Jeonghoon Ahn

Classifying patients by antipsychotic adherence patterns using latent class analysis: characteristics of nonadherent groups in the California Medicaid (Medi-Cal) program.

OBJECTIVES This study identifies latent classes defined by varying degrees of adherence to antipsychotic drug therapy and examines the sociodemographic, clinical, and resource utilization correlates associated with membership in each adherence class. DATA AND METHODS Patient-level data were drawn from the 1994 to 2003, 100%-sample California Medicaid fee-for-service paid claims data for patients with schizophrenia (N = 36,195). The date of the first antipsychotic medication filled after January 1, 1999 was then used to divide each patients data into a 6-month preindex (baseline) and a 12-month postindex (follow-up) period. Three categorical adherence indicators-a dichotomous variable of medication possession ratio greater than 0.80, the number of antipsychotic treatment attempts, and time to a change in antipsychotic medications-and two covariates-a categorical variable of duration of therapy and a dichotomous variable of polypharmacy-were used in the latent class model. RESULTS A three-class model returned the lowest values for all the information criteria and was therefore interpreted as follows: The prevalence rates of the latent classes were 1) 14.8% for the adherent; 2) 20.7% for the partially adherent; and 3) 64.5% for the nonadherent. Membership in the nonadherent class was associated with minority ethnicity, being female, eligibility due to welfare status, prior hospitalizations, and a higher number of prior treatment episodes. Membership in the partially adherent class was associated with higher use of outpatient care, higher rates of depot antipsychotic drug use, and polypharmacy. CONCLUSION Multiple indicators of adherence to antipsychotic medication can be used to define classes of adherence that are associated with patient characteristics and distinct patterns of prior health-care use.

Health Care Cost and Utilization Project analysis of comorbid illness and complications for patients undergoing hysterectomy for endometrial carcinoma

The objective was to study the association of race, comorbid illness, and lymph node dissection (LND) with complications in patients undergoing hysterectomy for endometrial carcinoma.

Comparisons of Hypertension-Related Costs from Multinational Clinical Studies

AbstractBackground: This study identifies and compares the individual cost components of hospital and ambulatory services that manage the care of hypertensive patients in eight countries: the US, the UK, France, Spain, Germany, Italy, Canada and Australia. Objective: Hypertension-related costs are classified according to four major cardiovascular events: (i) acute myocardial infarction; (ii) congestive heart failure; (iii) stroke; and (iv) renal failure, which was subdivided into renal failure treated by dialysis and renal failure treated by kidney transplantation. To make cross-country costs comparisons, we used the DRG codes used in the US and DRG-like codes from each country.US cost information was obtained from hypertension data available from the literature and health economics researchers. For costs in other countries, we consulted with national health economics experts in each country, used analyses by the Research Triangle Institute, and performed Medline and international literature searches. When available, we obtained information from the countries public and private nationally representative data sources. For cross-country currency adjustments, all currencies were converted using the Purchasing Power Parities from the Organisation for Economic Cooperation and Development, and then converted into inflation-adjusted year 2000 US dollars. Results: There exists considerable variation in hypertension-related costs from multinational clinical studies. This study documents that costs are generally higher in the US than in other countries; however, this is not always true. In particular, costs of treating heart failure in France and the costs of renal failure without transplantation in Germany and the UK are relatively high. Discussion: While analysing multinational hypertensive cost data, this study also addresses the impact of cross-country cost variations on cost analyses. During the last decade, drug-development researchers have drawn extensively upon multinational trials to resolve enrolment problems and drug-registration issues. At the same time, formulary decision-makers are increasingly demanding multinational cost-effectiveness analyses of the clinical differences found between drug-treatment regimens. Since these data are typically not captured by randomised clinical trials, standard cost estimates must be applied to the clinical trials’ resource data, although such standardised calculations do not necessarily account for clinical and cost variations between countries. Conclusion: This paper serves as an instrument for identifying which national and event cost data are comparable for analysis as well as highlighting specific problem areas for cost data integration. Although the study focuses on hypertension- related costs, its results may provide insight for multinational cost comparisons of other diseases where similar hospitalisation costs may be analysed.

Good Research Practices for Measuring Drug Costs in Cost-Effectiveness Analyses: An International Perspective: The ISPOR Drug Cost Task Force Report-Part VI

OBJECTIVE The pharmacoeconomic guidelines available in the literature or promulgated in many countries are either vague or silent about how drug costs should be established or measured so an international comparison of cost-effectiveness analysis (CEA) results can be made. The objective of this report is to provide guidance and recommendations on how drug costs should be measured for CEAs done from an internationally comparative perspective. METHODS Members of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Task Force on Good Research Practices-Use of Drug Costs for Cost Effectiveness Analysis (Drug Cost Task Force [DCTF]) subgroup from several countries were experienced developers or users of CEA models, and worked in academia, industry, and as advisors to governments. They solicited comments on drafts from a core group of 174 external reviewers and more broadly, from the members of the ISPOR at the ISPOR 12th Annual International meeting and via the ISPOR Web site. RESULTS Drug units should be standardized in terms of volume of active ingredient, regardless of packaging and dosing strength variations across countries. Drug costs should be measured in local currency per unit of active ingredient and should be converted to other currencies using sensitivity analyses of purchasing power parities (PPP) and exchange rates, whichever is more appropriate. When using drug prices from different years, the consumer price index for the local currency should be applied before the PPP and/or exchange rate conversion. CONCLUSION CEA researchers conducting international pharmacoeconomic analysis should tailor the appropriate measure of drug costs to the international perspective, to maintain clarity and transparency on drug cost measurement in the context of international drug comparison and report the sensitivity of CEA results to reasonable cost conversions.

Investigating differential item functioning by chronic diseases in the SF-36 health survey : A latent trait analysis using MIMIC models

Objectives: Differential item functioning (DIF) is present when respondents of unique subgroups endorse certain items differently given the respondents have the same underlying ability. This study investigates the presence of DIF regarding chronic illnesses among items of the physical functioning (PF) and mental health (MH) domains of the SF-36 health survey. Methods: Multiple indicators multiple causes (MIMIC) model was applied to data extracted from the Kaiser Permanente database for members who completed the SF-36 during 1994–1995 (N = 7538). DIF effects were evaluated for sociodemographic variables and for indicators of 5 chronic conditions: hypertension, rheumatic conditions, diabetes, respiratory diseases, and depression. An iterative strategy with backward selection was applied to build DIF models, which were estimated by weighted least squares. The Hochberg procedure was applied to P values for multiple tests. Results: After controlling for the selected covariates and the latent ability, DIF was present in 3 items for hypertension, one for respiratory diseases, and one for diabetes. Adjusting for DIF did not modify the overall pattern of exogenous variables’ effects on PF or MH, except Hispanic and other ethnicity on PF, education on MH became insignificant; and black ethnicity on PF, old ages and other ethnicity on MH became significant. Conclusions: Considering the number of items and disease subgroups compared, the presence of DIF was minimal among items of the PF and MH domains of the SF-36. DIF had little effect on comparisons of sociodemographic or disease groups.

Social values and healthcare priority setting in Korea

PURPOSE The purpose of this paper is to present the role of social values in setting healthcare priorities in Korea. DESIGN/METHODOLOGY/APPROACH Using Clark and Weales draft framework, Korean healthcare priority setting was analysed. The process values used were transparency, accountability, and participation, and the content values used were clinical effectiveness, cost effectiveness, justice/equity, solidarity and autonomy. FINDINGS In the Korean health priority setting, it was found that multiple factors influence the decision-making process. Effectiveness and safety are the two most important values mentioned in the process. Cost-effectiveness is also considered in reimbursement decisions for new drugs since 2007. Recently, health technology assessment (HTA) has begun to change the social value system traditionally used in the Korean healthcare priority setting. ORIGINALITY/VALUE The paper extends understanding of health priority setting in Korea, and how the interpretation and use of social values has changed over recent years.

Public participation in decision-making on the coverage of new antivirals for hepatitis C

Purpose - New hepatitis C medicines such as sofosbuvir underline the need to balance considerations of innovation, clinical evidence, budget impact and equity in health priority-setting. The purpose of this paper is to examine the role of public participation in addressing these considerations. Design/methodology/approach - The paper employs a comparative case study approach. It explores the experience of four countries - Brazil, England, South Korea and the USA - in making coverage decisions about the antiviral sofosbuvir and involving the public and patients in these decision-making processes. Findings - Issues emerging from public participation ac tivities include the role of the universal right to health in Brazil, the balance between innovation and budget impact in England, the effect of unethical medical practices on public perception in South Korea and the legitimacy of priority-setting processes in the USA. Providing policymakers are receptive to these issues, public participation activities may be re-conceptualized as processes that illuminate policy problems relevant to a particular context, thereby promoting an agenda-setting role for the public. Originality/value - The paper offers an empirical analysis of public involvement in the case of sofosbuvir, where the relevant considerations that bear on priority-setting decisions have been particularly stark. The perspectives that emerge suggest that public participation contributes to raising attention to issues that need to be addressed by policymakers. Public participation activities can thus contribute to setting policy agendas, even if that is not their explicit purpose. However, the actualization of this contribution is contingent on the receptiveness of policymakers.

Experiences and barriers to implementation of clinical practice guideline for depression in Korea.

BackgroundClinical guidelines can improve health-care delivery, but there are a number of challenges in adopting and implementing the current practice guidelines for depression. The aim of this study was to determine clinical experiences and perceived barriers to the implementation of these guidelines in psychiatric care.MethodsA web-based survey was conducted with 386 psychiatric specialists to inquire about experiences and attitudes related to the depression guidelines and barriers influencing the use of the guidelines. Quantitative data were analyzed, and qualitative data were transcribed and coded manually.ResultsAlmost three quarters of the psychiatrists (74.6%) were aware of the clinical guidelines for depression, and over half of participants (55.7%) had had clinical experiences with the guidelines in practice. The main reported advantages of the guidelines were that they helped in clinical decision making and provided informative resources for the patients and their caregivers. Despite this, some psychiatrists were making treatment decisions that were not in accordance with the depression guidelines. Lack of knowledge was the main obstacle to the implementation of guidelines assessed by the psychiatrists. Other complaints addressed difficulties in accessing the guidelines, lack of support for mental health services, and general attitudes toward guideline necessity. Overall, the responses suggested that adding a summary booklet, providing teaching sessions, and improving guidance delivery systems could be effective tools for increasing depression guideline usage.ConclusionIndividual barriers, such as lack of awareness and lack of familiarity, and external barriers, such as the supplying system, can affect whether physicians’ implement the guidelines for the treatment of depression in Korea. These findings suggest that further medical education to disseminate guidelines contents could improve public health for depression.

Resources and use of the intensive care unit in patients who undergo surgery for ovarian carcinoma

The objective of the current study was to determine the association of age, comorbid illness, and length of stay (LOS) in the intensive care unit (ICU) in women who underwent oophorectomy for ovarian carcinoma.

Venous Thromboembolism Following Hip and Knee Replacement Arthroplasty in Korea: A Nationwide Study Based on Claims Registry

The aim of this study was to examine the incidence and trends of clinically relevant venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) after hip and knee replacement arthroplasty (HKRA) in Korea. Between January 1 and December 31, 2010, 22,127 hip replacement arthroplasty (HRA) patients and 52,882 knee replacement arthroplasty (KRA) patients were enrolled in the analysis using the administrative claims database of the Health Insurance Review and Assessment Service (HIRA). All available parameters including procedure history and clinically relevant VTE during the 90 days after HKRA were identified based on diagnostic and electronic data interchange (EDI) codes. The overall incidence of VTE, DVT, and PE during the 90 days was 3.9% (n=853), 2.7% (n=597), and 1.5% (n=327) after HRA, while the incidence was 3.8% (n=1,990), 3.2% (n=1,699), and 0.7% (n=355) after KRA. The incidence of VTE after HKRA was significantly higher in patients who had previous VTE history (odds ratio [OR], 10.8 after HRA, OR, 8.5 after KRA), chronic heart failure (2.1, 1.3), arrhythmia (1.8, 1.7), and atrial fibrillation (3.4, 2.1) than in patients who did not. The VTE incidence in patients with chemoprophylaxis was higher than that in patients without chemoprophylaxis. The incidence of VTEs revealed in this retrospective review was not low compared with the results of the studies targeting other Asian or Caucasian populations. It may warrant routine prevention including employment of chemoprophylaxis. However, the limitation of the reviewed data mandates large scale prospective investigation to affirm this observation.