Abstract
Background and Aims
Dialysis patients are often prescribed a large number of medications to improve metabolic control and manage co-existing comorbidities. However, several studies suggest that a large number of medications can also detrimentally affect their health-related quality of life (HRQoL). Therefore, this study aims to provide insight in the association between the number of medications and various aspects of HRQoL in dialysis patients.
Method
A multicentre study was conducted among dialysis patients from Dutch dialysis centres three months after initiation of dialysis as part of the ongoing prospective DOMESTICO study. The number of medications, defined as the number of concomitantly prescribed types of drugs, was obtained from electronic patient records. Primary outcome was HRQoL measured with the Physical Component Summary (PCS) score and Mental Component Summary (MCS) score (range 0-100) of the Short Form 12. Secondary outcomes were number of symptoms (range 0-30) measured with the Dialysis Symptoms Index and self-rated health (range 0-100) measured with the visual analogue scale of the EuroQol-5D-5L. Data were analysed using linear regression and adjusted for possible confounders, including age, sex, dialysis modality, and comorbidity. Analyses for MCS and number of symptoms were performed after categorising patients in tertiles according to their number of medications because assumptions of linearity were violated for these outcomes.
Results
A total of 162 patients were included. Mean age of patients was 58 ± 17 years, 35% were female, and 80% underwent haemodialysis. The mean number of medications was 12.2 ± 4.5. Mean PCS and MCS were 36.6 ± 10.2 and 46.8 ± 10.0, respectively. The mean number of symptoms was 12.3 ± 6.9 and mean self-rated health 60.1 ± 20.6. In adjusted analyses, PCS was 0.6 point lower for each additional medication (95%CI -0.9 – -0.2; p=0.002). MCS was 4.9 point lower (95%CI -8.8 – -1.0; p=0.01) and 1.0 point lower (95%CI -5.1 – 3.1; p=0.63) for the highest and middle tertiles of medications, respectively, compared to the lowest tertile. Patients in the highest tertile of medications reported 4.1 more symptoms compared to the lowest tertile (95%CI 1.5 – 6.6; p=0.002) but no significant difference in the number of symptoms was observed between the middle and lowest tertile. Self-rated health was 1.5 point lower for each medication (95%CI -2.2 – -0.7; p<0.001).
Conclusion
After adjustment for comorbidity and other confounders, a higher number of medications was associated with a lower PCS, MCS, and self-rated health in dialysis patients and with more symptoms. This suggests that it may be relevant to weigh expected therapeutic benefits of medication against their possible harmful effects on HRQoL. An unfavourable balance between expected benefits and impact on HRQoL might be ground to deviate from clinical guidelines, especially for patients with a limited life-expectancy and for whom a kidney transplant is unattainable.
Health-related quality of life among dialysis patients on three continents: The Dialysis Outcomes and Practice Patterns Study
