Cumulative Illness Rating Scale was a reliable and valid index in a family practice context

The goal of this study was to validate an instrument measuring the clinical burden of several medical problems in the same patient (multimorbidity), in a family practice context and, more specifically, to verify if trained nurses can score the Cumulative Illness Rating Scale (CIRS) from chart review. A convenience sample of 40 patients was selected. The attending physicians scored the CIRS during clinical interview (CIRS-MD/I), then three nurses scored the CIRS during clinical interview (CIRS-NUR/I) and three other nurses scored the CIRS from chart review (CIRS-NUR/C) (interrater reliability). Two of these nurses scored the CIRS-NUR/C again 2 months later (intrarater reliability). For interrater reliability, the intraclass correlation coefficients were 0.81 (0.70–0.89) for the CIRS-NUR/I and 0.78 (0.66–0.87) for the CIRS-NUR/C. The intrarater reliability of the CIRS-NUR/C was 0.89 (0.80–0.94) for one of the nurses and 0.80 (0.65–0.89) for the other. Concomitant validity of these two forms of CIRS with the CIRS-MD/I ranged from 0.73 to 0.84. The CIRS appears to be a reliable and valid instrument in a primary care context and trained nurses can score the CIRS from chart review.