and safety contacts

Find the informed consent process, reviewing institutional review board (IRB), participant-rights contact, research-team contact, and after-hours safety contact. OHRP’s public question set (opens in a new tab) asks who reviewed the research, how risks will be reduced, how privacy will be protected, who pays for injury care, and what happens if a volunteer quits.

Ask how the study handles new information that could affect willingness to continue. Ask which test results are returned, which tests are research-only, and how urgent findings are communicated. Confirm where to report symptoms after hours. For remote studies, confirm who conducts home visits, where devices and specimens are shipped, and how you can verify a vendor.

5. Write down what you still need to know

Write the five missing facts most likely to change your decision. Phrase each question so the answer can be recorded. Replace “Is the schedule flexible?” with “Which visits have fixed windows, how wide is each window, and what happens when a visit falls outside it?” Replace “Do you pay for travel?” with “Which expenses qualify, what requires approval, what receipts are needed, and when is reimbursement issued?”

End the first review with one of three outcomes:

• Continue: the identity checks align and the remaining questions are appropriate for a screening call.
• Pause: a site, location, contact, procedure, privacy practice, or payment term needs independent verification.
• Decline: a known requirement conflicts with your health plan, schedule, privacy boundary, finances, or willingness to participate.