Winzenberg, T and Lamberg-Allardt, C and Fuleihan, GE-H and Molgaard, C and Zhu, K and Wu, F and Riley, RD, Does vitamin D supplementation improve bone density in vitamin D-deficient children? Protocol for an individual patient data meta-analysis, BMJ Open, 8, (1) Article e019584. ISSN 2044-6055 (2018) [Refereed Article]
© 2018 The Authors. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) https://creativecommons.org/licenses/by-nc-nd/4.0/
Introduction: Our previous study-level (aggregate data) meta-analysis suggested that vitamin D supplements may be beneficial for bone density specifically in children with vitamin D deficiency. However, the misclassification of vitamin D status inherent in study-level data means that the results are not definitive and cannot provide an accurate assessment of the size of any effect. Therefore, we propose to undertake an individual patient data (IPD) meta-analysis to determine whether the effect of vitamin D supplementation on bone density in children differs according to baseline vitamin D status, and to specifically estimate the effect of vitamin D in children who are vitamin D deficient.
Methods and Analysis: This study has been designed to adhere to the Preferred Reporting Items for Systematic Review and Meta-Analyses of IPD statement. We will include randomised placebo-controlled trials of vitamin D supplementation reporting bone density outcomes at least 6 months after the study commenced in children and adolescents (aged <20 years) without coexistent medical conditions or treatments causing osteoporosis. We will update the search of the original review to cover the period 2009-2017, using the same methods as the original review. Fully anonymised data on all randomised patients will be requested. Outcomes will be femoral neck, total hip, lumbar spine and proximal and distal forearm bone mineral density, and total body bone mineral content. A two-stage IPD meta-analysis will be used to examine the effect of baseline serum 25-hydroxyvitamin D (25(OH)D) on treatment effect for each bone density outcome. Restricted maximum likelihood will be used to estimate the random-effects meta-analysis models, with 95% CI for summary effects. Heterogeneity will be assessed by I2 and potential publication bias (small-study effects) and availability bias by funnel plots, Egger's test and Peter's test.
|Item Type:||Refereed Article|
|Keywords:||paediatric endocrinology, preventive medicine, rheumatology|
|Research Division:||Medical and Health Sciences|
|Research Group:||Clinical Sciences|
|Research Field:||Rheumatology and Arthritis|
|Objective Group:||Clinical Health (Organs, Diseases and Abnormal Conditions)|
|Objective Field:||Skeletal System and Disorders (incl. Arthritis)|
|UTAS Author:||Winzenberg, T (Professor Tania Winzenberg)|
|UTAS Author:||Wu, F (Dr Feitong Wu)|
|Deposited By:||Menzies Institute for Medical Research|
|Downloads:||5 View Download Statistics|
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