Efficiency of questionnaires used to screen for interstitial cystitis

Abstract

Purpose: Questionnaires for the evaluation of interstitial cystitis are widely used, but their value in discriminating interstitial cystitis from other diagnoses among patients with urological symptoms has not been determined. We assessed the validity of 2 frequently used interstitial cystitis questionnaires-the O'Leary-Sant Symptom Index and Problem Index and the Pain, Urgency, Frequency Symptom Scale-for screening for interstitial cystitis.

Materials and methods: The Pain, Urgency, Frequency Symptom Scale and the O'Leary-Sant Symptom Index and Problem Index were administered to the same 220 patients at a urology clinic before diagnosis. Questionnaire scores between patients with and without interstitial cystitis, as well as among diagnostic groups, were compared by parametric and nonparametric analyses. Receiver operating characteristic curves were constructed to determine the efficiency of each questionnaire in discriminating between patients with and without interstitial cystitis.

Results: Interstitial cystitis was distinguishable from the other diagnoses using both questionnaires (p <0.001). Separate analyses of bother and symptom scores yielded similar results. Receiver operating characteristic curves demonstrated the Pain, Urgency, Frequency Symptom Scale to be more efficient than the O'Leary-Sant Symptom Index and Problem Index in detecting interstitial cystitis in this population with an optimal cutoff value of 13 or greater.

Conclusions: While the Pain, Urgency, Frequency Symptom Scale and the O'Leary-Sant Symptom Index and Problem Index questionnaires distinguish interstitial cystitis from other urinary tract pathologies, neither questionnaire demonstrates sufficient specificity to serve as the sole diagnostic indicator. These questionnaires should not be used to define interstitial cystitis, but can be used to screen patients with urinary tract symptoms to identify those who should be further examined for interstitial cystitis or to follow those who have already been diagnosed.