Spyridon N Papageorgiou1, Georgios N Antonoglou2, Elli Tsiranidou3, Søren Jepsen4, Andreas Jäger5. 1. Department of Orthodontics, School of Dentistry, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany; Department of Oral Technology, School of Dentistry, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany; Clinical Research Unit 208, University of Bonn, 53111, Bonn, Germany. Electronic address: snpapage@gmail.com. 2. Department of Periodontology and Geriatric Dentistry, Institute of Dentistry, University of Oulu, Medical Campus, Aapistie 3A, PO 5281, 90014, Oulu, Finland. 3. Medical Research Methodology, Medical School, Aristotle University, PO 17034, 54210, Thessaloniki, Greece. 4. Clinical Research Unit 208, University of Bonn, 53111, Bonn, Germany; Department of Periodontology, Operative and Preventive Dentistry, School of Dentistry, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany. 5. Department of Orthodontics, School of Dentistry, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany; Clinical Research Unit 208, University of Bonn, 53111, Bonn, Germany.
Abstract
OBJECTIVES: To examine the influence of the following study characteristics on their study effect estimates: (1) indexing in MEDLINE, (2) language, and (3) design. For randomized trials, (4) trial size and (5) unequal randomization were also assessed. STUDY DESIGN AND SETTING: The CAtegorical Dental and Maxillofacial Outcome Syntheses meta-epidemiologic study was conducted. Eight databases/registers were searched up to September 2012 for meta-analyses of binary outcomes with at least five studies in the field of dental and maxillofacial medicine. The previously mentioned five study characteristics were investigated. The ratio of odds ratios (ROR) according to each characteristic was calculated with random-effects meta-regression and then pooled across meta-analyses. RESULTS: A total of 281 meta-analyses were identified and used to assess the influence of the following factors: non-MEDLINE indexing vs. MEDLINE indexing (n = 78; ROR, 1.12; 95% confidence interval [CI]: 1.05, 1.19; P = 0.001), language (n = 61; P = 0.546), design (n = 24; P = 0.576), small trials (<200 patients) vs. large trials (≥200 patients) (n = 80; ROR, 0.92; 95% CI: 0.87, 0.98; P = 0.009) and unequal randomization (n = 36; P = 0.828). CONCLUSION: Studies indexed in MEDLINE might present greater effects than non-indexed ones. Small randomized trials might present greater effects than large ones.
OBJECTIVES: To examine the influence of the following study characteristics on their study effect estimates: (1) indexing in MEDLINE, (2) language, and (3) design. For randomized trials, (4) trial size and (5) unequal randomization were also assessed. STUDY DESIGN AND SETTING: The CAtegorical Dental and Maxillofacial Outcome Syntheses meta-epidemiologic study was conducted. Eight databases/registers were searched up to September 2012 for meta-analyses of binary outcomes with at least five studies in the field of dental and maxillofacial medicine. The previously mentioned five study characteristics were investigated. The ratio of odds ratios (ROR) according to each characteristic was calculated with random-effects meta-regression and then pooled across meta-analyses. RESULTS: A total of 281 meta-analyses were identified and used to assess the influence of the following factors: non-MEDLINE indexing vs. MEDLINE indexing (n = 78; ROR, 1.12; 95% confidence interval [CI]: 1.05, 1.19; P = 0.001), language (n = 61; P = 0.546), design (n = 24; P = 0.576), small trials (<200 patients) vs. large trials (≥200 patients) (n = 80; ROR, 0.92; 95% CI: 0.87, 0.98; P = 0.009) and unequal randomization (n = 36; P = 0.828). CONCLUSION: Studies indexed in MEDLINE might present greater effects than non-indexed ones. Small randomized trials might present greater effects than large ones.
Authors: Iosief Abraha; Antonio Cherubini; Francesco Cozzolino; Rita De Florio; Maria Laura Luchetta; Joseph M Rimland; Ilenia Folletti; Mauro Marchesi; Antonella Germani; Massimiliano Orso; Paolo Eusebi; Alessandro Montedori Journal: BMJ Date: 2015-05-27
Authors: Kyle N Kunze; Michelle Richardson; David N Bernstein; Ajay Premkumar; Nicolas S Piuzzi; Alexander S McLawhorn Journal: J Am Acad Orthop Surg Glob Res Rev Date: 2020-12