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Concept: Post-hoc analysis

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Background A leadless intracardiac transcatheter pacing system has been designed to avoid the need for a pacemaker pocket and transvenous lead. Methods In a prospective multicenter study without controls, a transcatheter pacemaker was implanted in patients who had guideline-based indications for ventricular pacing. The analysis of the primary end points began when 300 patients reached 6 months of follow-up. The primary safety end point was freedom from system-related or procedure-related major complications. The primary efficacy end point was the percentage of patients with low and stable pacing capture thresholds at 6 months (≤2.0 V at a pulse width of 0.24 msec and an increase of ≤1.5 V from the time of implantation). The safety and efficacy end points were evaluated against performance goals (based on historical data) of 83% and 80%, respectively. We also performed a post hoc analysis in which the rates of major complications were compared with those in a control cohort of 2667 patients with transvenous pacemakers from six previously published studies. Results The device was successfully implanted in 719 of 725 patients (99.2%). The Kaplan-Meier estimate of the rate of the primary safety end point was 96.0% (95% confidence interval [CI], 93.9 to 97.3; P<0.001 for the comparison with the safety performance goal of 83%); there were 28 major complications in 25 of 725 patients, and no dislodgements. The rate of the primary efficacy end point was 98.3% (95% CI, 96.1 to 99.5; P<0.001 for the comparison with the efficacy performance goal of 80%) among 292 of 297 patients with paired 6-month data. Although there were 28 major complications in 25 patients, patients with transcatheter pacemakers had significantly fewer major complications than did the control patients (hazard ratio, 0.49; 95% CI, 0.33 to 0.75; P=0.001). Conclusions In this historical comparison study, the transcatheter pacemaker met the prespecified safety and efficacy goals; it had a safety profile similar to that of a transvenous system while providing low and stable pacing thresholds. (Funded by Medtronic; Micra Transcatheter Pacing Study ClinicalTrials.gov number, NCT02004873 .).

Concepts: Implantable cardioverter-defibrillator, Point, Artificial pacemaker, Post-hoc analysis, Transcutaneous pacing, Goal, Medtronic, Earl Bakken

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This post hoc analysis estimates time to transient and stable reductions in hot flush frequency in postmenopausal women using conjugated estrogens/bazedoxifene.

Concepts: Post-hoc analysis

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The purpose of this investigation was to examine the use of subjective rating of perceived exertion (RPE) as a tool to self-regulate the intensity of wheelchair propulsive exercise in individuals with tetraplegia. Eight motor complete tetraplegic (C5/6 and below; ASIA Impairment Scale = A) participants completed a submaximal incremental exercise test followed by a graded exercise test to exhaustion to determine peak oxygen uptake ([Formula: see text]) on a wheelchair ergometer. On a separate day, a 20-min exercise bout was completed at an individualised imposed power output (PO) equating to 70 % of [Formula: see text]. On a third occasion, participants were instructed to maintain a workload equivalent to the average RPE for the 20-min imposed condition. [Formula: see text], heart rate (HR) and PO were measured at 1-min intervals and blood lactate concentration [BLa(-)] was measured at 0, 10 and 20 min. No differences (P > 0.17) were found between mean [Formula: see text], % [Formula: see text], HR, % HR(peak), [BLa(-)], velocity or PO between the imposed and RPE-regulated trials. No significant (P > 0.05) time-by-trial interaction was present for [Formula: see text] data. A significant interaction (P < 0.001) for the PO data represented a trend for an increase in PO from 10 min to the end of exercise during the RPE-regulated condition. However, post hoc analysis revealed none of the differences in PO across time were significant (P > 0.05). In conclusion, these findings suggest that RPE can be an effective tool for self-regulating 20 min of wheelchair propulsion in a group of trained participants with tetraplegia who are experienced in wheelchair propulsion.

Concepts: Psychometrics, Test method, Post-hoc analysis, Quadriplegia

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Vitamin D is considered to be important for a healthy immune system. The aim of this study was to test the hypothesis that vitamin D supplementation reduces number of respiratory tract infections (RTIs) and prolong the time to the first RTI in adult patients with frequent RTIs.

Concepts: Immune system, Vitamin D, Post-hoc analysis

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A recent post hoc analysis suggested that driving pressure may be more important than traditional ventilatory variables in determining outcome in mechanically ventilated patients with acute respiratory distress syndrome. We conducted a systematic review and meta-analysis to summarize the risk of mortality for higher versus lower driving pressure.

Concepts: Pulmonology, Medical terms, Medical statistics, Acute respiratory distress syndrome, Meta-analysis, Post-hoc analysis

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Antimuscarinic agents are currently the predominant treatment option for the clinical management of the symptoms of overactive bladder (OAB). However, low rates of persistence with these agents highlight the need for novel, effective and better-tolerated oral pharmacological agents. Mirabegron is a beta3-adrenoceptor agonist developed for the treatment of OAB, with a mechanism of action distinct from that of antimuscarinics. In a randomized, double-blind, placebo- and active-controlled Phase 3 trial conducted in Europe and Australia (NCT00689104), mirabegron 50 mg and 100 mg resulted in statistically significant reductions from baseline to final visit, compared with placebo, in the co-primary end points – mean number of incontinence episodes/24 h and mean number of micturitions/24 h. We conducted a post hoc, subgroup analysis of this study in order to evaluate the efficacy of mirabegron in treatment-naive patients and patients who had discontinued prior antimuscarinic therapy because of insufficient efficacy or poor tolerability.

Concepts: Pharmacology, Clinical trial, Statistics, Medical statistics, Statistical significance, Effectiveness, Clinical research, Post-hoc analysis

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To examine the effect of ospemifene 60 mg/d on vasomotor symptoms in postmenopausal women using clinical safety and efficacy data from five phase 2 and 3 studies.

Concepts: Medical statistics, Effectiveness, Clinical research, Post-hoc analysis