Measuring illness uncertainty in men undergoing active surveillance for prostate cancer.

BACKGROUND AND PURPOSE Uncertainty is an aversive experience and plays an important role in the lives of men undergoing active surveillance (AS; earlier referred to as watchful waiting) for early-stage prostate cancer. Yet reliable and valid measures of uncertainty have not been fully tested in this population. This secondary analysis therefore tested the reliability of the Mishel Uncertainty in Illness Scale Community Form (MUIS-C; M.H. Mishel, 1997b) for use with men undergoing AS for prostate cancer. METHODS Item-Total correlations were conducted on the 23 items of the MUIS-C with four samples of men undergoing AS. RESULTS Cronbach's alpha for the full MUIS-C was .908; 22 of 23 items showed significant positive correlations with the total score. Removing the item without a significant correlation from the reliability analysis increased Cronbach's alpha to .913. CONCLUSIONS The Mishel Uncertainty in Illness Scale-Community Form for Active Surveillance is a reliable and valid tool for measuring uncertainty with men undergoing AS for prostate cancer.