Researchers frequently use Patient Reported Outcomes Measures (PROMs) to assess patients’ symptoms, functioning, and quality of life after they overcome a disease and/or receive medical treatment. PROMs are important because they allow patients to relay their own feelings and experiences regarding a disease or treatment, and they are not based solely on a provider’s examination.

Interestingly, although a patient’s self-assessment may remain constant, different survey modes can lead to different responses. For example, in a recent study, a large group of prostate cancer patients was asked to complete a survey over the phone, by email, or by mail, and the researchers observed different trends based on the type of survey mode that was used.

A total of 6,380 prostate cancer patients from Victoria, Australia agreed to the survey and responded to at least one question on the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire between April 2018 and December 2020.

The EPIC-26 includes 26 questions and assesses the following five domains in prostate cancer patients: urinary incontinence, urinary irritation, bowel function, sexual function, and hormonal function/vitality. Domain scores can be calculated if a participant answers all 4 questions for both the urinary incontinence and the urinary irritation domains, at least 5 out of 6 questions for the bowel function and sexual function domains, and at least 4 out of 5 questions for the hormonal/vitality domain.

Most of the participants (4,301) responded to the survey by email, 1,882 did the survey over the phone, and 197 completed it by mail. In general, the men who chose to respond by phone or conventional mail were older and had a lower socioeconomic status than those who chose to respond by email.

Email responders were the most likely to respond to all 26 survey questions, and 95% did so for this study. In comparison, 87% of the men surveyed by phone completed all 26 questions, and 67% of those who responded by mail completed all 26 questions.

With regards to those who did not answer all of the questions, 3.4 was the average number of unanswered questions for emailers, 4.4 for phone users, and 5.7 for mail users. For those who completed the survey over the phone, the unanswered questions tended to relate to sexual functioning. The most commonly skipped questions were about the frequency of erections and ability to orgasm.

Despite having more unanswered questions than the other groups, the phone users reported consistently higher scores for every functional domain after adjusting for patient and disease factors. The authors of the study hypothesized that this could be due to the external influence of speaking with another person as well as the pressure to respond more quickly over the phone than over email or mail.

This study indicates that the way data is collected can influence how people respond and/or the number of questions they leave unanswered. People may be more likely to skip questions that feel personal or intimate, like those related to sexual function. Researchers should keep this information in mind when they are designing studies that deal with sensitive topics.

References:

• Papa, N., Bensley, J.G., Perera, M., Evans, M., & Millar, J.L. (2022). How Prostate Cancer Patients are Surveyed may Influence Self-Reported Sexual Function Responses. The Journal of Sexual Medicine, 19(9), 1442-1450. DOI: https://doi.org/10.1016/j.jsxm.2022.07.001