Methodological issues in assessing changes in costs pre- and post-medication switch: a schizophrenia study example

<p>Abstract</p> <p>Background</p> <p>Schizophrenia is a severe, chronic, and costly illness that adversely impacts patients' lives and health care payer budgets. Cost comparisons of treatment regimens are, therefore, important to health care payers and researchers. Pre-Post analyses ("mirror-image"), where outcomes prior to a medication switch are compared to outcomes post-switch, are commonly used in such research. However, medication changes often occur during a costly crisis event. Patients may relapse, be hospitalized, have a medication change, and then spend a period of time with intense use of costly resources (post-medication switch). While many advantages and disadvantages of Pre-Post methodology have been discussed, issues regarding the attributability of costs incurred around the time of medication switching have not been fully investigated.</p> <p>Methods</p> <p>Medical resource use data, including medications and acute-care services (hospitalizations, partial hospitalizations, emergency department) were collected for patients with schizophrenia who switched antipsychotics (n = 105) during a 1-year randomized, naturalistic, antipsychotic cost-effectiveness schizophrenia trial. Within-patient changes in total costs per day were computed during the pre- and post-medication change periods. In addition to the standard Pre-Post analysis comparing costs pre- and post-medication change, we investigated the sensitivity of results to varying assumptions regarding the attributability of acute care service costs occurring just after a medication switch that were likely due to initial medication failure.</p> <p>Results</p> <p>Fifty-six percent of all costs incurred during the first week on the newly initiated antipsychotic were likely due to treatment failure with the previous antipsychotic. Standard analyses suggested an average increase in cost-per-day for each patient of $2.40 after switching medications. However, sensitivity analyses removing costs incurred post-switch that were potentially due to the failure of the initial medication suggested decreases in costs in the range of$4.77 to $9.69 per day post-switch.</p> <p>Conclusion</p> <p>Pre-Post cost analyses are sensitive to the approach used to handle acute-service costs occurring just after a medication change. Given the importance of quality economic research on the cost of switching treatments, thorough sensitivity analyses should be performed to identify the impact of crisis events around the time of medication change.</p

Adherence and persistence with branded antidepressants and generic SSRIs among managed care patients with major depressive disorder

Xianchen Liu1,2, Yi Chen3, Douglas E Faries31Former employee, Eli Lilly and Company, Indianapolis, Indiana, USA; 2Indiana University Department of Psychiatry, Indianapolis, Indiana, USA; 3Eli Lilly and Company, Indianapolis, Indiana, USAObjective: This study compared adherence and persistence of three branded antidepressants: the serotonin and norepinephrine reuptake inhibitors (SNRIs) duloxetine and venlafaxine XR, and the selective serotonin reuptake inhibitor (SSRI) escitalopram; and generic selective SSRIs, and examined demographic and clinical predictors of adherence and persistence in patients with major depressive disorder in usual care settings.Method: A total of 44,026 patients (18 to 64 years) from a large commercial administrative claims database were classified as initiators of duloxetine (n = 7,567), venlafaxine XR (n = 6,106), escitalopram (n = 10,239), or generic SSRIs (n = 20,114) during 2006. Adherence was defined as the medication possession ratio of &amp;ge; 0.8 and persistence as the length of therapy without exceeding a 15-day gap. Pairwise comparisons from multivariate logistic regression and Cox proportional hazards models were performed to examine predictors of adherence and persistence.Results: Adherence rate after one year was significantly higher in duloxetine recipients (38.1%) than patients treated with venlafaxine XR (34.0%), escitalopram (25.4%), or generic SSRIs (25.5%) (all P &amp;lt; 0.01). Duloxetine recipients stayed on medication longer (158.5 days) than those receiving venlafaxine XR (149.6 days), escitalopram (129.1 days), or generic SSRIs (130.2 days) (all P &amp;lt; 0.001). Compared with patients treated with escitalopram or generic SSRIs, venlafaxine XR recipients had better adherence and longer persistence (P &amp;lt; 0.001). In addition, being aged 36 years or more, hypersomnia, anxiety disorders, and prior use of antidepressants were associated with increased adherence and persistence, while the opposite was true for comorbid chronic pain conditions, alcohol and drug dependence, and prior use of amphetamine.Conclusion: Compared with SSRIs, the SNRIs appear to have better adherence and persistence. Among SNRIs, duloxetine had statistically significantly better adherence and persistence than venlafaxine XR, though differences were relatively small and further research is needed to assess whether these translate into clinically and economically meaningful outcomes. Adherence and persistence with antidepressant therapy were associated with age, multiple comorbid conditions, and prior use of medications.Keywords: treatment adherence, length of therapy, antidepressants, major depression, retrospective analysi

Medication adherence levels and differential use of mental-health services in the treatment of schizophrenia

<p>Abstract</p> <p>Background</p> <p>Adherence to antipsychotics for schizophrenia is associated with favorable clinical outcomes. This study compared annual mental-health service utilization by recent medication adherence levels for patients treated for schizophrenia, and assessed whether adherence levels change from pre- to post-psychiatric hospitalization.</p> <p>Methods</p> <p>We analyzed data from a large prospective, non-interventional study of patients treated for schizophrenia in the United States, conducted between 7/1997 and 9/2003. Detailed mental-health resource utilization was systematically abstracted from medical records and augmented with patients' self report. Medication possession ratio (MPR) with any antipsychotic in the 6 months prior to enrollment was used to categorize patients as: adherent (MPR ≥ 80%, N = 1758), partially adherent (MPR ≥ 60% < 80%, N = 36), or non-adherent (MPR < 60%, N = 216). Group comparisons employed propensity score-adjusted bootstrap re-sampling methods with 1000 iterations, adjusting for baseline patient demographic and clinical characteristics identified a priori.</p> <p>Results</p> <p>Adherent patients had a lower rate of psychiatric hospitalization compared with partially adherent and non-adherent patients (p < 0.001) and were more likely than non-adherent to engage in group therapy, individual therapy, and medication management. Most patients (92.0%) who were adherent in the 6 months prior to hospital admission continued to be adherent 6 months following hospitalization. However, 75.0% of previously partially adherent became adherent, and 38.7% of previously non-adherent became adherent following hospitalization.</p> <p>Conclusion</p> <p>Adherence is associated with lower utilization of acute care services and greater engagement in outpatient mental-health treatment. Adherence is a potentially dynamic phenomenon, which may improve, at least temporarily, following patients' psychiatric hospitalizations.</p

Involvement in the US criminal justice system and cost implications for persons treated for schizophrenia

<p>Abstract</p> <p>Background</p> <p>Individuals with schizophrenia may have a higher risk of encounters with the criminal justice system than the general population, but there are limited data on such encounters and their attendant costs. This study assessed the prevalence of encounters with the criminal justice system, encounter types, and the estimated cost attributable to these encounters in the one-year treatment of persons with schizophrenia.</p> <p>Methods</p> <p>This post-hoc analysis used data from a prospective one-year cost-effectiveness study of persons treated with antipsychotics for schizophrenia and related disorders in the United States. Criminal justice system involvement was assessed using the Schizophrenia Patients Outcome Research Team (PORT) client survey and the victimization subscale of the Lehman Quality of Life Interview (QOLI). Direct cost of criminal justice system involvement was estimated using previously reported costs per type of encounter. Patients with and without involvement were compared on baseline characteristics and direct annual health care and criminal justice system-related costs.</p> <p>Results</p> <p>Overall, 278 (46%) of 609 participants reported at least 1 criminal justice system encounter. They were more likely to be substance users and less adherent to antipsychotics compared to participants without involvement. The 2 most prevalent types of encounters were being a victim of a crime (67%) and being on parole or probation (26%). The mean annual per-patient cost of involvement was $1,429, translating to 6% of total annual direct health care costs for those with involvement (11% when excluding crime victims).</p> <p>Conclusions</p> <p>Criminal justice system involvement appears to be prevalent and costly for persons treated for schizophrenia in the United States. Findings highlight the need to better understand the interface between the mental health and the criminal justice systems and the related costs, in personal, societal, and economic terms.</p

A Bayesian approach to correct for unmeasured or semi-unmeasured confounding in survival data using multiple validation data sets

Purpose: The existence of unmeasured confounding can clearly undermine the validity of an observational study. Methods of conducting sensitivity analyses to evaluate the impact of unmeasured confounding are well established. However, application of such methods to survival data (“time-to-event” outcomes) have received little attention in the literature. The purpose of this study is to propose a novel Bayesian method to account for unmeasured confounding for survival data. &nbsp; Methods: The Bayesian method is proposed under an assumption that the supplementary information on unmeasured confounding in the form of internal validation data, external validation data or expert elicited prior distributions is available. The method for incorporating such information to Cox proportional hazard model is described.&nbsp; Simulation studies are performed based on the recently published instrumental variable method to assess the impact of unmeasured confounding and to illustrate the improvement of the proposed method over the naïve model which ignores unmeasured confounding. &nbsp; Results: Simulation studies illustrate the impact of ignoring the unmeasured confounding and the effectiveness of our Bayesian approach. The corrected model had significantly less bias and coverage of 95% intervals much closer to nominal. &nbsp; Conclusion: The proposed Bayesian method provides a useful and flexible tool in incorporating different types of supplemental information on unmeasured confounding to adjust the treatment estimates when the outcome is survival data.&nbsp; It out-performed the naïve model in simulation studies based on a real world study. &nbsp

Atomoxetine treatment in children and adolescents with attention-deficit hyperactivity disorder: what are the long-term health-related quality-of-life outcomes?

OBJECTIVE: Numerous investigations have examined the efficacy of pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD) in children. However, relatively few studies have addressed the impact of treatment on long-term subjective, psychosocial outcomes, such as health-related quality of life (HRQL). This study examines the long-term effects of pharmacological treatment with atomoxetine on HRQL in children and adolescents with ADHD. METHODS: Participants included 6- to 17-year-old children and adolescents (n = 912) with ADHD enrolled in a 24-month, multicenter, open-label trial of atomoxetine. Outcomes included clinician ratings of ADHD, parent ratings of ADHD, and a widely used measure of HRQL (The Child Health Questionnaire (CHQ)). Treatment response rates were calculated based on a CHQ improvement of at least 1 standard error of measurement. RESULTS: Significant improvements in HRQL were found following both acute and long-term treatment for psychosocial but not physical health. Of participants who completed treatment (n = 312 or 34.2% of those enrolled), 81% responded to acute treatment and 78% responded to long-term treatment. Improvements noted after acute treatment were maintained during long-term treatment with the majority of participants (86%) continuing to respond to treatment. CONCLUSIONS: Atomoxetine is associated with improvements in HRQL, and the improvements are generally stable over time

Adherence and Persistence with Once-Daily Teriparatide in Japan: A Retrospective, Prescription Database, Cohort Study

Adherence and persistence with osteoporosis treatments are essential for reducing fracture risk. Once-daily teriparatide is available in Japan for treating osteoporosis in patients with a high risk of fracture. The study objective was to describe real-world adherence and persistence with once-daily teriparatide 20 μg during the first year of treatment for patients who started treatment during the first eight months of availability in Japan. This prescription database study involved patients with an index date (first claim) between October 2010 and May 2011, a preindex period ≥6 months, and a postindex period ≥12 months and who were aged >45 years. Adherence (medication possession ratio (MPR)) and persistence (time from the start of treatment to discontinuation; a 60-day gap in supply) were calculated. A total of 287 patients started treatment during the specified time period; 123 (42.9%) were eligible for inclusion. Overall mean (standard deviation) adherence was 0.702 (0.366), with 61.0% of patients having high adherence (MPR > 0.8). The percentage of patients remaining on treatment was 65.9% at 180 days and 61.0% at 365 days. Our findings suggest that real-world adherence and persistence with once-daily teriparatide in Japan are similar to that with once-daily teriparatide in other countries and with other osteoporosis medications