Incidence, prevalence and prescription patterns of antipsychotic medications use in Asia and US: A cross-nation comparison with common data model.

The use of antipsychotic medications (APMs) could be different among countries due to availability, approved indications, characteristics and clinical practice. However, there is limited literature providing comparisons of APMs use among countries. To examine trends in antipsychotic prescribing in Taiwan, Hong Kong, Japan, and the United States, we conducted a cross-national study from 2002 to 2014 b y using the distributed network approach with common data model. We included all patients who had at least a record of antipsychotic prescription in this study, and defined patients without previous exposure of antipsychotics for 6 months before the index date as new users for incidence estimation. We calculated the incidence, prevalence, and prescription rate of each medication by calendar year. Among older patients, sulpiride was the most incident [incidence rate (IR) 11.0-23.3) and prevalent [prevalence rate (PR) 11.9-14.3) APM in Taiwan, and most prevalent (PR 2.5-3.9) in Japan. Quetiapine and haloperidol were most common in the United States (IR 8.1-9.5; PR 18.0-18.4) and Hong Kong (PR 8.8-13.7; PR 10.6-12.7), respectively. The trend of quetiapine use was increasing in Taiwan, Hong Kong and the United States. As compared to older patients, the younger patients had more propensity to be prescribed second-generation APM for treatment in four countries. Trends in antipsychotic prescribing varied among countries. Quetiapine use was most prevalent in the United States and increasing in Taiwan and Hong Kong. The increasing use of quetiapine in the elderly patients might be due to its safety profile compared to other APMs.

Penetration of new antidiabetic medications in East Asian countries and the United States: A cross-national comparative study.

BACKGROUND: The number of patients with diabetes is increasing particularly in Asia-Pacific region. Many of them are treated with antidiabetics. As the basis of the studies on the benefit and harm of antidiabetic drugs in the region, the information on patterns of market penetration of new classes of antidiabetic medications is important in providing context for subsequent research and analyzing and interpreting results. METHODS: We compared penetration patterns of dipeptidyl peptidase-4 (DPP-4) inhibitors in Taiwan, Hong Kong, Japan, and the United States. We used the Taiwan National Health Insurance Research Database, a random sample of the Hong Kong Clinical Data Analysis and Reporting System, the Japan Medical Data Center database, and a 5% random sample of the US Medicare database converted to the Observational Medical Outcomes Partnership's Common Data Model to identify new users of oral antidiabetic medications. We standardized prevalence and incidence rates of medication use by age and sex to those in the 2010 Taiwanese population. We compared age, sex, comorbid conditions, and concurrent medications between new users of DPP-4 inhibitors and biguanides. RESULTS: Use of DPP-4 inhibitors 1 year after market entry was highest in Japan and lowest in Hong Kong. New users had more heart failure, hyperlipidemia, and renal failure than biguanide users in Taiwan, Hong Kong, and the United States while the proportions were similar in Japan. In a country with low penetration of DPP-4 inhibitors (eg, Hong Kong), users had diabetes with multiple comorbid conditions compared with biguanidine users. In a country with high penetration (eg, Japan), the proportion of users with comorbid conditions was similar to that of biguanide users. CONCLUSIONS: We observed a marked difference of the penetration patterns of newly marketed antidiabetics in different countries in Asia. Those results will provide the basic information useful in the future studies.

The use of anticoagulants in patients with non-valvular atrial fibrillation between 2005 and 2014: A drug utilization study using claims data in Japan.

BACKGROUND: Anticoagulant therapy is recommended in patients with atrial fibrillation (AF) but remains underused. The proper use of anticoagulants has been encouraged in guidelines frequently published over the past two decades. MATERIALS AND METHODS: In this study, we used insurance claims data collected from 2005 to 2014 to investigate the prevalence and incidence of non-valvular AF (NVAF) patients aged 20 to 74 years standardized to the Japanese population in 2012 and subdivided by stroke prevention drug type. We estimated the frequency of coagulation monitoring in patients with incident NVAF undergoing warfarin therapy in 2011 and later. RESULTS: From 2005 to 2014, the standardized prevalence of NVAF increased from 117/100,000 to 278/100,000 and the proportion of anticoagulant users increased from 38.4% to 58.0%, while that of antiplatelet monotherapy decreased from 32.3% to 12.0%. The standardized incidence of NVAF was stable at ~40/100,000 patient-years. The proportion of those patients who started anticoagulant soon after the initial diagnosis increased from 19.9% to 49.1% from 2006 to 2013. Among patients who started warfarin, switchers to DOAC had more frequent coagulation monitoring than non-switchers. CONCLUSION: The use of anticoagulant therapy has gradually increased in patients with NVAF in Japan during the study period from 2005 to 2014.

Applying a common data model to Asian databases for multinational pharmacoepidemiologic studies: opportunities and challenges.

OBJECTIVE: The goal of the Asian Pharmacoepidemiology Network is to study the effectiveness and safety of medications commonly used in Asia using databases from individual Asian countries. An efficient infrastructure to support multinational pharmacoepidemiologic studies is critical to this effort. STUDY DESIGN AND SETTING: We converted data from the Japan Medical Data Center database, Taiwan's National Health Insurance Research Database, Hong Kong's Clinical Data Analysis and Reporting System, South Korea's Ajou University School of Medicine database, and the US Medicare 5% sample to the Observational Medical Outcome Partnership common data model (CDM). RESULTS: We completed and documented the process for the CDM conversion. The coordinating center and participating sites reviewed the documents and refined the conversions based on the comments. The time required to convert data to the CDM varied widely across sites and included conversion to standard terminology codes and refinements of the conversion based on reviews. We mapped 97.2%, 86.7%, 92.6%, and 80.1% of domestic drug codes from the USA, Taiwan, Hong Kong, and Korea to RxNorm, respectively. The mapping rate from Japanese domestic drug codes to RxNorm (70.7%) was lower than from other countries, and we mapped remaining unmapped drugs to Anatomical Therapeutic Chemical Classification System codes. Because the native databases used international procedure coding systems for which mapping tables have been established, we were able to map >90% of diagnosis and procedure codes to standard terminology codes. CONCLUSION: The CDM established the foundation and reinforced collaboration for multinational pharmacoepidemiologic studies in Asia. Mapping of terminology codes was the greatest challenge, because of differences in health systems, cultures, and coding systems.

Epidemiology of psoriasis and palmoplantar pustulosis: a nationwide study using the Japanese national claims database.

OBJECTIVE: The primary objective was to estimate the national prevalence of psoriasis and palmoplantar pustulosis (PPP) in Japan. Secondary objectives were to determine (1) whether psoriasis and PPP disease activity varies by season, and (2) whether disease severity is associated with concurrent diabetes mellitus, hyperlipidaemia and hypertension. SETTINGS: Patients with a psoriasis or PPP diagnosis code between April 2010 and March 2011 were identified using a Japanese national database. PARTICIPANTS: 565 903 patients with psoriasis or PPP were identified. No patient was excluded. PRIMARY AND SECONDARY OUTCOME MEASURES: National prevalence was calculated using census data. We estimated the difference in the proportion of patients who used healthcare services, as a proxy for disease activity, between the hot and cold seasons and the difference in the standardised prevalence of comorbidities between severe and mild disease. The measures were estimated separately for the two broad disease categories of psoriasis and PPP but not in all patients as planned because the two disease categories had major differences. RESULTS: The national prevalence of psoriasis and PPP was 0.34% (95% CI 0.34% to 0.34%) and 0.12% (0.12% to 0.12%), respectively. The difference in the proportion of patients who used healthcare services in the hot compared to the cold season was -0.3% (-0.5% to -0.1%) for psoriasis and 10.0% (9.8% to 10.3%) for PPP. The difference in the standardised prevalence between severe and mild psoriasis was 3.1% (2.7% to 3.4%), 3.2% (2.8% to 3.6%) and 5.1% (4.7% to 5.6%) for concurrent diabetes mellitus, hyperlipidaemia and hypertension, respectively. No significant difference in the prevalence of comorbidity was observed for PPP. CONCLUSIONS: The national prevalence, seasonal variation in disease activity and prevalence of comorbidities in Japanese patients with psoriasis and PPP estimated in this descriptive study may be used as basic information for future studies.

Ex-drinking may be a surrogate for unmeasured risk factors for upper gastrointestinal bleeding: reappraisal and an additional survey of subjects from a case-control study in Japan.

In our recent case-control study on the association between non-steroidal anti-inflammatory drugs (NSAIDs) and upper gastrointestinal bleeding (UGIB), the risk of UGIB was higher in non-drinkers than in heavy-drinkers. To explore this unexpected finding, we re-analyzed the data to test whether non-drinking represented risk factors for UGIB and also conducted an additional survey to find any disagreement with the original study that might suggest information bias. In the re-analysis, we estimated odds ratios (ORs) of UGIB by classifying 183 non-drinkers in the original study into 39 ex- and 144 never-drinkers. We also measured the prevalence of potential risk factors of UGIB in controls. In the new survey, we sent a self-administered questionnaire on previous alcohol consumption. In the re-analysis, the OR for ex-drinking (5.4) was higher and the OR for never-drinking (2.6) was lower than the OR for non- (ex- plus never-) drinking (3.2) in the original study. Ex-drinkers had higher prevalence of H. pylori infection, history of previous ulcer and use of GI drugs than other types of drinkers. The answers on their previous alcohol consumption were consistent between the original and new surveys both in cases (kappa = 0.74) and controls (kappa = 0.73). Ex-drinking may represent unmeasured risk factors for UGIB such as undiagnosed ulcer. In an observational study of UGIB, ex-drinking may be distinguished from never-drinking as a potential surrogate for UGIB risk. When prescribing an NSAID to an ex-drinker in clinical practice, one may make sure to explore whether an ex-drinker has a history of ulcer.

Hypertension management in diabetic patients: prescribing trends from 1999 to 2005 in three Japanese university hospitals.

PURPOSE: In hypertensive patients with diabetes, antihypertensive therapy is important in reducing the risk of macro- and microvascular complications. In contrast to the guidelines issued by the American Diabetes Association (ADA) in and after 2002, the guidelines issued by the Japanese Society of Hypertension (JSH) in 2000 and 2004 maintained the traditional view that beta-blockers and thiazides should be rated as second-line drugs. However, both sets of guidelines recommended angiotensin converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) as first-line agents for such patients. METHODS: We examined the use of antihypertensives in hypertensive patients with and without diabetes using the prescription data for 1999, 2002 and 2005 from three Japanese university hospitals. RESULTS: When compared with 1999, the proportion of patients with and without diabetes using ARBs was dramatically increased in 2005 from 1.5 to 55% and from 1.5 to 40%, while that of angiotensin converting enzyme inhibitors decreased from 52 to 32% and 35 to 23%, respectively. A relatively stable proportion of patients (around 10% with and without diabetes) used beta-blockers and around 60% of patients with and without diabetes used calcium channel blockers (CCBs) and very few (<5%) used thiazides. CONCLUSIONS: The rapid increase in use of ARBs and under-use of thiazides may be explained by the fee schedule in the Japanese health insurance system. The paucity of large-scale clinical trials may also hinder evaluation of the traditional view of the role of beta-blockers and thiazides in treatment of Japanese patients with diabetes.