Results Summary and Professional Abstract
Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.
The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments.
Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:
- The reviewers asked why overall survival was chosen as the primary outcome to measure rather than counting deaths specifically caused by prostate cancer. The researchers explained that the database they used provided data on overall survival only and not the cause of death.
- The reviewers asked for more discussion about the effects of race, ethnicity, and socioeconomic status on the frequency of prostate-specific antigen (PSA) surveillance. The researchers agreed that post-cancer treatment surveillance should reflect risk factors that affect recurrence rates. The researchers commented that race appears to be an independent risk factor and added a paragraph about the effects of race to the report’s background section. However, the researchers declined to add a discussion about socioeconomic status, which they said does not appear to be an independent risk factor when race and other factors are also considered.
- The reviewers asked how the researchers accounted for changes in treatment modality in their cohorts. The researchers stated that in one cohort, they did not record specific treatment characteristics and would not have been able to compare groups based on these characteristics because of small numbers in each group. In the second cohort, the researchers did collect treatment modality information, but they found that the time period for tracking that cohort was too short to see significant changes in treatment modality over time.
- The reviewers asked if the study looked at how frequency of clinic visits affected PSA surveillance and outcomes. The researchers said that they did not have data regarding patients’ physician visits, so they could not evaluate whether the frequency of visits correlated with testing frequency, cancer recurrence, or survival.
- The reviewers said that an important problem with this study is that they powered the study to detect a 7 to 10 percent difference in mortality between groups of patients. The reviewers pointed out that this is a very ambitious expectation in a sample of patients who already had prostate cancer and had viable options to treat co-occurrences and prevent death. The researchers stated that they had originally planned the study to include about 14,000 patients and to have the ability to detect a 5 percent difference in survival. Unfortunately, the researchers were unable to recruit a sample of that size, so they needed a larger difference between groups to find it to be statistically significant.
Conflict of Interest Disclosures
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^This project was previously titled: Determining How Often Prostate Cancer Survivors Should Get Follow-up Testing