People who participate in clinical research generally wish to know the research results

A review of past studies examining whether people who participate in clinical research wish to know the results has found that most people do wish to be told, even if receiving the results might cause distress or anxiety. The review is published in this week's PLoS Medicine.

David Shalowitz (University of Michigan Medical School, USA) and Franklin Miller (National Institutes of Health, Bethesda, Maryland, USA) searched the medical literature and found 28 studies on communicating research results to participants. The results of clinical research may be classified as either aggregate study results, representing synthesized data and conclusions drawn from groups of research participants, or individual results, representing distinct items of data collected from or about individual participants.

Eighteen studies provided data on participants' desire to receive study results. Nine studies involved aggregate study results, eight involved individual results, and one involved both. Of studies that reported desire to receive results as a percentage of respondents, a median of 90% (range 20%–100%) wished to receive study results.

Nine studies assessed participants’ reasons for wanting to know the study results. Participants in these studies cited the clinical importance of the results for themselves or their family (e.g. gaining information about a disease, its treatment, or its prevention), respect for participants in research or a “right” to receive results, and raising public awareness of research.

Eight studies, all involving aggregate results, assessed whether sharing the results of clinical research brings benefits or harms to participants. All but one study reported some incidence of negative psychological consequences for participants, including increased anxiety, anger, guilt, or upset. However, six studies reported psychological benefits for participants from receiving research results, including pleasure, satisfaction, and relief. "Importantly," say Shalowitz and Miller, "the vast majority of participants reported feeling that it was important to receive study results, despite potentially negative emotional impact."

The review found five studies that examined what researchers thought about giving study results to research participants—most of these studies found that a substantial majority of investigators supported communicating study results to participants.

The authors conclude: "Available data consistently indicate that research participants want aggregate and clinically significant individual study results made available to them. Participants’ desires do not necessarily determine policy, but respect for participants requires taking their preferences seriously.