Objective: The Fecal Incontinence Severity Index (FISI) is widely used in the assessment of patients with faecal incontinence, but the relationship between FISI and the measurements of quality of life, such as the Fecal Incontinence Quality of Life Scale (FIQL) and the Medical Outcomes Survey (SF-36) has not been evaluated previously. The aim of the present study was to evaluate the relationship between disease severity and quality of life in a large cohort of patients.
Method: Five hundred and two consecutive patients (84.4% female, mean age 56 years) were evaluated for faecal incontinence between May 2004 and October 2005. Patients completed FISI, FIQL and SF-36 questionnaires. Pearson's coefficients were determined for the relationships between FISI and subscales of FIQL and SF-36. Quality of life scores were compared between groups of patients with different levels of incontinence severity (mild, moderate, severe) using Student's t-test.
Results: Sixty-eight per cent of patients were incontinent of solid stool, 62% of liquid stool, and 90% of gas or mucus. The average FISI score was 36 (0-61). Moderate correlations were found between FISI and all subscales in FIQL (negative 0.29 to 0.41; P < 0.0001). Weak correlations were found between FISI and the social functioning (-0.21) and mental health (-0.17) scales in SF-36 (P < 0.05). Scores on the FIQL differed significantly between mild, moderate and severe incontinence.
Conclusion: FISI was only moderately correlated with a disease-specific quality of life measurement (FIQL). Even though this supports the common assumption that the quality of life in the patients with faecal incontinence worsens with an increase in disease severity, it also stresses the need of measuring both variables to determine the true impact of any treatment.