To ascertain the prevalence of the use of complementary/alternative medicine (CAM) among a random sample of Ontario (Canadian) men diagnosed with prostate cancer and to explore in what way users of CAM differ from nonusers.

A questionnaire was mailed to a random sample of 696 men diagnosed with prostate cancer.

The final response rate was 78.8%. Almost one third (29.8%) reported using CAM for their prostate cancer care. Natural health products (most commonly vitamin E, saw palmetto, and selenium) were used by 26.5% of the respondents. CAM therapies were used by 17.0% of the men (most commonly dietary changes), and only 9.1% visited CAM practitioners. Three characteristics appear to differentiate CAM users from nonusers. Men who had attended support groups were much more likely to use CAM. Men who had more advanced disease, and those who believed in the efficacy of CAM, but were not concerned about potential adverse effects of CAM, were also more likely to use CAM. CAM use was not related to education, income, or geographic location.

The data suggest that CAM use is no longer a phenomenon restricted to a unique segment of the population that is highly educated and enjoys a high family income. CAM use appears to be more related to other factors such as support group attendance, disease characteristics, and beliefs about CAM. Our findings highlight the need for urologists to ask all their patients about their use of CAM.