Biomedical subjects

Li-Fang Chou

Publications and source records attributed to Li-Fang Chou.

14 recordsLinked to original sources

PubMed2007

Functional epitopes on porcine endogenous retrovirus envelope protein interacting with neutralizing antibody combining sites.

Porcine cell and organ transplantation provides promise for maintaining normal physiological conditions in patients with end-stage organ failure. The approach however poses serious risk of transmitting pig pathogens to humans. Among many potential pathogens, porcine endogenous retroviruses (PERV) are of particular concern due to their ubiquitous nature in pigs and capability of infecting human cells. Major antigenic determinants and receptor binding domains on PERV remain unclear until now. Two monoclonal antibodies (mAb), named 8E10 and 7C4 capable of neutralizing PERV infection in HEK293 cells are isolated at an IC(50) of 3.0 and 2.7 microg/ml, respectively, in this work. Epitope location for mAb 8E10 was mapped to amino acids 427-434, residing at the C-terminal region of the gp70 component of type A PERV Env protein. The mAb 8E10 bound directly to the PERV indicating that the epitope is exposed on the virion surface. The mAb 7C4 epitope was assigned to the region comprising amino acids 517-537 on the p15E component of PERV. In contrast to mAb 8E10, the 7C4 mAb bound native PERV inefficiently suggesting that its epitope is accessible only after the virus interacts with its receptor. Finally, both mAbs variable regions were cloned and nucleotide sequence determined. All together, these results reveal that both mAbs 8E10 and 7C4 effectively neutralize PERV infection and may be used as a mean to prevent PERV infection in patients receiving xenotransplantation.

Amino Acid Sequence↗

PubMed2006

Hospice utilization during the SARS outbreak in Taiwan.

BACKGROUND: The severe acute respiratory syndrome (SARS) epidemic threw the world into turmoil during the first half of 2003. Many subsequent papers have addressed its impact on health service utilization, but few have considered palliative (hospice) care. The aim of the present study was to describe changes in hospice inpatient utilization during and after the SARS epidemic in 2003 in Taiwan. METHODS: The data sources were the complete datasets of inpatient admissions during 2002 and 2003 from the National Health Insurance Research Database. Before-and-after comparisons of daily and monthly utilizations were made. Hospice analyses were limited to those wards that offered inpatient services throughout these two years. The comparisons were extended to total hospital bed utilization and to patients who were still admitted to hospice wards during the peak period of the SARS epidemic. RESULTS: Only 15 hospice wards operated throughout the whole of 2002 and 2003. In 2003, hospice utilization began to decrease in the middle of April, reached a minimum on 25 May, and gradually recovered to the level of the previous November. Hospices showed a more marked reduction in utilization than all hospital beds (e.g. -52.5% vs. -19.9% in May 2003) and a slower recovery with a three-month lag. In total, 566 patients were admitted to hospice wards in May/June 2003, in contrast to 818 in May/June 2002. Gender, age and diagnosis distributions did not differ. CONCLUSION: Hospice inpatient utilization in Taiwan was indeed more sensitive to the emerging epidemic than general inpatient utilization. A well-balanced network with seamless continuity of care should be ensured.

Aged↗

PubMed2006

Patterns of ambulatory care utilization in Taiwan.

BACKGROUND: We used the insurance claims of a representative cohort to quantify the patterns of ambulatory care visits, especially the doctor-shopping phenomenon, in Taiwan. METHODS: The ambulatory visit files of the 200,000-person cohort datasets from the National Health Insurance Research Database in 2002 were analyzed. Only a visit with physician consultation would be considered. We computed the visit patterns both by visit count and by patient count. RESULTS: In 2002, there were 182,474 eligible people with 2,443,003 physician consultations. During the year, 87.4% of the cohort had visited physician clinics and 57.5% had visited hospital-based outpatient or emergency departments. On average, a person had 13.4 physician consultations and consulted 3.4 specialties, 5.2 physicians, and 3.9 healthcare facilities in a year. In 2002, 17.3% of the cohort had ever visited different healthcare facilities on the same day; 23.5% had ever visited physicians of the same specialty at different healthcare facilities within 7 days and the percentage of second visits was 3.8% of all visits. Besides, 7.6% of the cohort had visited two or more specialties at the same facility on the same day, and such visits make up 2.5% of all visits. CONCLUSION: The people in Taiwan did visit the physicians and outpatient departments frequently. Many patients not only consulted several physicians of different specialties and at different healthcare facilities during the year, but also switched the physicians and facilities quickly. An effective referral system with efficient data exchange between facilities might be the solution.

Adult↗

PubMed2006

Dynamic analysis of hepatoma spheroid formation: roles of E-cadherin and beta1-integrin.

A spheroid is an in vitro multicellular aggregate that provides a microenvironment resembling that of normal tissue in vivo. Although cell adhesion molecules such as integrins and cadherins have been implicated in participating in the process of spheroid formation, little is known about the timing of their action. In this study, we have employed an image-based quantitative method to investigate the compactness of cell aggregates during hepatoma spheroid formation in a dynamic fashion. By modulating beta1-integrin and E-cadherin activity with specific blocking antibodies, ion chelators, and RGD-sequence-containing peptides, we show that these cell adhesion molecules mediate the formation of spheroids through the establishment of complex cell-cell and cell-extracellular matrix (ECM) interactions. The dynamics of spheroid formation can be separated into three stages. In the first stage, ECM fibers act as a long-chain linker for the attachment of dispersed single-cells to form loose aggregations through the binding of integrins. This is followed by a delay period in which cell aggregates pause in compaction, presumably because of the accumulation of sufficient amounts of E-cadherins. In the third stage, strong homophilic interaction of E-cadherins is a major factor for the morphological transition from loose cell aggregates to compact spheroids. These findings thus provide comprehensive information on the molecular mechanisms and dynamics of hepatoma spheroid formation.

Cadherins↗

PubMed2006

The ecology of mental health care in Taiwan.

This paper applied the ecology model of general medical care by White et al. to analysis of mental health services utilization within the National Health Insurance in Taiwan. The ambulatory and inpatient claims of a 200,000-person cohort in 2001 were analyzed. The yearly and monthly prevalence estimates included psychotropic drug prescription, diagnosis of mental disorders, psychiatric ambulatory visit and admission, community psychiatric rehabilitation, and certificate of chronic psychosis. The results revealed one-fourth of people had received psychotropic drugs during the year, mostly from non-psychiatrists. Besides, the elderly might be excessively exposed to psychotropic drugs, and community rehabilitation programs were underutilized.

Adolescent↗

PubMed2006

Application of concentration ratios to analyze the phenomenon of "next-door" pharmacy in Taiwan.

BACKGROUND: In Taiwan, a policy of separation of prescribing and dispensing practices of practitioners at Western medical and dental clinics was implemented on an incremental basis in 1997. The purpose of this policy was to promote pharmacists' autonomy and increase the transparency and safety of prescribing medications. To avoid profit loss from no longer being able to dispense prescription medications, some clinics opened pharmacies located under the same roof as the clinic ("next-door" pharmacies) or hired an on-site pharmacist. This practice might compromise pharmacists' professional autonomy and patients' benefit in pharmaceutical care. OBJECTIVE: The aim of the current study was to clarify the relationship between practicing pharmacies and clinics that resulted from contracts between pharmacies and the Bureau of National Health Insurance from 1996 to 2004. METHODS: The National Health Research Institutes database in Taiwan supplied the complete claims data sets of practicing pharmacies from 1997 to 2004. The prescribing source of every dispensed prescription was used to calculate the 1-firm concentration ratio (CR-1) (ie, the proportion of prescriptions issued by the largest prescribing clinic/hospital in the total number of dispensed prescriptions of a pharmacy in each year). Similar processing was applied to the clinics. We identified each clinic's largest cooperating pharmacy and compared their CR-1s. Pharmacies that dispensed >900 prescriptions/mo during the study period were considered thriving. Pharmacies with a CR-1 > or =0.99 and whose largest cooperating clinic had a CR-1 > or =0.99 were considered to have a close business relationship, possibly indicating a next-door pharmacy. RESULTS: The total number of prescriptions dispensed at all pharmacies in the database grew from 226,901 in 1996 to 59,785,039 in 2004, and the number of pharmacies, from 481 to 3529. An increasing number of pharmacies had a higher CR-1 after 1999. We found that most prescriptions could be dispensed at only 1 pharmacy during the study period. In 2004, 1429 clinics had >900 prescriptions/mo dispensed externally and a CR-1 > or =0.99. They had released 75.8% of all prescriptions to be dispensed at practicing pharmacies; 811 of these clinics had a cooperating pharmacy with a CR-1 > or =0.99. CONCLUSIONS: In this data analysis in Taiwan, most prescriptions from practitioners at Western medical and dental clinics could be dispensed at only 1 pharmacy during the study period, suggesting that pharmacists' professional autonomy and the patients' benefit in pharmaceutical care might be compromised in Taiwan.

Ambulatory Care Facilities↗

PubMed2006

Health care utilization of home care patients at an academic medical center in Taiwan.

BACKGROUND: Previous surveys of home care patients in Taiwan have primarily concentrated on patients' status and needs. The aim of this study was to review the actual health care utilization of home care patients during the course of 1 year. METHODS: Home care patients at an academic medical center in Taiwan were selected and their insurance claims data at this hospital in 2001 were analyzed. Analyses included the patients' patterns and diagnoses of visits and admissions, and their drug utilization. For diagnoses made at outpatient departments, the grouping system from the National Hospital Ambulatory Medical Care Survey in the United States was used. The Anatomical Therapeutic Chemical Classification system was applied to drug grouping. RESULTS: The home care agency of the hospital cared for 165 patients (66 women, 99 men) in 2001. In total, these 165 patients received 1,358 home visits, 2,751 outpatient visits, and 108 inpatient admissions. While the most frequent diagnoses for all visits were cerebrovascular disease, hypertension, diabetes mellitus, chronic and unspecified bronchitis, psychoses, and other disorders of the central nervous system, the most frequent diagnoses at discharge from the hospital were urinary tract infection and pneumonia. In all visits, 12,282 items of drugs were prescribed in 2,337 prescriptions. On average, each prescription contained 5.3 +/- 2.8 items of drugs. The most frequently prescribed drugs were antacids, expectorants, laxatives, selective calcium channel blockers, and antithrombotic agents. CONCLUSION: The home care agency of the hospital should pay more attention to provision of comprehensive care and review of drug prescribing.

Academic Medical Centers↗

PubMed2004

Estimating medical costs of gastroenterological diseases.

AIM: To estimate the direct medical costs of gastroenterological diseases within the universal health insurance program among the population of local residents in Taiwan. METHODS: The data sources were the first 4 cohort datasets of 200,000 people from the National Health Insurance Research Database in Taipei. The ambulatory, inpatient and pharmacy claims of the cohort in 2001 were analyzed. Besides prevalence and medical costs of diseases, both amount and costs of utilization in procedures and drugs were calculated. RESULTS: Of the cohort with 183,976 eligible people, 44.2% had ever a gastroenterological diagnosis during the year. The age group 20-39 years had the lowest prevalence rate (39.2%) while the elderly had the highest (58.4%). The prevalence rate was higher in women than in men (48.5% vs. 40.0%). Totally, 30.4% of 14,888 inpatients had ever a gastroenterological diagnosis at discharge and 18.8% of 51,359 patients at clinics of traditional Chinese medicine had such a diagnosis there. If only the principal diagnosis on each claim was considered, 16.2% of admissions, 8.0% of outpatient visits, and 10.1% of the total medical costs (8,469,909 US dollars/83,830,239 US dollars) were attributed to gastroenterological diseases. On average, 46.0 US dollars per insured person in a year were spent in treating gastroenterological diseases. Diagnostic procedures related to gastroenterological diseases accounted for 24.2% of the costs for all diagnostic procedures and 2.3% of the total medical costs. Therapeutic procedures related to gastroenterological diseases accounted for 4.5% of the costs for all therapeutic procedures and 1.3% of the total medical costs. Drugs related to gastroenterological diseases accounted for 7.3% of the costs for all drugs and 1.9% of the total medical costs. CONCLUSION: Gastroenterological diseases are prevalent among the population of local residents in Taiwan, accounting for a tenth of the total medical costs. Further investigations are needed to differentiate costs in screening, ruling out, confirming, and treating.

Adult↗

PubMed2003

Application of a data-mining technique to analyze coprescription patterns for antacids in Taiwan.

BACKGROUND: Although antacids are popular drugs with a long history of use, their true utilization patterns-including over-the-counter use-have rarely been documented. Because all antacids are reimbursed under the National Health Insurance program in Taiwan, it is possible to access and analyze nationwide data for these drugs. OBJECTIVES: The purposes of this study were to estimate the scale of antacid prescribing in Taiwan using the national insurance claims for outpatient services and to analyze coprescribing patterns of antacids using modern data-mining techniques. METHODS: The National Health Insurance Research Database in Taiwan supplied the visit-based sampling data sets, which had a sampling ratio of 0.2% for all claims for outpatient medical services in the year 2000. In addition to the plain statistics (ie, data from simple calculations) for antacid prescriptions, we also analyzed relationships between prescriptions for antacids and nonantacid drugs. A data-mining technique-association rule mining-was applied to identify the drugs prescribed in combination with antacids. RESULTS: Among a total of 409,049 eligible prescriptions for 1,704,595 drug items to be administered orally, antacids were present in 213,494 prescriptions (52.2%). Antacid users were generally older than nonusers (mean [SD] age, 39.9 [23.4] years vs 32.4 [25.7] years). In all, 88.8% of antacid items (189,531/213,494) were prescribed without claims diagnoses of gastrointestinal disorders. Using association rule mining with a 1.0% minimum support factor, there were 36 strong association rules between prescriptions for antacids and other drug subgroups at the third level of Anatomical Therapeutic Chemical classification. Nonsteroidal anti-inflammatory drugs and drugs for treating upper respiratory infections played dominant roles in the associations with antacid prescriptions; vitamin B complex and antivertigo preparations were also strongly associated with antacids. CONCLUSIONS: Antacid coprescriptions were common in Taiwan in the year 2000. Further study should investigate whether antacid prescribing patterns are influenced by Taiwanese perceptions that Western drugs injure the stomach.

Adolescent↗

PubMed2003

Utilization of hepatoprotectants within the National Health Insurance in Taiwan.

BACKGROUND: Although the hepatoprotectants of Western medicine have centuries of history, their utilization patterns have been seldom documented. Because the National Health Insurance program in Taiwan reimburses hepatoprotectant use, we could estimate the age- and sex-specific prevalence and utilization patterns of hepatoprotectants in Western medicine within the health insurance system in Taiwan. METHODS: We analyzed the outpatient prescription data of 50000 randomly sampled insured patients in 2000. Only patients using drugs indicated for liver diseases and diagnostic codes related to liver diseases on the same visit were considered to be receiving hepatoprotectants. Drugs involved in Chinese medicine were not included. RESULTS: Among the valid cohort of 46614 people, 783 (1.7%) were identified as patients with liver disease and receiving hepatoprotectants. Highest prevalence of hepatoprotectant use was 4.9% in the 60-69 years age group. Silymarin, multivitamins, methionine, ursodeoxycholic acid, and liver hydrolysate accounted for 88.8% of the 3215 prescribed items of hepatoprotectants. Patients receiving hepatoprotectants had, on average, visited the clinics more frequently than those not using hepatoprotectants (30 vs 14 times in a year, P < 0.001), and used more insurance benefits (US dollars 1352 vs US dollars 456, P < 0.001). CONCLUSIONS: The frequency of use of major hepatoprotectants in Taiwan corresponded to the current modalities of treatment under discussion worldwide.

Adolescent↗

PubMed2003

Prevalence of anti-ulcer drug use in a Chinese cohort.

AIM: To estimate the age-specific prevalence of anti-ulcer drug use and to calculate the usage of different anti-ulcer drugs over 5 years within the universal health insurance program in Taiwan area. METHODS: The National Health Insurance Research Database in Taipei supplied the cohort data sets of 200 000 people. The ambulatory and inpatient claims of the cohort from 1997 to 2001 were analyzed. The anti-ulcer drugs included all drug items of the group A02B (drugs for treatment of peptic ulcer) in the Anatomical Therapeutic Chemical classification system (version 2000). The amount of drug usage was measured in unit of defined daily dose. RESULTS: Among the totally 13 034 393 visits with 56 672 631 ambulatory prescription items, there were 398 150 (0.7 %) prescribed items of anti-ulcer drugs in 378 855 (2.9 %) visits. Among the 107 649 admissions with 5 762 312 inpatient prescription items, there were 24 598 (0.4 %) prescribed items of anti-ulcer drugs in 11 548 (10.7 %) admissions. The annual prevalence of anti-ulcer drug use was 9.6 % in 1997, 11.6 % in 1998, 15.4 % in 1999, 14.5 % in 2000, and 15.9 % in 2001 respectively. The 5-year prevalence was 36.1 %. The age-specific prevalence among the people younger than 20 years was 9.2 % in 2001 and 23.7 % during the 5-year period. Cimetidine not only was the most popular ingredient among anti-ulcer drugs (57 634 cimetidine users in 70 729 all anti-ulcer drug users during the 5-year period) but also had the largest prescribed amount (42.3 % of DDDs for all anti-ulcer drug users during the 5-year period). The annually prescribed amount of anti-ulcer drugs had grown from 4.9 DDDs/1000 inhabitants/day in 1997 to 7.5 in 2001. This increase was largely attributed to H2-receptor antagonists and the expanding number of users. CONCLUSION: Prescribing of anti-ulcer drugs is indeed popular among the Chinese population in Taiwan area. The disproportionate use of anti-ulcer drugs by children demands further investigation.

Adolescent↗

PubMed2003

Prevalence of antilipemic drug use in Taiwan: analysis of a sampling cohort within the national health insurance.

BACKGROUND: Hyperlipidemia is a major risk factor of cardiovascular diseases. We investigated the utilization ofantilipemic drugs at the outpatient sector within the National Health Insurance in Taiwan. METHODS: We obtained the first cohort (n = 50,000) dataset from the National Health Insurance Research Database and analyzed the outpatient claim files of the cohort in 2000. The antilipemic drugs were defined as the drug items belonging to the group C10 (serum lipid reducing agents) of the Anatomical Therapeutic Chemical classification system. RESULTS: Among the cohort with 46,614 eligible people, 760 patients had ever received antilipemic drugs (prevalence: 1.6%). The group 60-69 years of age had the greatest age-specific prevalence (7.2%), followed by the group over 70 years of age (6.0%). There were more male than female patients, but female patients outnumbered male patients before the age of 49 years. The antilipemic drugs had been prescribed 3,850 times totally with 70,272 defined daily doses (DDDs). On an average, a patient with antilipemic therapy received 5.1 (+/- 4.5) prescriptions of antilipemic drugs in one year and a prescription contained 18.3 (+/- 11.5) DDDs. We measured 4.1 DDDs per 1,000 inhabitants per day for all antilipemic drug use in 2000. The statins and fibrates predominated the antilipemic drug use. While gemfibrozil was most popular in respect of recipients and prescription items, simvastatin had the largest amount of use in unit of DDDs. Diabetes mellitus co-existed in 37.8% of the patients with antilipemic therapy and the standardized morbidity ratio (SMR) was 3.34. The other concomitant diseases included essential hypertension (rate: 48.8%, SMR: 2.40) and other heart disease (rate: 30.7%, SMR: 2.36). CONCLUSIONS: Statins were the leading antilipemic drugs in Taiwan. The users of antilipemic drugs were more likely to have concomitant diabetes mellitus, hypertension and heart disease.

Adolescent↗

PubMed2002

Utilization of psychotropic drugs in Taiwan: an overview of outpatient sector in 2000.

BACKGROUND: Development of pharmacological treatment in mental disorders has risen drastically over the past decade in Taiwan. We performed a survey of the National Health Insurance claims for outpatient psychiatric services to study the utilization of psychotropic drugs. The analysis followed the drug classification and standardized measurements proposed by the World Health Organization. METHODS: The sampling datasets from the National Health Insurance Research Database served as data sources. They represented 0.2% of the entire claims for outpatient medical services in 2000. The measurement units used for psychotropic drugs were either prescription volumes (drug items) or the number of defined daily doses (DDDs). To estimate the proportion of the population treated daily with psychotropic drugs, numbers of DDDs per 1000 inhabitants per day were also calculated. Beside overall description, the data of psychotropic substance prescriptions were analyzed by stratifying patient's age, physician's specialty, accreditation status of hospital, and chemical subgroup of psychotropic drugs. RESULTS: Prescription of psychotropic drug items (n = 63,539) was 3.24% of the total drug items (n = 1,958,820) claimed. The psychotropic drugs were prescribed to 9.2% of the total patients and in 9% of the total visits. Major consumers of psychotropic drugs were between 35-74 years of age and there were more women than men. The psychiatrist was the largest group of physicians who had prescribed psychotropic drugs and contributed 18.5% of all drug items and 38.3% of total DDDs of psychotropic drugs. The number of DDDs per 1000 inhabitants per day for all kinds of psychotropic drugs was estimated to be 32.94 in Taiwan, where anxiolytics accounted 14.30, hypnotics and sedatives 10.64, antipsychotics 3.41, antidepressants 3.06 and mood stabilizers 1.43. Ordered by total DDDs, the top 10 most frequently used chemical substances were flunitrazepam, alprazolam, fludiazepam, oxazolam, lorazepam, diazepam, zolpidem, estazolam, zopiclone, and haloperidol. CONCLUSIONS: The usage level of psychotropic drugs in Taiwan was lower than in most industrialized countries, especially for antidepressants. The future goals are to focus on the longitudinal analysis of general trend for each psychotropic substance and to associate the pharmacoepidemiological data in parallel with the upcoming epidemiological study of mental disorders in Taiwan.

Adolescent↗

PubMedDate not supplied

Patterns and costs of antipsychotic drug use in Taiwan: 1997 to 2001.

The advent of atypical antipsychotics greatly changed the treatment pattern for mental illnesses worldwide. This study was designed to determine the trend in prevalence, prescribing pattern, and cost of antipsychotic agents in Taiwan from 1997 to 2001. Data were obtained from claims completed for a random sample of 200,000 people registered with the National Health Insurance program. The antipsychotics monitored included all group N05A drugs in the Anatomical Therapeutic Chemical classification system (version 2000). Conventional and atypical antipsychotics were handled separately. Of the 195,971 eligible registrants, 37,441 (19.1%) received any kind of antipsychotic during this 5-year period, but only 713 (0.4%) used atypical antipsychotics. The prevalence of conventional antipsychotic use during each successive year of this study was 5.2%, 5.7%, 6.6%, 6.2%, and 6.1% and 0.1%, 0.1%, 0.1%, 0.2%, and 0.3% for atypical agents. Although far fewer registrants used them, atypicals comprised 19.1% of all prescribed amounts measured in defined daily doses and 56.1% of the cost for all antipsychotics in 2001. During the 5-year study period, atypical antipsychotics were prescribed for 405 (57%) patients with schizophrenia, 132 (19%) with affective disorder, 128 (18%) with other psychiatric disorders, and 48 (7%) with a nonpsychiatric disorder. With the loosening of reimbursement restrictions in 2002, continued growth of atypical antipsychotic use in Taiwan might be expected.

Antipsychotic Agents↗