Background and purpose: A low concentration of albumin is a predictor of mortality in end-stage renal disease. The aim of this study was to assess the factors influencing albumin serum amongst hemodialysis patients using random effects model.

Materials and methods: In a retrospective cohort study, 297 hemodialysis patients (137 women and 160 men, mean age: 58.3 ± 15.86 and 59.1± 17.80 years, respectively) were randomly selected from Shahid Beheshti Medical Center in Babol, Iran, during 2007- 2013. Data was collected from patients' files and blood serum albumin level was considered as a response variable. Explanatory variables included sex, age, education level, marital status, smoking history, cause of kidney disease, history of cardiovascular disease, and age at diagnosis. Random effects model was applied to investigate the factors influencing the level of blood albumin using R software.

Results: The highest levels of albumin were found in patients who were under dialysis due to diabetes (70.2%). The random effect model showed that weight (P<0.001), age of diagnosis (P=0.012), sex (P<0.001), marital status (P=0.034), and time trend (P=0.004) had significant effects on serum albumin concentration.

Conclusion: According to this study, level of albumin serum was associated with individual characteristics such as weight, age of diagnosis, sex, marital status, and time trend. Applying random effects model could give more accurate estimates of the factors affecting the level of albumin, thereby, providing a better understanding of the state of disease.