Effects of policy interventions on psychotropic polypharmacy in Japanese older adults

Psychotropic polypharmacy is a significant health concern, particularly among older adults, due to adverse event risks.1 In Japan, policy interventions aimed at correcting psychotropic polypharmacy have been implemented (Table S1).2 The 2012 policy intervention reduced psychiatry-related reimbursement for prescribing ≥3 hypnotics or anxiolytics in one prescription. Subsequently, the 2014 policy intervention reduced reimbursement related to all departments prescribing ≥3 hypnotics or anxiolytics or ≥4 antidepressants or antipsychotics. In addition, the 2016 policy interventions reduced reimbursement for prescribing ≥3 antidepressants or antipsychotics. Furthermore, the 2018 policy interventions reduced reimbursement for ≥4 hypnotics and anxiolytics and >12 months of benzodiazepine anxiolytics and hypnotics prescription of the same dosage and regimen. Our previous study reported that the 2014 policy intervention led to reductions in polypharmacy of three or more for each psychotropic.3 However, the effects of the policy interventions on older adults remain unclear because our previous study analysed the Japan Medical Data Center (JMDC) database information of insureds and their dependents under the age of 75 years. The insureds are mainly company employees and are not included in the JMDC database when they retire. Therefore, the JMDC database has few older members.3 Compared with younger individuals, older adults are more susceptible to adverse health events4-6; assessing the effects of Japanese policy interventions aimed for this demographic population to accurately evaluate their impact is crucial. Therefore, we conducted a cross-sectional study to examine the effects of the Japanese policy interventions implemented in 2014, 2016, and 2018 on psychotropics polypharmacy among Japanese older adults using the DeSC database (DeSC Healthcare Inc., Tokyo, Japan). We selected the DeSC database because it includes a large number of older adults aged 75 years and older who are not included in the JMDC database. Prescription data were extracted from the DeSC database of health insurance service subscribers and their families aged 65 years and older in April each year from 2014 to 2021 (Table S2). The proportion of patients prescribed ≥3 psychotropics, ≥ 4 antidepressants and antipsychotics, and ≥4 hypnotics and anxiolytics among those prescribed each psychotropic (polypharmacy rate) every April was calculated by adjusting for the corresponding yearly Japanese Vital Statistics in April by 5-year age groups and sex. The polypharmacy rate was set as the benchmark for policy intervention, as described in our previous study.3 Hypnotics, anxiolytics, antidepressants, and antipsychotics were prescribed to 10.1%–14.0%, 5.9%–10.6%, 2.2%–2.9%, and 2.2%–3.4% of older patients, respectively (Fig. S1). After the 2014 policy intervention, polypharmacy rates decreased for all psychotropics except for ≥4 antidepressants and antipsychotics, which increased slightly, in April 2015 compared with April 2014 (Fig. 1 and Table S3). Since April 2016, polypharmacy rates for ≥4 antidepressants and antipsychotics have remained unchanged. The polypharmacy rates for ≥3 hypnotics, antidepressants, and antipsychotics decreased in April 2017 compared with April 2016 but remained unchanged for ≥3 anxiolytics. Since April 2018, polypharmacy rates for ≥3 hypnotics, ≥ 3 anxiolytics, and ≥4 hypnotics and anxiolytics slightly decreased but remained unchanged for ≥3 antidepressants and antipsychotics. As in our prior study using the JMDC database, the polypharmacy rates for three or more of each psychotropic decreased after the 2014 policy intervention in the older adult population. Interestingly, although this policy intervention targeted ≥4 antidepressants and antipsychotics, the proportion of patients using ≥3 antidepressants and antipsychotics decreased.3 This suggested that the policy intervention was effective in encouraging physicians to improve their prescribing behaviour. However, policy interventions did not reduce extreme polypharmacy with ≥4 antidepressants and antipsychotics. Extreme polypharmacy may be difficult to address using policy interventions alone. In addition, since the policy intervention in 2016, the downward trend in the polypharmacy rates for each psychotropic has generally ceased. Future research is needed to clarify the reasons older patients are prescribed multiple psychotropics, considering the disease or biological factors, physician prescribing attitudes, patient treatment preferences, and sociological factors.7 This study has some limitations. First, because the DeSC database includes reimbursement data from April 2014 onwards, we could not analyse any data prior to that year. Since our previous study showed a decreasing trend in polypharmacy for antidepressants and antipsychotics before 2014, the lower polypharmacy rates observed in this study may not be related to policy interventions.3 Second, because this study examined the total number of psychotropics prescribed to older adults within 1 month, the number of patients who switched medications was estimated to be higher than the actual number of prescribed medications. Third, this study used the DeSC database, which is not population-based. Some insurers were included in the study at only specific times during the study period, so the study population was not consistent throughout the study period. In particular, fewer insurers were included in the DeSC database in 2014 and 2015 than in 2016 and beyond, resulting in fewer subscribers. In addition, this study used data extracted in May 2022; therefore, collecting reimbursement data from all insurers for financial year 2021 was impossible. These situations might have impacted the results (e.g., a temporary increase in polypharmacy of ≥3 hypnotics and antipsychotics from April 2015 to April 2016). Fourth, the coronavirus disease 2020 pandemic may have affected the results of this study. During the pandemic, the number of patients with mental disorders was expected to increase; however, some patients avoided hospital visits. In conclusion, psychotropic polypharmacy among older adults has decreased since the 2014 Japanese policy intervention; however, the downward trend has plateaued. We hope future research will identify factors leading to psychotropic polypharmacy and develop strategies to guide appropriate use of psychotropics. DeSC database in this study was provided by DeSC Healthcare, Inc., under their academic research support program. We would like to thank Editage (www.editage.jp) for English language editing. We would like to thank Miyako Suzuki for her significant contribution to data management in this study. All authors had full access to the data included in the study and take responsibility for the integrity of the data and accuracy of the analyses. All authors made substantial contributions to the conception and design of the study and to the acquisition, analysis, and interpretation of the data. All authors contributed to the drafting and revision of the manuscript for important intellectual content. All authors agree to be accountable for all aspects of this study. This study was supported by an Intramural Research Grant (2-1) for Neurological and Psychiatric Disorders of NCNP. The authors declare that they have no conflicts of interest in the research. This study was approved by the Ethics Committee of the Akita University Graduate School of Medicine and the Faculty of Medicine Ethical Committee for Human Research of the same institution (No. 3085). The need for patient consent was waived due to the retrospective study design using anonymised DeSC data. The data that support the findings of this study are available from the DeSC database, but restrictions apply to the availability of these data. The data were used under licence for the current study, and thus are not publicly available. However, the data are available from the authors upon reasonable request and with permission from the DeSC. Figure S1. Proportion of older Japanese patients prescribed each psychotropic medication. The proportion of patients prescribed each psychotropic medication among the patients every April was calculated by adjusting for the 5-year age groups and sex in the Japanese Vital Statistics. The green, pink, blue, and yellow lines indicate hypnotics, anxiolytics, antidepressants, and antipsychotics, respectively. Table S1. Details of policy interventions aimed at the appropriate use of psychotropic medications. Table S2. Numbers of subscribers aged 65 years or older in April each year. Table S3. Percentages by the number of psychotropic medications among older adults prescribed each psychotropic medication in April each year. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. 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