Various authorities and national organizations encourage disclosing medical errors, but there is little information on how patients respond to disclosure.

To examine how the type of error, severity of adverse clinical outcome, and level of disclosure affect patients' responses to error and disclosure.

Mail questionnaire survey (8 versions were developed) varying 3 factors in a completely crossed, randomized, factorial design. Each questionnaire included a vignette describing 1) a medical error (failure to check for penicillin allergy or inadequate monitoring of antiepileptic medication); 2) an associated clinical outcome (life-threatening or less serious); and 3) a physician-patient dialogue, with either full disclosure (acceptance of responsibility and an apology) or nondisclosure (expression of regret without acceptance of responsibility or an apology).

New England-based health plan.

Random sample of 1500 adult members received the questionnaire, with a 66% response rate.

Likelihood of changing physicians, likelihood of seeking legal advice, ratings of patient satisfaction, trust and emotional reaction in response to a vignette and dialogue, and views on medical error and disclosure.

Full disclosure reduced the reported likelihood of changing physicians and increased patient satisfaction, trust, and positive emotional response. Full disclosure reduced the reported likelihood of seeking legal advice in only 1 error-and-outcome vignette. In the other vignettes, the percentage of patients indicating that they would seek legal advice was relatively high even with full disclosure. Almost all respondents (98.8%) wanted to be told of errors, most (83%) favored financial compensation if harm occurred, and few (12.7%) favored compensation if no harm occurred.

Since the study was done in the context of a managed care plan in one geographic area, it could not assess whether the results are generalizable to other populations. In addition, it could not determine whether responses to the simulated situations used predict responses to real situations.

Patients will probably respond more favorably to physicians who fully disclose medical errors than to physicians who are less forthright, but the specifics of the case and the severity of the clinical outcome also affect patients' responses. In some circumstances, the desire to seek legal advice may not diminish despite full disclosure.