Associations of drug burden index with falls, general practitioner visits, and mortality in older people

• Published in: Pharmacoepidemiology and drug safety 2014-07, Vol.23 (7), p.753-758
• Main Authors: Nishtala, Prasad S., Narayan, Sujita W., Wang, Ting, Hilmer, Sarah N.
• Format: Article
• Language: English
• Subjects: Accidental Falls - statistics & numerical data; Aged; Biological and medical sciences; Cholinergic Antagonists - administration & dosage; Cholinergic Antagonists - adverse effects; Cholinergic Antagonists - therapeutic use; Clinical trial. Drug monitoring; Cost of Illness; Databases, Factual; Drug Burden Index; Drug therapy; Falls; Female; General pharmacology; General Practitioners - statistics & numerical data; Hospitalization - statistics & numerical data; Humans; Hypnotics and Sedatives - administration & dosage; Hypnotics and Sedatives - adverse effects; Hypnotics and Sedatives - therapeutic use; Incidence; Male; Medical sciences; Mortality; New Zealand; Older people; pharmacoepidemiology; Pharmacology. Drug treatments; Polypharmacy; Practice Guidelines as Topic; Practice Patterns, Physicians' - standards; Proportional Hazards Models; Quality Indicators, Health Care
• ISSN: 1053-8569; 1099-1557
• DOI: 10.1002/pds.3624

ABSTRACT Aim On a population level in people aged ≥65 years old living in New Zealand, the aim of this study is to quantify each individual's cumulative exposure to anticholinergic and sedative medicines using the Drug Burden Index (DBI) and examine the impact of DBI on fall‐related hospitalisations, general practitioner (GP) visits, and all‐cause mortality. Method The study used data extracted from Pharmaceutical Claims Data Mart (2011), National Minimum Data set (2012), Births, Death and Marriages (2012) and GP Visits (2012) for patient demographics, hospitalisations and mortality. Cumulative anticholinergic and sedative exposure was measured using the DBI. Polypharmacy was defined as greater than or equal to five medicines dispensed concurrently at any time during the study period. Results Amongst the study population (n = 537 387; 45% male), 43.22% were exposed to DBI drugs (95% confidence intervals (CIs) = 43.09–43.35). The odds of DBI exposure for individuals with polypharmacy are 4.92 (95%CI = 4.86–4.98) times greater than that for individuals without polypharmacy. DBI drugs were associated with fall‐related hospitalisations (incidence rate ratio (IRR) 1.56, 95%CI = 1.47–1.65) and greater number of GP visits (IRR 1.13, 95%CI = 1.12–1.13). Individuals with DBI > 0 had a 1.29 times higher mortality risk (95%CI = 1.25–1.33). Polypharmacy is also associated with a higher mortality risk with a hazard ratio (HR) of 1.66 (95%CI = 1.59–1.73). Conclusion Polypharmacy and exposure to DBI drugs were independently associated with fall‐related hospitalisations, frequency of GP visits, and risk of mortality. On a population level, DBI may be useful as a quality indicator to guide policy to improve prescribing and optimize clinical outcomes in older people. Copyright © 2014 John Wiley & Sons, Ltd.