Rachael McCool

Searching ClinicalTrials.gov and the International Clinical Trials Registry Platform to inform systematic reviews: what are the optimal search approaches?

BACKGROUND Since 2005, International Committee of Medical Journal Editors (ICMJE) member journals have required that clinical trials be registered in publicly available trials registers before they are considered for publication. OBJECTIVES The research explores whether it is adequate, when searching to inform systematic reviews, to search for relevant clinical trials using only public trials registers and to identify the optimal search approaches in trials registers. METHODS A search was conducted in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) for research studies that had been included in eight systematic reviews. Four search approaches (highly sensitive, sensitive, precise, and highly precise) were performed using the basic and advanced interfaces in both resources. RESULTS On average, 84% of studies were not listed in either resource. The largest number of included studies was retrieved in ClinicalTrials.gov and ICTRP when a sensitive search approach was used in the basic interface. The use of the advanced interface maintained or improved sensitivity in 16 of 19 strategies for Clinicaltrials.gov and 8 of 18 for ICTRP. No single search approach was sensitive enough to identify all studies included in the 6 reviews. CONCLUSIONS Trials registers cannot yet be relied upon as the sole means to locate trials for systematic reviews. Trials registers lag behind the major bibliographic databases in terms of their search interfaces. IMPLICATIONS For systematic reviews, trials registers and major bibliographic databases should be searched. Trials registers should be searched using sensitive approaches, and both the registers consulted in this study should be searched.

The efficacy and safety of retigabine and other adjunctive treatments for refractory partial epilepsy: A systematic review and indirect comparison

INTRODUCTION Retigabine (RTG) is now approved in Europe and the US for the adjunctive treatment of partial-onset seizures in adults with epilepsy. To support submissions to EU reimbursement authorities, we explored its efficacy and tolerability relative to selected antiepileptic drugs (AEDs). METHODS A systematic review was conducted to identify placebo-controlled trials of RTG and selected AEDs approved for use in a similar position in the management pathway of partial epilepsy (eslicarbazepine acetate [ESL], lacosamide [LCM], pregabalin [PGB], tiagabine [TGB] and zonisamide [ZNS]). Using conventional and network meta-analyses as appropriate, we report efficacy and tolerability outcomes for each AED versus placebo and the performance of RTG relative to other AEDs. RESULTS Twenty studies met the inclusion criteria: three each for RTG, ESL, LCM, TGB and ZNS; five for PGB. Comparisons comprised 1-5 studies per AED. In the network meta-analysis, RTG was not found to be different from the other AEDs for responder rate (maintenance period), seizure freedom (maintenance period and double-blind period), withdrawals due to adverse events, and incidences of ataxia, dizziness, fatigue and nausea. Differences between RTG and other AEDs were found for a few comparisons, which did not reveal any trends: RTG was associated with a lower responder rate than PGB during the double-blind period, higher withdrawal rate due to any reason than ESL and a higher incidence of somnolence than TGB. CONCLUSIONS Findings suggest that the risk/benefit for RTG is similar to that for comparator AEDs. However, results should be interpreted in the context of the limitations of the analyses.

Comparative assessment of the efficacy of onabotulinumtoxinA and oral therapies (anticholinergics and mirabegron) for overactive bladder: a systematic review and network meta-analysis.

To compare the efficacy of onabotulinumtoxinA, mirabegron, and anticholinergics in adults with idiopathic overactive bladder (OAB) using network meta‐analysis (NMA).

Reporting methodological search filter performance comparisons: a literature review.

BACKGROUND Methodological search filters are tools for retrieving database records reporting studies which use a specific research method. Choosing a filter is likely to be based on filter performance data. This review examines which measures are reported, and the way that filter performance is presented, in filter comparisons. METHODS Studies were identified from the current content and pending update (2010) of a filter website. Eligible studies compared two or more methodological search filters designed to identify randomised controlled trials, diagnostic test accuracy studies, systematic reviews or economic evaluations. RESULTS Eighteen studies met the inclusion criteria. The number of filters compared in a single study ranged from 2 to 38. The most commonly reported measures were sensitivity/recall and precision. All studies displayed results in tables and gave results as percentages or proportions. Two studies supplemented results tables with graphical displays of data: a bar graph of the proportion of retrieved and missed gold standard references per filter; a forest plot of the overall sensitivity and specificity of each filter. CONCLUSIONS Sensitivity/recall and precision are the most frequently reported performance measures. This review highlights the potential for presenting results in novel and innovative ways to aid filter selection.

A systematic review of known interventions for the treatment of chronic nonhypovolaemic hypotonic hyponatraemia and a meta-analysis of the vaptans

International and national guidelines on the treatment of chronic nonhypovolaemic hypotonic hyponatraemia differ; therefore, we have undertaken this systematic review and meta‐analysis to investigate the efficacy and safety of interventions for the treatment of chronic nonhypovolaemic hypotonic hyponatraemia. Following registration of the review protocol with PROSPERO, systematic literature searches were conducted to identify randomized and quasi‐randomized controlled trials assessing any degree of fluid restriction or any drug treatment with the aim of increasing serum sodium concentration in patients with chronic nonhypovolaemic hypotonic hyponatraemia. Where appropriate, outcome data were synthesized in a meta‐analysis. A total of 45 716 bibliographic records were identified from the searches and 18 trials (assessing conivaptan, lixivaptan, tolvaptan and satavaptan) met the eligibility criteria. Results suggest that all four vasopressin receptor agonists (“vaptans”) significantly improve serum sodium concentration. Lixivaptan, satavaptan and tolvaptan were associated with greater rates of response versus placebo. There was no evidence of a difference between each of the vaptans compared with placebo for mortality, discontinuation and rates of hypernatraemia. No RCT evidence of treatments other than the vaptans for hyponatraemia such as oral urea, salt tablets, mannitol, loop diuretics demeclocycline or lithium was identified. Vaptans demonstrated superiority over placebo for outcomes relating to serum sodium correction. Few trials documented the potential benefit of vaptans on change in health‐related quality of life as a result of treatment. There was also a lack of high‐quality RCT evidence on the comparative efficacy of the vaptans and other treatment strategies for the treatment of chronic nonhypovolaemic hypotonic hyponatraemia.

Comparative assessment of onabotulinumtoxinA and mirabegron for overactive bladder: an indirect treatment comparison

Context OnabotulinumtoxinA and mirabegron have recently gained marketing authorisation to treat symptoms of overactive bladder (OAB). Objective To evaluate the relative efficacy of mirabegron and onabotulinumtoxinA in patients with idiopathic OAB. Design Network meta-analysis. Data sources A search of 9 electronic databases, review documents, guidelines and websites. Methods Randomised trials comparing any licensed dose of onabotulinumtoxinA or mirabegron with each other, anticholinergic drugs or placebo were eligible (19 randomised trials were identified). 1 reviewer extracted data from the studies and a second reviewer checked the data. Candidate trials were assessed for similarity and networks were developed for each outcome. Bayesian network meta-analysis was conducted using both fixed-effects and random-effects models. When there were differences in mean baseline values between mirabegron and onabotulinumtoxinA trials they were adjusted for using network meta-regression (NMR). Results No studies directly comparing onabotulinumtoxinA to mirabegron were identified. A network was created for each of the 7 outcomes, with 3–9 studies included in each individual network. The trials included in the networks were broadly similar. Patients in the onabotulinumtoxinA trials had more urinary incontinence and urgency episodes at baseline than patients in the mirabegron trials and these differences were adjusted for using NMR. Both onabotulinumtoxinA and mirabegron were more efficacious than placebo at reducing the frequency of urinary incontinence, urgency, urination and nocturia. OnabotulinumtoxinA was more efficacious than mirabegron (50 and 25 mg) in completely resolving daily episodes of urinary incontinence and urgency and in reducing the frequency of urinary incontinence, urgency and urination. NMR supported the results of the network meta-analysis. Conclusions In the absence of head-to-head trials comparing onabotulinumtoxinA to mirabegron, this indirect comparison indicates that onabotulinumtoxinA may be superior to mirabegron in improving symptoms of urinary incontinence, urgency and urinary frequency in patients with idiopathic OAB.

Systematic Review and Network Meta-analysis of Idiopathic Pulmonary Fibrosis Treatments

BACKGROUND The antifibrotics pirfenidone and nintedanib are both approved for the treatment of idiopathic pulmonary fibrosis (IPF) by regulatory agencies and are recommended by health technology assessment bodies. Other treatments such as N-acetylcysteine are used in clinical practice but have not received regulatory approval. No head-to-head trials have been conducted to directly compare the efficacy of these therapies in IPF. OBJECTIVE To compare the efficacy of treatments for IPF. METHODS A systematic review was conducted up to April 2015. Phase II/III randomized controlled trials in adults with IPF were eligible. A Bayesian network meta-analysis (NMA) was used to compare pirfenidone, nintedanib, and N-acetylcysteine with respect to forced vital capacity (FVC) and mortality. RESULTS Nine studies were included in the NMA. For change from baseline in FVC, the NMA indicated that pirfenidone and nintedanib were more effective than placebo after 1 year (pirfenidone vs. placebo: difference = 0.12 liter (L), 95% credible interval [CrI] = 0.03-0.21 L; nintedanib vs. placebo: difference = 0.11 L, 95% CrI = 0.00-0.22 L). There was no evidence that N-acetylcysteine had an effect on FVC compared with placebo (N-acetylcysteine vs. placebo: difference = 0.01 L, 95% CrI = -0.15-0.17 L). Patients treated with pirfenidone also had a lower risk of experiencing a decline in percent predicted FVC of ≥ 10% over 1 year (odds ratio [OR]: 0.58, 95% CrI = 0.40-0.88), whereas there was no conclusive evidence of a difference between nintedanib and placebo (OR: 0.65, 95% CrI = 0.42-1.02). The NMA indicated that pirfenidone reduced all-cause mortality relative to placebo over 1 year (hazard ratio [HR]: 0.52, 95% CrI = 0.28-0.92). There was no evidence of a difference in all-cause mortality between nintedanib and placebo (HR: 0.70, 95% CrI = 0.32-1.55), or N-acetylcysteine and placebo (HR: 2.00, 95% CrI=0.46-8.62). CONCLUSIONS Our primary analysis of the available evidence indicates that over 1 year, pirfenidone and nintedanib are effective at reducing lung-function decline, and pirfenidone may reduce the odds of experiencing a decline in percent predicted FVC of ≥10% compared with placebo in the first year of treatment. The results of our analysis also suggest that pirfenidone improves survival. DISCLOSURES Fleetwood is an employee of Quantics Consulting. McCool and Glanville are employees of York Health Economics Consortium (YHEC). Quantics and YHEC received funding from F. Hoffmann-La Roche for conducting the systematic review and network meta-analysis reported in this paper. Edwards, Gsteiger, and Daigl are employees of F. Hoffmann-La Roche. Fisher was employed by InterMune UK, a wholly owned Roche subsidiary, until July 2015. He is currently employed by FIECON, which has received funding from F. Hoffmann-La Roche for consulting services. The systematic review and network meta-analysis reported in this paper were conducted by Fleetwood (Quantics Consulting) and McCool and Glanville (YHEC), funded by F. Hoffmann-La Roche. The original network analysis was funded by InterMune. Study concept and design were contributed by Edwards, Gsteiger, and Daigl, along with Fleetwood, McCool, and Glanville. Fleetwood, McCool, and Glanville collected the data, with assistance from Edwards, Gsteiger, and Daigl. Data interpretation was performed by Fleetwood and Fisher, with assistance from the other authors. The manuscript was written by Fleetwood, McCool, and Glanville, with assistance from Edwards, Daigl, and Fisher, and revised by all the authors.

Systematic review and network meta-analysis of tedizolid for the treatment of acute bacterial skin and skin structure infections caused by MRSA

BackgroundTedizolid, the active moiety of tedizolid phosphate, is approved in the United States, the European Union, Canada and a number of other countries for the treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by certain susceptible bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). This network meta-analysis (NMA) evaluates the comparative effectiveness of tedizolid and other antibacterials indicated for the treatment of ABSSSI caused by MRSA.MethodsSystematic review of 10 databases was undertaken to inform an NMA to estimate the relative effectiveness of tedizolid and established monotherapy comparators (ceftaroline, daptomycin, linezolid, teicoplanin, tigecycline, vancomycin) for treating MRSA-associated ABSSSI. Randomized controlled trials enrolling adults with ABSSSI or complicated skin and skin structure infections caused by suspected/documented MRSA were eligible for inclusion. Networks were developed based on similarity of study design, patient characteristics, outcome measures and available data. Outcomes of interest included clinical response at end of therapy (EOT), post-therapy evaluation (PTE) or test-of-cure assessment and treatment discontinuations resulting from adverse events (AEs). Bayesian NMA was conducted for each outcome using fixed-effects and random effects models.ResultsLiterature searches identified 3,618 records; 15 trials met the inclusion criteria and were considered suitable for NMA comparison. In fixed-effects models, tedizolid had higher odds of clinical response at EOT (odds ratio [OR], 1.7; credible interval, 1.0, 3.0) and PTE than vancomycin (OR, 1.6; credible interval, 1.1, 2.5). No differences in odds of clinical response at EOT or PTE were observed between tedizolid and other comparators. There was no evidence of a difference among treatments for discontinuation due to AEs. Results from random effects and fixed-effects models were generally consistent.ConclusionsTedizolid was superior to vancomycin for clinical response at EOT and PTE. There was no evidence of a difference between tedizolid and other comparators and no evidence of a difference between tedizolid and all comparators when evaluating discontinuation due to AEs. These findings suggest that tedizolid provides an alternative option for the management of serious skin infections caused by suspected or documented MRSA. This study is subject to the limitations inherent in all NMAs, and the results should be interpreted accordingly.

A systematic review and meta-analysis of interventions for the treatment of chronic non-hypovolaemic hypotonic hyponatraemia

The searches retrieved 45,716 records and 18 trials met the eligibility criteria or reported data for an eligible subgroup of patients; 2 trials assessed conivaptan, 4 trials assessed lixivaptan, 3 trials assessed satavaptan, and 9 trials assessed tolvaptan*. No RCT evidence was identified in relation to the alternative strategies commonly employed such as oral urea, salt tablets, mannitol, loop diuretics, demeclocycline and lithium.