Comorbidity index was successfully validated among men but not in women.
OBJECTIVE
To validate the prognostic accuracy of a previously proposed comorbidity index using information of a different and separate population-based cohort.


METHODS
We assessed the predictive accuracy of a comorbidity index to predict mortality by looking at calibration and discrimination in the development cohort as well as in a new cohort for validation. Calibration of the model was assessed by comparing predicted and current mortality in the new cohort by means of Hosmer-Lemeshow test (HL). Discrimination of the models was analyzed using the area under the receiver operating characteristic curves (ROC).


RESULTS
In the development cohort, we have not detected differences between the predicted and the observed mortality in both, men (HL=7.7, P=0.46) and women (HL=11.7, P=0.16). The discrimination of the model accounted 81% in men and 79% in women. In the validation cohort, we obtained a good calibration among men (HL=10.1, P=0.43) but not in women (HL=21.4, P=0.01). The discrimination was quite similar to the development cohort in both sexes (ROC area=80% in men, ROC area=78% in women).


CONCLUSIONS
The comorbidity index has good calibration and discrimination and was successfully validated in a different population-based cohort among men but not among women.
Rius
Cristina
C
Public Health Agency of Barcelona, Epidemiology Service, Plaça Lesseps, 1. 08023 Barcelona, Spain. 32284mrg@comb.es
Pérez
Glòria
G
Rodríguez-Sanz
Maica
M
Fernàndez
Esteve
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000401:mortality*; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012720:Severity of Illness Index; D012737:Sex Factors