Article type
Abstract
"Background: PRECIS-2 is a tool to help trialists assess the pragmatism of their trial’s design characteristics and make design decisions consistent with the intended purpose.
Objective: To investigate the relevance of the consistency among the characteristics of randomized controlled trials (RCTs) design to its results in Chinese herbal medicine (CHM) for irritable bowel syndrome (IBS).
Methods: We searched four databases in Chinese and four databases in English from their inception until January 2023 to identify potentially eligible RCTs that evaluated the effects of oral CHM for IBS with an appropriate method of randomization. Six evaluators independently assessed the pragmatism of trials using the PRECIS-2 tool rating a scale of 1–5 for each criterion (1 = maximum explanatory, 5 = maximum pragmatic). The level of consistency of the rating results across 9 domains of trial design was calculated using the coefficient of variation with a lower value indicated a more consistent agreement. Linear regression models were adopted to explore influence factors of the pragmatism of RCTs.
Results: 2 4118 citations were retrieved from databases and 78 RCTs eligible for inclusion after full-text review. The level of consistency in the ratings across 9 domains on the PRECIS-2 tool trends toward a significant correlation with the effect size regardless of whether the primary outcome was binary or continuous (binary primary outcome, r = -0.413; P = 0.005; continuous primary outcome, r = -0.779, P < 0.001). PRECIS-2 score was higher for interventions modified according to individual’s symptoms trials than those with fixed interventions (mean [SD], 3.29 [0.32] vs 2.90 [0.32]; Cohen d relative effect size, 0.52; P < 0.001) and in standard or usual- treatment-controlled trials compared with placebo-controlled (mean [SD], 3.05 [0.37] vs 2.83 [0.28]; Cohen d relative effect size, 0.32; P = 0.048).
Conclusion:
The level of consistency of design characteristics of CHM IBS RCTs across 9 domains of the PRECIS-2 tool was found to be relevant to the effect size on the results. Applying the PRECIS-2 tool as a framework will aid in stimulating the consensus process of the design decisions in RCTs to facilitate the ideal results of trials."
Objective: To investigate the relevance of the consistency among the characteristics of randomized controlled trials (RCTs) design to its results in Chinese herbal medicine (CHM) for irritable bowel syndrome (IBS).
Methods: We searched four databases in Chinese and four databases in English from their inception until January 2023 to identify potentially eligible RCTs that evaluated the effects of oral CHM for IBS with an appropriate method of randomization. Six evaluators independently assessed the pragmatism of trials using the PRECIS-2 tool rating a scale of 1–5 for each criterion (1 = maximum explanatory, 5 = maximum pragmatic). The level of consistency of the rating results across 9 domains of trial design was calculated using the coefficient of variation with a lower value indicated a more consistent agreement. Linear regression models were adopted to explore influence factors of the pragmatism of RCTs.
Results: 2 4118 citations were retrieved from databases and 78 RCTs eligible for inclusion after full-text review. The level of consistency in the ratings across 9 domains on the PRECIS-2 tool trends toward a significant correlation with the effect size regardless of whether the primary outcome was binary or continuous (binary primary outcome, r = -0.413; P = 0.005; continuous primary outcome, r = -0.779, P < 0.001). PRECIS-2 score was higher for interventions modified according to individual’s symptoms trials than those with fixed interventions (mean [SD], 3.29 [0.32] vs 2.90 [0.32]; Cohen d relative effect size, 0.52; P < 0.001) and in standard or usual- treatment-controlled trials compared with placebo-controlled (mean [SD], 3.05 [0.37] vs 2.83 [0.28]; Cohen d relative effect size, 0.32; P = 0.048).
Conclusion:
The level of consistency of design characteristics of CHM IBS RCTs across 9 domains of the PRECIS-2 tool was found to be relevant to the effect size on the results. Applying the PRECIS-2 tool as a framework will aid in stimulating the consensus process of the design decisions in RCTs to facilitate the ideal results of trials."