Dataset Information

Comparison of intervention effects in split-mouth and parallel-arm randomized controlled trials: a meta-epidemiological study.

ABSTRACT:

Background

Split-mouth randomized controlled trials (RCTs) are popular in oral health research. Meta-analyses frequently include trials of both split-mouth and parallel-arm designs to derive combined intervention effects. However, carry-over effects may induce bias in split- mouth RCTs. We aimed to assess whether intervention effect estimates differ between split- mouth and parallel-arm RCTs investigating the same questions.

Methods

We performed a meta-epidemiological study. We systematically reviewed meta- analyses including both split-mouth and parallel-arm RCTs with binary or continuous outcomes published up to February 2013. Two independent authors selected studies and extracted data. We used a two-step approach to quantify the differences between split-mouth and parallel-arm RCTs: for each meta-analysis. First, we derived ratios of odds ratios (ROR) for dichotomous data and differences in standardized mean differences (?SMD) for continuous data; second, we pooled RORs or ?SMDs across meta-analyses by random-effects meta-analysis models.

Results

We selected 18 systematic reviews, for 15 meta-analyses with binary outcomes (28 split-mouth and 28 parallel-arm RCTs) and 19 meta-analyses with continuous outcomes (45 split-mouth and 48 parallel-arm RCTs). [corrected]. Effect estimates did not differ between split-mouth and parallel-arm RCTs (mean ROR, 0.96, 95% confidence interval 0.52-1.80; mean ?SMD, 0.08, -0.14-0.30).

Conclusions

Our study did not provide sufficient evidence for a difference in intervention effect estimates derived from split-mouth and parallel-arm RCTs. Authors should consider including split-mouth RCTs in their meta-analyses with suitable and appropriate analysis.

SUBMITTER: Smail-Faugeron V

PROVIDER: S-EPMC4023173 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature

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Publications

Comparison of intervention effects in split-mouth and parallel-arm randomized controlled trials: a meta-epidemiological study.

Smaïl-Faugeron Violaine V Fron-Chabouis Hélène H Courson Frédéric F Durieux Pierre P

BMC medical research methodology 20140511

<h4>Background</h4>Split-mouth randomized controlled trials (RCTs) are popular in oral health research. Meta-analyses frequently include trials of both split-mouth and parallel-arm designs to derive combined intervention effects. However, carry-over effects may induce bias in split- mouth RCTs. We aimed to assess whether intervention effect estimates differ between split- mouth and parallel-arm RCTs investigating the same questions.<h4>Methods</h4>We performed a meta-epidemiological study. We sy ...[more]

PMID: 24886043

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Project description:IntroductionLocal anaesthesia is commonly used in paediatric oral healthcare. Infiltration anaesthesia is the most frequently used, but recent developments in anaesthesia techniques have introduced an alternative: intraosseous anaesthesia. We propose to perform a split-mouth and parallel-arm multicentre randomised controlled trial (RCT) comparing the pain caused by the insertion of the needle for the injection of conventional infiltration anaesthesia, and intraosseous anaesthesia by the computerised QuickSleeper system, in children and adolescents.Methods and analysisInclusion criteria are patients 7-15 years old with at least 2 first permanent molars belonging to the same dental arch (for the split-mouth RCT) or with a first permanent molar (for the parallel-arm RCT) requiring conservative or endodontic treatment limited to pulpotomy. The setting of this study is the Department of Paediatric Dentistry at 3 University dental hospitals in France. The primary outcome measure will be pain reported by the patient on a visual analogue scale concerning the insertion of the needle and the injection/infiltration. Secondary outcomes are latency, need for additional anaesthesia during the treatment and pain felt during the treatment. We will use a computer-generated permuted-block randomisation sequence for allocation to anaesthesia groups. The random sequences will be stratified by centre (and by dental arch for the parallel-arm RCT). Only participants will be blinded to group assignment. Data will be analysed by the intent-to-treat principle. In all, 160 patients will be included (30 in the split-mouth RCT, 130 in the parallel-arm RCT).Ethics and disseminationThis protocol has been approved by the French ethics committee for the protection of people (Comité de Protection des Personnes, Ile de France I) and will be conducted in full accordance with accepted ethical principles. Findings will be reported in scientific publications and at research conferences, and in project summary papers for participants.Trial registration numberClinicalTrials.gov NCT02084433.

Project description:ObjectiveTo quantify and compare the treatment effect and risk of bias of trials reporting biomarkers or intermediate outcomes (surrogate outcomes) versus trials using final patient relevant primary outcomes.DesignMeta-epidemiological study.Data sourcesAll randomised clinical trials published in 2005 and 2006 in six high impact medical journals: Annals of Internal Medicine, BMJ, Journal of the American Medical Association, Lancet, New England Journal of Medicine, and PLoS Medicine.Study selectionTwo independent reviewers selected trials.Data extractionTrial characteristics, risk of bias, and outcomes were recorded according to a predefined form. Two reviewers independently checked data extraction. The ratio of odds ratios was used to quantify the degree of difference in treatment effects between the trials using surrogate outcomes and those using patient relevant outcomes, also adjusted for trial characteristics. A ratio of odds ratios >1.0 implies that trials with surrogate outcomes report larger intervention effects than trials with patient relevant outcomes.Results84 trials using surrogate outcomes and 101 using patient relevant outcomes were considered for analyses. Study characteristics of trials using surrogate outcomes and those using patient relevant outcomes were well balanced, except for median sample size (371 v 741) and single centre status (23% v 9%). Their risk of bias did not differ. Primary analysis showed trials reporting surrogate endpoints to have larger treatment effects (odds ratio 0.51, 95% confidence interval 0.42 to 0.60) than trials reporting patient relevant outcomes (0.76, 0.70 to 0.82), with an unadjusted ratio of odds ratios of 1.47 (1.07 to 2.01) and adjusted ratio of odds ratios of 1.46 (1.05 to 2.04). This result was consistent across sensitivity and secondary analyses.ConclusionsTrials reporting surrogate primary outcomes are more likely to report larger treatment effects than trials reporting final patient relevant primary outcomes. This finding was not explained by differences in the risk of bias or characteristics of the two groups of trials.

Dataset Information

Comparison of intervention effects in split-mouth and parallel-arm randomized controlled trials: a meta-epidemiological study.

Background

Methods

Results

Conclusions

Publications

Comparison of intervention effects in split-mouth and parallel-arm randomized controlled trials: a meta-epidemiological study.

Similar Datasets

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