A new risk scoring system for prediction of long-term mortality in patients on maintenance hemodialysis

Background: It has been reported that the survival of hemodialysis (HD) patients is poor, and the leading cause of death is cardiovascular disease. To identify high-risk patients and treat them carefully, we developed a scoring system to evaluate their 15-year prognosis in a prospective cohort study. Methods: We analyzed data from 312 and 310 patients to develop and validate the prediction model, respectively. The association of potential risk factors with death was tested by Cox proportional-hazards analysis, and a risk scoring model was developed. Then, the model was validated. Results: Two hundred patients (64.1 %) in the cohort for model development died. Six independent prognostic factors were retained in the final model, and each was assigned a score proportional to its regression coefficient: 65 years or older, 3; diabetic nephropathy, 3; hypotension, 1; pre-HD cardiothoracic ratio ≥50 %, 1; pre-HD BNP ≥250 pg/mL, 1; and pre-HD numbers of abnormal findings on electrocardiograms = 0, 1, 2, or larger, 0, 1, 5. The patients were categorized as follows with their scores: group 1 (low risk), 0; group 2, 1 to 3; group 3, 4 to 5; and group 4 (high risk), 6 and higher. In the cohort for model validation, groups 2 to 4 showed a higher risk than group 1: group 2, hazard ratio 4.66 (95 % confidence interval 2.25, 9.64); group 3, 13.62 (6.48, 28.63); and group 4, 20.86 (9.60, 45.31). Conclusions: A new risk scoring system for predicting 15-year mortality was developed. This system may be useful for evaluating HD patients’ prognosis.