Background
The Drug Burden Index (DBI) is used as a measure of exposure to medications that are potentially hazardous to older people by virtue of the intrinsic pharmacological characteristics of these drugs. The Life and Living in Advanced Age: a Cohort Study in New Zealand (LiLACS NZ) has recently studied determinants of healthy ageing: using data from study, researchers investigated if a higher DBI score was associated with poorer outcomes (hospitalisation, falls, mortality and cognitive function and functional status) over a 36-month follow-up period. Data waas separately examined for two groups: Māori (indigenous New Zealanders) aged ≥ 80 years and non-Māori aged 85 years at the time of enrollment. Data relating to regularly prescribed medications at baseline, 12 months and 24 months were used in this study. Those medicines with anticholinergic and/or sedative properties (medications with a DBI > 0) were identified and the DBI calculated for all subjects. Full demographic data were obtained for 671, 510 and 403 subjects at baseline, 12 months and 24 months, respectively, with 31%, 30% and 34% of individuals prescribed a medication with a DBI > 0 at baseline, 12 months and 24 months, respectively. Those from a non-Māori background had a greater mean DBI (0.28 ± 0.5 and 0.27 ± 0.5, respectively) compared to Māori (0.16 ± 0.3 and 0.18 ± 0.5, respectively) at baseline and at 12 months. The most commonly prescribed medicines with a DBI > 0 were zopiclone, doxazosin, amitriptyline and codeine. In Māori, a hiher DBI was significantly associated with a greater risk of mortality: at 36 months follow-up, adjusted hazard ratio [95% confidence interval (CI)] 1.89 (1.11–3.20), p = 0.02. In non-Māori, a higher DBI was significantly associated with a greater risk of mortality [at 12 months follow-up, adjusted hazard ratio (95% CIs) 2.26 (1.09–4.70), p = 0.03] and impaired cognitive function at 24 months follow-up p = 0.02). The authors of the study, published here, suggest that more strategies to reduce prescribing potentially hazardous drugs for older people would be a reasonable strategy to pursue in mitigating the associated risk demonstrated here.