Medical assessment in drug addicts: reliability and validity of the Cumulative Illness Rating Scale (Substance Abuse version)

Objective: To adapt the Cumulative Illness Rating Scale for its use in substance abuse patients (CIRS-SA) and to assess the reliability, internal consistency, and validity of the instrument.

Method: One-hundred outpatients of both sexes, 62 men and 38 women, with a mean (SD) age of 32.4 (7.9) years (range 19-57), all of them fulfilling the DSM-IV criteria for any substance abuse disorder. Internal consistency was calculated with Cronbach's alpha coefficient. Test-retest and interrater reliability was assessed with the intraclass correlation coefficient and Wilcoxon z. Validity of the scale was assessed with Kendall's tau correlation coefficient.

Results: The final CIRS-SA version had a total of 13 items. Cronbach's alpha coefficient was 0.57. All intraclass correlation coefficients were above 0.7, and some items showed exact coincidence. The stability of the CIRS-SA scale in a 1-month test re-test reassessment was demonstrated. The CIRS-SA score showed a significant correlation with all consultant scores.

Conclusion: CIRS-SA is a reliable and valid instrument to assess and to determine systematically the physical condition of substance abusers in whom infections, particularly by the HIV, are highly prevalent.