The impact of the Christmas holiday effect on interdialytic weight gain in hemodialysis patients: A multicenter observational retrospective cohort study.

Abstract

The 3-day interdialytic interval (IDI) is associated with high interdialytic weight gain (IDWG), but little is known about the effect of public or religious holidays on IDWG. Consequently, we evaluated the impact of the "Christmas holiday effect" on IDWG of hemodialysis patients. A retrospective cohort study of adult hemodialysis patients (over 18 years) was conducted across five dialysis units in Australia. Demographic and clinical data were collected from electronic medical records. IDWG was established for three time points; regular 3-day IDI, 2-day IDI preceding the Christmas holiday and a 3-day IDI that included the Christmas holiday. Paired t-tests and logistic regression were used to compare differences in mean IDWG before and after the Christmas holiday and to examine factors associated with high IDWG, respectively. Two hundred and fifty-two patients, 69% of whom were male, with mean (SD) age of 65.4 ± 15.3 years, were studied. Most had end-stage kidney disease due to diabetes (44%), and they had been on hemodialysis for a median of 25.5 (IQR, 60-10) months. There was a significant increase in absolute IDWG (MD 0.21 kg, 95% CI -0.07 to 0.36; P = 0.004) and relative IDWG (MD 0.3%, 95% CI 0.10-0.40; P = 0.01) after the holiday 3-day IDI compared with the regular 3-day IDI. Older age (OR 0.12; 95% CI 0.02-0.55) and a unit increase in hemoglobin (OR 0.94; 95% CI 0.89-0.99) were associated with lower odds of high relative IDWG while speaking a language other than English increased the odds for high relative IDWG (OR 5.03; 95% CI 1.12-22.65). Absolute and relative IDWG increased significantly after the Christmas holiday. Individualizing dialysis needs may improve outcomes for these patients.