Objectives: The Clinical Opiate Withdrawal Scale (COWS) is an observer scored assessment of eleven signs of clinical withdrawal. The aim of the study was to examine the interrater reliability and validity of the Turkish version of the COWS.
Methods: In order to adapt the COWS for the Turkish population, the authors’ permission was obtained. The scale was translated independently into Turkish by three physicians who are şuent in English and was then back translated by an instructor who is also şuent in English. English and Turkish versions of the scale were given to a bilingual individual to verify the consistency between the original and translated versions. Thirty-five consecutive opioid-dependent inpatients were enrolled. The participants were carefully monitored until they demonstrated signs of opioid withdrawal. All subjects were assessed with COWS by two observers independently and simultaneously. The COWS is a clinician-administered, pen and paper instrument that rates 11 common opiate withdrawal signs or symptoms, each of which is rated from 0 to 4 or 5. The maximum achievable score is 48. The patients were also asked to complete the Addiction Profile Index (API). The API is a self-report questionnaire consisting of 37 items and the following 5 subscales: characteristics of substance use; dependency diagnosis; the effects of substance use on the user; craving; motivation to quit using substances. The study was carried out in accordance with the latest version of the Declaration of Helsinki and the study protocol was approved by the local ethical committee (Akdeniz University Ethical Committee of Clinical Investigations). The interclass correlation coefficient was used to determine agreement between two observers. Cronbach’s alpha coefficients and item total score correlations were computed for the reliability of the scale. For the validity of the scale, correlations between the scales were calculated with Pearson’s correlation method.
Results: Correlation analyses indicated that API was significantly correlated positively with the COWS. Correlations of the total scores based on the psychiatrists’ ratings were found to be high; the interrater reliability coefficient of the items and total COWS score ranged between 0.703 and 0.938 and all correlations were highly significant (p<0.001). A Cronbach’s alpha coefficient of 0.874 was obtained for the COWS according to the first observer and of 0.842 according to the second observer, which suggests that the internal validity of the Turkish version of the COWS is acceptable. Item-total correlations ranged from 0.27 to 0.74 (p<0.001).
Conclusions: Our results indicate that the Turkish version of COWS yielded good interrater reliability and was significantly correlated with a self-report questionnaire scale. Although the small sample size hinders a conclusion, COWS showed significant results regarding validity measures. Thus, our results support that COWS has the potential to fulfill the need in clinical research settings.