Charlson comorbidity index using administrative database in incident PD patients.

AIMS

Mortality risks in ESRD (end stage renal disease) patients are related to comorbid diseases. The Charlson Comorbidity Index (CCI) has been reported to be a strong predictor of survival in incipient ESRD patients. The authors studied the validity of CCI using administrative database according to International Classification of Disease, 10th revision (ICD-10) codes, to devise a more straightforward method of determining CCI than that based on medical records review.

SUBJECTS AND METHODS

Incident peritoneal dialysis patients (N = 134) were enrolled from 1997 through 2007. We compared CCI scored by the administrative database (A-CCI) with CCI scored by medical records review (R-CCI). These CCI scores and patients' outcomes were analyzed.

RESULTS

For all patients, mean A-CCI and R-CCI were 5.3 +/- 2.1 (range 2 - 11) and 5.4 +/- 2.1 (range 2 - 11), respectively. High correlation was found between A-CCI and R-CCI scores (r = 0.88, p < 0.01). The sensitivity of A-CCI was high (0.57 - 1.00) for nine comorbidities, but sensitivities for chronic pulmonary disease and peptic ulcer disease were poor (< 0.50). However, specificity was excellent for most comorbidities. Three comorbidity groups were established by tertile ranking: low comorbidity (score = 2 - 4), moderate comorbidity (score = 5 - 6), and high comorbidity (score = 7-11). The mortality rates were; 7.17, 15.96, and 23.07/100 patient-years by A-CCI, and 6.69, 13.58 and 28.16/100 patient-years by R-CCI, respectively.

CONCLUSION

CCI scores from administrative database using ICD-10 were similar to CCI scores by medical records review. This method is simple and valid to predict the outcomes of incipient PD patients.