Retrieval of Individual Participant Data for Exercise Meta-Analyses May Not Be Worth the Time and Effort

Stauffer

2022

Science Progress

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Whether true inter-individual response differences (IIRD) exist with respect to walking training and chronic changes in resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults is not known. To address this gap, data from a meta-analysis representing up to 5060 normotensive and high normal/hypertensive (SBP ≥ 130 and/or DBP ≥ 85 mmHg) participants 16 to 84 years of age (2881 walking, 2179 control) nested in 73 randomized controlled trials were included. Walking and control group change outcome standard deviations treated as point estimates for both resting SBP and DBP were used to calculate true IIRD from each study. The inverse variance heterogeneity (IVhet) model was used to pool IIRD as well as traditional pairwise results. Both 95% confidence intervals (CI) and prediction intervals (PI) were calculated. While statistically significant reductions in resting SBP ([Formula: see text], −3.9 mmHg, 95% CI, −5.4 to −2.3 mmHg) and DBP ([Formula: see text], −1.4 mmHg, 95% CI, −2.5 to −0.3 mmHg) were found, true IIRD were neither statistically significant nor clinically important for both SBP ([Formula: see text], −1.4 mmHg, 95% CI, −2.0 to 2.8 mmHg) and DBP ([Formula: see text], 0.9 mmHg, 95% CI, −2.5 to 2.8 mmHg). The 95% prediction interval for true IIRD was −2.1 to 2.8 mmHg for SBP and −3.2 to 3.4 mmHg for DBP. Conclusions While walking is associated with reductions in resting SBP and DBP, a lack of true IIRD exists, suggesting that factors other than training response variation (random variation, physiological responses associated with behavioral changes that are not the result of walking) are responsible for the observed variation in resting SBP and DBP.

Section: Discussionmentioning

confidence: 99%

Section: Overall Findingsmentioning

confidence: 99%

Walking and resting blood pressure: An inter-individual response difference meta-analysis of randomized controlled trials

Stauffer

2022

Science Progress

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“…145 Consequently, the possibility exists that the findings observed at the group level in the current study would not be applicable at the individual level of the child or adolescent. While an individual participant data (IPD) metaanalysis would avoid this limitation, such an approach has to be considered with respect to (1) the inability to obtain IPD from original trial investigators, [146][147][148][149][150][151] (2) the loss of power and increased risk of bias with fewer eligible studies, (3) the substantially increased costs (up to 8 times greater) associated with conducting an IPD meta-analysis, 151,152 and (4) the general lack of differences in overall results observed between aggregate and IPD meta-analyses. [152][153][154][155][156][157] Finally, like any meta-analysis, the limitations of the included studies carry over to the current meta-analysis.…”

Section: Strengths and Limitationsmentioning

confidence: 99%

Exercise and Cardiovascular Disease Risk Factors in Children and Adolescents With Obesity: A Systematic Review With Meta-Analysis of Randomized Controlled Trials

American Journal of Lifestyle Medicine

Pate

2021

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The purpose of this study was to examine the effects of exercise on cardiovascular disease (CVD) risk factors in children and adolescents with obesity. Randomized controlled trials (RCTs) of exercise ≥4 weeks in children and adolescents with obesity were included if one or more CVD risk factors were included as an outcome. Studies were retrieved by searching 7 electronic databases, cross-referencing, and expert review. Data were pooled using the inverse-variance heterogeneity (IVhet) model and strength of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument. Thirty-nine studies representing 1548 participants (847 exercise, 701 control) met the inclusion criteria. Aerobic exercise improved 10 of 12 (83.3%) outcomes ( P < .05 for all) while combined aerobic and strength training improved 5 of 8 (62.5%) outcomes ( P < .05 for all). The strength of evidence ranged from “very low” to “moderate.” It was concluded that aerobic exercise, as well as combined aerobic and strength training, is associated with improvements in multiple CVD risk factors among children and adolescents with obesity. However, the generally low strength of evidence suggests a need for future well-designed and conducted RCTs on the effects of exercise, especially strength training, in children and adolescents with obesity.

“…Considered the 'gold standard' of meta-analyses, the potential advantages of an IPD meta-analysis, described in detail elsewhere (34) , include, but are not limited to, 'standardizing statistical analyses in each study; deriving desired summary results directly, independent of study reporting; checking modelling assumptions; and assessing participant-level effects, interactions and non-linear trends' (35) . However, one of the major disadvantages of an IPD meta-analysis is the ability to retrieve original data from study authors, with ranges of 25-100 % reported across different subject areas (36)(37)(38)(39) . As a result, this can lead to an increased risk of bias.…”

Section: Systematic Review With Meta-analysismentioning

confidence: 99%

Systematic reviews and meta-analysis in nutrition research

2019

Br J Nutr

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There exists an ever-increasing number of systematic reviews, with or without meta-analysis, in the field of nutrition. Concomitant with this increase is the increased use of such to guide future research as well as both practice and policy-based decisions. Given this increased production and consumption, a need exists to educate both producers and consumers of systematic reviews, with or without meta-analysis, on how to conduct and evaluate high-quality reviews of this nature in nutrition. The purpose of this paper is to try and address this gap. In the present manuscript, the different types of systematic reviews, with or without meta-analyses, are described as well as the description of the major elements, including methodology and interpretation, with a focus on nutrition. It is hoped that this non-technical information will be helpful to producers, reviewers and consumers of systematic reviews, with or without meta-analysis, in the field of nutrition.