Treatment adherence among patients with bipolar or manic disorder taking atypical and typical antipsychotics.
ABSTRACT This retrospective claims-based study evaluated treatment adherence among patients with bipolar or manic disorder treated with atypical and typical antipsychotics.
Claims data for 18,158 antipsychotic treatment episodes in 15,224 commercially insured patients with bipolar or manic disorder (ICD-9-CM criteria), from January 1999 through August 2003, were evaluated. Overall adherence was measured by adherence intensity (medication possession ratio) and treatment duration (length of treatment episodes). Treatment-related factors that may affect medication adherence were also investigated. Pairwise comparisons of the individual atypicals and a combined group of leading typical antipsychotics were undertaken using multiple regression analysis adjusting for differing patient characteristics.
Adherence intensity with quetiapine was 3% greater than with the typicals combined (p=.002) and was greater than with risperidone or olanzapine by 4% (p<.001) and 2% (p=.001), respectively. Olanzapine (2%, p<.001) and ziprasidone (3%, p=.001) showed significantly greater adherence intensity than risperidone. Risperidone (p=.002), olanzapine (p=.055), and the typicals (p=.021) demonstrated negative associations between dose and adherence intensity, while quetiapine showed a nonsignificant trend for a positive association (p=.074). Quetiapine and risperidone had significantly longer treatment durations than the typicals combined (1.05 and 1.00 months, respectively, p<.001) and longer treatment durations than olanzapine (0.75 and 0.79 months, respectively, p<.001) or ziprasidone (0.78 months, p=.002 and 0.69 months, p=.003, respectively). Shorter treatment durations were associated with switching to other antipsychotics or remaining on or switching to other psychotropics (e.g., traditional mood stabilizers) only. All of the atypicals except ziprasidone were associated with a significantly lower likelihood of switching compared with the typicals (p<.05).
The claims-based findings of this study suggest that, for bipolar or manic disorder, quetiapine therapy may be associated with better treatment adherence than typical or some atypical antipsychotics. Estimated differences, however, were relatively small, particularly for adherence intensity.
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ABSTRACT: This article briefly summarizes the burden of bipolar disorder and the clinical profile of quetiapine (Seroquel®) in the management of bipolar disorder, followed by a detailed review of pharmacoeconomic analyses. Quetiapine is an atypical antipsychotic that is available in numerous countries as immediate-release and extended-release tablets for the treatment of major psychiatric disorders, including bipolar disorder. Randomized, double-blind, placebo-controlled trials with quetiapine have demonstrated its efficacy in bipolar I and II disorders, and the drug has been generally well tolerated in clinical trials. Three cost-effectiveness analyses of maintenance therapy in bipolar I disorder, which used similar Markov models and incorporated data from key clinical trials and a number of other sources, showed that quetiapine, as adjunctive therapy with mood stabilizers (lithium or divalproex), was a cost-effective treatment option from the healthcare payer perspective in the UK and the US. Quetiapine either dominated comparators (typically mood stabilizers alone) or was associated with incremental cost-effectiveness ratios that were usually well below widely accepted thresholds of cost effectiveness. One of the studies evaluated extended-release quetiapine, although clinical efficacy data used in the Markov model were for the immediate-release formulation. In another analysis, which used a discrete-event simulation model and was conducted from the perspective of the UK healthcare payer, quetiapine monotherapy was cost effective compared with olanzapine monotherapy as maintenance treatment for all phases of bipolar I or II disorder. In this model, favourable results were also shown for quetiapine (with or without mood stabilizers) compared with a wide range of maintenance therapy regimens. Another modelled analysis conducted from the UK healthcare payer perspective showed that quetiapine was dominated by haloperidol in the short-term treatment of a manic episode in patients with bipolar I disorder. Both favourable and unfavourable results have been reported in cost analyses of quetiapine in bipolar disorder (type I or type not specified). Possible explanations for some of the variability in results of the pharmacoeconomic analyses include heterogeneity among the models in terms of input parameters or assumptions in the base-case analyses, country- or region-specific differences in estimates of healthcare resource use and associated costs, variability in treatment alternatives, and differences in the year of costing and discounting used in the analyses. In addition, some of the studies had short time horizons and focused on acute manic episodes only, whereas others were longer-term analyses that considered the full spectrum of health states in patients with bipolar disorder. Various limitations of the studies have been recognized, and results from one country may not be applicable to other countries. In conclusion, results of available pharmacoeconomic analyses provide evidence of the cost effectiveness of quetiapine as an adjunct to mood stabilizers for maintenance therapy in (primarily type I) bipolar disorder from a healthcare payer perspective in the UK and the US. Some evidence is available to support the cost effectiveness of quetiapine monotherapy or the use of extended-release quetiapine as adjunctive therapy with mood stabilizers in this setting, although further analyses appear to be warranted. Whether these findings apply to other geographical regions requires further study. Evidence for the long-term (>2-year) cost effectiveness of quetiapine in bipolar disorder is currently limited and further studies are also needed to address the cost effectiveness of quetiapine from a societal perspective and in bipolar II disorder.PharmacoEconomics 05/2012; 30(7):611-31. · 2.86 Impact Factor
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ABSTRACT: There are few psychosocial interventions specifically focused on improved treatment adherence in people with bipolar disorder (BD). Customized adherence enhancement (CAE) is a needs-based, manualized approach intended to improve medication adherence in individuals with BD. This was a six-month prospective trial of a CAE among 43 medication non-adherent individuals with BD who were receiving treatment in a community mental health clinic (CMHC). CAE was flexibly administered in modules applied as indicated by an initial adherence vulnerabilities screening. Screening identified reasons for non-adherence and modules were then administered using pre-set criteria. CAE effects were evaluated at six-week, three-month, and six-month follow-up. The six-month follow-up was our primary time point of interest. The primary outcome was change from baseline in adherence using the Tablets Routine Questionnaire (TRQ) and pill counts. Secondary outcomes included change from baseline in BD symptoms [Hamilton Depression Rating Scale (HAM-D), Young Mania Rating Scale (YMRS), and Brief Psychiatric Rating Scale (BPRS)]. Subjects completed 86% of scheduled sessions, with only two individuals (5%) not participating in any sessions. The number of dropouts at six months was 12 (28%). Mean baseline non-adherence by TRQ was 48% [standard error (SE) 4.8%] missed tablets within the previous week and 51% (4.1%) missed tablets within the previous month. At six-month follow-up, mean TRQ non-adherence improved to 25% (6.8%) missed tablets for the previous week (p = 0.002) and 21% (5.5%) for the previous month (p < 0.001). Symptoms improved, with a change in the baseline mean (SE) BPRS of 43.6 (1.8) versus an endpoint of 36.1 (2.3) (p = 0.001), and baseline mean (SE) HAM-D of 17.8 (1.1) versus an endpoint of 15.3 (1.6) (p = 0.044). CAE was associated with improvements in adherence, symptoms, and functional status. Controlled trials are needed to confirm these preliminary findings.Bipolar Disorders 05/2012; 14(3):291-300. · 4.62 Impact Factor
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ABSTRACT: 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. 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. 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. 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.BMC Psychiatry 01/2011; 11:6. · 2.23 Impact Factor