This study investigates how different survey modes (email, telephone, or mail) impact the quantity of missing data and self-reported function following prostate cancer treatment.
The study population consisted of men newly diagnosed with prostate cancer and enrolled in the Victorian Prostate Cancer Outcomes Registry. Approximately one year after initial treatment, participants completed the Expanded Prostate Cancer Index Composite (EPIC-26) survey, which measures self-reported function in sexual, urinary, bowel, and hormonal domains.
Results showed that email responders had the highest completion rate for all 26 questions (95% vs 87% by phone and 67% by mail). The sexual function score was missing for 1.3% of email responders, 8.8% by phone, and 8.1% by mail. Phone responders were nearly six times more likely than email responders to have a missing score in the sexual domain.
Adjusted mean functional scores were higher for phone respondents across all domains, with the largest difference in the hormonal domain. The findings suggest that survey mode affects the quality of responses, particularly in sexual health, and should be considered in analyses.
