Cindy L Cooper1, Daniel Hind2, Rosie Duncan3, Stephen Walters3, Adjoa Lartey3, Ellen Lee1, Mike Bradburn1. 1. The School of Health and Related Research (ScHARR), Clinical Trials Research Unit, University of Sheffield, Regent Court, 30 Regent Street, Sheffield, S1 4DA, UK. 2. The School of Health and Related Research (ScHARR), Clinical Trials Research Unit, University of Sheffield, Regent Court, 30 Regent Street, Sheffield, S1 4DA, UK. Electronic address: d.hind@sheffield.ac.uk. 3. The School of Health and Related Research (ScHARR), University of Sheffield, Regent Court, 30 Regent Street, Sheffield, S1 4DA, UK.
Abstract
OBJECTIVES: To test the hypothesis that the percentage of patients screened that randomize differs between prevention and therapy trials. STUDY DESIGN AND SETTING: Rapid review of randomized controlled trials (RCTs) identified through published systematic reviews in August 2013. Individually randomized, parallel group controlled RCTs were eligible if they evaluated metformin monotherapy or exercise for the prevention or treatment of type 2 diabetes. Numbers of patients screened and randomized were extracted by a single reviewer. Percentages were calculated for each study for those randomized: as a function of those approached, screened, and eligible. Percentages (95% confidence intervals) from each individual study were weighted according to the denominator and pooled rates calculated. Statistical heterogeneity was assessed using I(2). RESULTS: The percentage of those screened who subsequently randomized was 6.2% (6.0%, 6.4%; 3 studies, I(2) = 100.0%) for metformin prevention trials; 50.7% (49.9%, 51.4%; 21 studies, I(2) = 99.6%) for metformin treatment trials; 4.8% (4.7%, 4.8%; 14 studies, I(2) = 99.9%) for exercise prevention trials; and 43.3% (42.6%, 43.9%; 28 studies, I(2) = 99.8%) for exercise treatment trials. CONCLUSION: This study provides qualified support for the hypothesis that prevention trials recruit a smaller proportion of those screened than treatment trials. Statistical heterogeneity associated with pooled estimates and other study limitations is discussed.
OBJECTIVES: To test the hypothesis that the percentage of patients screened that randomize differs between prevention and therapy trials. STUDY DESIGN AND SETTING: Rapid review of randomized controlled trials (RCTs) identified through published systematic reviews in August 2013. Individually randomized, parallel group controlled RCTs were eligible if they evaluated metformin monotherapy or exercise for the prevention or treatment of type 2 diabetes. Numbers of patients screened and randomized were extracted by a single reviewer. Percentages were calculated for each study for those randomized: as a function of those approached, screened, and eligible. Percentages (95% confidence intervals) from each individual study were weighted according to the denominator and pooled rates calculated. Statistical heterogeneity was assessed using I(2). RESULTS: The percentage of those screened who subsequently randomized was 6.2% (6.0%, 6.4%; 3 studies, I(2) = 100.0%) for metformin prevention trials; 50.7% (49.9%, 51.4%; 21 studies, I(2) = 99.6%) for metformin treatment trials; 4.8% (4.7%, 4.8%; 14 studies, I(2) = 99.9%) for exercise prevention trials; and 43.3% (42.6%, 43.9%; 28 studies, I(2) = 99.8%) for exercise treatment trials. CONCLUSION: This study provides qualified support for the hypothesis that prevention trials recruit a smaller proportion of those screened than treatment trials. Statistical heterogeneity associated with pooled estimates and other study limitations is discussed.
Authors: Jordan M Braciszewski; Golfo K Tzilos Wernette; Roland S Moore; Beth C Bock; Robert L Stout; Patricia Chamberlain Journal: Child Youth Serv Rev Date: 2018-08-15
Authors: Rida Hasan; Maria Hanna; Song Zhang; Kendra Malone; Elizabeth Tong; Niavana Salas; Ravi Sarode; Janna Journeycake; Ayesha Zia Journal: Blood Adv Date: 2020-08-11
Authors: Petra J Havinga; Dominique F Maciejewski; Catharina A Hartman; Manon H J Hillegers; Robert A Schoevers; Brenda W J H Penninx Journal: Br J Clin Psychol Date: 2021-01-06
Authors: Stephen J Walters; Inês Bonacho Dos Anjos Henriques-Cadby; Oscar Bortolami; Laura Flight; Daniel Hind; Richard M Jacques; Christopher Knox; Ben Nadin; Joanne Rothwell; Michael Surtees; Steven A Julious Journal: BMJ Open Date: 2017-03-20 Impact factor: 2.692