Article type
Year
Abstract
Background: previous studies addressing the quality of systematic reviews/meta-analyses (SR/MAs) in several healthcare fields have demonstrated that review methodology and overall quality is often questionable; such an assessment is lacking in the nutrition field.
Objectives: we aimed to examine the characteristics, risk of bias assessments (RoB) and overall quality of SR/MAs articles published on nutritional interventions on cancer prevention.
Methods: we conducted a systematic survey of the Cochrane Library, MEDLINE and Embase for SR/MAs published between 2010 and 2018. Eligible for inclusion were articles identified as SR/MAs in the title or abstract that included primary studies with control group (randomized and non-randomized studies) on the effects of any nutritional intervention in the prevention of cancer incidence or mortality in the general population or people at risk for cancer.
Following calibration exercises review authors independently and in pairs screened titles and abstracts and then full texts, extracted the data and assessed quality of the studies. We resolved conflicts by discussion or with the help of third review author. We documented the general methodological characteristics (available protocol, methods used to assess RoB, meta-analysis, use of GRADE or assessments of overall quality of evidence) and the overall methodological quality of eligible SR/MAs evaluated using the AMSTAR 2 checklist. We registered our protocol in PROSPERO (CRD42019121116).
Results: our searches yielded 24,739 references. After de-duplication we screened 20,413 references and retrieved 1594 full texts, of which 750 studies met the inclusion criteria. We randomly selected a sample of 101 articles using the Excel RAND feature (proportional to the total number of studies per year of publication). We are in the process of data extraction and quality assessment of the studies. Preliminary data on 17 studies extracted thus far show limited to no information on pre-specified methods including an available protocol, limited to no use of RoB/quality assessment of primary studies included in SR/MAs (41% reported use of any quality assessment). None of the studies reviewed thus far reported use of GRADE or other overall quality of evidence assessments. Overall confidence in the results of the review evaluated on the basis of AMSTAR2 tool in all evaluated studies was critically low due to more than one serious methodological flaw identified. We will present full results at the Colloquium.
Conclusions: this project provides important information about methodological characteristics and overall quality of SR/MAs addressing nutritional interventions in cancer prevention.
Improvement of a patient-focused health outcome: our systematic survey focuses on patient-important cancer outcomes. Results based on poor-quality SR/MA methods may be misleading for the users of such evidence.
Funding: Project funded by National Science Centre, No. UMO-217/25/B/NZ7/0
Objectives: we aimed to examine the characteristics, risk of bias assessments (RoB) and overall quality of SR/MAs articles published on nutritional interventions on cancer prevention.
Methods: we conducted a systematic survey of the Cochrane Library, MEDLINE and Embase for SR/MAs published between 2010 and 2018. Eligible for inclusion were articles identified as SR/MAs in the title or abstract that included primary studies with control group (randomized and non-randomized studies) on the effects of any nutritional intervention in the prevention of cancer incidence or mortality in the general population or people at risk for cancer.
Following calibration exercises review authors independently and in pairs screened titles and abstracts and then full texts, extracted the data and assessed quality of the studies. We resolved conflicts by discussion or with the help of third review author. We documented the general methodological characteristics (available protocol, methods used to assess RoB, meta-analysis, use of GRADE or assessments of overall quality of evidence) and the overall methodological quality of eligible SR/MAs evaluated using the AMSTAR 2 checklist. We registered our protocol in PROSPERO (CRD42019121116).
Results: our searches yielded 24,739 references. After de-duplication we screened 20,413 references and retrieved 1594 full texts, of which 750 studies met the inclusion criteria. We randomly selected a sample of 101 articles using the Excel RAND feature (proportional to the total number of studies per year of publication). We are in the process of data extraction and quality assessment of the studies. Preliminary data on 17 studies extracted thus far show limited to no information on pre-specified methods including an available protocol, limited to no use of RoB/quality assessment of primary studies included in SR/MAs (41% reported use of any quality assessment). None of the studies reviewed thus far reported use of GRADE or other overall quality of evidence assessments. Overall confidence in the results of the review evaluated on the basis of AMSTAR2 tool in all evaluated studies was critically low due to more than one serious methodological flaw identified. We will present full results at the Colloquium.
Conclusions: this project provides important information about methodological characteristics and overall quality of SR/MAs addressing nutritional interventions in cancer prevention.
Improvement of a patient-focused health outcome: our systematic survey focuses on patient-important cancer outcomes. Results based on poor-quality SR/MA methods may be misleading for the users of such evidence.
Funding: Project funded by National Science Centre, No. UMO-217/25/B/NZ7/0
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