Prescribing patterns and medications costs in patients on maintenance hemodialysis and peritoneal dialysis.

Background And Hypothesis: Polypharmacy is a significant clinical issue for patients on dialysis but has been incompletely studied. We investigated the prevalence and costs of polypharmacy in a population-based cohort of participants treated with hemodialysis (HD) or peritoneal dialysis (PD).

Methods: We studied adults aged ≥ 20 years in Alberta, Canada receiving maintenance HD or PD as of March 31, 2019. We characterized participants as users of 0-29 drug categories of interest and those aged ≥ 65 as users/non-users of potentially inappropriate medications (PIM). We calculated the number of drug categories, daily pill burden, total annual cost, and annual cost per participant, and compared this to an age- and sex-matched cohort from the general Alberta population.

Results: Among 2 248 participants (mean age 63 years; 39% female) on HD (n = 1 781) or PD (n = 467), the median number of prescribed drug categories was 6 [interquartile range (IQR) 4, 8]; median daily pill burden was 8.0 (IQR 4.6, 12.6) pills/day, with 5% prescribed ≥ 21.7 pills/day, and 16.5% prescribed ≥ 15 pills/day. Twelve % were prescribed at least one drug that is contraindicated in kidney failure. The median annual per participant cost was ${\$}$3,831, totaling approximately ${\$}$11.6 million annually for all participants. When restricting to the 1 063 participants aged ≥ 65, the median number of PIM categories was 2 (IQR 1, 2), with a median PIM pill burden of 1.2 pills/day (IQR 0.5, 2.4). Compared to PD participants, HD participants had similar daily pill burden, higher use of PIM, and higher annual per participant cost. Pill burden and associated costs for participants on dialysis were more than 3-fold and 10-fold higher, respectively, compared to the matched participants from the general population.

Conclusion: Participants on dialysis have markedly higher use of prescription medications and associated costs than the general population. Effective methods to de-prescribe in the dialysis population are needed.