Cultural adaptation to Spanish (Spain) of the "Overactive Bladder - Family Impact Measure (OAB-FIM)" questionnaire.

Objective: The OAB-FIM was developed as a measure of the impact of an overactive bladder (OAB) on relatives who live with the patient. The objective of this study was conduct a cultural adaptation to Spanish (Spain) of the OAB-FIM questionnaire.

Methods: The adaptation included a conceptual and linguistic validation phase, as well as a phase for measuring the psychometric properties in 25 relatives [mean age, 63.0 years (SD, 14.3); 44% women] who regularly live with patients with OAB, who are of either sex and 18 years of age or older. We measured conceptual and linguistic equivalence, internal reliability, construct validity and content validity. We assessed the applicability and administration load.

Results: The OAB-FIM was conceptually and linguistically equivalent to the original, maintaining its 6 domains: social, travel, worry, irritability, sleep and sex. The interagreement correctly placed all items in their domain, except for number 10, which was placed more in worry than in irritability, motivates its reformulation. Some 2.95% of the items were missing. The floor and ceiling effects of the items varied, respectively, between 20-28%, and 0-16%. The mean time for completing the questionnaire was 5.2minutes (SD, 2.8), and 24% of the participants required some type of assistance. The α-Cronbach coefficient varied between 0.948-0.839. The correlations with similar scales in the family were moderate-high (0.407-0.753) or small-moderate with those administered to the patient (0.004-0.423).

Conclusion: We obtained a Spanish (Spain) version of the OAB-FIM that was conceptually and linguistically equivalent to the original. The questionnaire showed good internal consistency, content and construct validity and applicability.