Why is warfarin underused for stroke prevention in atrial fibrillation? A detailed review of electronic medical records

OBJECTIVE

Automated electronic queries of structured data fields in electronic medical records (EMR) found no barriers to warfarin in 42% of patients with atrial fibrillation or atrial flutter (AF) with moderate or high risk of stroke and no warfarin. A thorough manual review of records (including text reports) from the same EMR may better identify physicians' reasons for not using warfarin.

METHODS

This was a cross-sectional, retrospective, manual EMR review. Patients identified in a previous automated EMR study with a CHADS2 (Chronic heart failure, Hypertension, Age >75 years, Diabetes mellitus, Stroke) score≥2, no record of warfarin, no barrier to warfarin use, and (in the present study) confirmation of AF diagnosis were included in the manual EMR review. A structured chart abstraction form was used to extract data visible in the clinicians' EMR user interface. Reasons why warfarin had not been prescribed were reported using descriptive statistics.

RESULTS

Among 408 patients with 'no barriers' to warfarin in the automated EMR review, AF diagnosis was confirmed in 319 patients (mean age 74.8; 65% female). Forty-one percent (n=132) did not have chart records explaining why they were not on warfarin. Among the 59% (187) with a rationale against warfarin found in the records, the most common category (52%) was indicative of the risk of bleeding, either risk of fall or history of recent bleeding. The second most common category (16%) reflected that the patient was back in sinus rhythm. These findings are subject to inherent limitations of retrospective chart reviews.

CONCLUSIONS

Many patients with AF and moderate-to-high risk of stroke are not treated with warfarin, and reasons for not using warfarin could not always be identified in patient records. Among patients with documented reasons, risk of bleeding (risk of fall or recent bleeding) was the most common category.

Medical care costs and hospitalization in patients with bipolar disorder treated with atypical antipsychotics

BACKGROUND

A large proportion of costs associated with the treatment of bipolar disorder are attributable to patient hospitalization.

OBJECTIVE

To investigate medical care costs and hospitalization rates among patients with bipolar disorder who were managed with aripiprazole compared with olanzapine, quetiapine, risperidone, or ziprasidone.

METHODS

This retrospective cohort study assessed patients who were aged 18 to 64 years, diagnosed with bipolar disorder, and who were receiving therapy with aripiprazole, olanzapine, quetiapine, risperidone, or ziprasidone. This study was based on data from the PharMetrics claims database between January 1, 2003, and September 30, 2008. The study used a time-to-event framework. Cox proportional hazards models were used to assess the impact of each atypical antipsychotic on time to hospitalization, including all-cause and mental health-related reasons. Generalized linear models were used to compare costs per treated patient per month between the groups. Aripiprazole therapy was the reference group for all comparisons.

RESULTS

Aripiprazole therapy showed a significantly lower hazard ratio (HR) for all-cause hospitalizations compared with olanzapine (HR, 1.4), quetiapine (HR, 1.4), risperidone (HR, 1.2), and ziprasidone (HR, 1.7); and for mental health-related hospitalizations compared with olanzapine, quetiapine, risperidone (HR, 1.3 each), and ziprasidone (HR, 1.7). Ziprasidone had higher unadjusted all-cause medical costs (US $1151 ± $2928) and unadjusted mental health-related costs (US $711 ± $2263) than the other antipsychotics that were included in this study, whereas aripiprazole had the lowest all-cause (US $804 ± $2523) and mental health-related costs (US $475 ± $2145) compared with the other antipsychotics. Quetiapine had the highest all-cause costs (US $1221; 95% confidence interval [CI], 1180-1263), and ziprasidone had the highest mental health-related costs (US $823; 95% CI, 754-898). Adjusted inpatient and emergency department all-cause costs were significantly lower for aripiprazole compared with all other atypical antipsychotics (P <.05), except olanzapine; however, the adjusted inpatient and emergency department mental health-related costs were significantly lower for aripiprazole only when compared with ziprasidone (P <.05).

CONCLUSIONS

The costs of medical care for patients with bipolar disorder differ based on the type of medication used, which can affect the rate of hospitalization. Treatment with aripiprazole was associated with fewer hospitalizations, longer time to hospitalization, and therefore the lowest all-cause and mental health-related medical costs compared with olanzapine, quetiapine, risperidone, or ziprasidone. Therefore, aripiprazole may offer an economic advantage over other atypical antipsychotics in patients with bipolar disorder.

Downregulation of Mcl-1 through GSK-3β activation contributes to arsenic trioxide-induced apoptosis in acute myeloid leukemia cells

Arsenic trioxide (ATO) induces disease remission in acute promyelocytic leukemia (APL) patients, but not in non-APL acute myeloid leukemia (AML) patients. ATO at therapeutic concentrations (1-2 μM) induce APL NB4, but not non-APL HL-60, cells to undergo apoptosis through the mitochondrial pathway. The role of antiapoptotic protein Mcl-1 in ATO-induced apoptosis was determined. The levels of Mcl-1 were decreased in NB4, but not in HL-60, cells after ATO treatment through proteasomal degradation. Both GSK3β inhibitor SB216763 and siRNA blocked ATO-induced Mcl-1 reduction as well as attenuated ATO-induced apoptosis in NB4 cells. Silencing Mcl-1 sensitized HL-60 cells to ATO-induced apoptosis. Both ERK and AKT inhibitors decreased Mcl-1 levels and enhanced ATO-induced apoptosis in HL-60 cells. Sorafenib, a Raf inhibitor, activated GSK3β by inhibiting its phosphorylation, decreased Mcl-1 levels, and decreased intracellular glutathione levels in HL-60 cells. Sorafenib plus ATO augmented ROS production and apoptosis induction in HL-60 cells and in primary AML cells. These results indicate that ATO induces Mcl-1 degradation through activation of GSK3β in APL cells and provide a rationale for utilizing ATO in combination with sorafenib for the treatment of non-APL AML patients.

Synthesis and electrochemical performances of LiNiCuZn oxides as anode and cathode catalyst for low temperature solid oxide fuel cell

Low temperature solid oxide fuel cell (LTSOFC, 300-600 degrees C) is developed with advantages compared to conventional SOFC (800-1000 degrees C). The electrodes with good catalytic activity, high electronic and ionic conductivity are required to achieve high power output. In this work, a LiNiCuZn oxides as anode and cathode catalyst is prepared by slurry method. The structure and morphology of the prepared LiNiCuZn oxides are characterized by X-ray diffraction and field emission scanning electron microscopy. The LiNiCuZn oxides prepared by slurry method are nano Li0.28Ni0.72O, ZnO and CuO compound. The nano-crystallites are congregated to form ball-shape particles with diameter of 800-1000 nm. The LiNiCuZn oxides electrodes exhibits high ion conductivity and low polarization resistance to hydrogen oxidation reaction and oxygen reduction reaction at low temperature. The LTSOFC using the LiNiCuZn oxides electrodes demonstrates good cell performance of 1000 mW cm(-2) when it operates at 470 degrees C. It is considered that nano-composite would be an effective way to develop catalyst for LTSOFC.

Cost-effectiveness of adjunctive therapy with atypical antipsychotics for acute treatment of major depressive disorder

BACKGROUND

While the clinical utility of atypical antipsychotics has been established in patients with major depressive disorder (MDD) who are refractory to antidepressant therapy, their cost-effectiveness is unknown.

OBJECTIVE

To examine the cost-effectiveness of aripiprazole, quetiapine, and olanzapine/fluoxetine in adults with MDD who are refractory to antidepressant therapy.

METHODS

Using techniques of decision analysis, we estimated expected outcomes and costs over 6 weeks in adults with MDD receiving (1) aripiprazole 2-20 mg/day and antidepressant therapy; (2) quetiapine 150 mg/day or 300 mg/day and antidepressant therapy; (3) the fixed-dose combination of olanzapine 6, 12, or 18 mg/day with fluoxetine 50 mg/day; or (4) antidepressant therapy alone. Cost-effectiveness was assessed in terms of the cost per additional responder at 6 weeks, defined as the ratio of the difference in the cost of MDD-related care over 6 weeks versus antidepressant therapy alone to the difference in the number of patients achieving clinical response by 6 weeks. We estimated the model using data from Phase 3 clinical trials of atypical antipsychotics along with other secondary data sources.

RESULTS

With antidepressant therapy alone, the estimated clinical response rate at 6 weeks was 30%. Aripiprazole, quetiapine 150 mg/day, quetiapine 300 mg/day, and olanzapine/fluoxetine were estimated to increase clinical response at 6 weeks to 49%, 34%, 38%, and 45%, respectively. Costs of MDD-related care over 6 weeks were estimated to be $192 for antidepressant therapy, $847 for aripiprazole, $541 for quetiapine 150 mg/day, $672 for quetiapine 300 mg/day plus antidepressant therapy, and $791 for olanzapine/fluoxetine. Costs per additional responder (vs antidepressant therapy) over a 6-week period were estimated to be $3447 for aripiprazole, $8725 for quetiapine 150 mg/day, $6000 for quetiapine 300 mg/day, and $3993 for olanzapine/fluoxetine.

CONCLUSIONS

Atypical antipsychotics substantially increase clinical response at 6 weeks. Cost per additional responder is lower for aripiprazole than for quetiapine or olanzapine/fluoxetine.

Abstract 171: Warfarin Use And Stroke Risk Among Patients With Nonvalvular Atrial Fibrillation In A Large Managed Care Population

Introduction Warfarin discontinuation among real world nonvalvular atrial fibrillation (NVAF) patients is common.

Hypothesis We hypothesized that in a managed care population, warfarin discontinuation is associated with increased stroke risk.

Methods Patients who initiated warfarin therapy between Jan 2005 and Jun 2009 and had a healthcare claim related to AF within 30 days prior to the first warfarin claim, but no evidence of valvular disease, were included. Warfarin discontinuation was defined as a supply gap of >60 days without evidence of International Normalized Ratio (INR) measurements. Follow-up was divided into periods of warfarin treatment and discontinuation. Stroke events were identified based on claims for inpatient stays with a primary diagnosis for stroke or transient ischemic attack (TIA). Cox proportional hazards models were constructed to assess the relationship between warfarin discontinuation and incident stroke while adjusting for baseline demographics, stroke and bleeding risk, and comorbidities, as well as time-dependent antiplatelet use, stroke, and bleeding events in the prior warfarin treatment period.

Results The mean (SD) age of the study sample (N=16,253) was 67±12 years; 64.8% was male. Mean CHADS2 score was 1.84±1.30; mean HAS-BLED score was 2.00±1.18. Half (51.4%) of patients discontinued warfarin therapy at least once and the overall sample had a mean of 1.87 warfarin treatment periods during a mean of 668 days follow-up. Approximately 1186 patients (7%) had a stroke or TIA at any site of service during follow-up. Risk of stroke significantly increased during warfarin discontinuation periods compared with therapy periods (HR 1.60; 95%CI 1.35-1.90; P<.0001). Stroke risk was significantly increased for patients with baseline CHADS2 score ≥2 (HR 2.69; 95%CI 1.44-5.03; P=.002), HAS-BLED score ≥3 (HR 1.46; 95%CI 1.05-2.05; P=.027), or who had a bleeding (HR 1.29; 95%CI 1.06-1.57; P=.013) or stroke event (HR 3.04; 95%CI 2.47-3.75; P<.0001) in the prior treatment period.

Conclusions In the real world, over half of patients on anticoagulation therapy had treatment gaps or permanently discontinued therapy. These usage patterns, as well as prior bleeding, were associated with increased stroke risk.

Abstract 190: Evaluation of Total Medical Costs with the Use of Apixaban and Rivaroxaban vs. Warfarin Among Atrial Fibrillation Patients

Introduction: While clinical trials have demonstrated that apixaban and rivaroxaban are effective and safe alternatives to warfarin, little is known regarding the total medical costs associated with such usage of the new anticoagulants (NOACs).

Hypothesis: This study assessed the hypothesis that apixaban and rivaroxaban use among the general and elderly AF patients avoids medical costs when compared to warfarin, based on the results of the ARISTOTLE and ROCKET-AF trials.

Methods: Event rates in patients receiving warfarin, apixaban, and rivaroxaban were estimated for the general and elderly (age ≥ 75 years) AF patient populations. Event rates associated with warfarin were calculated as weighted averages from NOAC trials among AF patients; NOAC rates were estimated by adjusting trial hazard ratios to these weighted averages. Annual incremental costs among patients with clinical events from the US payer perspective were obtained from published literature and inflation adjusted to 2010 cost levels. Total medical costs were compared for each NOAC vs. warfarin.

Results: Apixaban use was associated with medical cost reductions (Table) in both the general and elderly populations compared to warfarin; cost avoidance was driven by reductions in major bleeding excluding hemorrhagic stroke (MBEHS) and stroke or systemic embolism (SSE). Rivaroxaban-mediated cost reductions among the both the general and elderly population came from reduced SSE which was offset by increased MBEHS costs; Myocardial infarction, pulmonary embolism or deep vein thrombosis and non-major bleeding each made smaller contributions to the medical cost differences among both populations.

Conclusions: Apixaban and rivaroxaban use may be associated with reduced total medical cost among the general AF patient population when compared to warfarin. Apixaban vs. warfarin usage among elderly AF patients may be associated with a substantial medical cost reduction due to reductions in both stroke and major bleeding events.

Abstract 249: Medical Cost Avoidance among the General and Elderly Atrial Fibrillation Populations Differs According to Specific Anticoagulant Use, Based on the ARISTOTLE and RE-LY Trials

Introduction: The randomized ARISTOTLE and RE-LY clinical trials demonstrated that the new oral anticoagulants (NOACs) apixaban and dabigatran were effective and safe options for stroke prevention among non-valvular atrial fibrillation (AF) patients. It is unclear how the use of NOACs for the treatment of AF affects total medical costs.

Hypothesis: This study evaluates the hypothesis that medical costs associated with the use of apixaban and dabigatran vs. warfarin are different among the general and elderly AF populations.

Methods: Clinical event rates in patients receiving warfarin, apixaban, and dabigatran were estimated for the general and elderly (age ≥ 75 years) AF patient populations. Event rates associated with warfarin were calculated as weighted averages from NOAC trials among AF patients; NOAC rates were estimated by adjusting trial hazard ratios to these weighted averages. Annual incremental costs among patients with clinical events from the US payer perspective were obtained from published literature and inflation adjusted to 2010 cost levels. Medical cost avoidance was evaluated for each NOAC vs. warfarin.

Results: Compared to warfarin, apixaban-mediated total medical cost reductions (Table) in both populations were driven by decreased major bleeding excluding hemorrhagic stroke (MBEHS) and stroke and systemic embolism (SSE). Dabigatran use reduced costs for the general population and increased costs for the elderly population; cost reduction in the general population was primarily due to reduced SSE while cost increase in the elderly population was primarily due to increased MBEHS. MI, PE or DVT, and non-major bleeding each made smaller contributions to the cost differences among both populations.

Conclusions: Compared to warfarin, apixaban use may be associated with reduced medical costs in both general and elderly AF populations. Dabigatran use may be associated with a reduction of medical costs in the general AF population, but increased medical costs among the elderly.

Effect of communicating depression severity on physician prescribing patterns: findings from the Clinical Outcomes in MEasurement-based Treatment (COMET) trial

OBJECTIVE

In this secondary analysis from the Clinical Outcomes in MEasurement-based Treatment trial (COMET), we evaluated whether providing primary care physicians with patient-reported feedback regarding depression severity affected pharmacological treatment patterns.

METHOD

Intervention-arm physicians received their patients' 9-item Patient Health Questionnaire scores monthly. Odds of having no change in antidepressant treatment during the 6-month study period were calculated. Relationships between depression symptom status (partial or nonresponse) at month 3 and treatment changes in months 3 through 6 were assessed.

RESULTS

Among 503 intervention and 412 usual care (UC) patients with major depressive disorder, most received antidepressant monotherapy at baseline (79.4% UC vs. 88.4% intervention; P=.047). Few switched their baseline antidepressant (17.4%), increased their dose (12.4%) or augmented with a second medication (2%). Odds of having no change in antidepressant therapy did not differ significantly between study arms (odds ratio 1.21; 95% confidence interval 0.78-1.88; P=.392). Few month 3 partial or nonresponders had a regimen change over the following 3 months; the study arms did not differ significantly (partial responders: 4.1% UC vs. 7.7% intervention; P=.429; nonresponders: 14.6% UC vs. 15.9% intervention; P=.888).

CONCLUSIONS

Among depressed patients treated in primary care, little active management was observed. The lack of treatment modification for the majority of partial and nonresponders was notable.

Abstract 3389: Why Warfarin was not used for Stroke Prevention in Atrial Fibrillation: A Detailed Review of Electronic Medical Charts

Purpose: In an automated analysis of Regenstrief Medical Record System (RMRS) data, approximately half of patients with atrial fibrillation or flutter (AF) and a CHADS2 score of ≥2 had not been treated with warfarin for stroke prevention. The automated query of diagnoses and other coded patient data identified predefined barriers to warfarin use (e.g. history of bleeding, alcohol abuse, or history of falls) in only about half of these patients. Therefore, a detailed review of electronic medical charts (including text reports) was conducted to explore why patients with AF at high risk of stroke are not treated with warfarin.

Methods: This retrospective study was a review of records from 1998 to 2007. Patients older than 18 with a diagnosis of non-valvular AF, CHADS2 score ≥2, at least one RMRS encounter within one year after the first record of AF diagnosis, and no barrier to warfarin in the automated RMRS analysis were included. A structured chart abstraction form was used to extract data. To confirm AF diagnosis, a record of AF in a clinical problem list, admission/discharge/progress report, or EKG report was required. In patients with confirmed AF, reasons why warfarin had not been prescribed were searched for, through one-by-one review of the patients, in the clinicians’ user interface. This interface displays laboratory results, diagnoses, medications, and text reports such as hospital admission and discharge summaries. Explicit (treating physician’s rationale) and implicit (potential barriers that were documented but not explicitly attached to the warfarin decision) reasons why warfarin was not used were reported using descriptive statistics.

Results: Among 408 patients (mean age 73.6; 62% women), the distribution of CHADS2 scores at baseline was 2: 49%; 3: 34%; 4:12%; and 5+:6%. AF diagnosis was confirmed in 319 patients, 41% (132) of whom did not have any records in the RMRS explaining why they were not on warfarin. Among the 59% (187) with reasons (explicit 47%, or implicit 53%) why warfarin had not been started, the most common category (52% of 187) was indicative of the risk of bleeding: either the risk of fall (40%) or a history of recent bleeding (13%). The second most common category (16% of 187) reflected that the patient was back in sinus rhythm: the AF was “intermittent,” “situational,” or paroxysmal, or had been converted or ablated. Other reasons included the patient’s desire not to take warfarin, use of enoxaparin, loss to follow up, or death.

Conclusion: Many patients with AF and at high risk of stroke are not treated with warfarin, and reasons for not using warfarin could not always be identified in patient records. Among patients with reasons recorded in charts, the most common reasons for not prescribing warfarin were indicative of avoiding the increased risk of bleeding.

Coronary artery bypass graft surgery in acute coronary syndrome: incidence, cost impact, and acute clopidogrel interruption

BACKGROUND

Guidelines stipulate that clopidogrel should be interrupted ≥ 5 days prior to elective coronary artery bypass graft (CABG) surgery to reduce the risk of bleeding unless the need for revascularization and/or the net benefit of the clopidogrel outweighs the potential risks of bleeding. This study describes real-world patterns of acute clopidogrel use, CABG surgery, and inpatient costs among patients with acute coronary syndrome (ACS).

METHODS

The study used the MarketScan® Commercial, Medicare Supplemental, and Hospital Drug databases, comprising health care data for > 63 million individuals in the United States. Acute coronary syndrome episodes, defined as hospitalizations for ACS (primary International Classification of Diseases, Ninth Revision, Clinical Modification codes 410.xx, 411.1x) occurring between January 1, 2005 and June 30, 2009, were identified from patients aged ≥ 18 years. Outcomes included cost of and length of stay (LOS) for ACS episodes and, among patients experiencing ACS episodes treated with acute clopidogrel administration followed by CABG surgery, the duration of clopidogrel interruption prior to CABG surgery. Analyses were descriptive.

RESULTS

A total of 160 168 ACS episodes were identified, and the mean patient age was 63.5 years. Coronary artery bypass graft surgery episodes comprised 9.3% (14 896 of 160 168) of all ACS episodes. The mean LOS was 9.8 (standard deviation [SD], 6.8) days per CABG surgery episode, and mean inpatient costs were $71 140 (SD, $68 012) per CABG surgery episode. Among patients experiencing ACS episodes with inpatient drug data and to whom acute clopidogrel was administered followed by CABG surgery (n = 8101), the mean duration of clopidogrel interruption was 3.3 (SD, 2.6) days, and the majority (62.1%) of these patients underwent surgery within 1 to 3 days after their last acute clopidogrel dose. The mean incremental increase in inpatient costs associated with 1 extra LOS day was $1991.

CONCLUSION

Coronary artery bypass graft surgery is used relatively infrequently among patients who experience ACS episodes. When CABG surgery is performed in a real-world setting, the majority or procedures are performed < 5 days after the last acute clopidogrel dose. However, among patients for whom urgent CABG surgery is not indicated, withholding CABG surgery to allow for clopidogrel interruption may only minimally affect inpatient costs and must be considered in the broader context of patient management.

Impact of cost-sharing on treatment augmentation in patients with depression

OBJECTIVES

Many patients with depression do not respond to first-line antidepressant therapy and may require augmentation with another concurrent treatment such as a second antidepressant, a stimulant, a mood stabilizer, or a second-generation antipsychotic (SGA). The objective of this study was to examine the relationship between patient cost-sharing and the use of augmentation among a sample of commercially insured patients.

STUDY DESIGN

Retrospective observational study of adult patients diagnosed with depression and receiving antidepressant therapy (n = 48,807).

METHODS

Logistic regression models estimated the likelihood of augmentation as a function of patient cost-sharing amounts. An alternative-specific conditional logit model of the likelihood of each augmentation class, varying the cost-sharing prices faced for each class, was also estimated. All models controlled for sociodemographic characteristics, physical and mental comorbidities, health plan type, and year of index antidepressant therapy initiation.

RESULTS

The range of mean copayments paid by patients for augmentation therapy was from $27.05 (antidepressant) to $38.81 (SGA). A $10- higher cost-sharing index for all augmentation classes was associated with lower odds of augmentation (adjusted odds ratio = 0.85; 95% confidence interval 0.79-0.91). Doubling the costsharing amount for each augmentation class was associated with a smaller percentage of patients utilizing each class of augmentation therapy.

CONCLUSIONS

Employers and payers should consider the relationship between cost-sharing and medication utilization patterns of patients with depression.

Medical cost reductions associated with the usage of novel oral anticoagulants vs warfarin among atrial fibrillation patients, based on the RE-LY, ROCKET-AF, and ARISTOTLE trials

OBJECTIVE

The randomized clinical trials, RE-LY, ROCKET-AF, and ARISTOTLE, demonstrate that the novel oral anticoagulants (NOACs) are effective options for stroke prevention among non-valvular atrial fibrillation (AF) patients. This study aimed to evaluate the medical cost reductions associated with the use of individual NOACs instead of warfarin from the US payer perspective.

METHODS

Rates for efficacy and safety clinical events for warfarin were estimated as the weighted averages from the RE-LY, ROCKET-AF and ARISTOTLE trials, and event rates for NOACs were determined by applying trial hazard ratios or relative risk ratios to such weighted averages. Incremental medical costs to a US health payer of an AF patient experiencing a clinical event during 1 year following the event were obtained from published literature and inflation adjusted to 2010 cost levels. Medical costs, excluding drug costs, were evaluated and compared for each NOAC vs warfarin. Sensitivity analyses were conducted to determine the influence of variations in clinical event rates and incremental costs on the medical cost reduction.

RESULTS

In a patient year, the medical cost reduction associated with NOAC usage instead of warfarin was estimated to be -$179, -$89, and -$485 for dabigatran, rivaroxaban, and apixaban, respectively. When clinical event rates and costs were allowed to vary simultaneously, through a Monte Carlo simulation, the 95% confidence interval of annual medical costs differences ranged between -$424 and +$71 for dabigatran, -$301 and +$135 for rivaroxaban, and -$741 and -$252 for apixaban, with a negative number indicating a cost reduction. Of the 10,000 Monte-Carlo iterations 92.6%, 79.8%, and 100.0% were associated with a medical cost reduction >$0 for dabigatran, rivaroxaban, and apixaban, respectively.

CONCLUSIONS

Usage of the NOACs, dabigatran, rivaroxaban, and apixaban may be associated with lower medical (excluding drug costs) costs relative to warfarin, with apixaban having the most substantial medical cost reduction.

Association between second-generation antipsychotic medication half-life and hospitalization in the community treatment of adult schizophrenia

OBJECTIVE

To examine the effect of antipsychotic medication half-life on the risk of psychiatric hospital admission and emergency department (ED) visits among adults with schizophrenia.

METHODS

Retrospective claims-based cohort study of adult Medicaid patients with schizophrenia who were prescribed second-generation antipsychotic monotherapy following hospital discharge between 1/1/04 and 12/31/06. Cox proportional hazards models were applied to compare adjusted hazards of mental disorder admission among patients treated with oral antipsychotics that have either a long [risperidone (t(1/2) = 20 h), olanzapine (t(1/2) = 30 h), aripiprazole (t(1/2) = 75 h)] (n = 1479) or short [quetiapine (t(1/2) = 6 h), ziprasidone (t(1/2) = 7 h)] (n = 837) half-life. Day-level models controlled for baseline background characteristics and antipsychotic adherence over time as measured by gaps in the prescription record. Similar analyses examined either hospitalization or ED visits as separate endpoints.

RESULTS

A significantly lower rate of hospitalization/ED visits was evident for long (0.74/patient-year) vs short (1.06/patient-year) half-life antipsychotics (p < 0.001). The unadjusted rate of hospitalization alone was significantly lower for long (0.38/patient-year) vs short (0.52/patient-year) half-life antipsychotics (p = 0.005). Compared with short half-life antipsychotic drugs, the adjusted hazard ratio associated with long half-life medications was 0.77 (95% CI = 0.67-0.88) for combined hospitalization/ED visits and 0.80 (95% CI = 0.67-0.96) for hospitalization. The corresponding number needed to treat with long, rather than short, half-life medications to avoid one hospitalization was 16 patients for 1 year and to avoid one hospitalization or ED visit was 11 patients for 1 year.

LIMITATIONS

This study demonstrated an association between antipsychotic medication half-life and hospitalization, not a causal link. Patients using long half-life medications had fewer comorbid mental health conditions and took fewer psychiatric medications at baseline. Other unmeasured differences may have existed between groups and may partially account for the findings.

CONCLUSIONS

In schizophrenia management, longer-acting second-generation antipsychotics were associated with a lower risk of hospital admission/ED visits for mental disorders.

Impact of dyspnea on medical utilization and affiliated costs in patients with acute coronary syndrome

BACKGROUND

Current clinical practice guidelines recommend dual antiplatelet therapy with aspirin and clopidogrel or prasugrel for patients with acute coronary syndrome (ACS). Ticagrelor, an experimental antiplatelet therapy, has been shown to be associated with significantly higher rates of dyspnea than clopidogrel in clinical trials. Patients with ACS presenting with dyspnea require additional medical attention to rule out possible heart failure or other serious diagnoses. This study used real-world data to quantify the direct medical costs of dyspnea among patients with a history of ACS.

OBJECTIVE

To determine the clinical and economic impact of a dyspnea episode for patients with a history of ACS using commercial and Medicare supplemental claims data.

METHODS

Patients with an emergency room (ER) visit with a primary diagnosis of dyspnea (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] diagnosis code, 786.0x) in 2008 or 2009 were identified using Thomson Reuters MarketScan(®) Research Databases. Patients were required to have 6 months of continuous medical enrollment prior to an ER visit and a history of ACS (ie, ≥ 1 inpatient claim, ≥ 1 ER visit, or ≥ 2 outpatient claims, with an ICD-9-CM diagnosis code for ACS [410.xx or 411.1x] in any position on the outpatient claim during either the baseline period or on the index date). An episode of dyspnea was defined as all ER and outpatient services on the day of an ER claim with a primary diagnosis of dyspnea, and any inpatient admissions occurring on the day of or day following the ER visit. Procedure utilization and expenditures were evaluated for the ER visit and associated outpatient services, as well as the proportion of ER visits that led to an inpatient stay. Costs were allowed charges (ie, provider payment plus member cost-share) adjusted to 2009 US constant dollars.

RESULTS

A total of 8433 ER visits for dyspnea were identified during 2008 to 2009 from these databases of approximately 74 million beneficiaries. The average cost per dyspnea episode was $6958, of which $1621 were outpatient costs associated with the ER visit (standard deviation, $3269). Along with physician services, assessment of dyspnea often included electrocardiogram (71.3%), chest radiograph (75.9%), and, occasionally, a B-type natriuretic peptide test (14.9%) or chest computed axial tomography scan (12.2%). More than one-fourth (25.8%) of dyspnea ER visits preceded an inpatient stay, with an average cost of $20 693 per patient.

CONCLUSIONS

Dyspnea is a significant event associated with high medical resource utilization and hospital costs. Ticagrelor, an experimental antiplatelet agent not yet available on the market, has been shown to be associated with significantly higher rates of dyspnea than clopidogrel in clinical trials. Considering that the increased risk of dyspnea for ticagrelor is well documented, these costs may be important to health plan decision-makers when evaluating costs associated with each antiplatelet therapy.

Intent-to-treat analysis of health care expenditures of patients treated with atypical antipsychotics as adjunctive therapy in depression

OBJECTIVE

To compare health care utilization and expenditures in patients with depression whose initial antidepressant (AD) treatment was augmented with a second-generation antipsychotic.

METHODS

Claims data from January 1, 2001, through June 30, 2009, were used to select patients aged 18 to 64 years with depression treated with ADs augmented with aripiprazole, olanzapine, or quetiapine. Patients were required to have 6 months of continuous eligibility before the first AD prescription and 6 months after the second-generation antipsychotic augmentation (index) date. Utilization and expenditures were assessed for 6 months after the index date. Multivariate regression was used to estimate adjusted expenditures and risks for hospitalizations and emergency department visits.

RESULTS

A total of 483 patients treated with aripiprazole, 978 with olanzapine, and 2471 with quetiapine were selected. Mean adjusted expenditures for aripiprazole were significantly lower than those for olanzapine for each service category (all-cause, all-cause medical care, mental health-related, and mental health-related medical care) and were significantly lower than those for quetiapine for each category with the exception of mental health-related. The adjusted risks for hospitalization and emergency department visits were significantly higher for quetiapine than for aripiprazole.

CONCLUSIONS

Compared with patients treated with ADs and aripiprazole, those treated with ADs and olanzapine or quetiapine had greater utilization and higher expenditures.

Using Administrative Claims Data to Estimate Virologic Failure Rates among Human Immunodeficiency Virus–Infected Patients with Antiretroviral Regimen Switches

Objective. To develop and validate a claims signature model that estimates proportions of HIV-infected patients in administrative claims databases who switched combination antiretroviral therapy (cART) regimens because of virologic failure. Methods. The authors used an HIV-specific registry (development data set) to develop logistic regression models to estimate odds of virologic failure among patients who switched cART regimens. Models were validated in a sample of administrative claims with laboratory values (validation data set). The final model was applied to an application data set as a worked example. Results. There were 1691, 1073, and 3954 eligible patients with cART switches in the development, validation, and application data sets, respectively. In the development data set, virologic failure before a switch was observed 21.8% of the time. Failure more likely caused the regimen switch among patients who were treatment experienced, had been receiving their baseline regimen for > 180 days, had ≥ 2 or more physician visits within 90 days, had > 1 HIV RNA or CD4 cell count test within 30 days, had any resistance test within 180 days, or had a change in regimen type. The final model had good discriminatory ability (C = 0.885) and fit (Hosmer-Lemeshow P = 0.8692). Failure was estimated to occur in 18.9% (v. 18.6% observed) of switches in the validation data set and 13.8% in the application data set. Conclusions. This claims signature model allows payers to use claims data to estimate virologic failure rates in their patient populations, thereby better understanding plan costs of failure.

One-year risk of psychiatric hospitalization and associated treatment costs in bipolar disorder treated with atypical antipsychotics: a retrospective claims database analysis

BACKGROUND

This study compared 1-year risk of psychiatric hospitalization and treatment costs in commercially insured patients with bipolar disorder, treated with aripiprazole, ziprasidone, olanzapine, quetiapine or risperidone.

METHODS

This was a retrospective propensity score-matched cohort study using the Ingenix Lab/Rx integrated insurance claims dataset. Patients with bipolar disorder and 180 days of pre-index enrollment without antipsychotic exposure who received atypical antipsychotic agents were followed for up to 12 months following the initial antipsychotic prescription. The primary analysis used Cox proportional hazards regression to evaluate time-dependent risk of hospitalization, adjusting for age, sex and pre-index hospitalization. Generalized gamma regression compared post-index costs between treatment groups.

RESULTS

Compared to aripiprazole, ziprasidone, olanzapine and quetiapine had higher risks for hospitalization (hazard ratio 1.96, 1.55 and 1.56, respectively; p < 0.05); risperidone had a numerically higher but not statistically different risk (hazard ratio 1.37; p = 0.10). Mental health treatment costs were significantly lower for aripiprazole compared with ziprasidone (p = 0.004) and quetiapine (p = 0.007), but not compared to olanzapine (p = 0.29) or risperidone (p = 0.80). Total healthcare costs were significantly lower for aripiprazole compared to quetiapine (p = 0.040) but not other comparators.

CONCLUSIONS

In commercially insured adults with bipolar disorder followed for 1 year after initiation of atypical antipsychotics, treatment with aripiprazole was associated with a lower risk of psychiatric hospitalization than ziprasidone, quetiapine, olanzapine and risperidone, although this did not reach significance with the latter. Aripiprazole was also associated with significantly lower total healthcare costs than quetiapine, but not the other comparators.

Comparison of second-generation antipsychotic treatment on psychiatric hospitalization in Medicaid beneficiaries with bipolar disorder

OBJECTIVE

To compare second-generation antipsychotics on time to and cost of psychiatric hospitalization in Medicaid beneficiaries with bipolar disorder.

METHODS

Retrospective study using healthcare claims from 10 US state Medicaid programs. Included beneficiaries were aged 18-64, initiated a single second-generation antipsychotic (aripiprazole, olanzapine, quetiapine, risperidone, or ziprasidone) between 1/1/2003-6/30/2008 (initiation date=index), and had a medical claim with an ICD-9-CM diagnosis code for bipolar disorder. A 360-day post-index period was used to measure time to and costs of psychiatric hospitalization (inpatient claims with a diagnosis code for a mental disorder [ICD-9-CM 290.xx-319.xx] in any position). Cox proportional hazards models and Generalized Linear Models compared time to and costs of psychiatric hospitalization, respectively, in beneficiaries initiating aripiprazole vs each other second-generation antipsychotic, adjusting for beneficiaries' baseline characteristics.

RESULTS

Included beneficiary characteristics: mean age 36 years, 77% female, 80% Caucasian, aripiprazole (n=2553), mean time to psychiatric hospitalization or censoring=85 days; olanzapine (n=4702), 81 days; quetiapine (n=9327), 97 days; risperidone (n=4377), 85 days; ziprasidone (n=1520), 82 days. After adjusting for baseline characteristics, time to psychiatric hospitalization in beneficiaries initiating aripiprazole was longer compared to olanzapine (hazard ratio [HR]=1.52, p<0.001), quetiapine (HR=1.40, p<0.001), ziprasidone (HR=1.33, p=0.032), and risperidone, although the latter difference did not reach significance (HR=1.18, p=0.13). The adjusted costs of psychiatric hospitalization in beneficiaries initiating aripiprazole were significantly lower compared to those initiating quetiapine (incremental per-patient per-month difference=$42, 95% CI=$16-66, p<0.05), but not significantly lower for the other comparisons.

LIMITATIONS

This study was based on a non-probability convenience sample of the Medicaid population. Analyses of administrative claims data are subject to coding and classification error.

CONCLUSIONS

Medicaid beneficiaries with bipolar disorder initiating aripiprazole had significantly longer time to psychiatric hospitalization than those initiating olanzapine, quetiapine, or ziprasidone, and significantly lower adjusted costs for psychiatric hospitalization than those initiating quetiapine.