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

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. 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. 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). A new risk scoring system for predicting 15-year mortality was developed. This system may be useful for evaluating HD patients’ prognosis.