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W arfarin, a vitamin K antagonist, is a commonly used anticoagulant in patients with atrial fibrillation (AF). Metaanalyses of randomized trials have shown that it reduces the risk of embolic stroke by 40% to 80% and of mortality by ≈30% but also doubles the risk of intracranial hemorrhage and increases the risk of extracranial bleeding by up to 66%. [1][2][3] It can be difficult to maintain patients in the therapeutic range (international normalized ratio of 2-3). A meta-analysis found that warfarintreated patients were in the therapeutic range 61% of the time. 4 In this study, an international normalized ratio <2 was associated with a 5-fold increase in stroke risk, and an international normalized ratio >3 was associated with a 3-fold increase in bleeding risk. Clinical Perspective on p 164Dabigatran is a competitive direct thrombin inhibitor approved in the United States to reduce the risk of stroke and systemic embolization in patients with nonvalvular AF. 5 In the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial, patients with AF were randomized to dabigatran doses of 110 or 150 mg twice daily or adjusted-dose warfarin. 6 At the dose subsequently approved in the United States (150 mg twice daily), dabigatran reduced the risk of stroke and intracranial hemorrhage and increased the risk of major gastrointestinal hemorrhage compared with warfarin. 6 Although dabigatranBackground-The comparative safety of dabigatran versus warfarin for treatment of nonvalvular atrial fibrillation in general practice settings has not been established. Methods and Results-We formed new-user cohorts of propensity score-matched elderly patients enrolled in Medicare who initiated dabigatran or warfarin for treatment of nonvalvular atrial fibrillation between October 2010 and December 2012. Among 134 414 patients with 37 587 person-years of follow-up, there were 2715 primary outcome events. The hazard ratios (95% confidence intervals) comparing dabigatran with warfarin (reference) were as follows: ischemic stroke, 0.80 (0.67-0.96); intracranial hemorrhage, 0.34 (0.26-0.46); major gastrointestinal bleeding, 1.28 (1.14-1.44); acute myocardial infarction, 0.92 (0.78-1.08) ; and death, 0.86 (0.77-0.96). In the subgroup treated with dabigatran 75 mg twice daily, there was no difference in risk compared with warfarin for any outcome except intracranial hemorrhage, in which case dabigatran risk was reduced. Most patients treated with dabigatran 75 mg twice daily appeared not to have severe renal impairment, the intended population for this dose. In the dabigatran 150-mg twice daily subgroup, the magnitude of effect for each outcome was greater than in the combined-dose analysis. Conclusions-In general practice settings, dabigatran was associated with reduced risk of ischemic stroke, intracranial hemorrhage, and death and increased risk of major gastrointestinal hemorrhage compared with warfarin in elderly patients with nonvalvular atrial fibrillation. These associations were most pronounced in patients treated...

Objective To examine the risk of suicidal behaviour within clinical trials of antidepressants in adults. Design Meta-analysis of 372 double blind randomised placebo controlled trials. Setting Drug development programmes for any indication in adults. Participants 99 231 adults assigned to antidepressants or placebo. Median age was 42 and 63.1% were women. Indications for treatment were major depression (45.6%), other depression (4.6%), other psychiatric disorders (27.6%), and non-psychiatric disorders (22.2%). Main outcome measures Suicidal behaviour (completed suicide, attempted suicide, or preparatory acts) and ideation. Results For participants with non-psychiatric indications, suicidal behaviour and ideation were extremely rare. For those with psychiatric indications, risk was associated with age. For suicidal behaviour or ideation and for suicidal behaviour only, the respective odds ratios were 1.62 (95% confidence interval 0.97 to 2.71) and 2.30 (1.04 to 5.09) for participants aged <25, 0.79 (0.64 to 0.98) and 0.87 (0.58 to 1.29) for those aged 25-64, and 0.37 (0.18 to 0.76) and 0.06 (0.01 to 0.58) for those aged ≥65. When age was modelled as a continuous variable, the odds ratio for suicidal behaviour or ideation declined at a rate of 2.6% per year of age (−3.9% to −1.3%, P=0.0001) and the odds ratio for suicidal behaviour declined at a rate of 4.6% per year of age (−7.4% to −1.8%, P=0.001).Conclusions Risk of suicidality associated with use of antidepressants is strongly age dependent. Compared with placebo, the increased risk for suicidality and suicidal behaviour among adults under 25 approaches that seen in children and adolescents. The net effect seems to be neutral on suicidal behaviour but possibly protective for suicidal ideation in adults aged 25-64 and to reduce the risk of both suicidality and suicidal behaviour in those aged ≥65.

Among patients in the US Medicare nondialysis population with first exposure to IV iron, the risk of anaphylaxis was highest for iron dextran and lowest for iron sucrose.

Background: Although certain drugs that target the renin-angiotensin-aldosterone system are linked to an increased risk for angioedema, data on their absolute and comparative risks are limited. We assessed the risk for angioedema associated with the use of angiotensinconverting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and the direct renin inhibitor aliskiren.Methods: We conducted a retrospective, observational, inception cohort study of patients 18 years or older from 17 health plans participating in the Mini-Sentinel program who had initiated the use of an ACEI (n=1 845 138), an ARB (n=467 313), aliskiren (n=4867), or a ␤-blocker (n = 1 592 278) between January 1, 2001, and December 31, 2010. We calculated the cumulative incidence and incidence rate of angioedema during a maximal 365-day follow-up period. Using ␤-blockers as a reference and a propensity score approach, we estimated the hazard ratios of angioedema separately for ACEIs, ARBs, and aliskiren, adjusting for age, sex, history of allergic reactions, diabetes mellitus, heart failure, or ischemic heart disease, and the use of prescription nonsteroidal antiinflammatory drugs.Results: A total of 4511 angioedema events (3301 for ACEIs, 288 for ARBs, 7 for aliskiren, and 915 for ␤-blockers) were observed during the follow-up period. The cumulative incidences per 1000 persons were 1.79 (95% CI, 1.73-1.85) cases for ACEIs, 0.62 (95% CI, 0.55-0.69) cases for ARBs, 1.44 (95% CI, 0.58-2.96) cases for aliskiren, and 0.58 (95% CI, 0.54-0.61) cases for ␤-blockers. The incidence rates per 1000 person-years were 4.38 (95% CI, 4.24-4.54) cases for ACEIs, 1.66 (95% CI, 1.47-1.86) cases for ARBs, 4.67 (95% CI, 1.88-9.63) cases for aliskiren, and 1.67 (95% CI, 1.56-1.78) cases for ␤-blockers. Compared with the use of ␤-blockers, the adjusted hazard ratios were 3.04 (95% CI, 2.81-3.27) for ACEIs, 1.16 (95% CI, 1.00-1.34) for ARBs, and 2.85 (95% CI, 1.34-6.04) for aliskiren.Conclusions: Compared with ␤-blockers, ACEIs or aliskiren was associated with an approximately 3-fold higher risk for angioedema, although the number of exposed events for aliskiren was small. The risk for angioedema was lower with ARBs than with ACEIs or aliskiren.

Recent legislation mandates that the US Food and Drug Administration issue guidance regarding when real‐world evidence (RWE) could be used to support regulatory decision making. Although RWE could come from randomized or nonrandomized designs, there are significant concerns about the validity of RWE assessing medication effectiveness based on nonrandomized designs. We propose an initiative using healthcare claims data to assess the ability of nonrandomized RWE to provide results that are comparable with those from randomized controlled trials (RCTs). We selected 40 RCTs, and we estimate that approximately 30 attempted replications will be completed after feasibility analyses. We designed an implementation process to ensure that each attempted replication is consistent, transparent, and reproducible. This initiative is the first to systematically evaluate the ability of nonrandomized RWE to replicate multiple RCTs using a structured process. Results from this study should provide insight on the strengths and limitations of using nonrandomized RWE from claims for regulatory decision making.

No abstract

The problem of determining a consensus value and its uncertainty from the results of multiple methods or laboratories is discussed. Desirable criteria of a solution are presented. A solution motivated by the ISO Guide to the Expression of Uncertainty in Measurement (ISO GUM) is introduced and applied in a detailed worked example. A Bayesian hierarchical model motivated by the proposed solution is presented and compared to the solution.