Effects of antiepileptic drug substitutions on epileptic events requiring acute care.

STUDY OBJECTIVES: To determine the odds of antiepileptic drug substitution among patients who had an epileptic event requiring acute care-ambulance service, emergency department visit, or hospitalization-relative to patients who did not have an event, and to compare these results with those from a recent study involving a similar method but different patients. DESIGN: Case-control analysis. DATA SOURCE: United States health care claims from the PharMetrics database. PATIENTS: A cohort of patients aged 12-64 years with a primary diagnosis of epilepsy between October 1, 2005, and December 31, 2006; 991 cases (patients who experienced an epileptic event requiring acute care) and 2973 controls (patients who did not have an event) were matched in a 1:3 ratio for sex, age, and type of epilepsy. MEASUREMENTS AND MAIN RESULTS: Using discordant pairs analysis, we calculated the odds ratio of an epileptic event that required acute care occurring in patients whose antiepileptic drug underwent substitution to an A-rated (therapeutically equivalent) alternative (switch from branded product to generic, generic to branded, or generic to generic) versus those whose drugs were not substituted. For matched data, 109 (11.0%) of 991 cases had an A-rated antiepileptic drug substitution in the 6 months before the event, whereas only 186 (6.3%) of 2973 controls had a substitution (odds ratio 1.84, 95% confidence interval 1.44-2.36). Our results were similar to those of a previous study involving a different patient database, which showed substitution rates of 11.3% for cases versus 6.5% for controls (odds ratio 1.81, 95% confidence interval 1.25-2.63). Our sensitivity analyses were robust, and we found a temporal relationship in that numerous substitutions occurred in the month before the acute event. CONCLUSION: Patients who had an epileptic event requiring acute care were about 80% more likely than matched controls without an acute event to have recently had an antiepileptic drug substitution. Our replication of a previously published case-control analysis revealed a similar association between substitution involving A-rated antiepileptic drugs and subsequent epileptic events requiring acute care, thereby lending credibility to the findings.

Patient adherence and reimbursement amount for antidiabetic fixed-dose combination products compared with dual therapy among Texas Medicaid recipients.

BACKGROUND: Little is known about the potential for improved adherence with and cost savings of fixed-dose combination therapy (FDCT) products compared with analogous dual therapy for type 2 diabetes mellitus. OBJECTIVES: The objectives of this study were as follows: (1) to describe patient adherence to various oral antidiabetic regimens (ie, dual therapy and FDCT); (2) to determine whether there is a difference in medication adherence between FDCT users and analogous dual-therapy users; and (3) to assess whether there is a difference in reimbursement amounts between an FDCT product and its individual components. METHODS: This study was a retrospective cohort analysis using the Texas Medicaid prescription claims database. The study subjects included those who used antidiabetic FDCT or dual therapy from August 1, 2000, to July 31, 2004. The identification period of study subjects was between August 1, 2000, and July 31, 2004, including 12 months before and after the index date, so that the overall time frame was from August 1, 1999, through July 31, 2005. Prescription claims were analyzed over a 12-month preindex and 12-month postindex period. Adherence was measured using medication possession ratio (MPR), and regimen costs per tablet were assessed utilizing the index prescription. RESULTS: Overall, 7570 FDCT users and 14,762 dual-therapy users were identified. Regarding the postindex period, FDCT users had 1.8% higher MPR compared with dual-therapy users (78.6% vs 77.2%). Patients who switched from monotherapy to FDCT had a 1.5% decrease in adherence (from 79.7% to 78.5%), whereas those who switched from monotherapy to dual therapy had a 10.0% decrease in adherence (from 83.0% to 74.7%). Those who switched from dual therapy to FDCT had a 12.4% increase in adherence (from 72.7% to 81.7%). Multivariate logistic regression analyses revealed that among preindex monotherapy users, FDCT users were significantly more likely to have higher adherence than dual-therapy users (odds ratio [OR] = 1.867; 95% CI, 1.716-2.032) after controlling for covariates, and the results were similar among preindex dual-therapy users (OR = 1.551; 95% CI, 1.204-1.999). From the perspective of the third-party payer, all FDCT products were significantly less expensive than their equivalent individual components (P < 0.001). CONCLUSIONS: Among these Texas Medicaid beneficiaries, antidiabetic FDCT users were more adherent to their regimen than dual-therapy users, and FDCT was less expensive than the analogous dual therapy. Because multiple agents are often required to achieve adequate glycemic control, it may be clinically and economically beneficial to treat eligible patients with FDCT products.

Physician specialty associated with antipsychotic prescribing for youths in the Texas Medicaid program.

BACKGROUND/OBJECTIVE: The use of antipsychotics in children and adolescents in the Texas Medicaid program has increased with the introduction of newer atypical antipsychotics. The purpose of this study was to examine physician specialty associated with antipsychotic prescribing from 1996 to 2001. METHODS: All antipsychotic prescription claims records for children and adolescents younger than the age of 20 years from 1996 to 2001 were extracted from the Texas Medicaid Drug Vendor prescription database. Physician specialty associated with youths receiving all, atypical, and conventional antipsychotic prescriptions was examined for time trends. Physician specialty categories included psychiatry, primary care, neurology, other, and unspecified. RESULTS: Psychiatrists accounted for more than 80% of youths receiving antipsychotic prescriptions from 1996 to 2001. The proportion of youths receiving antipsychotic prescriptions from primary care physicians remained fairly steady over the course of time (1996: 19%; 2001: 16%). The number of youths prescribed conventional antipsychotics decreased in all specialty groups, whereas the number prescribed atypical antipsychotic prescriptions increased dramatically. CONCLUSIONS: Although the majority of children and adolescents in the Texas Medicaid program were prescribed antipsychotics by psychiatrists and child and adolescent psychiatrists, youths may often receive treatment within the primary care setting. Future research is necessary to evaluate patient outcomes associated with antipsychotic treatment across different treatment settings.

Drug adherence: effects of decreased visit frequency on adherence to clozapine therapy.

OBJECTIVE: To study the effects of visit frequency on drug-adherence parameters subsequent to the change in the United States Food and Drug Administration (FDA)-mandated monitoring of white blood cell counts from weekly to every 2 weeks (biweekly) after 6 months of clozapine therapy. METHODS: Paid prescription claims records for clozapine from September 1, 1995-August 31, 2001, were extracted from the Texas Medicaid Vendor Drug Program database. Two groups of subjects were identified: subjects treated before and those treated after the FDA labeling change in monitoring frequency, which occurred on April 1, 1998. Prescription claims records for each subject were assessed for 365 days after the initial 6 months of therapy. Adherence measures included persistence, medication possession ratio (MPR), and time taking clozapine. RESULTS: Subjects receiving weekly hematologic monitoring had significantly higher rates of persistence (0.79 +/- 0.35 vs 0.70 +/- 0.38, p < 0.001) and MPRs (0.75 +/- 0.36 vs 0.66 +/- 0.38, p < 0.001) and continued to take clozapine longer (p < 0.002) compared with subjects receiving biweekly monitoring. Fewer subjects in the weekly monitoring group discontinued clozapine therapy during the 1-year study period (49.4% vs 57.9%, p = 0.008). Similar results were observed when cohorts were matched according to age, sex, and index clozapine dosage. CONCLUSION: Significant effects of visit frequency on adherence to clozapine therapy were noted. For patients inadequately adherent to therapy, an increase in visit frequency may improve adherence, and based on these results, the extra visits do not need to be with a physician or have any specific purpose other than contact with a provider.

Trends in the use of typical and atypical antipsychotics in children and adolescents.

OBJECTIVE: To estimate prevalence rates of antipsychotic use in children and adolescents from 1996 to 2001 in three state Medicaid programs (midwestern [MM], southern [SM], and western [WM]) and one private managed care organization (MCO). METHOD: Prescription claims were used to evaluate antipsychotic prevalence, defined as the number of children and adolescents up to the age of 19 years with at least one prescription claim for an antipsychotic per 1,000 enrolled youths. RESULTS: From 1996 to 2001, the prevalence of total antipsychotic use increased in each program (MM: 4.7 to 14.3 per 1,000; SM: 6.3 to 15.5; WM: 4.5 to 6.9; and MCO: 1.5 to 3.4). Typical antipsychotic use decreased (MM: 3.7 to 2.0 per 1,000; SM: 4.6 to 1.5; WM: 4.4 to 1.3; and MCO: 1.2 to 0.9), while atypical antipsychotic use dramatically increased (MM: 1.4 to 13.1 per 1,000; SM: 2.5 to 14.9; WM: 0.3 to 6.2; and MCO: 0.4 to 2.7). CONCLUSIONS: The increased prevalence of antipsychotic use in children and adolescents from 1996 to 2001 was attributed to increased use of atypical antipsychotics. Given the limited data with atypical antipsychotics in youths, this emphasizes the need for additional studies of these agents and other treatment modalities in this population.

Quantitative analysis of sponsorship bias in economic studies of antidepressants.

BACKGROUND: Concern is widespread about potential sponsorship influence on research, especially in pharmacoeconomic studies. Quantitative analysis of possible bias in such studies is limited. AIMS: To determine whether there is an association between sponsorship and quantitative outcomes in pharmacoeconomic studies of antidepressants. METHOD: Using all identifiable articles with original comparative quantitative cost or cost-effectiveness outcomes for antidepressants, we performed contingency table analyses of study sponsorship and design v. study outcome. RESULTS: Studies sponsored by selective serotonin reuptake inhibitor (SSRI) manufacturers favoured SSRIs over tricyclic antidepressants more than non-industry-sponsored studies. Studies sponsored by manufacturers of newer antidepressants favoured these drugs more than did non-industry-sponsored studies. Among industry-sponsored studies, modelling studies favoured the sponsor's drug more than did administrative studies. Industry-sponsored modelling studies were more favourable to industry than were non-industry-sponsored ones. CONCLUSIONS: Pharmacoeconomic studies of antidepressants reveal clear associations of study sponsorship with quantitative outcome.

Impact of atypical coverage for patients with community-acquired pneumonia managed on the medical ward: results from the United States Community-Acquired Pneumonia Project.

STUDY OBJECTIVE: As current guidelines for treatment of community-acquired pneumonia (CAP) recommend empiric antimicrobial coverage for atypical pathogens, we evaluated the need for atypical coverage by examining length of hospital stay (LOS) and mortality in patients with CAP who were managed on the medical ward. METHODS: Medical records of patients with CAP admitted from January 1, 1997-December 31, 2001, from 176 United States nonteaching community hospitals were reviewed. Patients were divided into one of three mutually exclusive groups on the basis of intravenous antimicrobials received on days 1 or 2 of hospital stay: ceftriaxone monotherapy, ceftriaxone plus a macrolide, or levofloxacin. Variables evaluated for their ability to predict outcome were patient age, year of hospital admission, geographic region, preadmission setting, preadmission antimicrobial treatment, timing of antimicrobial administration, comorbid disease, and duration of intravenous antimicrobial treatment. The impact of initial antimicrobial regimen on LOS and mortality was evaluated in regression models while controlling for significant predictors of outcome. RESULTS: Of 8975 patients evaluated, 2453 met the inclusion criteria. Significant differences were noted among patients who received ceftriaxone (932 patients), ceftriaxone plus a macrolide (872), and levofloxacin (649) with respect to mean +/- SD age (72 +/- 16, 67 +/- 18, and 70 +/- 17 yrs, respectively; p<0.0001), admission from a nursing home (21%, 11%, and 15%, respectively; p<0.0001), and duration of intravenous antimicrobial treatment (4.4 +/- 2.7, 4.0 +/- 2.6, and 3.6 +/- 2.5 days, respectively; p<0.0001). The LOS predictors were age, geographic region, coexisting heart failure, and duration of intravenous antimicrobial therapy. Mortality predictors were age, admission from a nursing home, coexisting heart failure, and coexisting cancer. After controlling for these predictors of outcome, no significant differences were noted among the three groups for LOS (5.5 +/- 3.5, 4.8 +/- 2.9, and 4.8 +/- 2.9 days, respectively; p=0.2791) or mortality (3.1%, 2.0%, and 2.6%, respectively; p=0.8461). CONCLUSION: Initial coverage for atypical pathogens does not affect LOS or mortality among patients with CAP managed on the medical ward.

Olanzapine versus risperidone in the treatment of schizophrenia : a comparison of costs among Texas Medicaid recipients.

OBJECTIVE: To examine both schizophrenia-related costs and total (schizophrenia plus non-schizophrenia) healthcare costs among Texas Medicaid recipients who had been diagnosed with a schizophrenic disorder and had been initiated on olanzapine or risperidone. METHODS: Cost data for services and prescription use were retrieved for 2,885 patients with schizophrenia who were initiated on olanzapine or risperidone between 1 January 1997 and 31 August 1998. Each patient was followed for 1 year before and 1 year after initiation of therapy. Multivariate analysis was used to control for a wide range of factors (drug choice, patient demographics, pre-utilisation costs, region, health conditions, and treatment patterns) that may influence schizophrenia-related costs and total healthcare costs. Estimation was conducted via a two-stage instrumental variables model. RESULTS: The mean unadjusted total schizophrenia-related cost per patient per year during the observation period was 4,892 US dollars, and the total unadjusted healthcare cost per patient was 7,101 US dollars. Results revealed significant regional variation in schizophrenia-related and total healthcare costs. Significantly higher total healthcare costs were found for patients with other (nonpsychiatric) diagnoses, such as HIV and diabetes mellitus. Although, on average, patients taking olanzapine stayed on therapy longer than those taking risperidone (248.2 days vs 211.1 days; p < 0.0001), multivariate analysis revealed no significant difference in schizophrenia-related costs between patients who received olanzapine and risperidone (123 US dollars lower with olanzapine; p = 0.6439). However, patients who received olanzapine compared with risperidone had significantly lower total medical costs (693 US dollars lower with olanzapine; p = 0.0311). CONCLUSION: This naturalistic study used data from a Texas Medicaid population to examine the schizophrenia-related costs and total healthcare costs for patients who received olanzapine versus risperidone. Multivariate analysis revealed no significant differences in schizophrenia-related costs for patients receiving olanzapine compared with risperidone, although total medical costs were significantly lower for patients initiated on olanzapine.

Ethnic differences in use of antipsychotic medication among Texas medicaid clients with schizophrenia.

BACKGROUND: Culture and ethnicity have been suggested to influence the presentation of patients with schizophrenia. These factors are thought to affect the diagnoses, courses of treatment, and medical utilization patterns of patients with schizophrenia. Specifically, the differences between whites, African Americans, and Mexican Americans are of particular importance, as these groups comprise the majority of the population in the United States today. The traditional course of treatment for many patients with schizophrenia is the drug haloperidol. However, research has shown that some ethnic groups (African Americans and Mexican Americans) may respond better to atypical drugs, such as olanzapine, but may be less likely to receive these drugs. A better response to the course of treatment results in improved medical utilization patterns. The purpose of this study was to examine if ethnicity helped predict whether Texas Medicaid patients were prescribed haloperidol versus olanzapine when other factors were controlled for. METHOD: The study population consisted of 726 patients whose index drug was haloperidol and 1875 patients whose index drug was olanzapine. Patients had an ICD-9-CM diagnosis of schizophrenia or schizoaffective disorder. Texas medical and prescription claims data were used in a logistic regression analysis to determine significant predictors of the type of antipsychotic (haloperidol vs. olanzapine) patients were prescribed. Variables included in the analysis were ethnicity, gender, age, region, other mental illness comorbidities, and previous utilization of medications and resources. Data were collected from Jan. 1, 1996, to Aug. 31, 1998. RESULTS: The results show that when other demographic and utilization factors were controlled for, African Americans were less likely than whites to receive olanzapine rather than haloperidol. CONCLUSION: Ethnicity is a significant predictor of the type of antipsychotic that is prescribed.

Trends in antipsychotic use in a Texas medicaid population of children and adolescents: 1996 to 2000.

The purpose of this study was to examine the current trends in prescribing antipsychotics to children and adolescents within the Texas Medicaid Program. Total enrollments of children and adolescents, ranging from infants to 19-year-olds, in the Texas Medicaid Program were determined for each calendar year from 1996 to 2000. Prevalence was defined as the number of children and/or adolescents with at least one Medicaid prescription claim for an antipsychotic per 1,000 enrollees. Trends in prevalence were assessed over a 5-year period using annual descriptive analyses. In addition, total expenditures for antipsychotics were evaluated within this population. Over the 5-year period, an additional 12.25 children and adolescents per 1,000 enrollees (+160%) were prescribed antipsychotics. The prevalence of atypical antipsychotics increased by 13.29 per 1,000 enrollees (+494%) over the same period. In children and adolescents above 2 years of age, the prevalence of antipsychotic use increased in all groups. Antipsychotic usage was more common in children and adolescents between the ages of 10 and 14 years compared to other age groups. Male and female antipsychotic prevalence rates increased during the 5-year period. The increase in total expenditures was related to the increased utilization of atypical antipsychotics.

Economic evaluation of citalopram use and expenditures among recipients in the Texas Medicaid program.

OBJECTIVE: To describe the trends in the utilization and expenditures of selective serotonin reuptake inhibitors (SSRIs) and venlafaxine within the Texas Medicaid program in 1999 and 2000; more specifically, to compare the use of citalopram with other SSRI agents and venlafaxine. METHODS: A retrospective analysis of Texas Medicaid paid prescription claims data involving Texas Medicaid clients aged 18 to 64. The main outcome measures were allowed, discounted cost per day; dose per day; treatment days (persistence); adherence rates; and switching rates. RESULTS: Citalopram had a significantly lower calculated cost per day than all other comparator agents. There were no statistically significant differences between study agent groups when comparing treatment days and adherence days for newly started patients, except for lower rates with venlafaxine IR. CONCLUSIONS: Within the Texas Medicaid Program, citalopram had a positive economic impact on prescription drug costs compared to other comparator agents, while showing similar outcomes in utilization measures such as treatment days and adherence rates.