Measuring disease-specific health status in men with benign prostatic hyperplasia. Measurement Committee of The American Urological Association

Abstract

In preparation for an outcomes study of benign prostatic hyperplasia (BPH), two measures of disease-specific health status were developed to supplement a symptom score and overall health status measures. The symptom problem index (SPI) captures how troublesome patients find their urinary symptoms. The BPH impact index (BII) measures how much their urinary problems affect various domains of health. A prospective revalidation of the refined instruments (N = 108 BPH patients and 50 controls) documented that both indices had good internal consistency (Cronbach's alpha = 0.88 and 0.79, respectively) and test-retest (r = 0.88 for both) reliabilities, correlated strongly with symptom scores (r = 0.86 and 0.77), and discriminated between BPH and control subjects (receiver-operating characteristic areas = 0.87 and 0.85, respectively). These indices were nearly as responsive as symptom scores in 50 men actively treated for BPH, and much more responsive than a non-disease-specific General Health Index (GHI), a Mental Health Index (MHI), and an Activity Index (AI). Finally, these measures capture most of the health status significance of BPH symptoms. In linear regression models constructed to predict scores on the GHI, MHI, and AI, symptom scores added little explanatory power to the SPI and, particularly, to the BII. These measures help clarify how BPH affects overall health status and function. Such measures have an important role to play in studies of the outcomes of treatment for BPH, and probably for other conditions that interfere with health status and function.