Abstract: FR-PO930

Polypharmacy and Outcomes in Older Dialysis Patients

Session Information

  • Geriatric Nephrology
    November 03, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Geriatric Nephrology

  • 901 Geriatric Nephrology

Authors

  • Samaranayaka, Sashika, University of Otago, Dunedin, New Zealand
  • Walker, Robert J., University of Otago, Dunedin, New Zealand
  • Samaranayaka, Ari, University of Otago, Dunedin, New Zealand
  • Derrett, Sarah, University of Otago, Dunedin, New Zealand
  • Schollum, John B.W., Dunedin Hospital, Dunedin, New Zealand
Background

The impact of polypharmacy on patients with end stage kidney disease (ESKD) and associated comorbidities is uncertain since a direct causation cannot be determined. More medications could be an indicator of more complex patients with a higher risk of poor health outcomes, regardless of polypharmacy. This study investigated the association between polypharmacy, comorbidities and patients’ health outcomes as measured by hospital admissions and mortality in a cohort of ESKD patients ≥65 years

Methods

225 participants aged ≥ 65 years, either already on dialysis or eligible for dialysis (eGFR<15 ml/mn/1.73m2) were recruited and followed for 3 years1. Individual medications and the number of ‘medication groups’ (by therapeutic indication) per person were recorded at baseline. Hospitalisation, irrespective of cause, was measured as the number of days per person per 12 month follow up. Comorbidities were dichotomised to 0-2 and ≥3. Negative Binomial (NB) regression and Modified Poisson regression were used to assess associations medication had with hospitalisation rate and mortality respectively, first at univariate level, then after adjusting for confounders including comorbidities.

Results

Individual medications ranged from 2 to 20 (IQR 8 to 12) while the medication groups ranged from 2 to 15 (IQR 6 to 10).Most participants (83.5%) took between 3-8 ‘medication groups’. The most common ‘medication groups’ were metabolic bone disease related (87%), haemotenics (76%), cholesterol management (66%) and antithrombotics (65%). There was a significant increase in hospitalisation rates for each increase in medication group (RR 1.12, 95% CI: 1.02-1.23). Univariate analysis showed an 8% increase in the risk of mortality with each medication (RR 1.08, 95th CI 1.05-1.11) and an 11% increase in risk of mortality with each increase in ‘medication group’ (RR 1.11, 95% CI 1.09-1.13). Similarly, multivariate analysis showed an increase in individual medications increased the risk of death by 8% (RR= 1.08, 95% CI: 1.07-1.09) and each individual ‘medication group’ by 11% (RR= 1.11, 95% CI: 1.09-1.12)

Conclusion

In this high risk population, who may require polypharmacy, polypharmacy is also an indicator of increased risk of hospitalisation and mortality in those with ESKD ≥65 years.
1. Walker et al. BMC Nephrology 2013, 14:175