Comparative analysis of summary scoring systems in measuring fecal incontinence

PURPOSE: For measuring symptoms of fecal incontinence, summary scoring systems are widely used, but rigorous psychometric validation or assessment of such systems in terms of patients' subjective perception has rarely been done to date. This study was designed to assess the correlation between each severity measure and patients' subjective perception or clinicians' clinical assessment. We attempted to compare summary scoring systems of severity measures and searched for which of them showed higher validity among them. METHODS: Consecutive patients who visited our clinic with fecal incontinence were prospectively evaluated. A total of 43 patients were included. Four summary scoring systems were chosen for comparison: the Rothenberger, Wexner, Vaizey and Fecal Incontinence Severity Index systems. They are correlated with subjective perception scores by patients, and also with clinical assessment scores by investigators. RESULTS: There was no significant difference between clinical scores of two investigators (paired t-test, P = 0.988). Inter-observer reliability was 0.95 (Intra-class correlation coefficient, 95% confidence interval 0.91 to 0.98). Significant correlations were proved between patients' subjective perception scores and all the summary scoring systems, and also between the mean clinical scores and all the summary scoring systems. The highest was with the Wexner scale (r = 0.66, P < 0.001) (r = 0.70, P < 0.001), and the lowest was with the Rothenberger scale (r = 0.58, P < 0.001) (r = 0.61, P < 0.001) in both correlations. CONCLUSION: The Wexner scale correlates the most closely with subjective perception of severity of symptoms by patients, and also with clinical assessment by investigators. We recommend the Wexner scale among summary scoring systems as a tool for measuring fecal incontinence.