C.M. Kelton

PHP16 a COMPREHENSIVE STUDY OF GENERIC DRUG ENTRY IN THE UNITED STATES: 1991–2008

PHP13 FACTORS ASSOCIATED WITH THE PROVISION OF LAPAROSCOPIC SURGERY IN THAILAND: RESULTS FROM THE NATIONWIDE INPATIENT DATABASE Vongkom W, Tosanguan K, Chaikledkaew U, Teerawattananon Y Division of Social and Administrative Pharmacy, Bangkok, Thailand, Health Intervention and Technology Assessment Program (HITAP), Nonthaburi, Thailand OBJECTIVES: Laparoscopic surgery (LS) requires advanced and expensive surgical instruments but offers better quality of life and shorten hospitalization compared to conventional surgery. This study aimed to evaluate the utilization of LS between patients under Civil Servant Medical Benefi t scheme (CSMBS) and those under Universal Coverage scheme (UC) and to determine the factors associated with the provision of LS in most common diseases. METHODS: A hospital data of patients undergoing LS were obtained from the Central Offi ce for Healthcare Information. The database contained 686,553 admissions with principle diagnoses related to LS from January 2005 to December 2007. Descriptive analyses and binary logistic regression models were used to analyze the data. RESULTS: The total of 24,175 hospitalizations (3.52%) was operated with LS. The proportion of CSMBS patients undergoing LS (7.8%) was higher than that of UC patients (2.68%). It was found that diseases of gallbladder and cholecystitis, diseases of gynecology and acute appendicitis were the most diseases performing LS in Thailand. The provision of LS was signifi cantly associated with age, sex, principal diagnosis, admission year, type of hospitals and type of health insurance coverage. Patients with CSMBS were about two or three times more likely to undergo LS compared to UC. Type of health insurance was the most signifi cant factor associated with the use of LS. CONCLUSIONS: There is an unequal access to LS among patients owing to both medical and nonmedical indications. Health insurance coverage plays a signifi cant role in LS provision in Thailand.

MH2 ECONOMIC AND CLINICAL CONSEQUENCES ASSOCIATED WITH POTENTIAL DRUG-DRUG INTERACTIONS BETWEEN ANTIPSYCHOTICS AND CONCOMITANT MEDICATIONS IN PATIENTS WITH SCHIZOPHRENIA

were estimated. RESULTS: A total of 1179 eligible patients were identified with mean age 15.2 years (SD, 2.16) and 51% female. The distribution was: FGA’s 19% (n = 253), aripiprazole 11% (n = 129), olanzapine 15% (n = 182), quetiapine 25% (n = 297), risperidone 26% (n = 308), and ziprasidone 3% (n = 32). In the linear model, adolescents on olanzapine experienced a significant increase in BMI [0.84 kg/m (CI, 0.17–1.52)] compared to those on aripiprazole. Logistic model results indicated a significant likelihood of a 5 to 20% increase in BMI for those on olanzapine [OR: 1.54 (CI, 0.96–2.5) to 4.53 (CI, 1.79–11.48) and a 10 to 20% increase for those on risperidone [OR: 1.84 (CI, 1.15–3.0) to 2.18 (CI, 1.21–3.96)], compared to aripiprazole. In the BMI z-score analysis, adolescents on olanzapine experienced a significant increase in BMI [OR: 1.65 (CI, 1.02–2.67)]. Results for FGA’s, quetiapine, and ziprasidone were not statistically significant. CONCLUSION: Potential for weight gain varies by antipsychotics and should be taken into account while prescribing these medications to adolescents.

PHP34 PRINCIPAL COMPONENTS ANALYSIS OF DRUG UTILIZATION AND EXPENDITURETRENDS FOR MAJORTHERAPEUTIC CLASSES IN U.S. MEDICAID PROGRAMS

PHP31 DRUG PROXIES FOR IDENTIFYING SPECIFIC DIAGNOSES IN MEDICARE PART D Livengood KB, Harada A, Gong S, Stockl K, Le L, Zhang S Prescription Solutions, United Health Group, Irvine, CA, USA OBJECTIVE: The purpose of this analysis was to develop a method for identifying Medicare Part D members with cardiovascular disease using medication proxies. METHODS: A binary matrix was created from cardiovascular medication prescription claims for Medicare Part D MAPD and commercial members from the first quarter of 2007. The binary matrix was subjected to factor/principal component analysis. The maximum valued factor loading for each of the generated components were then used to create a member/factor loading matrix. This matrix was used to derive beta coefficients, from logistic regression, to calculate a member’s probability of having hypertension, CAD, or CHF. RESULTS: One-hundred and twelve factors were produced over 696,471 members prescribed cardiovascular medications. Different probability thresholds were evaluated to determine the sensitivity and specificity for the identification method. The threshold probabilities ran from >0.30 to >0.975. As the threshold probabilities increased, sensitivity/specificity for hypertension, CAD, and CHF ran from 0.99/0.50–0.50/0.99, 0.61/0.91– 0.50/0.99, and 0.63/0.96–0.50/0.99, respectively. A similar result was produced using maximum score coefficients resulting from the principal component analysis. CONCLUSION: Although this approach to identifying members with medication proxies appears to separate members with and without certain cardiovascular conditions, it tends to exclude members at the cost of minimizing erroneously identified members.

PMH15 ANALYSIS OF POTENTIAL DRUG-DRUG INTERACTION PAIRS ASSOCIATED WITH ANTIPSYCHOTICS AMONG MEDICAID PATIENTS WITH SCHIZOPHRENIA OR BIPOLAR DISORDER

Objectives: Patients with schizophrenia, schizoaffective disorder, or bipolar disorder often receive multiple medications as part of their treatment regimens. Since many antipsychotics are metabolized by cytochrome P450 (CYP450) isoenzymes (1A2, 2D6, and 3A4), we proposed to assess the risk of receiving potential drug-drug interaction (DDI) pairs associated with the inhibition or induction of CYP450 isoenzymes.

PMH23 A COMPARISION OF HEALTH CARE UTILIZATION AND COST OF CHILDREN AND ADOLESCENTS WITH BIPOLAR DISORDER TREATED WITH ATYPICAL ANTIPSYCHOTIC MONOTHERAPYVERSUS MOOD STABILIZER MONOTHERAPY

A COMPARISION OF HEALTH CARE UTILIZATION AND COST OF CHILDREN ANDADOLESCENTSWITH BIPOLAR DISORDERTREATEDWITH ATYPICAL ANTIPSYCHOTIC MONOTHERAPYVERSUS MOOD STABILIZER MONOTHERAPY Jing Y, Guo JJ, Patel NC, Heaton PC, Li H, Kelton CM University of Cincinnati, Cincinnati, OH, USA, University of Georgia, Augusta, GA, USA, Bristol-Myers Squibb Company, Singapore, Singapore OBJECTIVE: To compare health care utilization and cost of children and adolescents with bipolar disorder treated with atypical antipsychotic (ATYP) versus with mood stabilizer (MS) monotherapy. METHODS: We conducted a retrospective cohort study using Pharmetrics administrative claims data from January 1, 1998 to December 31, 2002. The study population included youths (6 < AGE < 19). RESULTS: After matching on the propensity score, 486 subject pairs were retained. On average, ATYP monotherapy subjects had fewer bipolar-related office visits (p = 0.0041), but similar bipolar-related outpatient hospitalization (p = 0.084), bipolar-related days of hospitalization (p = 0.1707), and bipolar-related emergency department visits (p = 1.00). ATYP monotherapy subjects had a lower cost of bipolar-related office visits (p = 0.0246) but higher medication costs (p < 0.0001). There were no cost differences between groups for bipolar-related emergency department visits (p = 0.5477), bipolar-related outpatient hospitalization (p = 0.9817), and bipolar-related inpatient hospitalizations (p = 0.521). Total bipolar-related medical service (p = 0.6501) and general health-related medical service (p = 0.885) costs were also not significantly different between the two groups. CONCLUSION: Compared to patients with MS monotherapy, patients with ATYP monotherapy had fewer bipolar-related office visits and higher medication costs, but similar total bipolarrelated and overall medical service costs.

PCV30 TREND ANALYSIS OF PRICE AND UTILIZATION OF STATIN DRUGS IN U.S. MEDICAID PROGRAMS

Results are expressed as cost per life year gained (LYG). RESULTS: The results for a hypothetical male with a 10-year risk of cardiovascular death of 5% are reported. Compared to no statin the incremental cost-effectiveness ratio (ICER) of rosuvastatin 10mg, atorvastatin 20mg, simvastatin 80mg branded, and simvastatin 80mg generic were €17,080/LYG, €27,090/LYG, €36,261/LYG and €19,206/LYG, respectively. Using atorvastatin 10mg, simvastatin 40mg branded, and simvastatin 40mggeneric reduces ICER to €20,348/LYG, €23,123/LYG and €13,454/LYG respectively. CONCLUSION: To obtain the same relative reduction in TC rosuvastatin 10mg seems more costeffective compared to atorvastatin 20mg and simvastatin 80mg. Using higher doses of the same drug results in increased ICERs.