The external validity of randomized controlled trials of hypertension within China: from the perspective of sample representation

Multivariate analysis of the population representativeness of related clinical studies

OBJECTIVE

To develop a multivariate method for quantifying the population representativeness across related clinical studies and a computational method for identifying and characterizing underrepresented subgroups in clinical studies.

METHODS

We extended a published metric named Generalizability Index for Study Traits (GIST) to include multiple study traits for quantifying the population representativeness of a set of related studies by assuming the independence and equal importance among all study traits. On this basis, we compared the effectiveness of GIST and multivariate GIST (mGIST) qualitatively. We further developed an algorithm called "Multivariate Underrepresented Subgroup Identification" (MAGIC) for constructing optimal combinations of distinct value intervals of multiple traits to define underrepresented subgroups in a set of related studies. Using Type 2 diabetes mellitus (T2DM) as an example, we identified and extracted frequently used quantitative eligibility criteria variables in a set of clinical studies. We profiled the T2DM target population using the National Health and Nutrition Examination Survey (NHANES) data.

RESULTS

According to the mGIST scores for four example variables, i.e., age, HbA1c, BMI, and gender, the included observational T2DM studies had superior population representativeness than the interventional T2DM studies. For the interventional T2DM studies, Phase I trials had better population representativeness than Phase III trials. People at least 65years old with HbA1c value between 5.7% and 7.2% were particularly underrepresented in the included T2DM trials. These results confirmed well-known knowledge and demonstrated the effectiveness of our methods in population representativeness assessment.

CONCLUSIONS

mGIST is effective at quantifying population representativeness of related clinical studies using multiple numeric study traits. MAGIC identifies underrepresented subgroups in clinical studies. Both data-driven methods can be used to improve the transparency of design bias in participation selection at the research community level.

Traditional Chinese Patent Medicine for Acute Ischemic Stroke: An Overview of Systematic Reviews Based on the GRADE Approach

The aim of the study is to conduct an overview of systematic reviews (SRs) to provide a contemporary review of the evidence for delivery of Traditional Chinese Patent Medicine (TCPMs) for patients with acute ischemic stroke.SRs were assessed for quality using the Assessment of Multiple Systematic Reviews (AMSTAR) tool and the Oxman-Guyatt Overview Quality Assessment Questionnaire (OQAQ). We assessed the quality of the evidence of high methodological quality (an AMSTAR score ≥9 or an OQAQ score ≥7) for reported outcomes using the GRADE (the Grading of Recommendations Assessment, Development and Evaluation) approach.(1) Dan Shen agents: tiny trends toward the improvement in different neurological outcomes (RR = 1.16, 1.10, 1.23, 1.08, 1.12); (2) Mailuoning: a tiny trend toward improvement in the neurological outcome (RR = 1.18); (3) Ginkgo biloba: tiny trends toward improvement in the neurological outcome (RR = 1.18, MD = 0.81); (4) Dengzhanhua: a tiny trend toward an improvement in neurological (RR = 1.23); (5) Acanthopanax: a small positive (RR = 1.17, 1.31) result on neurological improvement reported; (6) Chuanxiong-type preparations: neurological functional improved (MD = 2.90);(7) Puerarin: no better effect on the rate of death or disability (OR = 0.81, 95% CI 0.35-1.87); (8) Milk vetch: no better effect on the rate of death (OR = 0.66, 95% CI: 0.11-2.83);(9) Qingkailing: rate of death reduced (OR = 0.66, 95% CI: 0.11-2.83). Limitations in the methodological quality of the RCTs, inconsistency and imprecision led to downgrading of the quality of the evidence, which varied by review and by outcome. Consequently, there are currently only weak evidences to support those TCPMs.The 9 TCPMs may be effective in the treatment of acute ischemic stroke, as the GRADE approach indicated a weak recommendation for those TCPMs' usage.

GRADE in Systematic Reviews of Acupuncture for Stroke Rehabilitation: Recommendations based on High-Quality Evidence

Systematic reviews (SRs) of randomized controlled trials (RCTs) have demonstrated acupuncture's effectiveness in stroke rehabilitation. The current study reviews the quality of evidence in SRs of acupuncture in stroke rehabilitation, and rates the strength of recommendation for its use based on this evidence using the GRADE (grading of recommendations, assessment, development and evaluations) approach. A comprehensive literature search was performed using multiple databases (e.g., Medline, Embase) with advanced search strategies. Two authors independently selected articles, collected data, and assessed the methodological quality of each identified SR according to AMSTAR (a measurement tool to assess systematic reviews) and OQAQ (Oxman and Guyatt's overview quality assessment questionnaire). Outcomes related to stroke rehabilitation were evaluated. SRs of high methodological quality (AMSTAR score ≥9 and OQAQ score ≥7) were graded using GRADE. Ultimately, acupuncture yields benefits in stroke rehabilitation (neurological function improvement: RR = 1.34; swallowing improvement: RR = 1.61, 1.49, 1.07; disability: SMD = 0.49 or 0.07). Poor evidentiary quality and insufficient information about harm led to weak recommendations. In conclusion, acupuncture may improve stroke rehabilitation, as the GRADE approach indicated a weak recommendation for acupuncture's usage in this context.