Incidence, prescription patterns and risk factors of antipsychotic initiation in elderly stroke survivors.

OBJECTIVES: Epidemiological data regarding antipsychotic initiation in elderly patients with stroke are limited. We aimed to investigate the incidence, prescription patterns and determinants of antipsychotic initiation in elderly patients with stroke. METHODS: We conducted a retrospective cohort study to identify patients aged above 65 years who had been admitted for stroke from the National Health Insurance Database (NHID). The index date was defined as the discharge date. The incidence and prescription pattern of antipsychotics were estimated using the NHID. To evaluate the determinants of antipsychotic initiation, the cohort identified from the NHID was linked to the Multicenter Stroke Registry (MSR). Demographics, comorbidities and concomitant medications were obtained from the NHID. Information including smoking status, body mass index, stroke severity and disability was retrieved by linking to the MSR. The outcome was antipsychotic initiation after the index date. Hazard ratios for antipsychotic initiation were estimated using the multivariable Cox model. RESULTS: In terms of prognosis, the first 2 months after a stroke was the highest-risk period for antipsychotic use. A high burden of coexisting diseases carried an increased risk of antipsychotic use; in particular, chronic kidney disease (CKD) had the highest adjusted hazard ratio (aHR = 1.73; 95% CI 1.29-2.31) as compared with other risk factors. Furthermore, stroke severity and disability were significant risk factors for antipsychotic initiation. CONCLUSIONS: Our study indicated that elderly stroke patients with chronic medical conditions, particularly CKD, and a higher stroke severity and disability were at greater risk of psychiatric disorders during the first 2 months after a stroke. CLINICAL TRIAL REGISTRATION: NA.

Risk of age-related macular degeneration in aspirin users and non-aspirin users: A population-based cohort study in Taiwan.

BACKGROUND: The association between cardioprotective aspirin and risk of age-related macular degeneration (AMD) is still controversial up to date. We aimed to analyze the risk of AMD between aspirin users and non-aspirin users. METHOD: This was a retrospective cohort study by using claims data from the National Health Insurance Research Database. Patients aged more than 45 years old who initiated aspirin during 2002 to 2012 were followed till 2013. We first selected an age and sex-matched cohort, then identified aspirin users and non-aspirin users as propensity score-matched cohort. Cox proportional hazard regression model was applied to compare their hazards and 95% confidence intervals. Incidence of newly developed AMD, neovascular AMD, and other-AMD was calculated. RESULTS: We identified 204 085 regular aspirin users and 478 048 non-aspirin users from our datasets. The univariate HR was 2.85 (95% CI, 2.75-2.96), and the multivariate HR was 2.54 (95% CI, 2.44-2.65). In the PS-matched cohort, the HR was 2.38 (95% CI, 2.25-2.52). The incidence of aspirin users for AMD risk was 11.95 per 1000 person-year, while the incidence of non-aspirin users was only 3.92 per 1000 person-year. CONCLUSION: Patients with regular use of aspirin had higher risk in developing AMD compared to non-aspirin users and suggest to have regular visual acuity and funduscopic examination.

Not all aspirin products have equivalent antiplatelet efficacy-Aspirin formulated with magnesium stearate is less effective in preventing ischemic stroke.

PURPOSE: Magnesium stearate (MgSt) is a widely used excipient in pharmaceutical formulations but should be avoided in aspirin preparations as it hydrolyzes aspirin. We hypothesized that preparations of aspirin-containing MgSt (MgSt-ASA) are less effective in preventing thrombosis in clinical settings. The risk of composite cardiovascular events in patients treated with MgSt-ASA preparations for preventing secondary stroke was evaluated. METHODS: This retrospective cohort study used Taiwan's claims data from 1997 to 2013. Patients who were discharged after ischemic stroke (IS) and administered with only MgSt-ASA or non-MgSt-ASA preparations were enrolled. Composite events including all-cause mortality, IS hospitalization, and myocardial infarction-related hospitalization in the follow-up period under therapy with MgSt-ASA or non-MgSt-ASA preparations were considered primary outcomes. Hazard ratios (HRs) were adjusted with the baseline comorbidities and medications using the Cox model. RESULTS: A total of 19 500 patients with IS (60% males, average age 67 years) were identified, which included 2064 patients receiving MgSt-ASA treatment initially and 17 436 patients receiving non-MgSt-ASA preparation initially. The crude incidence of composite events was 11.65 per 100 person-years, whereas it was 11.45 and 13.90 per 100 person-years for patients receiving non-MgSt-ASA and MgSt-ASA treatments, respectively. The risk of composite events was higher in patients receiving MgSt-ASA preparations than in those receiving non-MgSt-ASA formulations, with the adjusted HR being 1.23 at 95% confidence interval of 1.02 to 1.47. CONCLUSIONS: MgSt-ASA preparation use was associated with a higher risk of composite events than non-MgSt-ASA preparations. Review of aspirin formulations under regulatory intervention is warranted.

Validation of a novel claims-based stroke severity index in patients with intracerebral hemorrhage.

BACKGROUND: Stroke severity is an important outcome predictor for intracerebral hemorrhage (ICH) but is typically unavailable in administrative claims data. We validated a claims-based stroke severity index (SSI) in patients with ICH in Taiwan. METHODS: Consecutive ICH patients from hospital-based stroke registries were linked with a nationwide claims database. Stroke severity, assessed using the National Institutes of Health Stroke Scale (NIHSS), and functional outcomes, assessed using the modified Rankin Scale (mRS), were obtained from the registries. The SSI was calculated based on billing codes in each patient's claims. We assessed two types of criterion-related validity (concurrent validity and predictive validity) by correlating the SSI with the NIHSS and the mRS. Logistic regression models with or without stroke severity as a continuous covariate were fitted to predict mortality at 3, 6, and 12 months. RESULTS: The concurrent validity of the SSI was established by its significant correlation with the admission NIHSS (r = 0.731; 95% confidence interval [CI], 0.705-0.755), and the predictive validity was verified by its significant correlations with the 3-month (r = 0.696; 95% CI, 0.665-0.724), 6-month (r = 0.685; 95% CI, 0.653-0.715) and 1-year (r = 0.664; 95% CI, 0.622-0.702) mRS. Mortality models with NIHSS had the highest area under the receiver operating characteristic curve, followed by models with SSI and models without any marker of stroke severity. CONCLUSIONS: The SSI appears to be a valid proxy for the NIHSS and an effective adjustment for stroke severity in studies of ICH outcome with administrative claims data.

Brief Report: Databases in the Asia-Pacific Region: The Potential for a Distributed Network Approach.

BACKGROUND: This study describes the availability and characteristics of databases in Asian-Pacific countries and assesses the feasibility of a distributed network approach in the region. METHODS: A web-based survey was conducted among investigators using healthcare databases in the Asia-Pacific countries. Potential survey participants were identified through the Asian Pharmacoepidemiology Network. RESULTS: Investigators from a total of 11 databases participated in the survey. Database sources included four nationwide claims databases from Japan, South Korea, and Taiwan; two nationwide electronic health records from Hong Kong and Singapore; a regional electronic health record from western China; two electronic health records from Thailand; and cancer and stroke registries from Taiwan. CONCLUSIONS: We identified 11 databases with capabilities for distributed network approaches. Many country-specific coding systems and terminologies have been already converted to international coding systems. The harmonization of health expenditure data is a major obstacle for future investigations attempting to evaluate issues related to medical costs.

Medication knowledge to be improved in participants in community universities in Taiwan: Outcome of a nationwide community university program.

BACKGROUND/PURPOSE: To assess knowledge improvement by the participants in a pharmacist-facilitated national community education program over a 4-month semester and to identify the educational needs of adults related to medications. METHODS: This was a single-group, pre- and post-program comparative study. From February 2005 to February 2006, 1983 community residents participating in the education program implemented at 57 community universities nationwide were included. A questionnaire consisting of 50 true/false questions was administered before and after the program to assess the participants' medication knowledge. Paired t test was used to analyze the pre- and post-program differences and generalized linear mixed models were applied to examine the demographic variables that might influence the background knowledge and outcome after adjusting for school effects. RESULTS: A total of 848 participants (42.8%) completed the pre-to-post questionnaire. Baseline medication knowledge was positively correlated with participants' education level and negatively correlated with age. Significant improvement (11.3%, p < 0.001) in medication knowledge was evident at the end of the program. The age and education level were significant determinants in the improvement of the pre-to-post program test score. The specific areas that required improvement most in the knowledge of the participants were: instructions on refill prescriptions, proper storage of medication, the health insurance system, drug use in special populations, and over-the-counter drugs. CONCLUSION: This national program improved participants' medication knowledge over a 4-month period. Patient counseling focusing more on the knowledge deficiency identified in this study during patient care is recommended.

Does renal dysfunction modify the effect of intravenous thrombolysis for acute ischemic stroke within 4.5 hours of onset? A multicenter observational study.

BACKGROUND: About one third of stroke patients have renal dysfunction. Effect of renal dysfunction on outcome of intravenous thrombolysis (IVT) for acute ischemic stroke (AIS) has not been determined in Asia using patients without IVT as comparators. The aim of this study was to examine the interaction between renal dysfunction and IVT on the outcomes in AIS patients admitted within 4.5 hours of onset in a multicenter stroke registry of Taiwan. METHODS: We identified all consecutive AIS patients admitted within 4.5 hours of onset between 2007 and 2013. Renal dysfunction was defined by an estimated glomerular filtration rate less than 60 mL/minute/1.73 m(2) on initial admission. Patients older than 80 years of age and a National Institute of Health Stroke Scale score less than 4 or greater than 25 were excluded. The primary outcome was a modified Rankin Scale score 3-6 at 3 months. We determined the effect of IVT and renal dysfunction on outcome in a multivariate analysis. RESULTS: Of the 929 patients analyzed, 39% had renal dysfunction, and 51% received IVT. Primary outcomes occurred in 45% versus 41% of patients with and without renal dysfunction, respectively, (P = .197). In a multivariate analysis, the odds ratios (95% confidence interval; P value) of IVT and renal dysfunction for primary outcome were .70 (.51-.96; P = .029) and .97 (.71-1.33; P = .865), respectively. No significant interaction was noted between IVT and renal dysfunction (P = .218). CONCLUSIONS: Renal dysfunction did not modify the effect of IVT for AIS and should not be a reason for withholding treatment from otherwise-eligible patients.

Utilization patterns of antihyperuricemic agents following safety announcement on allopurinol and benzbromarone by Taiwan Food and Drug Administration.

OBJECTIVE: The purpose of this study is to evaluate the utilization of four approved antihyperuricemic agents in Taiwan before and after two safety announcements rescinded an indication for allopurinol and added a warning on benzbromarone-induced hepatotoxicity in the year 2005. METHODS: An interrupted time series design and segmented regression models were used to examine impacts of the safety announcements on the utilization of allopurinol, benzbromarone, probenecid, or sulfinpyrazone. All outpatient prescriptions of the four antihyperuricemic agents were extracted from a longitudinal cohort dataset with 1000000 individuals randomly sampled from the National Health Insurance Research Database. We examined utilization patterns of antihyperuricemic agents before and after the policy intervention (i.e., safety announcements and labeling changes of allopurinol and benzbromarone) in the year 2005. RESULTS: Following the safety announcements, there was a reduction in the number of allopurinol users in the first year of intervention (-95.82 users per 100000 persons, 95%CI, [-166.84, -24.80]) and a continuous reduction afterward at a rate of -53.17 per 100000 persons per year. The utilization of benzbromarone grew steadily before 2005 but decreased drastically after the intervention, with a 30.12% reduction in the number of users by the end of year 2008. There was no commensurate change in the number of probenecid or sulfinpyrazone users after the intervention. CONCLUSIONS: Further research is required to evaluate the direct impacts of the safety announcements on clinical outcomes, treatment costs, and patient's quality of life.

Validation of acute myocardial infarction cases in the national health insurance research database in taiwan.

BACKGROUND: The aim of this study was to determine the validity of acute myocardial infarction (AMI) diagnosis coding in the National Health Insurance Research Database (NHIRD) by cross-comparisons of discharge diagnoses listed in the NHIRD with those in the medical records obtained from a medical center in Taiwan. METHODS: This was a cross-sectional study comparing records in the NHIRD and discharge notes in one medical center (DNMC) in the year 2008. Positive predictive values (PPVs) for AMI diagnoses were evaluated by reviewing the relevant clinical and laboratory data recorded in the discharge notes of the medical center. Agreement in comorbidities, cardiac procedures, and antiplatelet agent (aspirin or clopidogrel) prescriptions between the two databases was evaluated. RESULTS: We matched 341 cases of AMI hospitalizations from the two databases, and 338 cases underwent complete chart review. Of these 338 AMI cases, 297 were confirmed with clinical and lab data, which yielded a PPV of 0.88. The consistency rate for coronary intervention, stenting, and antiplatelet prescription at admission was high, yielding a PPV over 0.90. The percentage of consistency in comorbidity diagnoses was 95.9% (324/338) among matched AMI cases. CONCLUSIONS: The NHIRD appears to be a valid resource for population research in cardiovascular diseases.

Disease severity at the first hospitalization as a predictor for mechanical ventilation dependency in elderly patients with chronic obstructive pulmonary disease.

Patients with chronic obstructive pulmonary disease (COPD) are predisposed to respiratory failure with ventilator dependency. This study aims to determine the risk of prolonged mechanical ventilation (PMV), defined as 22 days or more of mechanical ventilation dependency after the first day of hospital admission (index date) in patients diagnosed with COPD. A retrospective cohort was conducted using medical claim data of Taiwan's National Health Insurance Research Database. Eligible study subjects were those who had a diagnosis of COPD made between January 1, 2005 and December 31, 2009. Patients were then followed until being registered as a PMV case, death, or the end of the study. The comorbidities were measured from January 1, 1997 to the index date by the ICD-9 code. The study sample consisted of 6,341 patients with COPD with a mean age of 73.89 (± 12.01) years. Over a maximum of 6 years of follow-up, 654 patients developed PMV dependency, with an incidence density of 41.56 per 1,000 person-years. Patients aged 70 years and older were at significantly increased risk for PMV dependency, compared to those aged 40-49 years after adjusting for confounders. Expenses per visit and hospital visits per year, representing the severity of the COPD, were also associated with an elevated risk of PMV. Most patients developed PMV dependency within the first two years after the index date. Physicians should be aware that elderly patients with COPD have a high risk of PMV after first hospitalization, and these patients need to be closely monitored.

Comparative stroke risk of antiepileptic drugs in patients with epilepsy.

PURPOSE: Patients with epilepsy have higher stroke-related morbidity and mortality, leading to the suspicion that the increased stroke events may be associated with antiepileptic drug (AED) exposure. We evaluated the comparative risk of stroke in adult patients with epilepsy receiving phenytoin (PHT), valproic acid (VPA), or carbamazepine (CBZ) to help determine the stroke risk for Asian patients with specific AED exposure. METHODS: We conducted a population-based, retrospective cohort study using the Taiwan National Health Insurance Research Database (NHIRD). The cohort consists of adult patients with epilepsy who were new to PHT, CBZ, or VPA monotherapy and without prior stroke history. Patients were followed for 5 years. The event of interest was a hospitalization or emergency visit due to stroke. Cox proportional hazard models were used to estimate the comparative risk of AEDs. Subanalyses included an evaluation of different subtypes of stroke, the propensity score matched technique, the intention-to-treat approach, and stratification analyses. KEY FINDINGS: Patients receiving PHT had a significantly higher stroke risk (adjusted hazard ratio [HR] 1.72; 95% confidence interval [CI] 1.20-2.47), followed by VPA (adjusted HR 1.27; 95% CI 0.78-2.07), when compared with CBZ. The results of all subanalyses showed a consistent trend of higher stroke risk with PHT use. In addition, there appeared to be a dose-response relationship between stroke risk and PHT prescriptions. SIGNIFICANCE: The stroke risk was higher in PHT but not significantly different in VPA as compared to CBZ. Physicians should reconsider using PHT for patients with epilepsy who already have a higher risk of stroke.

Use of antiepileptic drugs and risk of hypothyroidism.

PURPOSE: This study aimed to investigate the risk of clinically significant hypothyroidism among all the currently available antiepileptic drugs (AED). METHODS: The Taiwan National Health Insurance Research Database (NHIRD) from 2004 to 2010 was analyzed using a prescription sequence symmetry analysis, and thyroxine treatment was used as a proxy to identify a hypothyroidism event. A cohort of patients who have been treated with both AED and thyroxine was selected, and the chronological order of AED and thyroxine use constituted the basis of the prescription sequence symmetry analysis. A causal relationship was suspected if there was a significantly higher proportion of patients who initiated thyroxine after AED than those who initiated thyroxine before AED. The ratio of the two proportions was described as a sequence ratio. To benchmark the effect size of AEDs on thyroid function, amiodarone was selected as the reference indicator. RESULTS: A total of 1,878,189 AED users was found in the database, with 16,200 of them also used thyroxine. The adjusted sequence ratio of thyroxine use after each AED was 1.75 (99% confidence interval, 1.58-1.94) for phenytoin, 1.34 (1.20-1.49) for valproate, 1.25 (1.15-1.36) for phenobarbital, 1.21 (1.08-1.34) for carbamazepine, and 1.22 (1.03-1.46) for oxcarbazepine. The risk of hypothyroidism from phenytoin use within a shorter time frame was similar that associated with amiodarone use. No association was shown in most of the new generation AEDs. CONCLUSION: The results indicated an increased risk of hypothyroidism among patients using AEDs, especially phenytoin, valproate, phenobarbital, carbamazepine, and oxcarbazepine. The findings also provided strong grounds for further investigations on acute thyroid adverse effect induced by phenytoin.

Multi-country rapid adverse drug event assessment: the Asian Pharmacoepidemiology Network (AsPEN) antipsychotic and acute hyperglycaemia study.

PURPOSE: To undertake a multi-country study to investigate the risk of acute hyperglycaemia with antipsychotic use. METHODS: Using a distributed network model with a common minimal data set, we performed a prescription sequence symmetry analysis (PSSA) to investigate the risk of acute hyperglycaemia associated with antipsychotic initiation. Incident insulin prescriptions were used as a proxy indicator of acute hyperglycaemia. Participating countries and population datasets included Australia (300,000 persons), Japan I (300,000 persons), Japan II (200,000 persons), Korea (53 million persons) Taiwan (1 million persons), Sweden (9 million persons), USA-Public (87 million persons) and USA-Private (47 million persons). RESULTS: Olanzapine showed a trend towards increased risk in most databases, with a significant association observed in the USA-Public database (Adjusted sequence ratio (ASR) = 1.14; 95% Confidence Interval (CI) 1.10-1.17) and Sweden (ASR = 1.53; 95% CI 1.13-2.06). Null or negative associations were observed for haloperidol, quetiapine and risperidone. CONCLUSION: Acute hyperglycaemia appears to be associated with olanzapine use, however, this effect was only observed in two large databases. Despite different patterns of utilization of both antipsychotics and insulin, PSSA analysis results for individual antipsychotic medicines were qualitatively similar across most countries. PSSA, used in conjunction with existing methods, may provide a simple and timely method further supporting multi-national drug safety monitoring.

Statins and intracerebral hemorrhage: collaborative systematic review and meta-analysis.

BACKGROUND: A recent large, randomized trial suggested that statins may increase the risk of intracerebral hemorrhage. Accordingly, we systematically reviewed the association of statins with intracerebral hemorrhage in randomized and observational data. METHODS AND RESULTS: We screened 17 electronic bibliographic databases to identify eligible studies and consulted with experts in the field. We used DerSimonian-Laird random-effects models to compute summary risk ratios with 95% confidence intervals. Randomized trials, cohort studies, and case-control studies were analyzed separately. Only adjusted risk estimates were used for pooling observational data. We included published and unpublished data from 23 randomized trials and 19 observational studies. The complete data set comprised 248 391 patients and 14 784 intracerebral hemorrhages. Statins were not associated with an increased risk of intracerebral hemorrhage in randomized trials (risk ratio, 1.10; 95% confidence interval, 0.86-1.41), cohort studies (risk ratio, 0.94; 95% confidence interval, 0.81-1.10), or case-control studies (risk ratio, 0.60; 95% confidence interval, 0.41-0.88). Substantial statistical heterogeneity was evident for the case-control studies (I(2)=66%, P=0.01), but not for the cohort studies (I(2)=0%, P=0.48) or randomized trials (I(2)=30%, P=0.09). Sensitivity analyses by study design features, patient characteristics, or magnitude of cholesterol lowering did not materially alter the results. CONCLUSIONS: We found no evidence that statins were associated with intracerebral hemorrhage; if such a risk is present, its absolute magnitude is likely to be small and outweighed by the other cardiovascular benefits of these drugs.

The role of chemoprevention by selective cyclooxygenase-2 inhibitors in colorectal cancer patients - a population-based study.

BACKGROUND: There are limited population-based studies focusing on the chemopreventive effects of selective cyclooxygenase-2 (COX-2) inhibitors against colorectal cancer. The purpose of this study is to assess the trends and dose-response effects of various medication possession ratios (MPR) of selective COX-2 inhibitor used for chemoprevention of colorectal cancer. METHODS: A population-based case-control study was conducted using the Taiwan Health Insurance Research Database (NHIRD). The study comprised 21,460 colorectal cancer patients and 79,331 controls. The conditional logistic regression was applied to estimate the odds ratios (ORs) for COX-2 inhibitors used for several durations (5 years, 3 years, 1 year, 6 months and 3 months) prior to the index date. RESULTS: In patients receiving selective COX-2 inhibitors, the OR was 0.51 (95% CI=0.29~0.90, p=0.021) for an estimated 5-year period in developing colorectal cancer. ORs showing significant protection effects were found in 10% of MPRs for 5-year, 3-year, and 1-year usage. Risk reduction against colorectal cancer by selective COX-2 inhibitors was observed as early as 6 months after usage. CONCLUSION: Our results indicate that selective COX-2 inhibitors may reduce the development of colorectal cancer by at least 10% based on the MPRs evaluated. Given the limited number of clinical reports from general populations, our results add to the knowledge of chemopreventive effects of selective COX-2 inhibitors against cancer in individuals at no increased risk of colorectal cancer.

Sex difference in heart failure risk associated with febuxostat and allopurinol in gout patients.

Background: Gout or rapid reduction in serum uric acid level may increase the incidence of heart failure (HF). To compare the risk of HF between febuxostat and allopurinol in gout patients with coexisting cardiovascular (CV) diseases, the varying severity would be likely to confound the risk estimation. Gout and HF are both sex-related diseases, and the risk difference from the urate-lowering agents between women and men remains unknown. Aims: To evaluate the HF hospitalisations risk of febuxostat and allopurinol in gout patients in real-world settings. Methods: A population-based cohort enrolled patients with allopurinol or febuxostat initiation from 2011 to 2018. Participants were grouped into, without (low CV risk group) or with (high CV risk group) a history of recent major CV admission. The primary outcome was HF hospitalization. The secondary outcomes were composite CV events, all-cause mortality, and the cause of CV mortality. We used the 'as-treated' analysis and Cox proportional hazards model after propensity score (PS) matching. Patients were further stratified into men and women to evaluate the gender differences. Results: Febuxostat users had a significantly higher risk of HF hospitalization than allopurinol users in gout patients either with low CV risk [hazard ratio (HR) 1.39; 95% confidence interval (CI) 1.25-1.55] or high CV risk [HR 1.36; 95% CI 1.22-1.52]. Particularly, women with gout had a higher risk of HF hospitalization than men. Conclusion: The HF hospitalization risk was highest in gout women with high CV risk and febuxostat use. Monitoring of HF is warranted in these patients.

Epidemiology and predictors of short-term mortality in symptomatic venous thromboembolism.

BACKGROUND: The epidemiology of symptomatic venous thromboembolism (VTE) in Taiwan has not been well investigated. The aim of this study was to report on the epidemiology and short-term prognosis of symptomatic VTE. METHODS AND RESULTS: This nationwide population-based cohort study used the Taiwanese National Health Insurance claims databases to identify adults older than 18 years of age with symptomatic VTE diagnosed in 2002. We investigated the clinical features of VTE and determined independent risk factors of 1-month mortality. A total of 2,774 patients were identified with a mean age of 62.8 years and the female-to-male ratio was 1.15:1. The crude incidence of symptomatic VTE was 16.5 per 100,000 persons, which steadily increased with age, ranging from 4 per 100,000 in patients <40 years old to 108 per 100,000 in patients ≥ 80 years. We observed no seasonal and meteorological variations in the incidence of VTE. The overall 1-month mortality rate was 8.8%, with 7.1% in deep venous thrombosis and 12.9% in pulmonary embolism. Multivariate analysis demonstrated that pulmonary embolism, cancer, neurologic disease with extremity paresis or paralysis, older age, longer hospital stay, and major abdominal and thoracic surgery in the 3 months preceding VTE were independent predictors of 1-month death. CONCLUSIONS: Although the incidence of VTE was lower in Taiwanese populations than in Western ones, short-term mortality rates were high in specific populations. These findings suggest optimal treatment is needed in higher-risk patients.

Pharmacovigilance systems and databases in Korea, Japan, and Taiwan.

PURPOSE: The aim of this article is to qualitatively describe the characteristics of spontaneous reporting systems, signal detection methods, and observational databases in Korea, Japan, and Taiwan. METHODS: National statistics and published literature were reviewed to determine the annual number of spontaneous reports and the main source (reporters) for each country. The data items collected for spontaneous reports, mode of transmission, availability of reports, and quantitative methods for signal detection were compared across the countries. The characteristics of the national insurance claims databases also were summarized. RESULTS: The number of annual domestic spontaneous reports in 2007 from Korea, Japan, and Taiwan were 3751, 32,391, and 6971, respectively, which increased to 26,827, 34,649, and 10,320, respectively, over the next 2 years. If adjusted by total population, the latter would be 5.59, 2.71, and 4.49 per 10,000 persons, respectively. The reports were directly submitted mainly by physicians (51%) in Korea and hospital pharmacists (65%) in Taiwan, whereas 89% of the reports in Japan were submitted by manufacturers. Routine data mining of the national spontaneous report database has been implemented in Japan and will be in Korea and Taiwan. CONCLUSIONS: Differences in quantity and submission practice of spontaneous reports should be noted for potential comparison among these countries/regions, as well as with those from Western countries, even after the full implementation of national data mining system. Nationwide claims databases with nearly 100% coverage are great assets for pharmacovigilance and pharmacoepidemiology and can be major contributors to global pharmacovigilance.

Using spatial analysis to demonstrate the heterogeneity of the cardiovascular drug-prescribing pattern in Taiwan.

BACKGROUND: Geographic Information Systems (GIS) combined with spatial analytical methods could be helpful in examining patterns of drug use. Little attention has been paid to geographic variation of cardiovascular prescription use in Taiwan. The main objective was to use local spatial association statistics to test whether or not the cardiovascular medication-prescribing pattern is homogenous across 352 townships in Taiwan. METHODS: The statistical methods used were the global measures of Moran's I and Local Indicators of Spatial Association (LISA). While Moran's I provides information on the overall spatial distribution of the data, LISA provides information on types of spatial association at the local level. LISA statistics can also be used to identify influential locations in spatial association analysis. The major classes of prescription cardiovascular drugs were taken from Taiwan's National Health Insurance Research Database (NHIRD), which has a coverage rate of over 97%. The dosage of each prescription was converted into defined daily doses to measure the consumption of each class of drugs. Data were analyzed with ArcGIS and GeoDa at the township level. RESULTS: The LISA statistics showed an unusual use of cardiovascular medications in the southern townships with high local variation. Patterns of drug use also showed more low-low spatial clusters (cold spots) than high-high spatial clusters (hot spots), and those low-low associations were clustered in the rural areas. CONCLUSIONS: The cardiovascular drug prescribing patterns were heterogeneous across Taiwan. In particular, a clear pattern of north-south disparity exists. Such spatial clustering helps prioritize the target areas that require better education concerning drug use.