Assessing ethics and equity issues in systematic reviews and primary studies of nutrition interventions

Article type
Authors
Welch V1, Petticrew M2, Tugwell P3, Christie T4, Moher D5, Ueffing E6, Nickerson J1, Sculthorp M7
1Bruyere Research Institute, University of Ottawa, Canada
2London School of Hygiene and Tropical Medicine, UK
3Department of Medicine, University of Ottawa, Canada
4Faculty of Arts, University of New Brunswick (St John), Canada
5Ottawa Hospital Research Institute, University of Ottawa, Canada
6Canadian Cochrane Centre, Ottawa Hospital Research Institute, Canada
7University of Ottawa, Canada
Abstract
Background: Public health policy decisions require evidence about ethics, equity and tradeoffs in moral values. For example, taxes on sugar-sweetened beverages may produce overall reductions in sugar consumption but may be regressive by penalizing the poorest and most disadvantaged. Choices about systematic review methods influence the ability to inform decisions about ethics and equity.

Objectives: We aim to assess the extent to which systematic reviews provide evidence to assess ethics, equity and tradeoffs in moral values and compare this with evidence from their included primary studies.

Methods: We selected a purposeful sample of 21 systematic reviews on nutrition interventions, with a balance of individual, health systems and regulatory interventions; and whether they were Cochrane (n = 10) or non-Cochrane Reviews (n = 11). We extracted data from the systematic reviews and their primary studies on justification of methodological choices (e.g. eligible study designs, populations, outcomes, and analysis methods such as process evaluation) and the discussion of whether these choices influenced the generalizability to disadvantaged populations and ability to inform decisions about tradeoffs in justice, respect for persons and concern for welfare. We used duplicate data extraction and a pre-tested form.

Results: The systematic reviews assessed a range of interventions such as education, health system integration, and taxes for sugar sweetened beverages. The justification of methods for the systematic reviews such as eligibility of different study designs, choice of outcomes and use of implementation or process evaluation was rarely described. Implications on ability to inform tradeoffs such as between population health and personal autonomy were rarely discussed. The results of the 514 primary studies will be presented and compared to the systematic reviews.

Conclusions: There is a need to improve the justification of methods in systematic reviews and for greater reflection on the influence of methodological choices on informing ethics and tradeoffs in moral values.