[The interrater reliability of four common comorbidity indexes used in elderly patients]

Objective: To report on the interrater reliability of four common comorbidity indexes used in the hospitalised elderly: Charlson Index (CI), Geriatric Cumulative Illness Rating Scale (CIRS-G), Index of Co-existent Disease (CoD) and Kaplan-Feinstein Index (KFI).

Method: Four trained observers, independently reviewed the same 40 medical charts of hospitalised geriatric patients. Scores for the four indexes were calculated, along with the intraclass correlations coefficient (ICC) (quantitative index: CI and CIRS-G) and Kappa coefficient (qualitative index: CoD and KFI). The agreement <0.4 was considered deficient, 0-4-0.75 acceptable and >0.75 excellent.

Results: A total of 40 patients (29 women) of 85.93 (±5.35) years were analysed. Intraclass correlations coefficient: CI: 0.78 (95% CI: 0.67-0.86); CIRS-G (score): 0.66 (95% CI: 0.53-0.78). Kappa coefficient: KFI: 0.51 to 0.76; CoD: 0.44-0.66. The application time was lower for the Charlson index (median of 39seconds [30-45]) and the KFI (42seconds [35-52]) and higher for CIRS-G (score) (128seconds [110-160]) and CoD (102seconds [80-124]).

Conclusions: Of the four comorbidity indexes used in a hospitalised elderly population, the CI, and CIRS-G (score), are those that have better interrater reliability. The Charlson index and KFI show a lower application time than the CIRS-G (score).