Indirect comparisons of relative efficacy estimates of zuranolone and selective serotonin reuptake inhibitors for postpartum depression.

AIMS: Estimate relative efficacy of zuranolone, a novel oral, Food and Drug Administration-approved treatment for postpartum depression (PPD) in adults vs. selective serotonin reuptake inhibitors (SSRIs) and combination therapies used for PPD in the United States. MATERIALS AND METHODS: Randomized controlled trials (RCTs) for zuranolone and SSRIs, identified from systematic review, were used to construct evidence networks, linking via common comparator arms. Due to heterogeneity in placebo responses, matching-adjusted indirect comparison (MAIC) was applied, statistically weighting the zuranolone treatment arm of Phase 3 SKYLARK Study (NCT04442503) to the placebo arm of RCTs investigating SSRIs for PPD. MAIC outputs were applied in Bucher indirect treatment comparisons (ITCs) and network meta-analysis (NMA), using Edinburgh Postnatal Depression Scale (EPDS) and 17-item Hamilton Rating Scale for Depression (HAMD-17) change from baseline (CFB) on Days 3, 15, 28 (Month 1), 45, and last observation (Day 45, Week 12/18). RESULTS: Larger EPDS CFB was observed among zuranolone-treated vs. SSRI-treated patients from Day 15 onward. Zuranolone-treated (vs. SSRI-treated) patients exhibited 4.22-point larger reduction in EPDS by Day 15 (95% confidence interval: -6.16, -2.28) and 7.43-point larger reduction at Day 45 (-9.84, -5.02) with Bucher ITC. NMA showed EPDS reduction for zuranolone was 4.52 (-6.40, -2.65) points larger than SSRIs by Day 15 and 7.16 (-9.47, -4.85) larger at Day 45. Lack of overlap between study populations substantially reduced effective sample size post-matching, making HAMD-17 CFB analysis infeasible. LIMITATIONS: Limited population overlap between SKYLARK Study and RCTs reduced feasibility of undertaking HAMD-17 CFB ITCs and may introduce uncertainty to EPDS CFB ITC results. CONCLUSIONS: Analysis showed zuranolone-treated patients with PPD experienced greater symptom improvement than SSRI-treated patients from Day 15 onward, with largest mean difference at Day 45. Adjusting for differences between placebo arms, zuranolone may be associated with greater PPD symptom improvement (measured by EPDS) vs. SSRIs.

Indirect treatment comparisons of avapritinib versus midostaurin for patients with advanced systemic mastocytosis.

Objective: This research aimed to compare the relative efficacy of avapritinib versus midostaurin for patients with advanced systemic mastocytosis. Method: A systematic literature review was performed to identify relevant evidence. Unanchored matching-adjusted indirect comparisons were conducted for overall survival (OS), overall response rate (ORR) and complete remission (CR). Results: The systematic literature review identified the clinical trials EXPLORER and PATHFINDER (investigating avapritinib) and D2201 and A2213 (investigating midostaurin). The avapritinib versus midostaurin adjusted hazard ratio for OS was 0.44 (95% CI: 0.25-0.76), and the adjusted odds ratios for ORR and CR were 4.06 (95% CI: 3.09-5.33) and 9.56 (95% CI: 0.97-93.81), respectively. Conclusion: The results suggest that avapritinib improves survival and response (ORR and CR) compared with midostaurin.

Systemic mastocytosis is a rare blood disorder caused by the build-up of too many abnormal mast cells, a type of white blood cell, in the skin and organs. Patients with advanced systemic mastocytosis have a low life expectancy and limited treatment options. This research aimed to compare the effectiveness of two recent and innovative treatments (called avapritinib and midostaurin) in extending life expectancy and decreasing mast cells and organ damage. As avapritinib and midostaurin were not investigated in the same clinical studies, it was necessary to compare the two treatments using the results from studies of each individual treatment. The published evidence used to support this comparison was systematically searched for and consisted of four clinical studies: the EXPLORER and PATHFINDER studies (investigating avapritinib) and D2201 and A2213 studies (investigating midostaurin). An indirect comparison between the studies was made that adjusted for differences in key patient characteristics. The results suggest that compared with midostaurin, avapritinib has the potential to extend life expectancy and decrease disease burden.

Indirect treatment comparison of nivolumab versus placebo for the adjuvant treatment of melanoma.

INTRODUCTION: Until recently, adjuvant treatment options for stage III and IV resectable melanoma have been limited. Patients were often managed through routine surveillance. The phase III randomised controlled trial (RCT) CheckMate 238 (238) demonstrated the safety and efficacy of nivolumab as an adjuvant treatment for melanoma in patients with stage IIIB/C or IV disease (American Joint Committee on Cancer [AJCC], 7th edition) versus ipilimumab. The study objective was to estimate the relative efficacy, safety and health-related quality of life (HRQoL) between nivolumab and routine surveillance. METHODS: Indirect treatment comparisons (ITCs) of nivolumab versus placebo were constructed using data from 238 and EORTC 18071. EORTC 18071 is a phase III RCT comparing ipilimumab with placebo in patients with resected stage IIIA-IIIC melanoma (AJCC, 6th edition). ITCs were performed using the Bucher comparison method and patient-level data for efficacy, safety and HRQoL. RESULTS: For the efficacy outcomes, nivolumab performed significantly better than placebo for recurrence-free survival (hazard ratio [HR]: 0.53 [95% confidence interval {CI}: 0.41, 0.68]) and distant metastases-free survival (HR: 0.59 [95% CI: 0.44, 0.78]). Safety ITCs indicated that patients receiving nivolumab had a greater hazard of experiencing an adverse event (AE) and AEs leading to treatment discontinuation, whereas there was a non-significant increased hazard of experiencing a serious AE. HRQoL ITCs showed comparable time to deterioration in 14 of the 15 QLQ-C30 domains; only the dyspnoea domain significantly favoured placebo. CONCLUSION: Nivolumab was associated with significantly improved efficacy outcomes versus placebo, whereas maintaining patient's overall HRQoL. Across the different analysis and populations, there was a high level of consistency in the effect size.

Using Matching-Adjusted Indirect Comparisons and Network Meta-analyses to Compare Efficacy of Brexanolone Injection with Selective Serotonin Reuptake Inhibitors for Treating Postpartum Depression.

BACKGROUND: Brexanolone injection, the first therapy approved by the US FDA for the treatment of postpartum depression (PPD) in adults, has been shown to produce a significantly greater decrease in the Hamilton Rating Scale for Depression (HAM-D) total score than placebo in randomised controlled trials (RCTs) of women with PPD. OBJECTIVES: Given the rapid effect of brexanolone injection (within 60 h) sustained throughout the length of the trials (30 days), we sought to compare its efficacy data against selective serotonin reuptake inhibitors (SSRIs), the class of antidepressants most commonly prescribed for PPD, using HAM-D and Edinburgh Postnatal Depression Scale (EPDS) outcomes from currently available RCTs. METHODS: We extracted data from 26 studies identified in a systematic literature review of pharmacological and pharmacological/nonpharmacological combination therapies in PPD. Six studies were suitable to form evidence networks through which to perform indirect treatment comparisons (ITCs) of HAM-D and EPDS outcomes between brexanolone and SSRIs. Having assessed the comparability and suitability of the available evidence for analysis, we discovered significant heterogeneity in the study designs, most notably in the placebo arms of the trials. We therefore conducted matching-adjusted indirect comparisons (MAICs) between brexanolone and the placebo arms of comparator studies, subsequently using the MAIC results of brexanolone versus placebo, and results for SSRIs versus placebo, to form ITCs of brexanolone versus SSRIs at three separate time points-day 3, week 4 and last observation. ITCs were calculated as the differences in change from baseline (CFB) in HAM-D and, separately, CFB in EPDS, between treatments, and reported with 95% confidence intervals (CIs). RESULTS: For all time points, MAICs showed larger differences in CFB for brexanolone compared with SSRIs. Differences (95% CIs) between brexanolone and SSRIs were 12.79 (8.04-17.53) [day 3], 5.87 (- 1.62 to 13.37) [week 4] and 0.97 (- 6.35 to 8.30) [last observation] for the HAM-D. For the EPDS, the differences in CFB were 7.98 (5.32-10.64) [day 3], 6.35 (3.13-9.57) [week 4] and 4.05 (0.79-7.31) [last observation]. Other analytical approaches are also presented to demonstrate the similarity of results, using a network meta-analysis approach, and the importance of using the MAIC method to control for the important heterogeneity between placebo arms. CONCLUSIONS: Acknowledging the limitations of ITCs and this evidence base, when compared with SSRIs, these analyses suggest that brexanolone demonstrated larger differences in CFB for both patient- and clinician-reported PPD outcomes and at all investigated time points after adjusting for differences between placebos in the included studies.

The impact of home parenteral nutrition on the burden of disease including morbidity, mortality and rate of hospitalisations.

INTRODUCTION: Home parenteral nutrition (HPN) provides fluid and nutrition essential for the survival of patients with type 3 intestinal failure (IF). However, it is associated with complications and re-admission to hospital. This study aims to investigate the effect of HPN on mortality, morbidity and hospital re-admissions. METHOD: This is a retrospective cohort study. All patients newly dependent on HPN discharged over a 4-year period between 2011 and 2015 were included. Patients' characteristics, nutritional status and diagnosis were recorded, along with frequency and duration of HPN administration. Outcomes collected included hospital re-admissions, morbidity, catheter related blood stream infections (CRBSIs) and mortality. Regression analyses were performed to estimate the rate of different outcomes adjusted for prognostic factors. RESULTS: There were 210 patients included, 561 separate HPN prescriptions equating to 110,537 catheter days. Total number of deaths was 44 (0.398 deaths per 1000 catheter days). There were 196 re-admissions to hospital recorded for a total of 5594 days, 69 (33%) of these re-admissions were unplanned (2484 days in hospital). Principle reasons for unplanned re-admissions included: CRBSIs (n = 31, 45%); other sepsis (n = 10, 14.5%) and abdominal symptoms (n = 9, 13%). CRBSIs were recorded in 22 (10%) patients, equating to a rate of 0.199 per 1000 catheter days. Days per week on HPN increased the relative rate (RR) of time in hospital due to any reason or for unplanned readmissions, RR 1.50 (95% CI: 1.26, 1,78 p < 0.001) and RR 1.39 (95% CI: 1.10, 1.75 p = 0.006) respectively. However, there was no association between days per week on HPN and CRBSI occurrence. CONCLUSION: Unplanned re-admissions for patients with IF accounted for a third of all hospitalisations in those on HPN and the majority were due to CRBSI. The number of HPN dependent days per week was related to all-cause unplanned re-admissions, although not to CRBSI rate.

The cost-effectiveness of nivolumab monotherapy for the treatment of advanced melanoma patients in England.

BACKGROUND: Nivolumab was the first programmed death receptor 1 (PD-1) immune checkpoint inhibitor to demonstrate long-term survival benefit in a clinical trial setting for advanced melanoma patients. OBJECTIVE: To evaluate the cost effectiveness of nivolumab monotherapy for the treatment of advanced melanoma patients in England. METHODS: A Markov state-transition model was developed to estimate the lifetime costs and benefits of nivolumab versus ipilimumab and dacarbazine for BRAF mutation-negative patients and versus ipilimumab, dabrafenib, and vemurafenib for BRAF mutation-positive patients. Covariate-adjusted parametric curves for time to progression, pre-progression survival, and post-progression survival were fitted based on patient-level data from two trials and long-term ipilimumab survival data. Indirect treatment comparisons between nivolumab, ipilimumab, and dacarbazine were informed by these covariate-adjusted parametric curves, controlling for differences in patient characteristics. Kaplan-Meier data from the literature were digitised and used to fit progression-free and overall survival curves for dabrafenib and vemurafenib. Patient utilities and resource use data were based on trial data or the literature. Patients are assumed to receive nivolumab until there is no further clinical benefit, assumed to be the first of progressive disease, unacceptable toxicity, or 2 years of treatment. RESULTS: Nivolumab is the most cost-effective treatment option in BRAF mutation-negative and mutation-positive patients, with incremental cost-effectiveness ratios of £24,483 and £17,362 per quality-adjusted life year, respectively. The model results are most sensitive to assumptions regarding treatment duration for nivolumab and the parameters of the fitted parametric survival curves. CONCLUSIONS: Nivolumab is a cost-effective treatment for advanced melanoma patients in England.

Once-daily long-acting beta-agonists for chronic obstructive pulmonary disease: an indirect comparison of olodaterol and indacaterol.

PURPOSE: In the absence of head-to-head clinical trials comparing the once-daily, long-acting beta2-agonists olodaterol and indacaterol for the treatment of chronic obstructive pulmonary disease (COPD), an indirect treatment comparison by systematic review and synthesis of the available clinical evidence was conducted. METHODS: A systematic literature review of randomized, controlled clinical trials in patients with COPD was performed to evaluate the efficacy and safety of olodaterol and indacaterol. Network meta-analysis and adjusted indirect comparison methods were employed to evaluate treatment efficacy, using outcomes based on trough forced expiratory volume in 1 second (FEV1), Transition Dyspnea Index, St George's Respiratory Questionnaire total score and response, rescue medication use, and proportion of patients with exacerbations. RESULTS: Eighteen trials were identified for meta-analysis (eight, olodaterol; ten, indacaterol). Olodaterol trials included patients of all severities, whilst indacaterol trials excluded patients with very severe COPD. Concomitant maintenance bronchodilator use was allowed in most olodaterol trials, but not in indacaterol trials. When similarly designed trials/data were analyzed for change from baseline in trough FEV1 (liters), the following mean differences (95% confidence interval) were observed: trials excluding concomitant bronchodilator: indacaterol 75 mcg versus olodaterol 5 mcg, -0.005 (-0.077 to 0.067), and indacaterol 150 mcg versus olodaterol 5 mcg, 0.020 (-0.036 to 0.077); trials with concomitant tiotropium: indacaterol 150 mcg versus olodaterol 5 mcg, 0.000 (-0.043 to 0.042). In sensitivity analyses of the full network, results for change from baseline in trough FEV1 favored indacaterol, but this dataset suffered from trial design heterogeneity. For the other endpoints investigated, no statistically significant differences were found when analyzed in the full network. CONCLUSION: When compared under similar trial conditions, olodaterol and indacaterol have similar efficacy in patients with COPD. This research highlights the importance of considering the concomitant COPD medication when evaluating treatment effects in COPD.

Major bleeding in patients with atrial fibrillation receiving vitamin K antagonists: a systematic review of randomized and observational studies.

AIMS: Clinical trials have shown that anticoagulation with vitamin K antagonists (VKAs), e.g. warfarin, decreases the risk of stroke in patients with atrial fibrillation (AF); however, increased bleeding risk is one of the safety concerns. The primary objective was to conduct a systematic review of the published literature, assessing the risk of major bleeding and mortality in patients with AF treated with VKAs. METHODS AND RESULTS: Online searches of MEDLINE, EMBASE, BIOSIS, and the Cochrane Library were performed to a pre-specified protocol from 1960 to March 2012 for randomized controlled trials (RCTs) and from January 1990 to March 2012 for observational studies. A total of 47 studies (16 RCTs and 31 observational studies) were included. Cumulative follow-up was 61,563 patient-years for RCTs and 484 241 patient-years for observational studies. The overall median incidence of major bleeding was 2.1 per 100 patient-years (range, 0.9-3.4 per 100 patient-years) for RCTs and 2.0 per 100 patient-years (range, 0.2-7.6 per 100 patient-years) for observational studies. With study year as a proxy for changing management patterns, some evidence of bleeding rates and/or their reporting increasing over time was noted. Mortality rates from observational studies were inadequately reported to allow comparison with those from RCT data. CONCLUSION: The median rate of major bleeding in observational studies and RCTs is similar. The larger heterogeneity in bleeding rates observed in a real-life setting could reflect a high variability in standard of care of patients on VKAs and/or methodological differences between observational studies and/or variability in data sources.

Dabigatran versus rivaroxaban for the prevention of stroke and systemic embolism in atrial fibrillation in Canada. Comparative efficacy and cost-effectiveness.

Canadian patients with atrial fibrillation (AF) in whom anticoagulation is appropriate have two new choices for anticoagulation for prevention of stroke and systemic embolism--dabigatran etexilate (dabigatran) and rivaroxaban. Based on the RE-LY and ROCKET AF trial results, we investigated the cost-effectiveness of dabigatran (twice daily dosing of 150 mg or 110 mg based on patient age) versus rivaroxaban from a Canadian payer perspective. A formal indirect treatment comparison (ITC) of dabigatran versus rivaroxaban was performed, using dabigatran clinical event rates from RE-LY for the safety-on-treatment population, adjusted to the ROCKET AF population. A previously described Markov model was modified to simulate anticoagulation treatment using ITC results as inputs. Model outputs included total costs, event rates, and quality-adjusted life-years (QALYs). The ITC found when compared to rivaroxaban, dabigatran had a lower risk of intracranial haemorrhage (ICH) (relative risk [RR] = 0.38; 95% confidence interval [CI] 0.21 - 0.67) and stroke (RR = 0.62; 95%CI 0.45-0.87). Over a lifetime horizon, the model found dabigatran-treated patients experienced fewer ICHs (0.33 dabigatran vs. 0.71 rivaroxaban) and ischaemic strokes (3.40 vs. 3.96) per 100 patient-years, and accrued more QALYs (6.17 vs. 6.01). Dabigatran-treated patients had lower acute care and long-term follow-up costs per patient ($52,314 vs. $53,638) which more than offset differences in drug costs ($7,299 vs. $6,128). In probabilistic analysis, dabigatran had high probability of being the most cost-effective therapy at common thresholds of willingness-to-pay (93% at a $20,000/QALY threshold). This study found dabigatran is economically dominant versus rivaroxaban for prevention of stroke and systemic embolism among Canadian AF patients.

Clinical burden and incremental cost of fractures in postmenopausal women in the United Kingdom.

This cohort study of postmenopausal women in the United Kingdom aged ≥50years determined the incremental cost of health care and clinical outcomes in the 12months following incident, selected fractures (non-vertebral non-hip [NVNHF], vertebral [VF] and multiple [MF]). Incremental costs and outcomes of the fracture cohorts were compared with those of cohorts comprised of women without fractures who were individually matched on age and comorbidity. Cohorts were identified from The Health Improvement Network database, a primary health care database, from 2001 to 2005. We estimated 1-year incremental costs (hospitalizations; general practice, accident/emergency, and referral visits; and prescription medications) associated with each fracture type. Descriptive analyses examined occurrence of subsequent fractures and death. No long-term health care costs or outcomes were assessed. Overall, 14,030 women had NVNHF, 1471 had VF, and 193 had MF. The risk of death was greater for women with fractures than for women in the non-fracture cohorts. Mean incremental cost for fractures compared with no fractures was £1152 for VF; £690 for NVNHF, and £2581 for MF. Of the total incremental cost, hospitalizations represented 54%-90% and medications represented 7%-29%. In all fracture cohorts, most of the total annual costs were concentrated in the 6months after the date of fracture. Fractures among postmenopausal women represent an important burden to the health system due to the increase in health resource utilization and related costs. In this study, hospitalizations were the main driver of the overall incremental cost during the 12months following the fracture. Mortality in women in the selected fracture cohorts was higher than in women in the non-fracture cohorts.

Study of the incremental cost and clinical burden of hip fractures in postmenopausal women in the United Kingdom.

OBJECTIVE: To determine the incremental cost of healthcare and clinical outcomes in the 12 months following incident hip fractures among postmenopausal women in the UK. METHODS: Retrospective cohort study of women aged 50 years or older hospitalized for an incident hip fracture within 1 week of the fracture date who were age- and comorbidity-matched to women without fracture. Cohorts were identified in the Health Improvement Network database, and followed up for 1 year. RESULTS: Among 2,427 women who had a hip fracture and a recorded hospitalization, the mean [SD] age was 81 [9.3] years. About 18% of women without fractures were hospitalized during follow-up and 18% of women with hip fractures and 4% of women without fractures had at least one emergency admission (RR, 4.7; 95% CI, 3.8-5.8). There were no major differences in use of general practitioner visit, referral visits, or in prescription of medications. Mortality was 18% in the hip fracture cohort and 7% in the non-fracture cohort (RR, 2.5; 95% CI, 2.1-3.0). The overall 1-year mean incremental cost of hip fractures was £4,222 (95% CI, £4,105-4,339); most of this cost (97%) was for hospitalizations, with an increment of £4,095. About 98% of the incremental cost occurred in the first 6 months following hip fracture. CONCLUSIONS: The results of this study indicate that the cost and clinical burden associated with hip fractures in postmenopausal women in the UK are considerable. The incremental cost is mostly related to the cost of hospitalization and treatment of the hip fracture. Key limitations were the inclusion of only those women with a recorded hospitalization, and that costs associated with rehabilitation services, social services, and long-term care were not recorded in this study, although these are important contributors to the total cost of fractures.

A meta-analysis of pain response in the treatment of fibromyalgia.

OBJECTIVE: This meta-analysis compared efficacy (pain response) of drugs that are licensed or commonly used in the treatment of fibromyalgia. A meta-analysis of safety measured via discontinuation because of adverse events was also performed. METHODS: We conducted a meta-analysis of 21 clinical trials to estimate treatment differences vs. placebo, separately, for duloxetine, fluoxetine, gabapentin, milnacipran, pramipexole, pregabalin, either of two tricyclic antidepressants, and tramadol plus paracetamol. Indirect treatment comparisons using mixed treatment comparisons methodology were conducted for all pairwise comparisons. Pain response was analyzed as improvement of at least 30%, and separately of 50%, from baseline. RESULTS: When compared with placebo, statistically significant pain responses (improvement of 30% and 50%) were observed for patients treated with duloxetine, milnacipran 200 mg/day, pregabalin 300 or 450 mg/day, and tramadol plus paracetamol. Treatment with fluoxetine, gabapentin, or milnacipran 100 mg/day resulted in significant findings for the 30% improvement in pain response. The meta-analysis showed a statistically increased risk of discontinuation because of adverse events for milnacipran 100 and 200 mg/day (both P < 0.001), and pregabalin 300 and 450 mg/day (P = 0.009 and P < 0.001, respectively). All other treatments, except fluoxetine, showed numerically increased risk over placebo for discontinuation because of adverse events. In the indirect comparisons, no pairwise comparison of active treatments reached statistical significance for either pain response end point. CONCLUSION: All eight active treatments displayed evidence suggesting improvement over placebo in the treatment of pain in patients suffering from fibromyalgia. Indirect comparison of active treatments found no strong differences.

Treatments for stroke prevention in atrial fibrillation: a network meta-analysis and indirect comparisons versus dabigatran etexilate.

Patients with atrial fibrillation at moderate to high risk of stroke are not always anticoagulated despite a lack of contraindications to vitamin K antagonists (VKAs) like warfarin. These patients are treated with aspirin, aspirin-clopidogrel combination therapy or even receive no thromboprophylaxis. The oral direct thrombin inhibitor, dabigatran etexilate 150 mg BID and 110 mg BID, might represent an alternative for these patients; however, no head-to-head clinical trial data exist versus these alternative treatments. A network meta-analysis (NMA) was performed to indirectly compare dabigatran etexilate with antiplatelets and placebo. Compared with placebo, dabigatran etexilate 150 mg BID was estimated to significantly reduce the risk of any stroke (ischaemic and haemorrhagic) by 75% (relative risk [RR] 0.25; 95% confidence interval [CI] 0.12-0.51), ischaemic stroke by 77% (RR 0.23; 95% CI 0.14-0.38), systemic embolism by 83% (RR 0.17; 95% CI 0.05-0.50) and mortality by 36% (RR 0.64; 95% CI 0.45-0.91). Dabigatran etexilate 150 mg BID was estimated to significantly reduce the risk of any stroke compared with aspirin monotherapy by 63% (RR 0.37; 95% CI 0.20-0.69) and aspirin plus clopidogrel by 61% (RR 0.39; 95% CI 0.21-0.72). Trends toward reduced risk with both dabigatran etexilate regimens were found for most clinical outcomes. Relative risk estimates of dabigatran etexilate versus adjusted-dose VKAs within the NMA were consistent with results from the head-to-head randomised trial of these two strategies. Indirect evidence suggests treatment with dabigatran etexilate offers benefit for the prevention of stroke, systemic embolism and mortality over antiplatelets and placebo. There was no indication of increased intracranial or extracranial haemorrhage with dabigatran etexilate compared to antiplatelet agents.

Economic evaluation of dabigatran etexilate for the prevention of venous thromboembolism after total knee and hip replacement surgery.

OBJECTIVE: This was an evaluation of the cost-effectiveness of oral dabigatran etexilate compared with subcutaneous low-molecular-weight heparin (enoxaparin) for the prevention of venous thromboembolism (VTE) after total knee replacement (TKR) and total hip replacement (THR) surgery from the perspective of the UK National Health Service. METHODS: Dabigatran etexilate (220 mg once daily) was compared with enoxaparin (40 mg once daily) in patients undergoing TKR (duration of prophylaxis, 6-10 days) and THR (duration of prophylaxis, 28-35 days). The 10-week acute postsurgical phase was modeled using a decision tree. A Markov process (1-year cycle length) was used to model long-term events (recurrent VTE, postthrombotic syndrome, and consequences of intracranial hemorrhage) for patients' remaining lifetimes. Relative risks for VTE and bleeding events were derived from 2 Phase III studies that compared dabigatran etexilate with enoxaparin 40 mg once daily. The probabilities of long-term events were estimated using data from published longitudinal studies. RESULTS: Rates of VTE and bleeding events did not differ significantly between dabigatran etexilate and enoxaparin. Dabigatran etexilate was less costly than enoxaparin in TKR and substantially less costly in THR, primarily due to differences in administration costs. The cost of prophylaxis for THR patients, including drugs and administration costs, was estimated at pound 137 for dabigatran etexilate and pound 237 for enoxaparin ( pound 7 for nursing time during the hospital stay, pound 91 for nurse home visits for administration after hospital discharge, and an additional pound 2 in drug costs). At a willingness-to-pay threshold of pound 20,000 per quality-adjusted life-year, the probability of cost-effectiveness for dabigatran etexilate was 75% in TKR and 97% in THR. These results were robust across a range of sensitivity analyses. CONCLUSION: From the perspective of the UK National Health Service, thromboprophylaxis with dabigatran etexilate was cost-saving compared with enoxaparin 40 mg once daily, with comparable efficacy and safety profiles.

Efficacy and safety of dabigatran etexilate for the prevention of venous thromboembolism following total hip or knee arthroplasty. A meta-analysis.

Dabigatran etexilate has been investigated in three phase III trials for the prevention of venous thromboembolism (VTE). Health technology assessment agencies increasingly require meta-analyses of all relevant evidence for an intervention, if appropriate. The objective of this study was to perform a meta-analysis of efficacy and safety data for the recommended dose of dabigatran etexilate, 220 mg once daily (od), for VTE prophylaxis after total knee arthroplasty (TKA) and total hip arthroplasty (THA), and discuss the appropriateness of combining the data. Risk ratios (RR) for VTE and bleed end-points were estimated using fixed and random effects meta-analysis. Analyses were performed combining RE-MODEL and RE-NOVATE, which compared dabigatran etexilate with enoxaparin 40 mg od after TKA and THA, respectively, and also including RE-MOBILIZE, which compared dabigatran etexilate with enoxaparin 30 mg twice daily after TKA. Tests for statistical heterogeneity were performed using the Chi-squared statistic. No significant differences were detected between dabigatran etexilate and enoxaparin in any of the end-points analysed, either in the two trial analysis (all p > 0.15), or when all three trials were combined ( all p > 0.30). RRs (random effects) for the composite end-point total VTE and all-cause mortality were 0.95 [95% confidence intervals 0.82 - 1.10] and 1.05 [0.87 - 1.26] in the two and three trial analyses, respectively. Meta-analysis of RE-MODEL and RE-NOVATE supported the conclusions of the individual trials that dabigatran etexilate is non-inferior to enoxaparin 40 mg od, with a similar safety profile. Meta-analysis of all three trials found no significant differences between treatments in any of the end-points analysed. Heterogeneity between the trials cannot be ruled out.

A predictive model of health state utilities for HIV patients in the modern era of highly active antiretroviral therapy.

OBJECTIVE: Existing estimates of human immunodeficiency virus (HIV)-related health state utilities are inadequate for comparing alternative treatments on the basis of regimen-specific attributes such as dosing requirements or tolerability. The objective of this study was to examine the marginal impact of dosing, adverse events (AEs), and other factors on patients' health state utilities. METHODS: Treatment naive and experienced HIV patients participating in five open-label trials of highly active antiretroviral therapy (HAART) completed the 36-Item Short Form Health Survey (SF-36) instrument at various time points. SF-36 responses were converted to utilities using a previously reported algorithm. Expected utilities were estimated as a function of patient demographics, regimen attributes, disease status, and AEs using a mixed-effects maximum likelihood model. Mean utilities for five HIV health states were derived from predicted patient utilities. RESULTS: Negative predictors of utility included greater age (-0.001), prior acquired immune deficiency syndrome-defining events (-0.036), female gender (-0.038), and injection drug use (-0.056; P < 0.01 for all). Utility also depended on CD4+ cell count (P < 0.01), but not the presence of undetectable viral load. Regimen attributes were marginally associated with changes in utility. Depression was associated with the largest decrease in utility (-0.054, P < 0.001) among the AEs examined. Using the model to generate predicted utilities from the sample provided mean estimates ranging from 0.742 (SD 0.058) to 0.798 (0.052) for CD4+ counts between 0 and 99 and > or =500 cells/mm(3), respectively. CONCLUSIONS: HIV patients' health-related quality of life may be substantially affected by clinically relevant patient-, disease-, and treatment-related factors, such as injection drug use, disease status, food/drink restrictions, and AEs.

Cost effectiveness of pegaptanib for the treatment of age-related macular degeneration in the UK.

BACKGROUND: Age-related macular degeneration (AMD) is the primary cause of vision loss in the elderly and results in significant economic and humanistic burden. The selective vascular endothelial growth factor inhibitor, pegaptanib (Macugen) is indicated for patients with neovascular AMD. Guidance is needed regarding the cost effectiveness of treatment, any variation between sub-populations of differing clinical characteristics and the optimum duration of treatment. OBJECTIVE: To estimate the cost effectiveness of pegaptanib versus best supportive care (BSC) for AMD from the perspective of the UK government, and to evaluate the impact of patient characteristics and differing treatment discontinuation scenarios. METHODS: A cohort of 1000 patients aged >45 years with a best-corrected visual acuity (VA) in their better-seeing eye of < or =6/12 was modelled. Patients were either treated with pegaptanib (0.3mg every 6 weeks for a maximum of 2 years in their better-seeing eye only) or received BSC (no active treatment). Supportive services were provided for patients with a VA < or =6/60. A 10-year Markov model composed of 12 VA states (defined by individual Snellen lines) and a dead state was constructed. The model reported herein was used to support submissions to the National Institute for Health and Clinical Excellence (NICE) and the Scottish Medicines Consortium (SMC). NICE guidance is expected to be available in October 2007 and the SMC advice was issued on 7 July 2006. SMC accepted pegaptanib for use in patients with visual acuity between 6/12 and 6/60 (inclusive) and should be stopped if visual acuity falls below 6/60 during treatment or where severe visual loss is experienced. Time-dependent transition probabilities for the loss and gain of Snellen lines were derived from parametric survival curves fitted to patient-level data from the VISION trials. Survival curves were fitted with treatment and baseline Snellen scores as covariates; additional curves were fitted with the addition of age, gender, lesion type or lesion size as covariates. Mortality rates were adjusted for the age, gender and VA of the population. Cost effectiveness was expressed as the incremental cost (IC) per vision-year saved and IC/QALY. Uncertainty was explored by probabilistic and univariate sensitivity analysis. Costs (year 2005 values) and outcomes were discounted at 3.5% per anum. RESULTS: In the base-case analysis, treatment was targeted to patients with a VA of 6/12 to 6/95 and discontinued after 2 years, or earlier if VA fell below 6/95 or by > or =6 lines. The IC/QALY was estimated as 8023 pounds(upper 95% CI 20,641 pounds). Cost effectiveness varied by age (age <75 years = 2033 pounds/QALY; age > or =75 years = 11,657 pounds/QALY) and by pre-treatment VA (6/12-6/95 = 8023 pounds/QALY; 6/12-6/60 = 6664 pounds/QALY; 6/12-6/24 = 1920 pounds/QALY). Gender and lesion type or size had little effect. Cost effectiveness was not sensitive to precise rules for treatment discontinuation, but was maximised if treatment was discontinued in patients no longer likely to benefit. CONCLUSIONS: The results suggest that pegaptanib treatment is likely to be cost effective across all groups studied, and marginally more cost effective in younger patients and those with better pre-treatment VA. Cost effectiveness appears to be optimised if treatment is discontinued after 1 year if individual patients' VA has dropped by > or =6 lines from pre-treatment levels, or at any time if it drops below 6/95. However, strict application of discontinuation rules does not appear to be necessary for pegaptanib to be cost effective. Clinical judgement and patient preference should be an important determinant in decisions about stopping treatment.

Risk of suicide during treatment with venlafaxine, citalopram, fluoxetine, and dothiepin: retrospective cohort study.

OBJECTIVE: To compare the risk of suicide in adults using the antidepressant venlafaxine compared with citalopram, fluoxetine, and dothiepin. DESIGN: Retrospective cohort study. SETTING: UK General Practice Research Database. PARTICIPANTS: 219,088 patients, aged 18-89 years, who were prescribed venlafaxine, citalopram, fluoxetine, or dothiepin from 1995 to 2005. MAIN OUTCOME MEASURES: Completed suicide and attempted suicide. RESULTS: Venlafaxine users had a higher burden of risk factors for suicide, including previous suicide attempts and proxies for severe depression or depression that was difficult to treat. In the analysis for completed suicides, unadjusted and adjusted hazard ratios for venlafaxine compared with citalopram were 2.44 (95% confidence interval 1.12 to 5.31) and 1.70 (0.76 to 3.80), for venlafaxine compared with fluoxetine were 2.85 (1.37 to 5.94) and 1.63 (0.74 to 3.59), and for venlafaxine compared with dothiepin were 2.54 (1.07 to 6.02) and 1.31 (0.53 to 3.25). Compared with other study drugs, venlafaxine was also associated with an increased risk of attempted suicide, but adjustment for measured confounders substantially reduced the hazard ratios. CONCLUSIONS: Venlafaxine use was consistently associated with higher risk of suicide compared with citalopram, fluoxetine, and dothiepin. Venlafaxine users had a higher burden of suicide risk factors, however, and adjustment for measured confounders substantially reduced the excess risks. Since the secondary data used in this analysis allowed only indirect and partial measurements of potential confounders, it is possible that residual confounding explains much, if not all, of the observed excess risk.

Atovaquone-proguanil versus chloroquine-proguanil for malaria prophylaxis in nonimmune pediatric travelers: results of an international, randomized, open-label study.

Atovaquone-proguanil has been shown to be effective and well tolerated for malaria prophylaxis in residents of countries of endemicity and in nonimmune adult travelers, but data about traveling children are limited. In a randomized, open-label, multicenter prophylaxis trial, 221 nonimmune pediatric travelers (age, 2-17 years) received either atovaquone-proguanil or chloroquine-proguanil. Safety and clinical outcome were evaluated 7, 28, and 60 days after travel. By posttravel day 7, a total of 39 (35%) of 110 atovaquone-proguanil and 41 (37%) of 111 chloroquine-proguanil recipients reported > or =1 adverse event. The data indicate that, over the course of treatment, fewer atovaquone-proguanil recipients had treatment-related adverse events (8% vs. 14%), including gastrointestinal complaints (5% vs. 10%). Two subjects discontinued prophylaxis because of drug-related adverse events; both had received chloroquine-proguanil. Observed compliance with prophylaxis was similar before and during travel, but it was higher for atovaquone-proguanil in the posttravel period. No study participant developed malaria. Atovaquone-proguanil was well tolerated and is an important addition to the limited arsenal of prophylactic agents available to children.