Background and objective: 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.
Study design and setting: 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).
Results: 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.
Conclusion: 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.