Determining Some Factors Affecting the Longevity of Hemodialysis Patients. Using Survival Analysis
Abstract Background Dialysis is a method for removing excess fluid and uremic waste from the body of chronic renal-failure patients. In patients with CRF, blood dialysis stops death. Hemodialysis prevents the death of patients with chronic renal failure. Various factors can affect the survival of patients undergoing dialysis treatment. The current study aimed to determine such factors.Methods This descriptive-analytic study examined 252 patients undergoing dialysis from 2010 to 2016 in all of hospitals in Bandar Abbas- Iran, whose data had been recorded in the dialysis unit or it was possible to get their files. The study used Lasso Regression in Cox's proportional hazards model in case with multi variables, background diseases, Body Mass Index,…… The collected data was analyzed using SPSS software and through installing glmnet and survival packages in R software.Results In this study, 35 (13.9%) death events and 217 (86.1%) censored events were observed. The mean survival time of 252 patients was equal to 10.93 ± 7.82 years and the median survival time of these patients was calculated to be ten years. Based on the results of the Cox model under the penalized method of Lasso, The risk of mortality for patients with diploma degree was by 49% lower than that of the illiterate group (HR = 0.51). The risk of death for unemployed patients and farmers was equal to 0.66 (HR = 1.66) and 0.29 (HR = 1.29), respectively, higher than that of employees. Another significant factor in this study is the duration of each dialysis session. The risk of mortality has been reduced by 0.34 (HR = 0.66) for a single increase during dialysis.Conclusions Apart from congenital and underlying diseases which early diagnosis will prevent kidney failure, the risk of mortality will be reduced by training behavioral issues in patients undergoing dialysis such as dialysis at predetermined hours and times and appropriate nutritional behaviors.