Translation and validation of a Spanish version of the xerostomia inventory

Objective The aim of this study was to validate a Spanish cross‐cultural adaptation of the xerostomia inventory ( XI ). Materials and methods The original English version of XI was translated into Spanish, cross‐culturally adapted and field tested. The Spanish version of XI ( XI ‐Sp) was tested with a sample of 41 patients with xerostomia. The reliability of the XI ‐Sp was determined through internal consistency and test–retest methods. The construct validity of XI ‐Sp was determined by means of correlation between XI ‐Sp scores and salivary flow measurements. Results Overall XI ‐Sp scores were 40.8 (SD = 10) for the first application and 40.2 (SD = 9.5) for the second. Cronbach's alpha value for the XI ‐Sp was 0.89 and 0.87, respectively, while interitem correlation averages were r = 0.44 and r = 0.39 for each application. Interitem correlation and corrected total was r c ≥0.30. The test–retest intraclass correlation coefficient value for the XI ‐Sp score was 0.59 and 0.91. Convergent validity for construct validity correlation with salivary flow showed a medium effect size ( r 2 = 0.10) for the first application but did not make a statistically significant prediction for the second ( r 2 = 0.7). Conclusions This study provides evidence concerning the reliability of the XI ‐Sp, showing that it may be a useful tool for Spanish‐speaking xerostomia patients for both clinical and epidemiologic research.