Antipsychotic use and related factors among people with dementia aged 75 years or older in <scp>J</scp> apan: <scp>A</scp> comprehensive population‐based estimation using medical and long‐term care data

Objectives Antipsychotics are used to manage the behavioral and psychological symptoms of dementia (BPSD), despite their association with greater risks for mortality and cerebrovascular events. Previous studies in Japan have estimated the prevalence of antipsychotics among older adults who took antidementia drugs. Using long-term care (LTC) data, we aimed to obtain more accurate estimates of the prevalence of antipsychotics and to determine factors related to their use in older adults with dementia. Methods Medical and LTC claims data and LTC certification data between April 2012 and September 2013 were obtained from a middle-sized suburban city. The 1-year prevalence of antipsychotic use was estimated among individuals with probable dementia aged greater than or equal to 75 years who were prescribed antidementia drugs and/or had dementia based on LTC needs certification data. Results Of 25 919 participants, 4865 had probable dementia and 1506 were prescribed antidementia drugs. The prevalence of antipsychotics among participants with probable dementia was 10.7%, which was lower than that in those who were prescribed antidementia drugs (16.4%). Among participants with probable dementia with LTC certification data available (N = 4419), lower cognitive function (vs mild; adjusted odds ratio 2.16, 95% confidence interval 1.63-2.86), antidementia drug use (2.27, 1.84-2.81), and institutional LTC services use (2.34, 1.85-2.97) were associated with greater odds of antipsychotic use, whereas older age (greater than or equal to 92 years) was associated with lower odds (vs less than 77 years; 0.42, 0.27-0.65). Conclusions These findings may be useful for estimating the burden of BPSD and for taking measures to reduce inappropriate antipsychotic prescription.