The fecal incontinence quality of life scale (FIQL) and fecal incontinence severity index (FISI): Validation of the Dutch versions

Aims: Fecal incontinence (FI) is known to have a major impact on quality of life. The Fecal Incontinence Quality of Life scale (FIQL) and Fecal Incontinence Severity Index (FISI) have been developed to assess this impact. The aim of this study was to validate the FIQL and FISI in the Dutch language.
Methods: The study population consisted of women and men experiencing FI and a reference group. The FIQL (four domains) and FISI questionnaires were validated by testing standardized measurement properties: discriminative ability, internal consistency, reproducibility, construct validity, and responsiveness.
Results: A total of 55 patients and 277 reference participants were included. Patients had significant lower and higher scores at the FIQL and FISI, respectively, than references, indicating worse functioning in patients and with this the discriminative abilities of the measures. The FIQL demonstrated adequate internal consistency on all domains, except for the embarrassment domain. The reproducibility was good for both measures. A negative correlation was found between the FIQL and FISI. Furthermore, the FIQL showed a positive and the FISI a negative correlation with the Mental Component Summary scale of the SF-12. Responsiveness analysis showed a minimal important change of 0.40 points for the FIQL.
Conclusions: Validity and reliability were good in the Dutch FIQL, but inconclusive in the FISI. The Dutch FIQL can support physicians in determining the impact of FI on patient's quality of life.