The Effects of Survival Predictors before Hemodialysis Initiation is Different in Adults and the Elderly

Background The aim of this study is to investigate the effects of the risk markers of sex, education, marital status, nephrology referral, and progression of comorbid conditions before hemodialysis (HD) on the survival of incident HD patients in different age groups. Methods A total of 7729 incident HD patients were recruited in this retrospective cohort study in 2006 and followed up to the end of 2007. Patients were divided according to their age, being classified as Adult (18-64 years), Young Elderly (65-74 years), or Old Elderly ≥ 75 years. The progressive Romano-Charlson Comorbidity Index (CCIp) was used to predict survival outcomes, CCIp = CCI_-1-CCI_-3, where CCI_-1 and CCI_-3 are the CCI scores in the 1^st year and 3^rd year before HD initiation, respectively. The Cox regression model was used to analyze the associated factors of survival. Results Male patients were found to have a higher risk of mortality than females in each age group. Education ≤ 6 years was an independent risk marker for mortality in the Adult group. The effect of marital status and early nephrology referral on survival was more significant in the elderly groups. The CCIp and CCI₃ ≤ 3 were independent risk markers for mortality in each group. The CCIp was a more valuable predictor of survival in adults than in elderly HD patients. Conclusion The effects of sex, education, marital status, early nephrology referral, and severity of CCI_-3 and CCIp before HD initiation on patient survival vary in different age groups.