Background: Antipsychotic (AP) polypharmacy (APP), the coprescription of more than 1 AP, is frequently practiced in psychiatric inpatients and is considered to be a risk factor for adverse drug events (ADEs). However, the association between APP and ADEs among psychiatric inpatients has not been well investigated. Methods: The Japan Adverse Drug Events (JADE) study was a series of cohort studies conducted in several clinical settings. In particular, the JADE study for psychiatric inpatients was a retrospective cohort study of 448 psychiatric inpatients with a cumulative 22,733 patient-days. We investigated the relationship between APP, defined as a concurrent prescription of 2 or more APs and ADEs. We also assessed the relationship between potential risk factors for ADEs due to APs. Results: Among the 448 patients included in this study, 106 patients (24%) had APP and the remaining 342 patients were prescribed 1 AP or none. Risperidone was the most frequent drug (25%, 109/442 AP prescriptions) used, and levomepromazine was most frequently prescribed as a concurrent medication with other APs (91%, 29/32). The median number of ADEs among the patients with APP was significantly higher than in those without APP (P = 0.001). Antipsychotic polypharmacy was a risk factor for the occurrence of first (adjusted hazard ratio, 1.54; 95% confidence interval, 1.15–2.04) and second (adjusted hazard ratio, 1.99; 95% confidence interval, 1.40–2.79) ADEs. Conclusions: Antipsychotic polypharmacy was a risk factor for the occurrence of single and multiple ADEs. Antipsychotic polypharmacy should be conservatively and minimally practiced.

Background Worldwide, the emergence of super-ageing societies has increased the number of older people requiring support for daily activities. Many elderly residents of nursing homes (NHs) take drugs to treat chronic conditions; however, there are few reports of medication safety in NHs, especially from non-western countries. Objective We examined the incidence and nature of adverse drug events (ADEs) and medication errors (MEs) in NHs for the elderly in Japan. Design, setting, and participants The Japan Adverse Drug Events Study for NHs is a prospective cohort study that was conducted among all residents, except for short-term admissions, at four NHs for older people in Japan for 1 year. Measurements Trained physicians and psychologists, five and six in number, respectively, reviewed all charts of the residents to identify suspected ADEs and MEs, which were then classified by the physicians into ADEs, potential ADEs and other MEs after the exclusion of ineligible events, for the assessment of their severity and preventability. The kappa score for presence of an ADE and preventability were 0.89 and 0.79, respectively. Results We enrolled 459 residents, and this yielded 3315 resident-months of observation time. We identified 1207 ADEs and 600 MEs (incidence: 36.4 and 18.1 per 100 resident-months, respectively) during the study period. About one-third of ADEs were preventable, and MEs were most frequently observed in the monitoring stage (72%, 433/600), with 71% of the MEs occurring due to inadequate observation following the physician’s prescription. Conclusion In Japan, ADEs and MEs are common among elderly residents of NHs. The assessment and appropriate adjustment of medication preadmission and postadmission to NHs are needed to improve medication safety, especially when a single physician is responsible for prescribing most medications for the residents, as is usually the case in Japan.

Knowledge of the epidemiology of adverse drug events (ADEs) and medication errors in psychiatric inpatients is limited outside Western countries. The nature of ADEs and medication errors are important for improving the quality of care worldwide; therefore, we conducted the Japan Adverse Drug Events Study, a series of cohort studies at several settings in Japan. This report included 448 inpatients with 22,733 patient-days in a psychiatric hospital and psychiatric units at a tertiary care teaching hospital over 1 year. Four psychiatrists and two other physicians reviewed all medical charts and related documents to identify suspected incidents. The physicians later classified those incidents into ADEs, potential ADEs, medication errors, or exclusions and evaluated the severity and preventability if the incidents were events. During the study period, we identified 955 ADEs and 398 medication errors (incidence: 42.0 and 17.5 per 1000 patient-days, respectively). Among ADEs, 1.4 %, 28 %, and 71 % were life-threatening, serious, and significant, respectively. Antipsychotics were associated with half of all ADEs. The incidence of medication errors was higher in medical care units than in acute and nursing care units (40.9, 15.6, and 17.4 per 1000 patient-days, respectively). The monitoring and ordering stages were the most common error stages (39 % and 34 % of all medication errors, respectively), and 76 % of medication errors with ADEs were found at the monitoring stage. Non-psychiatric drugs were three times as likely to cause ADEs with errors compared to psychiatric drugs. Antipsychotic use, inadequate monitoring, and treatment of physical ailments by psychiatrists may contribute to the high incidence of medication errors and ADEs among psychiatric inpatients in Japan. Psychiatrists should be cautious in prescribing antipsychotics or unfamiliar medications for physical problems in their psychiatric patients, and should monitor patients after medication administration.

Several studies have investigated the association between benzodiazepine receptor agonist (BZDRA) use during the perioperative period and an elevated incidence of delirium. However, no study has focused on the time course of BZDRA use, including continuation, discontinuation, initiation, and no use. This study aimed to examine the influence of the time course of BZDRA use on post-operative delirium. This retrospective cohort study was conducted by reviewing medical records. We included patients who were scheduled for surgery under general anesthesia and had been referred to a liaison psychiatrist for pre-operative psychiatric assessment. The patients were classified into four groups based on the pre- and post-operative time course of oral BZDRA use, as follows: continuation, discontinuation, initiation, and no use (never used). The primary outcome was the prevalence of post-operative delirium in non-intensive care unit settings. We also performed stratified analyses according to age, the presence of cognitive impairment, the presence of delirium history, and antipsychotic drug use on admission. Among 250 patients, 78 (31%) developed post-operative delirium. The Discontinuation group had a higher rate of delirium (49%, 24/49) than the other groups (Continuation [14%, 4/29]; Initiation [38%, 3/8], Never used [29%, 47/164], p = 0.008). Abrupt discontinuation of BZDRAs during the perioperative period may be a risk factor for post-operative delirium and should therefore be avoided.

Medication use can increase the risk of falls and injuries in nursing homes, creating a significant risk for residents. We performed a retrospective cohort study over one year to identify the incidence of drug-related falls with and without injury among four Japanese nursing homes with 280 beds. We evaluated the relationship between potential risk factors for falls and fall-related injuries while considering well-known risks such as ADLs and chronic comorbidities. By collaboratively reviewing care records, we enrolled 459 residents (mean age, 87) and identified 645 falls, including 146 injurious falls and 16 severe injurious falls requiring inpatient care, incidence: 19.5, 4.4, 0.5 per 100 resident-months, respectively. Medication influenced around three-quarters of all falls, >80% of which were psychotropic drugs. Regularly taking ≥5 medications was a risk factor for the initial falls (HR 1.33: CI 1.00–1.77, p = 0.0048) and injuries after falls (OR 2.41: CI 1.30–4.50, p = 0.006). Our findings on the incidence of falls with and without injury were similar to those in Western countries, where the use of psychotropic medication influenced >50% of falls. Discontinuing unnecessary medication use while simultaneously assessing patient ADLs and comorbidities with physicians and pharmacists may help to avoid falls in nursing homes.

This study aimed to clarify the frequency of perioperative psychiatric symptom worsening among patients with psychiatric disorders and investigate factors predictive of symptom aggravation. This study adopted a retrospective cohort study design. The sample consisted of perioperative inpatients who were diagnosed with psychiatric disorders on admission and received psychiatric intervention between January 1, 2015 and November 31, 2017. Of 176 inpatients who met our inclusion criteria, 15 (8.5%) exhibited symptom worsening. Factors associated with symptom worsening included changes in surface morphology during surgery (p<0.01; odds ratio (OR)=10.58; 95% confidence interval (CI), 3.40-32.87), otolaryngological surgery (p=0.01; OR=6.95; 95% CI, 1.81-26.75), stay in the intensive care unit (p<0.01; OR=5.65; 95% CI, 1.79-17.81), and surgery duration longer than 180min (p=0.03; OR=3.40; 95% CI, 1.04-11.13). This was the first retrospective analysis to focus on the perioperative worsening of psychiatric symptoms. As only few inpatients exhibited symptom aggravation, general hospitals without psychiatric beds can receive perioperative patients with psychiatric comorbidity. However, caution should be exercised to address the potential worsening of symptoms in cases of surface-morphology changing surgery, otolaryngological surgery, long-duration operations, and when ICU stay is required.