Prescribing patterns and medication costs in patients on maintenance haemodialysis and peritoneal dialysis.

Abstract

Background: 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 haemodialysis (HD) or peritoneal dialysis (PD).

Methods: We studied adults ≥20 years of age in Alberta, Canada receiving maintenance HD or PD as of 31 March 2019. We characterized participants as users of 0-29 drug categories of interest and those ≥65 years of age as users/non-users of potentially inappropriate medications (PIMs). 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 2248 participants (mean age 63 years; 39% female) on HD (n = 1781) or PD (n = 467), the median number of prescribed drug categories was 6 [interquartile range (IQR) 4-8] and the median daily pill burden was 8.0 (IQR 4.6-12.6), with 5% prescribed ≥21.7 pills/day and 16.5% prescribed ≥15 pills/day. Twelve percent were prescribed at least one drug that is contraindicated in kidney failure. The median annual per-participant cost was ${\$}$3831, totalling ≈${\$}$11.6 million annually for all participants. When restricting to the 1063 participants ≥65 years of age, 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 with PD participants, HD participants had a similar daily pill burden, higher use of PIMs and higher annual per-participant cost. Pill burden and associated costs for participants on dialysis were >3-fold and 10-fold higher, respectively, compared with 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.