Evidence synthesis serves as a bridge between clinical practice and the best available evidence. Evidence synthesis based on high-quality randomized controlled trials is generally considered the highest level of evidence, but its external validity is limited. In some scenarios, the inclusion of non-randomized intervention studies (NRSI) in evidence synthesis may further supplement or even replace randomized controlled trial evidence, such as assessing intervention effectiveness and rare events in a broader population to provide more information for health care decision-making. With the rapid development of real-world data and the improvement of statistical analysis methods, real-world evidence, as an important source of evidence for NRSI, has accelerated the development of high-quality NRSI. However, there are numerous challenges in integrating evidence from randomized and non-randomized intervention studies due to selection and confounding biases caused by the lack of randomization. Based on previous studies, this paper systematically examines the current status of integrated randomized and non-randomized intervention studies, including integration premise, timing, methods, and result interpretation, in order to provide references for researchers and policy-makers to correctly use non-randomized research evidence and further promote optimal evidence generation and clinical practice translation.
ObjectiveTo systematically evaluate the prevalence of diabetes in the elderly with frailty.MethodsPubMed, EMbase, Web of Science, CNKI, CBM, VIP and WanFang Data databases were electronically searched to collect cross-sectional studies on the prevalence of diabetes in the elderly with frailty from inception to November 2020. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies; meta-analysis was then performed by using Stata 15.0 software.ResultsA total of 21 cross-sectional studies involving 22 403 subjects were included. The pooled prevalence of diabetes in the elderly with frailty was 34% (95%CI 26% to 43%). Subgroup analysis showed that the prevalence of diabetes in patients with frailty in Asia and South America was higher than those in Europe and North America. The prevalence of diabetes in patients with frailty using physical frailty measures to evaluate frailty was higher than using multidimensional frailty measures. The prevalence of diabetes in patients with frailty in outpatient and hospital were higher than those in the community.ConclusionsCurrent evidence suggests that the prevalence of diabetes is high in the elderly with frailty.
ObjectiveTo systematically investigate the registration status, methodology and reporting quality of the systematic review protocols for animal experiment registered on PROSPERO platform.MethodsSystematic review protocols of animal experiments registered on PROSPERO platform were searched up to December 31st, 2019. Two reviewers independently screened literature, extracted data, and performed a descriptive analysis of the methodological quality and reporting characteristics of the included studies.ResultsA total of 351 protocols from 50 countries were included, involving 22 diseases. The intervention measures were primarily "pharmaceutical chemicals". Only approximately 1/3 of the studies reported the search strategy from at least one database, approximately half of the studies were prepared to report heterogeneity analysis and publication bias, and only approximately 1/3 of the studies were prepared to report sensitivity analysis.ConclusionsThe quantity of systematic reviews of animal experiments registered on the PROSPERO platform is increasing annually, however, there are still some limitations in the methodology and reporting quality.
ObjectiveTo systematically review the relationship between frailty and risk of orthostatic hypotension.MethodsPubMed, EMbase, Web of Science, CNKI, CBM, VIP and WanFang Data databases were electronically searched to collect studies on the association between frailty and orthostatic hypotension from inception to July 7th, 2020. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies. Meta-analysis was then performed by RevMan 5.3 software.ResultsFive cross-sectional studies involving 8 671 patients were included. The results of meta-analysis showed that prefrailty (OR=1.04, 95%CI 0.99 to 1.09, P=0.11) and frailty (OR=1.02, 95%CI=0.92 to 1.13, P=0.70) were not associated with orthostatic hypotension. The results of subgroup analysis showed that differences of sample size (<500 or ≥500), using different frailty assessment tools (Fried scale, clinical frailty scale, and frailty index), different regions (Europe, Asia, and America) and different sources of studied subjects (hospitals and communities), the risk of orthostatic hypotension were not increased with frailty.ConclusionsCurrent evidence shows that frailty does not increase the risk of orthostatic hypotension. Due to limited quality and quantity of included studies, the above conclusions are needed to be validated by more high-quality studies.
ObjectiveTo systematically review the dose-response relationship between body mass index (BMI) and all-cause mortality in the elderly with frailty.MethodsPubMed, EMbase, Web of Science, CNKI, VIP, WanFang Data, and CBM databases were electronically searched to collect cohort studies on the association of BMI and mortality in frail adults from inception to November 2019. Two reviewers independently screened literature, extracted data and assessed risk bias of included studies; Stata 15.0 software was then used to analyze the dose-response analysis of BMI and mortality by restricted cubic spline function and generalized least squares method.ResultsA total of 4 cohort studies involving 12 861 frail adults were included. Meta-analysis results showed that compared with normal BMI, the frail elderly who were overweight (HR=0.80, 95%CI 0.74 to 0.88, P<0.001) and obese (HR=0.89, 95%CI 0.79 to 1.00, P=0.047) had lower all-cause mortality. The results of dose-response meta-analysis showed that there was a non-linear relationship between BMI and all-cause mortality in the elderly with frailty (P value for nonlinearity was 0.035), for which the elderly with frailty had a BMI nadir of 27.5-31.9 kg/m2. For linear trends, and when BMI was less than 27.5 kg/m2, the risk of all-cause death was reduced by 4% for every 1 kg/m2 increase in BMI (RR=0.96, 95%CI 0.90 to 1.03, P=0.320), when BMI was greater than 27.5 kg/m2, the risk of all-cause death increased by 4% for every 1 kg/m2 increase in BMI (RR=1.04, 95%CI 1.03 to 1.05, P<0.001).ConclusionsThere is a paradox of obesity and a significant nonlinear relationship between BMI and all-cause mortality in the frailty elderly, with the lowest all-cause mortality in the frailty elderly at BMI 27.5-31.9 kg/m2. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusions.