Socioeconomic representativeness of Australian, Canadian and British cohorts from the paediatric diabetes AdDIT study: comparisons to regional and national data
Farid H. Mahmud,
Antoine B. M. Clarke,
Yesmino Elia,
Jacqueline Curtis,
Paul Benitez-Aguirre,
Fergus J. Cameron,
Scott T. Chiesa,
Cheril Clarson,
Jennifer J. Couper,
Maria E. Craig,
R. Neil Dalton,
Denis Daneman,
Elizabeth A. Davis,
John E. Deanfield,
Kim C. Donaghue,
Timothy W. Jones,
Sally M. Marshall,
Andrew Neil,
M. Loredana Marcovecchio
Affiliations
Farid H. Mahmud
Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto
Antoine B. M. Clarke
Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto
Yesmino Elia
Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto
Jacqueline Curtis
Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto
Paul Benitez-Aguirre
Institute of Endocrinology and Diabetes, The Children’s Hospital at Westmead, University of Sydney
Fergus J. Cameron
Department of Paediatrics, University of Melbourne
Scott T. Chiesa
Institute of Cardiovascular Science, University College London
Cheril Clarson
London Health Sciences Center
Jennifer J. Couper
Departments of Endocrinology and Diabetes and Medical Imaging, Women’s and Children’s Hospital
Maria E. Craig
Institute of Endocrinology and Diabetes, The Children’s Hospital at Westmead, University of Sydney
R. Neil Dalton
Evelina London Children’s Hospital, Guy’s and St Thomas’ NHS Foundation Trust
Denis Daneman
Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto
Elizabeth A. Davis
Telethon Kids Institute, University of Western Australia
John E. Deanfield
Institute of Cardiovascular Science, University College London
Kim C. Donaghue
Institute of Endocrinology and Diabetes, The Children’s Hospital at Westmead, University of Sydney
Timothy W. Jones
Telethon Kids Institute, University of Western Australia
Sally M. Marshall
Faculty of Clinical Medical Sciences, Diabetes Research Group, Translational and Clinical Research Institute, Newcastle University
Andrew Neil
Oxford Centre for Diabetes, Endocrinology & Metabolism, University of Oxford
M. Loredana Marcovecchio
Department of Paediatrics, University of Cambridge
Abstract Background Given limited data regarding the involvement of disadvantaged groups in paediatric diabetes clinical trials, this study aimed to evaluate the socioeconomic representativeness of participants recruited into a multinational clinical trial in relation to regional and national type 1 diabetes reference populations. Methods Retrospective, cross-sectional evaluation of a subset of adolescent type 1 diabetes cardiorenal intervention trial (AdDIT) participants from Australia (n = 144), Canada (n = 312) and the UK (n = 173). Validated national measures of deprivation were used: the Index of Relative Socioeconomic Disadvantage (IRSD) 2016 (Australia), the Material Resources (MR) dimension of the Canadian Marginalisation index 2016 (Canada) and the Index of Multiple Deprivation (IMD) 2015 (UK). Representativeness was assessed by comparing the AdDIT cohort’s distribution of deprivation quintiles with that of the local paediatric type 1 diabetes population (regional), and the broader type 1 diabetes population for which the trial’s intervention was targeted (national). Results Recruited study cohorts from each country had higher proportions of participants with higher SES, and significant underrepresentation of lower SES, in relation to their national references. The socioeconomic make-up in Australia mirrored that of the regional population (p = 0.99). For Canada, the 2nd least deprived (p = 0.001) and the most deprived quintiles (p < 0.001) were over- and under-represented relative to the regional reference, while the UK featured higher regional and national SES bias with over-representation and under-representation from the least-deprived and most-deprived quintiles (p < 0.0001). Conclusions Significant national differences in trial participation of low SES participants were observed, highlighting limitations in access to clinical research and the importance of reporting sociodemographic representation in diabetes clinical trials. Trial registration NCT01581476. Registered on 20 April 2012.
