User’s Guide to the Comprehensive Assessment of Population Approaches to Improve Lifestyle Behaviors
Disclosure: Dr Gardner and Dr. Otten have nothing to disclose.
Pub Date: Monday, Aug. 20, 2012
Author: Christopher Gardner, PhD, and Jennifer Otten, PhD
Affiliation: Stanford Prevention Research Center, Stanford University and Stanford University School of Medicine, Stanford, California
Citation: Mozaffarian D, Afshin A, Benowitz NL, Bittner VA, Daniels SR, Franch HA, Jacobs DR Jr, Kraus WE, Kris-Etherton PM, Krummel DA, Popkin BM, Whitsel LP, Zakai NA, on behalf of the American Heart Association Council on Epidemiology and Prevention, Council on Nutrition, Physical Activity and Metabolism, Council on Clinical Cardiology, Council on Cardiovascular Disease in the Young, Council on the Kidney in Cardiovascular Disease, Council on Peripheral Vascular Disease, and the Advocacy Coordinating Committee. Population approaches to improve diet, physical activity, and smoking habits: a scientific statement from the American Heart Association. Circulation. 2012: published online before print August 20, 2012, 10.1161/CIR.0b013e318260a20b.
The major chronic diseases responsible for the current global morbidity and mortality burden – coronary disease, cancer, stroke, and diabetes – are considered to be largely attributable to three specific lifestyle factors: suboptimal diet, physical inactivity, and tobacco use. These chronic diseases, therefore, are potentially preventable through improvement of these modifiable lifestyle factors. The solutions, however, are far from simple. In the last 50 years there have been unprecedented rapid transformations in food production, distribution, and consumption with an overall shift to greater access to an abundance of highly palatable foods and beverages with high sugar, high sodium, high fat and high energy density, and low nutrient density. The same time period has witnessed an unprecedented increase in access to labor-saving devices allowing for and promoting physical inactivity and sedentary behaviors. Tobacco use trends are a bit more complex – prevalence is down in the United States compared to recent decades, but the decline has plateaued, there are still geographic pockets and subpopulations in the United States with relatively high prevalence rates; and tobacco use is increasing in some of the most vulnerable and fastest growing developing regions (e.g., China and India) due to major shifts in the energies and resources of tobacco marketers away from countries like the United States with the most aggressive anti-tobacco policies and toward the developing countries. Reversing these powerful global trends requires going far beyond providing a rationale and guidelines to eat better, exercise more, and smoke less; it requires overcoming innate human preferences and inclinations to 1) eat highly palatable food of poor nutritional quality, 2) avoid unnecessary physical exertion, and 3) fall prey to addictive tobacco use behaviors. This requires population approaches.
Mozaffarian et al have taken on the herculean task of identifying, reviewing, organizing, grading, and summarizing the vast literature in the area of Population Approaches to Improve Diet, Physical Activity and Smoking Habits in a Scientific Statement from the American Heart Association. As they so aptly state in the Executive Summary, “Whereas the most relevant specific lifestyle targets are increasingly evident, the most effective strategies to achieve these changes have been less clear.” The scope of the Statement is bold and ambitious. There are 529 citations referenced, 8 primary tables, and 14 supplementary tables (19 tables if the subsections of supplementary table #10 are counted). The search strategies and data extraction methods are methodical, systematic, and clearly defined. The overall objective of the Statement was to systematically review and grade the current scientific evidence for effective population approaches to improve dietary habits, increase physical activity, and reduce tobacco use. More specifically, the Statement’s authors intended for the review and grading of this evidence to help identify (a) which approaches work and should be implemented, (b) which approaches are promising and deserving of further intensive investigation, and (c) what critical research gaps remain.
It is the objective of this brief commentary to highlight its strengths and to provide suggestions as to how the Statement could be most efficiently and effectively utilized by readers with different backgrounds, interests, and goals.
Abstract, Executive Summary and Table 1 Summary
Both the abstract and the Executive Summary provide a framework for understanding the objectives of the Statement and the methods used to address the objectives. Most importantly, these two sections of the Statement both provide a list of the six domains the authors identified as the most practical and useful for the purpose of organizing the report around specific population approach strategies: (1) media and education campaigns; (2) labeling and consumer information; (3) taxation, subsidies, and other economic incentives; (4) school and workplace approaches; (5) local environmental changes; and (6) direct restrictions and mandates. All six of these domains are addressed separately for diet, physical activity, and smoking. There are no specific conclusions offered in the abstract or Executive Summary for the 18 domain X lifestyle factor topics (6 domains X 3 lifestyle factors). Rather, conclusions about the best practices identified are presented in Table 1. This table presents all of the population approach strategies that the authors rated as being at least likely to be beneficial with at least some evidence for benefit (see below for specifics about recommendation classifications and ranking levels of evidence). For diet this included 16 population approach strategies that were spread out across all 6 domains. For physical activity this included 17 strategies spread out across 5 of the 6 domains (none for restrictions and mandates). For smoking there were 11 strategies spread across all 6 domains, with the bulk of these (5 of 11) falling into the restrictions and mandates domain.
Usefulness: A must-read. Anyone considering diving into this exhaustive review should at least start with Table 1 plus either the abstract or the Executive Summary (considerable overlap between the two) to find out right from the start how it ends.
Table 2 – Classification of Recommendations and Levels of Evidence.
Every section of the population approach strategy assessment ends with a rating in two dimensions. The first dimension is the classification of recommendations, which ranges from beneficial, useful and effective, to not useful or effective and potentially harmful. The second dimension is the level of evidence available to support the classification of recommendation, and this ranges from strong evidence/multiple sources/replicated/strong study design to only consensus opinion of experts/case studies/standard-of-care.
Usefulness: For some readers it will be sufficient to understand that I is the highest and best classification of recommendation and III is the worst, and that A is the strongest level of evidence and C is the weakest. For others it will be important to know the subtle differences between a strategy ranked IIa-B vs. IIb-A. For those readers trying to evaluate the importance of the ranking differences in Table 1, or who intend to go on to read through subsections and pertinent conclusions of the main text, this concise table of definitions will be very useful.
Main body of text
The bulk of the Statement is the detailed content organized around the six domains described above. Diet, physical activity, and smoking are addressed separately for each domain (except in cases where some of the population approaches were designed to address more than one domain simultaneously). It is in these sections, sub-sections, and sub-sub-sections that the authors try to provide a level of detail about the studies, policies, or programs being reviewed that is both necessary and sufficient to justify or explain the classification of recommendations and level of evidence assigned to each population approach.
Usefulness: The key to using this section most efficiently and effectively is to recognize how consistently the authors followed their organizational structure. There are 18 main sections to the Statement – 6 domains X 3 lifestyle topics. The six domains are presented in the order outlined in the executive summary, and the lifestyle topics are always addressed in the order of diet, then physical activity, then smoking. When warranted, subtopics are labeled and addressed within the general 18 domain X lifestyle factor outline. The main body of text is dense and long. It does not make for pleasurable and entertaining reading, nor was it meant to. There is no advantage to be gained by reading this straight through from beginning to end. Rather, the reader should be encouraged to first identify and prioritize the population approaches of greatest interest and start there, and then continue to skip around through subsections as needed.
Tables 3-8, organized and ordered by domain
The end of every one of the 6 domain subsections in the main body of text refers to one of the Tables 3 through 8. Each table covers the conclusions about all three lifestyle factors for a specific domain. The conclusions presented here go beyond those in Table 1. In the earlier table only those conclusions with a classification of recommendation at level I or IIa, and a level of evidence of “A” or “B,” were included. In these tables all of the topics discussed in the main body of text are represented and summarized, and all of them receive a rating by classification of recommendation and a level of evidence.
Usefulness: For the individual or community activist or advocate whose activities tend to involve one specific domain rather than or more than another, and extend across lifestyle factors, the organization of the tables is particularly useful. On the other hand, for the content expert that specializes in one lifestyle factor more than others and is interested in how that particular factor (e.g., physical activity) fares across different domains, doing the comparison will involve jumping from one table to the next.
500+ references cited
Usefulness: The usefulness of this impressive assemblage of references is obvious. On top of all the other contributions made by this Scientific Statement, putting together this collection is useful in and of itself for those who may simply be looking for what has been published in the area of population approaches to improving lifestyle factors. While the authors acknowledge that they can’t be certain this is exhaustively complete, they appropriately note that if they have missed some relevant publications in their search, it is unlikely that the few items they might have missed would overturn any of the main conclusions derived from the publications that were identified and included. Then, beyond the impressive list of references cited, the authors have taken this to the next level of usefulness by summarizing details of most of these citations in the supplementary tables described below.
Extensive set of supplementary tables
Finally, many readers will find it to be an extremely useful and important resource that the statement includes a set of 14 supplementary tables that provide succinct summaries of the extensive list of studies, interventions, and surveys that were reviewed. These tables are related, but not directly parallel, to the six domains addressed in the main body of the statement. They are referenced in order throughout the main body of the text. Six of the supplementary tables specifically address diet-related issues (e.g., nutrient and front of package labels, school vending machines). Four of the tables specifically address tobacco-related issues (e.g., media and education campaigns, labeling, and consumer information). Supplementary table #10 specifically addresses physical activity in terms of local environmental changes in community settings, for which there are 6 subcategories (e.g., land use design, street and sidewalk design).Two of the tables address interventions targeting combinations of diet and physical activity factors – one in schools and another in worksites. All of these tables provide summary details under column headings that include population, study type/study design, duration, intervention/evaluation/exposure, and findings/evidence/results/outcomes.
The 14th supplementary table is somewhat different in that it provides a list of examples of major surveillance surveys for diet, physical activity, and tobacco use in the United States. The column headings under which summary data for the surveys are presented include a general description, methodologies used, frequency of survey or surveillance instrument administration, and the measures assessed.
Usefulness: This is a reference treasure trove for those readers who are interested in obtaining specific details about the studies and surveys cited in the statement. A summary table of the names of each supplementary table allows the reader to quickly identify and prioritize what is available. The succinct summaries of the critical design elements and major findings may be sufficient in and of themselves to satisfy the purposes of the reader. If even further details are needed from the full publications, the information provided in the tables will at least help the interested scholar or health advocate to triage the publications into those that are and are not most likely to be worth the investment of time and energy to be obtained in full. The organization of the tables into the categories described above will also help the interested reader to efficiently hone in on the subtopics with sets of studies likely to most closely match their needs and interests.
Relevant and complementary resources to this Statement: Several already existing resources may serve as complements to this Statement in helping readers choose, implement, and measure evidence-based and promising programs and strategies. These include but are not limited to the following:
- Guide to Community Preventive Services: A government resource that uses systematic reviews to help readers choose programs and policies to prevent health, based on answering the following questions: Which program and policy interventions have been proven effective? Are there effective interventions that are right for my community? What might effective interventions cost; what is the likely return on investment? Find it at http://www.thecommunityguide.org/uses/general.html.
- CDC Recommended Community Strategies and Measurements to Prevent Obesity in the United States: Implementation and Measurement Guide: This guide gives 24 recommended strategies to communities to implement to improve eating and physical activity behaviors, plus shows communities how to implement and track their impacts. Find it at http://www.cdc.gov/obesity/downloads/community_strategies_guide.pdf
- The CDC Guide to Fruit and Vegetable Strategies to Increase Access, Availability and Consumption: A guide that summarizes current research support for strategies to increase fruit and vegetable consumption. Find it at http://www.cdph.ca.gov/SiteCollectionDocuments/StratstoIncreaseFruitVegConsumption.pdf
- Institute of Medicine reports such as Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation (http://www.iom.edu/Reports/2012/Accelerating-Progress-in-Obesity-Prevention.aspx); Local Government Actions to Prevent Childhood Obesity (http://www.iom.edu/Reports/2009/Local-Government-Actions-to-Prevent-Childhood-Obesity.aspx); Bridging the Evidence Gap in Obesity Prevention: A Framework to Inform Decision Making (examines case studies and existing reviews; http://www.iom.edu/Reports/2010/Bridging-the-Evidence-Gap-in-Obesity-Prevention-A-Framework-to-Inform-Decision-Making.aspx); Early Childhood Obesity Prevention Policies (http://www.iom.edu/Reports/2011/Early-Childhood-Obesity-Prevention-Policies.aspx); Front-of-Package Nutrition Rating Systems and Symbols: Promoting Healthier Choices (http://www.iom.edu/Reports/2011/Front-of-Package-Nutrition-Rating-Systems-and-Symbols-Promoting-Healthier-Choices.aspx); Ending the Tobacco Problem: A Blueprint for the Nation (http://www.iom.edu/Reports/2007/Ending-the-Tobacco-Problem-A-Blueprint-for-the-Nation.aspx); and State Programs Can Reduce Tobacco Use (http://www.iom.edu/Reports/2000/State-Programs-Can-Reduce-Tobacco-Use.aspx).
-- The opinions expressed in this commentary are not necessarily those of the editors or of the American Heart Association --