To the Editor: Dr Bliwise and colleagues1 found that patients who received dialysis in the
morning had lower mortality rates than those who received dialysis in the
afternoon. My clinical experiences suggest an explanation. I have noticed
that dialysis times are not assigned randomly. Priority assignment for morning
dialysis often goes to patients who can return to their previous employment.
Bliwise et al, however, do not provide occupational histories for these patients.
Perhaps patients who cannot return to work are sicker and therefore have decreased
survival. Also, patients most recently starting maintenance hemodialysis frequently
are assigned to the afternoon or evening dialysis slots because there may
not be available times in the morning period. Recent onset of hemodialysis
may be a marker for patients who were recently hospitalized and have comorbid
conditions that independently increase the risk of mortality.
Oserman S. Does Time of Day of Hemodialysis Affect Survival?. JAMA. 2002;287(10):1262-1264. doi:10-1001/pubs.JAMA-ISSN-0098-7484-287-10-jlt0313