Swu Jane Lin

Validation of the national health insurance research database with ischemic stroke cases in Taiwan

The National Health Insurance Research Database (NHIRD) is commonly used for pharmacoepidemiological research in Taiwan. This study evaluated the validity of the database for patients with a principal diagnosis of ischemic stroke.

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.

Similarity as a risk factor in drug-name confusion errors: the look-alike (orthographic) and sound-alike (phonetic) model.

BACKGROUND One of every four medication errors reported in the United States is a name-confusion error. The rate of name-confusion errors might be reduced if new and confusing names were not allowed on the market and if safeguards could be put in place to avoid confusion between existing names. OBJECTIVES To evaluate several prognostic tests of drug-name confusion, alone and in combination, with respect to their sensitivity, specificity, and overall accuracy. RESEARCH DESIGN Case-control study. Twenty-two different computerized measures of orthographic similarity, orthographic distance, and phonetic similarity were used to compute similarity/distance scores for n = 1,127 cases (ie, pairs of names that appeared in published error reports or national error databases) and n = 1,127 controls. MAIN OUTCOME MEASURES Mean similarity/distance scores were compared across cases and controls. The performance of each measure at distinguishing between cases and controls was evaluated by tenfold crossvalidation. Dose-response relationships were examined. Univariate and multivariate logistic regression models were formed and evaluated by 10 fold crossvalidation. RESULTS Cases had significantly higher similarity scores than controls. Every measure of similarity proved to be a significant risk factor for error. There was a significant increasing trend in the odds-ratio as a function of similarity. A three-predictor logistic regression model had crossvalidated sensitivity of 93.7%, specificity of 95.9% and accuracy of 94.8%. CONCLUSIONS A sensitive and specific test of drug-name confusion potential can be formed using objective measures of orthographic similarity, orthographic distance, and phonetic distance.

Effect of orthographic and phonological similarity on false recognition of drug names

Health professionals and patients tend to confuse drugs with similar names, thereby threatening patient safety. One out of four medication errors voluntarily reported in the US involves this type of drug name confusion. Cognitive psychology offers insight into how and why these errors occur. The objective of this investigation was to examine the effect of orthographic (i.e., spelling) and phonological (i.e., sound) similarity on the probability of making recognition memory errors (i.e., false recognitions). Prospective, computer-based, recognition memory experiments on 30 pharmacists and 66 college students were conducted. Participants viewed a study list of drug names and then a test list. The test list was twice as long as the study list and contained distractor names at progressively increasing levels of similarity to the study words. The task was to identify which test names were on study list and which were new. The main outcome measure was probability of making a false recognition error (i.e., of saying a new name was on the study list). Among pharmacists and college students, there was a strong and significant effect of similarity on the probability of making a false recognition error. It was concluded that both orthographic (i.e., spelling) and phonological (i.e., sound) similarity increase the probability that experts and novices will make false recognition errors when trying to remember drug names. Similarity is easily and cheaply measured, and therefore, steps should be taken to monitor and reduce similarity as a means of reducing the likelihood of drug name confusions.

Designing Safe Drug Names

Recent observational studies of medication errors in community pharmacies suggest that ‘wrong drug’ errors, which occur when a patient receives a drug other than the one prescribed, may occur as many as 3.9 million times per year in the US. Similarity between drug product attributes, especially similarity between drug names, is thought to be a contributing cause of these errors. The challenge facing drug companies is to design new drug names that will not be confused with existing names. In this paper, we attempt to lay out a systematic approach to the design of safe drug names by characterising the process of design as a multiple-objective optimisation problem. We then identify and define the most important constraints (both technical and legal/regulatory) and objectives (such as meaning, memorability, and pronouncability) that a drug name must satisfy and critique methods for evaluating a given name with respect to each safety objective and constraint.There are a variety of preapproval tests that can be done on a name to test its vulnerability to confusion. These include computerised searches for existing similar names or products, soliciting expert judgements, doing traditional psycholinguistic tests on memory and perception and observing error rates during simulated ordering, dispensing and administration tasks. A different set of strategies is needed to prevent confusion between similar names that are already in use. Preventing confusion between already marketed products typically involves collecting voluntary reports of names involved in confusion errors, posting warnings and alerts both electronically and in areas where drugs are used, including the indication on the prescription, storing confusing drugs in different locations, improving lighting, providing magnifiers, removing one of the confusing drugs from the system or insisting on double-checking for products thought to be vulnerable to confusion.Finally, since no single design will be optimal with respect to all of the objectives, we describe several approaches to selecting one design from a set of competing alternatives. The pharmaceutical industry and the US FDA have taken important steps recently to improve the preapproval screening of new drug names, but a great deal of research still needs to be done to establish a valid scientific basis for these decisions.

Access to Community Pharmacies by the Elderly in Illinois: A Geographic Information Systems Analysis

Community pharmacies play an important role in maintaining population health in the United States. They are large in number, distribute widely across geographic areas, and operate for long hours. Because the elderly population tends to use more medications and have more frequent interaction with pharmacies and pharmacists, this study was carried out to understand the geographic access to community pharmacies by the elderly in Illinois and to estimate the disparity in the access between rural and urban areas. The addresses of all community pharmacies operating in 2001 were geocoded to identify their locations. The Census 2000 data on demographics at the census block group level was used to estimate the geographic distribution of the Illinois population by age group. Using the centroid of each census block group and the locations of community pharmacies, the distance to a nearest pharmacy for each census block group was calculated. The distance was then weighted to compute the aggregated distance required for the elderly to access a pharmacy. There were 1373 community pharmacies operating in Illinois in 2001. Most pharmacies (93.8%) were located in urban areas. On average, there were 1.27 and 0.38 pharmacies per 10,000 people in urban and rural areas, respectively. The average distance for an elderly person in Illinois to locate a community pharmacy was 0.9 miles in urban areas, but it was six times more (5.9 miles) in rural areas. At least 10% of the rural elderly had to travel more than 11.8 miles to find a community pharmacy, but only 0.1% had to travel more than 20 miles. The geographic access to community pharmacies appears to be appropriate in Illinois. However, a small portion of rural elderly who do not have a pharmacy in their nearby areas may warrant special attention.

A Patient Empowerment Model to Prevent Medication Errors

Each year, untold deaths occur because of medical and medication errors in the United States. In generally, most people have the naïve perception that the health-care enterprise is a fail-safe system and as such do not take proactive measures to prevent potential medication errors. This paper is timely in light of the proliferation of medication use in outpatient settings and thus warrants the education of patients to take the responsibility in proper drug use. Patients and the health-care professionals must understand the need to see patients as part of the health-care team to ensure quality of care and decrease medication errors. A patient empowerment model to prevent medication error is therefore proposed.

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.

Use of antiepileptic drugs and risk of hypothyroidism

This study aimed to investigate the risk of clinically significant hypothyroidism among all the currently available antiepileptic drugs (AED).

Descriptive Analysis of the Drug Name Lexicon

The complexity of the drug use process is managed in part by developing systematic nomenclature for drugs. This nomenclature is cataloged in a variety of drug information databases. Answers to simple questions about the whole population of brand and generic drug names, however, are not easily obtained. This paper provides a descriptive analysis of the drug name lexicon, with a primary (though not exclusive) emphasis on drugs marketed in the United States. Using the techniques of computational lexicography, one large database of trademark names (the US Patent and Trademark database) and one large database of nonproprietary names (the USP Dictionary of USAN and International Drug Names) were analyzed. Results describe a variety of distributional characteristics of drug names, including the number of characters per name, the number of syllables per name, and the number of words per name. Distributions of pairwise similarity and distance scores for a large sample of names are provided, as are lists of the 25 most common initial and terminal bigrams and trigrams. The information should be of interest to trademark attorneys, patient safety advocates, regulators, and students of drug nomenclature.