An overview on the methodological and reporting quality of dose–response meta-analysis on cancer prevention

Adaptive designs were primarily used but inadequately reported in early phase drug trials

BACKGROUND

Faced with the high cost and limited efficiency of classical randomized controlled trials, researchers are increasingly applying adaptive designs to speed up the development of new drugs. However, the application of adaptive design to drug randomized controlled trials (RCTs) and whether the reporting is adequate are unclear. Thus, this study aimed to summarize the epidemiological characteristics of the relevant trials and assess their reporting quality by the Adaptive designs CONSORT Extension (ACE) checklist.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) and ClinicalTrials.gov from inception to January 2020. We included drug RCTs that explicitly claimed to be adaptive trials or used any type of adaptative design. We extracted the epidemiological characteristics of included studies to summarize their adaptive design application. We assessed the reporting quality of the trials by Adaptive designs CONSORT Extension (ACE) checklist. Univariable and multivariable linear regression models were used to the association of four prespecified factors with the quality of reporting.

RESULTS

Our survey included 108 adaptive trials. We found that adaptive design has been increasingly applied over the years, and was commonly used in phase II trials (n = 45, 41.7%). The primary reasons for using adaptive design were to speed the trial and facilitate decision-making (n = 24, 22.2%), maximize the benefit of participants (n = 21, 19.4%), and reduce the total sample size (n = 15, 13.9%). Group sequential design (n = 63, 58.3%) was the most frequently applied method, followed by adaptive randomization design (n = 26, 24.1%), and adaptive dose-finding design (n = 24, 22.2%). The proportion of adherence to the ACE checklist of 26 topics ranged from 7.4 to 99.1%, with eight topics being adequately reported (i.e., level of adherence ≥ 80%), and eight others being poorly reported (i.e., level of adherence ≤ 30%). In addition, among the seven items specific for adaptive trials, three were poorly reported: accessibility to statistical analysis plan (n = 8, 7.4%), measures for confidentiality (n = 14, 13.0%), and assessments of similarity between interim stages (n = 25, 23.1%). The mean score of the ACE checklist was 13.9 (standard deviation [SD], 3.5) out of 26. According to our multivariable regression analysis, later published trials (estimated β = 0.14, p < 0.01) and the multicenter trials (estimated β = 2.22, p < 0.01) were associated with better reporting.

CONCLUSION

Adaptive design has shown an increasing use over the years, and was primarily applied to early phase drug trials. However, the reporting quality of adaptive trials is suboptimal, and substantial efforts are needed to improve the reporting.

Predictors of Higher Quality of Systematic Reviews Addressing Nutrition and Cancer Prevention

Systematic reviews/meta-analyses (SR/MAs) are considered a reliable source of information in healthcare. We aimed to explore the association of several characteristics of SR/MAs addressing nutrition in cancer prevention and their quality/risk of bias (using assessments from AMSTAR-2 and ROBIS tools). The analysis included 101 SR/MAs identified in a systematic survey. Associations of each specified characteristic (e.g., information about the protocol, publication year, reported use of GRADE, or other methods for assessing overall certainty of evidence) with the number of AMSTAR-2 not met (‘No’ responses) and the number of ROBIS items met (‘Probably Yes’ or “Yes’ responses) were examined. Poisson regression was used to identify predictors of the number of ‘No’ answers (indicating lower quality) for all AMSTAR-2 items and the number of ‘Yes’ or ‘Probably Yes’ answers (indicating higher quality/lower concern for bias) for all ROBIS items. Logistic regression was used to identify variables associated with at least one domain assessed as ‘low concern for bias’ in the ROBIS tool. In multivariable analysis, SR/MAs not reporting use of any quality/risk of bias assessment instrument for primary studies were associated with a higher number of ‘No’ answers for all AMSTAR-2 items (incidence rate ratio (IRR) 1.26, 95% confidence interval (CI) 1.09–1.45), and a lower number of ‘Yes’ or ‘Probably Yes’ answers for all ROBIS items (IRR 0.76, 95% CI 0.66–0.87). Providing information about the protocol and search for unpublished studies was associated with a lower number of ‘No’ answers (IRR 0.73, 95% CI 0.56–0.97 and IRR 0.75, 95% CI 0.59–0.95, respectively) and a higher number of ‘Yes’ or ‘Probably Yes’ answers (IRR 1.43, 95% CI 1.17–1.74 and IRR 1.28, 95% CI 1.07–1.52, respectively). Not using at least one quality/risk of bias assessment tool for primary studies within an SR/MA was associated with lower odds that a study would be assessed as ‘low concern for bias’ in at least one ROBIS domain (odds ratio 0.061, 95% CI 0.007–0.527). Adherence to methodological standards in the development of SR/MAs was associated with a higher overall quality of SR/MAs addressing nutrition for cancer prevention.

Methodological quality was critically low in 9/10 systematic reviews in advanced cancer patients-A methodological study

OBJECTIVE

To assess the methodological quality and the consideration of heterogeneity in systematic reviews (SRs).

STUDY DESIGN AND SETTING

We conducted a methodological study (CRD42019134904) and searched three databases from January 2010 to July 2019. Interventional SRs with a statistically significant meta-analysis of at least four randomized controlled trials in advanced cancer patients were included. A MeaSurement Tool to Assess Systematic Reviews (AMSTAR) 2 was used to evaluate the SRs' methodological quality. The consideration of heterogeneity was categorized in clinical or/and methodological heterogeneity and not explored.

RESULTS

From 6234 identified references, 261 SRs were included. Most SRs had a critically low quality (230, 88.1%). The majority of them (209, 80.1%) was classified as critically low because of non-registration (222, 85.1%) combined with the non-reporting of excluded full-texts and missing justifications for exclusion (218, 83.5%). Heterogeneity in trial results was not explored at all in 51 (19.5%) SRs whereas clinical heterogeneity was considered in 117 (44.8%), methodological heterogeneity in 13 (5.0%), and both clinical and methodological heterogeneity in 80 (30.7%) SRs.

CONCLUSION

The consideration of these findings in trainings for review authors and peer reviewers could improve the awareness of quality criteria and the quality of future SRs.

TRIAL REGISTRATION

PROSPERO-ID: CRD42019134904.

Methodological issues of systematic reviews and meta-analyses in the field of sleep medicine: A meta-epidemiological study

An increasing number of systematic reviews and meta-analyses (SRMAs) have been published in the field of sleep medicine. We evaluated the methodological issues of these SRMAs. A protocol was developed in advance. Three databases were searched from inception to October 2019 for SRMAs published in major academic journals of sleep medicine that assessed healthcare interventions. The AMSTAR 2.0 instrument was used to evaluate the methodological issues and a multivariable regression analysis was conducted to investigate potential measures associated with methodological validity. We identified 163 SRMAs. The median number of missing safeguards of these SRMAs was 7 out of 16 (Interquartile range, IQR: 6-9), and on average, two of these missing safeguards were critical weaknesses. Our regression analysis suggested that SRMAs published in recent years (β = 0.16; 95%CI: 0.08, 0.24; p = 0.002), with the first author from Europe (β = 0.08; 95%CI: 0.02, 0.14; p = 0.013) tend to have higher relative methodological ranks. In conclusion, the methodological validity for current SRMAs in sleep medicine was poor. Further efforts to improve the methodological validity are needed.

The association between body mass index and the risk of different urinary cancers: Protocol for an overview of systematic reviews

BACKGROUND

The relationship between cancer with body mass index has been extensively reported. However, association between urinary cancers with these risk factors remains unclear, with existing reports showing conflicting findings. The current review, therefore, sought to clarify the latter association by assessing the methodological and reporting quality of existing systematic reviews on the subject.

METHODS

We will screen PubMed, EMBASE, and Cochrane Library databases for relevant literature and subjected the resulting articles to meta-analysis. We will adopt the AMSTAR and PRISMA checklists for assessing methodological, and reporting quality, respectively. The association between BMI and different urinary cancers will be estimated by computing the pooled relative risk (RR) and its 95% confidence interval (CI), which will be calculated from the adjusted RR, odds ratio, or hazard ratio, and 95% CI offered in the studies. Heterogeneity between studies will be assessed with the I statistic as a measure of the proportion of total variation in estimates that is due to heterogeneity, where I values of 25%, 50%, and 75% correspond to cut-off points for low, moderate, and high degrees of heterogeneity. The random effects model will be used as the pooling method when significant heterogeneity existed and the fixed effect model will be used when no heterogeneity was observed. Possible publication bias will be tested by Begg and Egger test.

CONCLUSION

Our evidence synthesis will provide a new commentary on the current systematic review evidence for the association between BMI and the risk of different urinary cancers.

PROSPERO REGISTRATION NUMBER

CRD42019119459.

Methodological and reporting quality in non-Cochrane systematic review updates could be improved: a comparative study

OBJECTIVES

The aim of the study was to compare the methodological and reporting quality of updated systematic reviews (SRs) and original SRs.

STUDY DESIGN AND SETTING

We included 30 pairs of non-Cochrane updated and original SRs, identified from a search of PubMed and Embase.com. We used Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) to assess methodological quality and Preferred Reporting Items of Systematic reviews and Meta-Analyses (PRISMA) for reporting quality. Stratified analyses were conducted to compare the differences between updated SRs and original SRs and explore factors that might affect the degree of quality change.

RESULTS

Of the 60 non-Cochrane SRs, only two (3.3%) were of low quality, the remaining 58 (96.7%) were of critical low quality. There were no statistically significant differences in methodological quality between the updated SRs and original SRs, although the compliance rates of eight items of updated SRs were higher than that of original SRs. Updated SRs showed an improvement on 15 PRISMA items, but no items with statistically significant differences. The differences in fully reported AMSTAR-2 and PRISMA items between original SRs and updated SRs were also not statistically significant after adjusting for multiple review characteristics.

CONCLUSION

The methodological and reporting quality of updated SRs were not improved compared with original SRs, although the quality could be further improved for both updated SRs and original SRs.