Seasonal variation in emergent hemodialysis initiation in the late elderly: A single-center study

The number of new dialysis patients, particularly among the elderly population, has been globally increasing. In Japan, patients aged ≥65 years and ≥75 years comprised 72% and 45% of patients on dialysis in 2018, respectively. Few studies have reported seasonal variations in the initiation of dialysis. We investigated the seasonal prevalence of the emergent hemodialysis initiation in the elderly.

We reviewed 479 elderly patients who initiated hemodialysis between January 2006 and December 2018. Early elderly patients were defined as patients aged between 65 and 74 years, and late elderly patients were defined as those aged ≥75 years. Emergent hemodialysis initiation was defined as initiation with a temporary vascular catheter without elective permanent vascular access or unplanned hemodialysis initiation due to patients requiring critical care regardless of elective permanent vascular access. The information collected included age, sex, and details of the initiation of hemodialysis.

The early elderly group consisted of 199 patients, and the late elderly group consisted of 279 patients. In the late elderly group, hemodialysis initiation was most frequent in winter, followed by spring, autumn, and summer (p = 0.018). Moreover, emergent hemodialysis initiation was most frequent in winter, followed by spring, autumn, and summer (p = 0.009). Emergent hemodialysis initiation due to fluid overload was most frequent in winter, followed by autumn, spring, and summer (p < 0.001). Among late elderly patients who initiated hemodialysis, 78% did not have permanent hemodialysis access at the time of the initiation of hemodialysis.

In the late elderly group, hemodialysis initiation and emergent hemodialysis initiation were significantly more frequent in the winter than in the remaining seasons. In addition, emergent hemodialysis initiation due to fluid overload was most frequent in winter in the late elderly group.