Local control for identifying subgroups of interest in observational research: persistence of treatment for major depressive disorder.

Caregivers are regularly faced with decisions between competing treatments. Large observational health care databases provide a golden opportunity for research on heterogeneity in patient response to guide caregiver decisions, due to their sample size, diverse populations, and real-world setting. Local control is a promising tool for using observational data to detect patient subgroups with differential response on one treatment relative to another. While standard data mining approaches find subgroups with optimal responses for a particular population, detecting subgroups that reveal treatment differences while also adjusting for confounding in observational data is challenging. Local control utilizes unsupervised clustering to form non-parametric patient-level counterfactual treatment differences and displays them as an observed distribution of effect-size estimates. Classification and regression trees (CART) then find the factors that drive the greatest outcome differentiation between treatments. In this manuscript, we demonstrate the use of this two-step strategy using local control plus CART to identify depression patients most (least) likely to benefit from treatment with duloxetine relative to extended-release venlafaxine. Prior medication costs and age were found to be factors most associated with differential outcome, with prior medication costs remaining as an important factor after sensitivity analyses using a second dataset.

Changes in the utilization of venlafaxine after the introduction of generics in Sweden.

BACKGROUND: There has been an appreciable increase in the prescribing efficiency of proton pump inhibitors, statins, and renin-angiotensin inhibitor drugs in Sweden in recent years. This has been achieved through multiple reforms encouraging the prescription of generics at low prices versus patented drugs in the same class. Generic venlafaxine also presents an opportunity to save costs given the prevalence of depression. However, depression is more complex to treat, with physicians reluctant to change prescriptions if patients are responding to a particular antidepressant. OBJECTIVES: We assessed (a) changes in the utilization pattern of venlafaxine versus other newer antidepressants before and after the availability of generic venlafaxine and before and after the initiation of prescription restrictions for duloxetine limiting its prescription to refractory patients, (b) utilization of generic versus original venlafaxine after its availability, and (c) price reductions for generic venlafaxine and the subsequent influence on total expenditure on newer antidepressants over time. METHODOLOGY: We performed interrupted time series analysis of changes in monthly reimbursed prescriptions using defined daily doses (DDDs) of patients dispensed at least one newer antidepressant from January 2007 to August 2011. DDDs was defined as the average maintenance dose of a drug when used in its major indication in adults. This included 19 months after the availability of generic venlafaxine and before initiation of prescription restrictions for duloxetine to 13 months after prescription restrictions. Total expenditure and expenditure/DDD for venlafaxine were measured over time. RESULTS: No appreciable change in the utilization pattern for venlafaxine was observed after generic availability when no appreciable demand-side activities by the regions (counties) were implemented to encourage its use. The utilization of venlafaxine significantly increased after prescription restrictions for duloxetine. Generic venlafaxine was dispensed once available, reaching 99.6 % of total venlafaxine (DDD basis) by August 2011. There was an appreciable fall in expenditure for newer antidepressants in Sweden after generic venlafaxine despite increased utilization, helped by a 90 % reduction in expenditure/DDD for venlafaxine by the end of the study versus prepatent loss prices. CONCLUSION: Multiple demand-side measures are needed to change physician prescribing habits. Authorities should not rely on a spillover effect between drug classes to effect change. Limited influence of prescription restrictions on the subsequent utilization of duloxetine reflects the complexity of this disease area. This is exacerbated by heterogeneous indications for duloxetine.

Economic evaluation of St. John's wort (Hypericum perforatum) for the treatment of mild to moderate depression.

BACKGROUND: The burden of rising health care expenditures has created a demand for information regarding the clinical and economic outcomes associated with Complementary and Alternative Medicines. Clinical controlled trials have found St. John's wort to be as effective as antidepressants in the treatment of mild to moderate depression. The objective of this study was to develop a model to assess the cost-effectiveness of St. John's wort based on this evidence. METHODS: A Markov model was constructed to estimate health and economic impacts of St. John's wort versus antidepressants. Outcomes were treatment costs, quality-adjusted life years (QALYs) and Net Monetary Benefits (NMB). Probabilistic analyses were conducted on key model parameters. RESULTS: The average NMB across 5000 simulations identified St. John's wort as the strategy with the highest net benefit. The total cost savings for SJW were $359.66 and $202.56 per individual for venlafaxine and sertraline respectively, with a gain of 0.08 to 0.12 QALYs over the 72 weeks of the model. LIMITATIONS: A lack of direct comparative clinical trial data comparing SJW to venlafaxine and limited data with sertraline as a comparator was a major limitation. CONCLUSIONS: In this model, St. John's wort was shown to be a cost-effective alternative to generic antidepressants. Patients are more likely to receive treatment for a duration consistent with professional guidelines for treatment of major depression due to reduced incidence of adverse effects, improving outcomes. This represents an important option in the treatment of Major Depressive Disorder.

Switching to sertraline or venlafaxine after failure of SSRIs treatment in major depressive disorder: an economic evaluation of the STAR*D trial.

BACKGROUND: Switching to another antidepressant is one of the alternative treatment strategies employed in major depressive disorder (MDD) patients who have no remission despite an adequate trial of an antidepressant. The aim of the present study was to present an economic evaluation of sertraline compared with venlafaxine after unsuccessful treatment for depression with citalopram. MATERIAL AND METHOD: An economic model was constructed in line with the design of the sequenced treatment alternatives to relieve depression (STAR*D) study. MDD patients who did not have a remission with or who had an intolerance to citalopram were randomly assigned to be switched to either sertraline or venlafaxine. Patients who had no remission at the end of the switching treatment phase still continued the antidepressants and received an adjunctive treatment with aripiprazole. The event probabilities were used to derive the transitional probabilities use in the model. The primary model outcome was remission of symptoms and the secondary outcome was quality-adjusted life-years (QALYs). Incremental cost-effectiveness ratios (ICEs) were estimated for the costs per unit of effectiveness. Sensitivity analyses were done to assess the effects of model assumptions. RESULTS: The total direct costs per remission were 27,830 Baht for sertraline and 30,147 Baht for venlafaxine. Sertraline had lower total costs per QALY than venlafaxine (34,788 Baht vs. 37,683 Baht). The more cost-effectiveness of sertraline resulted in 7.68% of cost saving. The incremental cost of venlafaxine compared with sertraline was 2,316 Baht per remission gained and 2895 Baht per QALY gained. By varying the remission rate of venlafaxine from 20% to 40%, the sensitivity analysis results in a decrease in total costs of venlafaxine from 31,926 Baht to 24,808 Baht. In addition, incremental cost per remission gained changed from 4096 Baht in favour of sertraline to 3023 Baht in favour of venlafaxine. Similarly, incremental cost per QALY gained changedfrom in favour of sertraline to in favour of venlafaxine. CONCLUSION: Based on the STAR*D trial, the results of the economic study indicate that a switch to sertraline is a cost-effectiveness treatment option compared with a switch to venlafaxine in MDD patients who have no remission or cannot tolerate citalopram.

Cost-effectiveness evaluation in Sweden of escitalopram compared with venlafaxine extended-release as first-line treatment in major depressive disorder.

OBJECTIVES: Major depressive disorder (MDD) is a major public health concern associated with a high burden to society, the health-care system, and patients and an estimated cost of €3.5 billion in Sweden. The objective of this study was to assess the cost-effectiveness of escitalopram versus generic venlafaxine extended-release (XR) in MDD, accounting for the full clinical profile of each, adopting the Swedish societal perspective, and identifying major cost drivers. METHODS: Cost-effectiveness of escitalopram versus venlafaxine XR was analyzed over a 6-month time frame, on the basis of a decision tree, for patients with MDD seeking primary care treatment in Sweden. Effectiveness outcomes for the model were quality-adjusted life-years and probability of sustained remission after acute treatment (first 8 weeks) and sustained for 6 months. Cost outcomes included direct treatment costs and indirect costs associated with sick leave. RESULTS: Compared with generic venlafaxine XR, escitalopram was less costly and more effective in terms of quality-adjusted life-years (expected gain 0.00865) and expected 6-month sustained remission probability (incremental gain 0.0374). The better tolerability profile of escitalopram contributed to higher expected quality-adjusted life-years and lower health-care resource utilization in terms of pharmacological treatment of adverse events (though only a minor component of treatment costs). Expected per-patient saving was €169.15 for escitalopram versus venlafaxine. Cost from sick leave constituted about 85% of total costs. CONCLUSIONS: Escitalopram was estimated as more effective and cost saving than generic venlafaxine XR in first-line MDD treatment in Sweden, driven by the effectiveness and tolerability advantages of escitalopram. The study findings are robust and in line with similar pharmacoeconomic analyses.

Incremental cost-effectiveness of combined therapy vs medication only for youth with selective serotonin reuptake inhibitor-resistant depression: treatment of SSRI-resistant depression in adolescents trial findings.

CONTEXT: Many youth with depression do not respond to initial treatment with selective serotonin reuptake inhibitors (SSRIs), and this is associated with higher costs. More effective treatment for these youth may be cost-effective. OBJECTIVE: To evaluate the incremental cost-effectiveness over 24 weeks of combined cognitive behavior therapy plus switch to a different antidepressant medication vs medication switch only in adolescents who continued to have depression despite adequate initial treatment with an SSRI. DESIGN: Randomized controlled trial. SETTING: Six US academic and community clinics. PATIENTS: Three hundred thirty-four patients aged 12 to 18 years with SSRI-resistant depression. INTERVENTION: Participants were randomly assigned to (1) switch to a different medication only or (2) switch to a different medication plus cognitive behavior therapy. MAIN OUTCOME MEASURES: Clinical outcomes were depression-free days (DFDs), depression-improvement days (DIDs), and quality-adjusted life-years based on DFDs (DFD-QALYs). Costs of intervention, nonprotocol services, and families were included. RESULTS: Combined treatment achieved 8.3 additional DFDs (P = .03), 0.020 more DFD-QALYs (P = .03), and 11.0 more DIDs (P = .04). Combined therapy cost $1633 more (P = .01). Cost per DFD was $188 (incremental cost-effectiveness ratio [ICER] = $188; 95% confidence interval [CI], -$22 to $1613), $142 per DID (ICER = $142; 95% CI, -$14 to $2529), and $78,948 per DFD-QALY (ICER = $78,948; 95% CI, -$9261 to $677,448). Cost-effectiveness acceptability curve analyses suggest a 61% probability that combined treatment is more cost-effective at a willingness to pay $100,000 per QALY. Combined treatment had a higher net benefit for subgroups of youth without a history of abuse, with lower levels of hopelessness, and with comorbid conditions. CONCLUSIONS: For youth with SSRI-resistant depression, combined treatment decreases the number of days with depression and is more costly. Depending on a decision maker's willingness to pay, combined therapy may be cost-effective, particularly for some subgroups. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00018902.

Treatment patterns associated with Duloxetine and Venlafaxine use for Major Depressive Disorder.

BACKGROUND: Duloxetine and venlafaxine extended release (venlafaxine XR) are SNRIs indicated for the treatment of MDD. This study addresses whether duloxetine and venlafaxine XR are interchangeable in their patterns of use with patients who are depressed or are used more selectively based on treatment history, background characteristics, and presenting symptoms. METHODS: This was a retrospective analysis of an administrative insurance claims database. We studied patients in managed care with major depressive disorder (MDD) treated with duloxetine or venlafaxine XR. Predictors of treatment and cost were assessed using Chi-square and logistic regression analyses of demographics and past-year medication use and comorbidities. RESULTS: Patients with MDD treated with duloxetine (n = 9,641) versus venlafaxine XR (n = 8,514) tended to be older, slightly more likely to be female, and treated by a psychiatrist (P < 0.0001). In the prior year, more duloxetine patients (vs. venlafaxine XR) received ≥ 3 unique antidepressants (20.8% vs. 16.6%), ≥ 3 unique pain medications (25.5% vs. 15.6%), and had ≥ 8 unique diagnosed comorbid medical and psychiatric conditions (38.6% vs. 29.1%). The prior 6-month total health care costs were $1,731 higher for duloxetine than for venlafaxine XR and declined for both medications in the 6 months after treatment began. Logistic regression analysis revealed that 61% of duloxetine patients and 61% of venlafaxine XR patients were predictable from prior patient and treatment factors. CONCLUSIONS: Patients with MDD treated with duloxetine tended to have a more complex and costly antecedent clinical presentation compared with venlafaxine XR patients, suggesting that physicians do not use the medications interchangeably.

Comparison of escitalopram vs. citalopram and venlafaxine in the treatment of major depression in Spain: clinical and economic consequences.

STUDY OBJECTIVE: Population based study to determine the clinical consequences and economic impact of using escitalopram (ESC) vs. citalopram (CIT) and venlafaxine (VEN) in patients who initiate treatment for a new episode of major depression (MD) in real life conditions of outpatient practice. METHODS: Observational, multicenter, retrospective study conducted using computerized medical records (administrative databases) of patients treated in six primary care centers and two hospitals between January 2003 and March 2007. STUDY POPULATION: patients >20 years of age diagnosed with a new episode of MD who initiate treatment with ESC, CIT or VEN who had not received any antidepressant treatment within the previous 6 months, and were followed for 18 months or more. MAIN VARIABLES: socio-demographic variables, remission (defined as a patient completing 6 months of therapy), comorbidity, annual health care costs (medical visits, diagnostic and therapeutic tests, hospitalizations, emergency room and psychoactive drugs prescribed) and non-health care costs (productivity losses at work, mainly sick leave and disability). STATISTICAL ANALYSES: logistic regression and ANCOVA models. RESULTS: A total of 965 patients (ESC = 131; CIT = 491; VEN = 343) were identified and met study criteria. ESC-treated patients were younger, with a higher proportion of males, and had a lower specific comorbidity (p < 0.01). ESC-treated patients achieved higher remission rates compared to CIT (58.0% vs. 38.3%) or VEN patients (32.4%), p < 0.001, and had lower productivity work losses compared to VEN patients (32.7 vs. 43.8 days), p = 0.042. No differences in productivity work losses were observed between ESC and CIT patients. Compared to the ESC group, higher costs in average/unit of psychoactive drugs were found in the VEN group (€643.00), p = 0.003, whereas no differences were observed between the ESC and CIT groups (€294.70 vs. €265.20). In the corrected model, total costs (health care and non-health care cost) were lower with ESC (€2276.20) compared to CIT (€3093.80), p = 0.047 and VEN (€3801.20), p = 0.045. CONCLUSIONS: ESC appears to be dominant in the treatment of new MD episodes when compared to CIT and VEN, resulting in higher remission rates and lower total costs.

Cost effectiveness of escitalopram versus SNRIs in second-step treatment of major depressive disorder in Sweden.

OBJECTIVES: Escitalopram is the S-enantiomer of citalopram and is the most discriminating of the selective serotonin reuptake inhibitors (SSRI). The aim of the current analysis was to assess the cost effectiveness of escitalopram versus the serotonin norepinephrine reuptake inhibitors (SNRI) duloxetine and generic venlafaxine as second-step treatment of major depressive disorder. METHODS: The analysis was based on a decision analytic model. Effectiveness outcomes were quality-adjusted life-years (QALYs) and remission rates; cost outcomes were direct medical costs, including impact of treating adverse events, and indirect costs associated with lost productivity. The analysis was performed from the societal perspective in Sweden over a 6-month timeframe. RESULTS: Estimated remission rates showed an incremental effectiveness in favour of escitalopram of 16.4 percentage points compared with both SNRI comparators. The escitalopram strategy was associated with a 0.025 increase in QALYs. Sensitivity analyses demonstrated that the model is robust and that escitalopram remains a cost-effective option when considering future predicted price reductions of generic venlafaxine. LIMITATIONS: The main limitation in this study was the lack of data available for second-step treatment. The remission rates, which are a key input to the model, were obtained from a relatively small sample of patients on second-step treatment and there are no published relapse rates for second-step treatment. The model also assumed that there was no difference in the adverse event (AE) rates between treatments after the first 8 weeks. CONCLUSIONS: This cost-effectiveness analysis indicates that, at a willingness-to-pay threshold of £30,000, escitalopram is the most cost-effective second-step treatment option for MDD in Sweden in over 85% cases compared with both venlafaxine and with duloxetine. Benefits for escitalopram included both increased effectiveness and reduced overall costs. The major contributing costs were those associated with productivity loss. The model was shown to have internal validity and robustness through the use of stochastic simulations and sensitivity analyses, which were conducted around the key efficacy parameters.

Healthcare expenditure in severely depressed patients treated with escitalopram, generic SSRIs or venlafaxine in the UK.

OBJECTIVE: To retrospectively compare the 12-month healthcare utilisation and direct medical costs associated with the use of escitalopram, generic SSRIs, and venlafaxine in patients with severe depression in the United Kingdom (UK). METHODS: Data for this retrospective cohort study were extracted from the GPRD, a large primary care database in the UK. Data from adults with an incident prescription of escitalopram, venlafaxine, or generic SSRI were extracted. The initial prescription had to fall within 3 months of a physician visit when severe depression according to the GPRD definition was mentioned. Frequency of antidepressant treatment, GP consultations, referrals, hospitalisations, and concomitant psychiatric medication was assessed on the 12-months after initial prescription and 2006 unit costs for healthcare services obtained from published literature were applied, and then compared between treatment cohorts using a propensity score-adjusted generalised linear model. RESULTS: The total annual healthcare expenditure per patient was similar with escitalopram and generic SSRIs (916 pounds vs. 974 pounds, adjusted p = 0.48) and significantly lower than venlafaxine (916 pounds vs. 1367 pounds, adjusted p < 0.0001), a pattern repeated when antidepressant costs were excluded from the analysis (escitalopram vs. SSRIs, 831 pounds vs. 957 pounds, adjusted p = 0.10; escitalopram vs. venlafaxine, 831 pounds vs. 1156 pounds, adjusted p = 0.006). Over the 12-month analysis period, there were significantly fewer hospitalisations per patient in the escitalopram vs. venlafaxine (0.12 vs. 0.27; adjusted p = 0.01) or generic SSRI (0.12 vs. 0.19; adjusted p = 0.046) groups. CONCLUSION: Despite some limitations associated with the system of data collection in the GPRD (need to apply proxies for severity assessment and external unit costs to resource consumption), the results of this real-life study brings additional evidence of escitalopram appearing to be a cost-effective treatment for patients suffering from severe depression as diagnosed in routine practice and could be considered for first-line treatment in these patients.

Economic evaluation of duloxetine versus serotonin selective reuptake inhibitors and venlafaxine XR in treating major depressive disorder in Scotland.

BACKGROUND: Major depressive disorders (MDD) are responsible for substantial direct and indirect health care costs. Despite the availability of numerous treatments, the need for effective pharmacotherapy remains. Duloxetine is a relatively balanced serotonin norepinephrine reuptake inhibitor (SNRI) with favourable clinical and tolerability profile. The cost-effectiveness of duloxetine versus established SSRIs, venlafaxine XR and mirtazapine was estimated in the UK. METHODS: A decision analysis simulating clinical management of MDD was developed to estimate health and economic impacts of alternative treatments over one year. Patients on treatment experience remission, response without remission, no response, relapse or discontinue the initial regimen. Model outcomes were total treatment costs and quality-adjusted life years. Resource utilization data were derived from literature and practising UK psychiatrists and GPs. The robustness of findings with respect to modelling assumptions was assessed in extensive sensitivity analyses. RESULTS: With similar efficacy to venlafaxine XR but lower drug costs, duloxetine is less costly and marginally more effective than venlafaxine XR both in the overall MDD population and in a more severe subgroup. Duloxetine has a low cost-effectiveness ratio in primary care against SSRIs and mirtazapine, and was found cost-saving against mirtazapine in more severe patients. LIMITATIONS: Cost-effectiveness results are sensitive to changes in efficacy parameters and resource use data were collected from physician panel. CONCLUSIONS: Duloxetine represents an important option in the treatment of MDD in the UK that can be recommended on economic grounds. With similar efficacy and different side-effect profile to venlafaxine XR it represents a valuable choice to MDD patients.

Cost-effectiveness of pregabalin versus venlafaxine in the treatment of generalized anxiety disorder: findings from a Spanish perspective.

The objective of the present study was to describe a new model of the cost-effectiveness of treatment of generalized anxiety disorder (GAD) and its application to a comparison of pregabalin versus venlafaxine extended-release (XR) from a Spanish healthcare perspective. Microsimulation techniques, including Hamilton Anxiety Scale (HAM-A) score, number of weeks with minimal or no anxiety (HAM-A

Change in formulation and its potential clinical and pharmacoeconomic value: example of extended release venlafaxine.

INTRODUCTION: The 505(b)(2) route of a New Drug Application (NDA) allows published literature or previous FDA findings of safety and effectiveness to be used for approval. Such drugs are not therapeutic equivalents (i.e., generics); instead, the FDA calls them pharmaceutical alternatives. A recent example is the approval of venlafaxine extended-release (ER) tablets, developed as an alternative to the widely used ER venlafaxine capsules. The smaller size of the tablets makes them available in a 225-mg strength, which is the approved maximum dose in major depressive disorder after up-titration but currently unavailable in the capsule formulation, requiring patients on this dose to take two or three capsules; in addition, the tablets are priced at a discount compared to the capsules. METHODS: The objective of this review was to investigate how the change in formulation of ER venlafaxine from capsules to tablets, as an example of such a change in formulation, can potentially offer value to patients and society, with a specific focus on pill burden, drug cost, and adherence. Based on a MEDLINE literature search, the pertinent literature was reviewed in a qualitative manner. REVIEW OF THE LITERATURE: Simplifying treatment regimens, reducing pill burden, and reducing drug costs are recognized strategies for improving adherence. This can be of particular benefit in psychiatric illness because of high rates of nonadherence to treatment. Lack of adherence may negatively impact treatment outcomes and increase disease cost. As such, the ER venlafaxine tablets have the potential to reduce pill burden, improve adherence and outcomes, and reduce cost to patients and society. These preliminary findings need to be corroborated with more primary research and a systematic review of formulation changes. CONCLUSION: A change in formulation of established therapies such as ER venlafaxine has the potential to offer clinical and pharmacoeconomic benefits to patients and society.

Cost effectiveness of venlafaxine compared with generic fluoxetine or generic amitriptyline in major depressive disorder in the UK.

OBJECTIVE: To estimate the cost effectiveness of venlafaxine compared with generic fluoxetine and generic amitriptyline used in major depressive disorder in primary care in the UK. METHODS: A decision-tree model for the treatment of major depressive disorder was constructed using a Delphi panel. The tree was populated with clinical success rates from a pooled analysis of fluoxetine compared with venlafaxine and a clinical trial of amitriptyline compared with venlafaxine using remission as the key endpoint. Where there was insufficient data from clinical trials, the Delphi panel was used. Costs within the tree were taken from contemporary UK sources. Six-monthly costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios were then estimated. RESULTS: Treatment costs for 6 months were pound1530 for venlafaxine, pound1539 for fluoxetine and pound1558 for amitriptyline (year of costing 2006). Cost effectiveness as assessed by incremental cost per QALY ratio at 8 weeks was pound20 600 for venlafaxine compared with fluoxetine, with fluoxetine dominating (being less costly and more effective than) amitriptyline. To test the robustness of the model a Rank Order Stability Assessment was performed that showed that even if fluoxetine and/or amitriptyline were given away free, a scenario starting with venlafaxine would still be the least costly treatment over a 6-month period. CONCLUSION: In this model, venlafaxine was shown to be a cost-effective alternative to generic fluoxetine and amitriptyline when used as a first-line therapy. Thus, cost of therapy should not be a barrier to use of venlafaxine as a first-line option in treating major depressive disorder in primary care in the UK.

Pharmacoeconomics of antidepressants in moderate-to-severe depressive disorder in Colombia / Farmacoeconomía de antidepresivos en trastornos de depresión moderada e intensa en Colombia

OBJECTIVE: To compare three antidepressant drugs from different classes used in treating moderate-to-severe major depressive disorder (MDD) in Colombian adults. METHODS: Based on expert input, a decision-tree model was adapted for Colombia to analyze data over 6 months from the government-payer perspective. The cost-effectiveness of amitriptyline, fluoxetine, and venlafaxine was determined. The clinical outcome was remission of depression (a score <7 on the Hamilton Depression [HAM-D] scale or <12 on the Montgomery-Åsberg Depression Rating Scale [MADRS]) after 8 weeks of treatment. Clinical data were obtained from the literature and costs from standard Colombian price lists. One-way and multivariate sensitivity analyses tested model robustness. RESULTS: Costs per patient (in 2007 US$) for treatment were: venlafaxine, $1 618; fluoxetine, $1 207; and amitriptyline, $1 068. Overall remission rates were 73.1 percent, 64.1 percent, and 71.3 percent, respectively. Amitriptyline dominated fluoxetine (i.e., it had lower costs and higher outcomes). The incremental cost-effectiveness ratio (ICER) of venlafaxine over amitriptyline was US$ 31 595. The acquisition price of venlafaxine was the model's cost driver, comprising 53.4 percent of the total cost/patient treated, compared with 18.5 percent and 24.8 percent for fluoxetine and amitriptyline, respectively. For the others, hospitalization comprised the major cost (72.1 percent and 65.2 percent, respectively). Probabilistic (Monte Carlo) sensitivity analysis confirmed the original findings of the pharmacoeconomic model. CONCLUSIONS: Amitriptyline is cost-effective in comparison to fluoxetine and venlafaxine in Colombia. However, the cost of venlafaxine was estimated for the brand-name product, as generics were not currently available. These cost-effectiveness results can be substantially affected by the presence of generics or drug cost regulations.

OBJETIVO: Comparar tres medicamentos antidepresivos de diferentes clases empleados para tratar trastornos depresivos mayores moderados e intensos en adultos colombianos. MÉTODOS: A partir de los aportes de expertos se adaptó un modelo de árbol de decisión para Colombia a fin de analizar los datos de seis meses desde la perspectiva del gobierno como pagador de los servicios. Se determinó la relación costo-efectividad de la amitriptilina, la fluoxetina y la venlafaxina. El desenlace clínico fue la remisión de la depresión (una puntuación <7 en la escala de depresión de Hamilton o <12 en la escala de valoración de la depresión de Montgomery-Åsberg) después de 8 semanas de tratamiento. Los datos clínicos se obtuvieron de la literatura especializada y los costos, de las listas habituales de precios de Colombia. Se realizaron análisis de sensibilidad simples y multifactoriales para probar la robustez de los modelos. RESULTADOS: Los costos del tratamiento por paciente (en dólares estadounidenses de 2007) fueron: US$ 1 618 para la venlafaxina, US$ 1 207 para la fluoxetina y US$ 1 068 para la amitriptilina. Las tasas de remisión general fueron 73,1 por ciento, 64,1 por ciento y 71,3 por ciento, respectivamente. La amitriptilina tuvo un menor costo y una mayor remisión que la fluoxetina. La razón de rentabilidad incremental de la venlafaxina sobre la amitriptilina fue de US$ 31 595. El inductor de costos (cost driver) del modelo fue el valor de adquisición de la venlafaxina, que representó 53,4 por ciento del total del costo por paciente tratado, en comparación con la fluoxetina (18,5 por ciento) y la amitriptilina (24,8 por ciento). En los otros casos, la hospitalización representó el mayor costo (72,1 por ciento y 65,2 por ciento, respectivamente). El análisis de sensibilidad probabilístico (Monte Carlo) confirmó los resultados preliminares del modelo farmacoeconómico. CONCLUSIONES: En Colombia, la amitriptilina es más efectiva en función del...

Desvenlafaxine: another "me too" drug?

OBJECTIVE: To compare desvenlafaxine with its parent drug, venlafaxine, to determine the usefulness of this new medication. DATA SOURCES: Information was obtained through a MEDLINE search (1966-June 2008) and from published abstracts. Search terms included desvenlafaxine, O-desmethylvenlafaxine, Pristiq, major depressive disorder, and venlafaxine. STUDY SELECTION AND DATA EXTRACTION: All English-language studies and abstracts pertaining to desvenlafaxine and venlafaxine were considered for inclusion. Preference was given to human data. DATA SYNTHESIS: Desvenlafaxine is a serotonin-norepinephrine reuptake inhibitor and is the active metabolite of the antidepressant venlafaxine. The recommended dose is 50 mg daily, based on the efficacy and safety data of 50, 100, 150, 200, and 400 mg of desvenlafaxine. The response and remission rates of depression at 8 weeks for the 50-mg dose are 51-63% and 31-45%, respectively. These rates are comparable with those seen with venlafaxine (58% and 45%, respectively). Adverse effects are also similar to those of venlafaxine, with the most common being insomnia, somnolence, dizziness, and nausea. The decreased potential of CYP2D6 activity with desvenlafaxine compared with the parent drug may be a potential advantage in patients on other medications metabolized via this enzymatic pathway. Also, desvenlafaxine tablets are less expensive than extended-release (XR) venlafaxine, which may decrease healthcare costs in the short term. However, venlafaxine XR is expected to go off patent in 2010. CONCLUSIONS: With the overall similarity between these 2 drugs and the potential lack of cost savings, the need for desvenlafaxine and its ultimate utility in treating major depressive disorder appears to be insignificant.

Adequacy of venlafaxine dose prescribing in major depression and hospital resources implications.

Venlafaxine, a dual serotonin and noradrenaline re-uptake inhibitor, has been found to be effective at doses below 375 mg daily, but for patients with major depression higher doses can be required. In this retrospective naturalistic study, we investigated the effectiveness and resource implications of prescribing higher than standard doses of venlafaxine (tablet preparation). Ninety-six outpatients fulfilling DSM-IV criteria for major depressive disorder were assigned to two demographically matched cohorts: cohort A, receiving high doses (n = 38; doses > or =375 mg/day) and cohort B, receiving standard doses (n = 58; doses <375 mg/day). Data on hospital resources, drugs and medical profiles were extracted from patients' records. Information on cohort A was also obtained before their high-dose regime, while taking standard doses. A within-group analysis of cohort A showed that patients spent fewer days in hospital (P = 0.03) and had fewer outpatients visits (P < 0.01) when on high doses than when on standard doses. A between-group analysis found that cohort A, while on higher doses, had fewer outpatient visits compared with cohort B (P < 0.01). Patients in both groups had satisfactory drug tolerability and efficacy profiles. There were no differences between cohorts with regard to baseline characteristics, a part from the more intensive use of additional medications made by cohort A. Our preliminary investigation suggests that higher doses of venlafaxine may be cost-saving in relation to selected hospital resources. However, one cannot firmly conclude that the change in service use is due to the higher-dose regime, and we recommend further research to ascertain the cost-effectiveness of adequate dose prescribing in patients with poor symptom resolution at lower doses of venlafaxine.

Pharmacy and medical costs associated with switching between venlafaxine and SSRI antidepressant therapy for the treatment of major depressive disorder.

BACKGROUND: While much has been published on utilization of antidepressants and associated resource use, surprisingly little information is available on the relationship between a change in antidepressant agent and health care utilization. Given that many patients will not respond to initial therapy (and therefore would be candidates for switching treatment) and the array of antidepressant medications on the market, information on the impact of switching would be beneficial to both providers and policymakers. OBJECTIVE: To explore patterns of antidepressant drug use and depression-related and all-cause medical costs for patients who switched therapy between 2 drug classes, selective serotonin reuptake inhibitors (SSRIs) and the selective norepinephrine reuptake inhibitor (SNRI) venlafaxine. METHODS: Using an administrative claims database of 36 million members from 61 health plans, this retrospective cohort analysis examined patients who had (1) a diagnosis of major depressive disorder (MDD, International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 296.2x for MDD single episode, 296.3x for MDD recurrent episode, 300.4 for dysthymic disorder, and 311 for depressive disorder not elsewhere classified) and (2) a newly prescribed antidepressant during the year 2002. Costs were defined as amounts paid by health plans for all inpatient, outpatient, physician and pharmacy services (i.e., allowed charges after subtraction of member cost-share). Depression-related costs were defined using (1) medical claims with primary diagnosis of depression and (2) pharmacy claims for antidepressants. Using an index date of the first antidepressant claim, 12 months of pre-index and postindex data were available for all eligible patients. Switching was defined as occurring between the SSRIs and venlafaxine (i.e., patients who switched within the SSRI drug class across different SSRIs were treated as non-switchers until they switched to venlafaxine), and there was no minimum or maximum gap in therapy. The SSRIs included fluoxetine, citalopram, sertraline, and paroxetine; the only SNRI on the market at the time was venlafaxine. Multivariate regression analyses determined predictors of switching and factors influencing overall and depression-related costs, while controlling for confounding factors. For the 12-month period following the index date (fixed length of follow-up), the study compared per-patient per-year (PPPY) costs for (1) patients who switched versus those who did not switch and (2) patients with single versus multiple trials of SSRI for the subgroup of patients who switched from an SSRI to venlafaxine. For the time periods before versus after the switch (variable lengths of follow-up), per-patient means and medians of monthly cost averages (with follow-up periods <1 month set to 1 month for 16.5% [n=272] of SSRI-to-venlafaxine switchers and 14.1% [n=103] of venlafaxine-to-SSRI switchers) were calculated for the subgroup of patients who made a switch. RESULTS: A total of 48,950 patients were included in the study, with 43,653 (89.2%) treated first with SSRIs and 5,297 (10.8%) treated first with venlafaxine. Of the initial SSRI users, 1,645 (3.8%) switched to venlafaxine, and of the initial venlafaxine users, 733 (13.8%) switched to an SSRI. Mean (standard deviation [SD]) 12-month total (medical plus pharmacy) depression-related costs in 2002-2003 dollars were 118.0% higher for SSRI switchers ($1,225 [$3,438] vs. $562 [$2,153], P<0.001) and 18.4% higher for venlafaxine switchers ($863 [$1,503] vs. $729 [$1,185], P=0.021) as compared with non-switchers. From the pre-switch to post-switch periods, depression-related mean monthly medical costs declined by 66.4% among switchers from SSRIs ($113 [$912] vs. $38 [$347], P=0.001) and by 61.1% among switchers from venlafaxine ($54 [$299] vs. $21 [$138], P=0.005). Monthly mean depression-related pharmacy costs increased by 62.2% following a switch from an SSRI to venlafaxine (from $45 [$38] to $73 [$62], P<0.001) and declined by 17.3% following a switch from venlafaxine to an SSRI (from $52 [$45] to $43 [$38], P<0.001). After adjustment for multiple covariates including demographic characteristics, 10 selected comorbidities, and physician specialty, general linear models with log-transformed costs as the dependent variables demonstrated significant associations between switching and total costs (both all-cause and depression-related) in both the SSRI and the venlafaxine cohorts. CONCLUSIONS: Although relatively few patients switched antidepressant drug classes, patients who made a switch had higher all-cause health care costs and higher depression-related costs than patients who did not switch. Switching drug classes was associated with lower mean monthly depression-related health care costs following the switch. For those patients switching from an SSRI to venlafaxine, mean medical cost reductions offset higher pharmacy costs; for patients switching from venlafaxine to an SSRI, mean medical and pharmacy costs declined.

The cost-utility of maintenance treatment with venlafaxine in patients with recurrent major depressive disorder.

AIMS: The Prevention of Recurrent Episodes of Depression with venlafaxine XR for Two Years trial has reported advantages with maintenance treatment for patients with recurrent depressive disorder. The aim of this study was to assess the cost-utility of maintenance treatment with venlafaxine in patients with recurrent major depressive disorder, based on a recent clinical trial. METHODS: A Markov simulation model was constructed to assess the cost-utility of maintenance treatment for 2 years in recurrently depressed patients in Sweden. Risk of relapse and recurrence was based on a recent randomised clinical trial assessing the efficacy and tolerability of maintenance treatment with venlafaxine over 2 years. Costs and quality of life estimations were retrieved from a naturalistic longitudinal observational study conducted in Sweden. Health effects were quantified as quality-adjusted life-years (QALYs). Sensitivity analyses were conducted on key parameters employed in the model. RESULTS: In the base-case analysis, the cost per QALY gained of venlafaxine compared with no treatment was estimated at $18,500 over 2 years. In a probabilistic sensitivity analysis, we found that maintenance treatment with venlafaxine is cost-effective with 90% probability at a willingness to pay per QALY of $67,000 or less. Our long-term analyses also indicate that even under conservative assumptions about future risks of recurrences, maintenance treatment is cost-effective. CONCLUSION: The present study indicates that maintenance treatment for 2 years with venlafaxine is cost-effective in patients with recurrent major depressive disorder.