SP206POLYPHARMACY IN THE ELDERLY IS ASSOCIATED WITH INCREASED MORTALITY AND ACUTE KIDNEY INJURY

Abstract

Introduction and Aims: In older people anti-hypertensive and other medications can cause adverse effects which are often related to hypotension. To describe the incidence of hypotension in the elderly (Over 70) and explore its association with adverse events including acute kidney injury and death. Methods: Using data extracted from primary care databases by an automated Clinical Advisory System, data from 29 General practice surgeries were analysed including a population of approximately 200,000. Inclusion criteria were: patients with a valid serum creatinine test, a BP measurement between 01/04/11 and 01/01/12 and aged over 70 years at first screening. Ethical approval had previously been sought to extract anonymous patient data from primary care practices. Approval was subsequently sought to reanalyse the dataset for the purposes of this study. Results: 11,160 patients over 70 years old were analysed, 6369 (57%) were female. 128 people had a systolic blood pressure of less than 100mmHg (89, 70% were taking anti-hypertensive medication), 346 people had systolic BP 100-109mmHg (223, 64% were taking anti-hypertensive medication), 823 people had a systolic BP of 110-119mmHg (532, 65% were on anti-hypertensive medication). Kaplan-Meyer survival curves indicate survival was reduced in patients with index BP <100mmHg and average (over one year prior to index) systolic BP < 100mmHg; 3.4% died over the one-year of follow-up. Cox regression analysis showed that age, sex, index BP less than 100mmHg and index diagnoses of stroke and heart failure were significant variables associated with mortality. Over one-year's follow-up, 10.6% of patients had an episode of acute kidney injury (AKI) 0.8% had 2 episodes, 0.3% had three episodes. Of the 128 patients with index systolic BP<100mmHg 30 patients (23%) had an episode of AKI in follow-up compared to 11% in those with systolic BP≥100mmHg (Chi2 20.9, p<0.05). Variables associated with AKI included age, sex, index systolic BP less than 100mmHg, current number of anti-hypertensive groups, and index diagnoses of diabetes, hypertension, stroke, chronic kidney disease (stage 3-5) and heart failure. Of the 44 patients with average BP<100mmHg, 7 (16%) had AKI in follow up. Conclusions: A significant number of elderly patients with hypotension remain on anti-hypertensive medication. Hypotension in the elderly is associated with acute kidney injury and mortality. Medication review and intervention in these groups may reduce the incidence of adverse incidents associated with low blood pressure.