Reliability and Validity of the Turkish Version of the Clinical Opiate Withdrawal Scale (COWS)

Objective: The Clinical Opiate Withdrawal Scale (COWS) is an observer-based instrument that grades the signs and symptoms of opiate withdrawal. Our purpose was to evaluate the interrater reliability and validity of the Turkish version of the COWS.

Method: Fifty-three opiate-dependent patients showing signs of opioid withdrawal were enrolled. The patients were assessed with the Turkish version of the COWS by two observers independently and simultaneously. The patients were also asked to complete the Addiction Profile Index (API). The intra-class correlation coefficient was used to determine agreement between two observers. Pearson’s correlation method was utilized to analyze the correlations between the COWS and the API.

Results: The interrater reliability coefficient of the items and total COWS score ranged between 0.704 and 0.921 and all correlations were highly significant. Cronbach’s alpha coefficients of 0.938 (first observer) and 0.917 (second observer) were obtained for the COWS. Correlation analyses indicated that API was significantly correlated positively with the COWS.

Conclusion: We found that the Turkish version of COWS had good interrater reliability, internal consistency, and construct validity. Our results suggest that the Turkish COWS is a valid and reliable instrument for determining opiate withdrawal severity.