Translation, cultural adaptation and validation of the Tamil version of the Cardiff Acne Disability Index (CADI) in Sri Lanka.

Background: Assessment of QoL has become an essential component in the holistic care of patients with acne. The Cardiff Acne Disability Index (CADI) is used globally to assess quality of life (QoL) in patients with acne. This study was done to validate CADI in Tamil, as 90 million of the global population are native speakers and Tamil is an official language of several countries.

Methods: CADI was translated and validated into Tamil according to published guidelines. The Tamil versions of both CADI and Dermatology Life Quality Index (DLQI), was administered to 150 Sri Lankan young adults with acne. The clinical severity was assessed using the Global Acne Grading System (GAGS). Discriminant validity was tested by comparing the results of CADI with those of GAGS and DLQI, using reliability, validity, Cronbach's alpha, and Spearman's correlation coefficient measurements. Construct validity was assessed by factor analysis.

Results: 70% were female, and the mean age was 25.1 (SD, 5.2). The majority (91.3%) had acne of mild to moderate severity when measured by GAGS. CADI-Tamil showed high internal consistency and reliability (Cronbach's alpha coefficient = 0.83). The CADI total score showed a strong correlation (0.86) with that of DLQI. The correlation between CADI and GAGS was low, whereas CADI had a high and significant correlations with the DLQI. The construct validity explained 61% of the variability.

Conclusions: The CADI-Tamil is a reliable and valid tool for assessing the QoL of Tamil speaking patients with acne. This tool will help clinicians understand the patient's perspective on acne.