Scope and quality of Cochrane reviews of nutrition interventions: a cross-sectional study

Abstract

BackgroundAll countries face significant challenges from complex manifestations of malnutrition, which affects one in three people globally. Systematic reviews provide ready-to-use syntheses of quality-appraised evidence to inform decision-making for actions. To enhance the utility and quality of future Cochrane nutrition evidence, we described the scope and quality of all nutrition systematic reviews in the Cochrane Database of Systematic Reviews (CDSR).MethodsWe screened all active CDSR records (31 July 2015) to identify reviews and protocols using pre-specified eligibility criteria and definitions. Duplicate, independent data extraction included criteria for inclusion of studies in completed reviews (PICOS). We assessed methodological quality (AMSTAR), use of GRADE, mapped reviews against 2013 Global Burden of Disease data, and categorised the paradigm (medical, lifestyle and socio-ecological) of the review question. We analysed our results using descriptive statistics.ResultsWe screened 8484 records, and included 470 (8%) completed reviews (in 45 Cochrane Review Groups (CRGs)) and 169 (7%) protocols (in 41 CRGs) published by 47 of 53 CRGs with reviews. Most completed reviews were produced by the Pregnancy and Childbirth (n = 73), Neonatal (n = 64), Metabolic and Endocrine Disorders (n = 33), Developmental, Psychosocial and Learning Problems (n = 26), Kidney and Transplant (n = 18) and Heart (n = 18) CRGs. Only 27% (n = 129) of reviews had searches for new studies in 2013 or thereafter. Supplementation/supplement interventions were most common (50%; n = 235; majority with micronutrients; 73%, n = 173), followed by food interventions (20%; n = 95). All reviews included randomised controlled trials; about 5% included other designs; 25% used GRADE; the median AMSTAR score was 9 (interquartile range: 7 to 10), 51% were high (AMSTAR 9-11) and 49% moderate (AMSTAR 5-8) quality. More than 80% framed questions using a medical paradigm. For top causes of years-of-life-lost, most reviews addressed preterm birth, diabetes and ischaemic heart disease; for leading risk factors for disability-adjusted-life-years, most targeted childhood undernutrition and high body mass index.ConclusionsNutrition reviews comprised 8% of active CDSR records, were widely distributed across nearly all CRGs and reflected the double nutrition burden. This analysis presents a comprehensive description of the scope and quality of Cochrane nutrition reviews, and identifies gaps for future activities to support actions to address the nutrition burden, in line with the current nutrition agenda and impetus.

A call to action to reshape evidence synthesis and use for nutrition policy

“…[5] The profile of nutrition reviews in the Cochrane Database of Systematic Reviews is dominated by nutrition-specific interventions; 50% of nutrition reviews address nutrient supplementation alone. [4] Similar domination has been reported with the profiles of nutrition policies and guidelines recorded in the WHO e-Library of Evidence for Nutrition Actions (eLENA), and with the implementation of nutrition actions listed in the WHO Global database on the Implementation of Nutrition Action (GINA). [6] Nutrition-specific interventions may constitute appropriate responses for some micronutrient deficiency problems, but nutrition-sensitive interventions may be equally, or more, e ective in combating these problems, as well as being better suited to tackling dietary imbalances associated with diet-related chronic diseases and obesity.…”

“…Mark Lawrence 1 , Celeste Naude 2,3 , Rebecca Armstrong 4,5 , Lisa Bero 6,7 , Namukolo Covic 8 , Solange Durao 3,9,10 , Davina Ghersi 11 , Geraldine Macdonald 12,13 , Harriet MacLehose 14 , Barrie Margetts 15 , David Tovey 16 , Jimmy Volmink 2,9,10 , Taryn Young 2,10…”

“…3 Cochrane Nutrition. 4 Jack Brockho Child Health & Wellbeing Program, Melbourne School of Population and Global Health, University of Melbourne, Australia. 5 Cochrane Public Health.…”

Making nutrition guidelines fit for purpose

“…Randomised trials present several problems when studying nutrition exposures or interventions,89 although advances in trial design, such as pragmatic trials, can help improve problems related to generalisability of results 9…”

Research Priorities for Studies Linking Intake of Low-Calorie Sweeteners and Potentially Related Health Outcomes

“…However, none to date are related to nutrition topics. Furthermore, nutrition-related systematic reviews only comprise ∼8% of all systematic reviews in the Cochrane Database of Systematic Reviews and, among these, approximately half focus on nutritional supplementation or supplements ( 3 ). Due to the anticipated need to consider broader research questions for public health nutrition, we previously modified the ARHQ's FRN approach by integrating an evidence-mapping process ( 4 ).…”