December 6 — 7, 2007 Advisory Committee Meeting Minutes

Overview and Update of CDC Literature Review

Dr. Haskell asked Bill Kohl, Ph.D., from CDC to provide an overview of the CDC literature review database. Dr. Kohl indicated his presentation was centered around two broad goals, one, to give a brief background of the work CDC did leading up to the first Committee Meeting, and two, highlight subsequent steps that have been taken following the first Committee Meeting.

The basic goals that guided CDC staff were to develop and implement a feasible approach for systematic review of physical activity and health literature and provide an initial literature database in preparation for the initial Committee Meeting and finally supporting the Committee as they developed recommendations. We developed a conceptual framework around which to work, focusing on six basic physical activities, types of physical activity exposures, intensity, frequency, duration, pattern and type and eight major health outcomes: cardiovascular health, cardiovascular-respiratory health, metabolic health, musculoskeletal health, cancers, functional health, mental health, all-cause mortality and adverse events. It is important to note this frame-work drove the development of the database which focused on health outcomes and not all existing studies for risk factors and other predictors of health outcomes. As a result of the discussion at the June meeting two additional subcommittees were formed in addition to the existing eight health outcomes, Youth and Energy Balance.

Following the June meeting, in anticipation of receiving additional research requests from the Committee, CDC focused on four broad questions:

1. What is the evidence that physical activities associated with a particular outcome?

2. What is the evidence that the dose of physical activity is associated with this outcome or its precursors?

3. What is the evidence that physical activity might increase the risk of a certain outcome?

4. What is the evidence that an exposure of physical activity other than 30 minutes a day is associated with the outcome?

Since the parameters of the initial literature search was 1996, the date of the Surgeon General's report, through January 2007, the Committee Chair requested additional searches through June 2007. Through this process an additional 740 abstracts were reviewed and triaged, netting 100 additional papers that were deemed relevant.

Additionally, CDC liaisons were identified to work with each subcommittee on additional research needs. Six of the ten subcommittees requested additional searches based on questions in the areas of cardiovascular disease, metabolic health, musculoskeletal health, cancer adverse events and youth, that were not asked during the initial search. This process added 1,444 abstracts, netting 266 papers deemed relevant. Twelve additional papers were also added as they were missed in the initial review for miscellaneous reasons.

Finally, through the assistance of a librarian scientist 352 additional publications, research reports, meta-analysis, and review papers were provided at the request of the Committee. The publications were not necessarily abstracted as some were utilized as background information.

At the conclusion of Dr. Kohl's report, Dr. Haskell inquired into the plans for the database after the Guideline process has been concluded. Dr. Kohl responded that the database is a product of the federal government and as such is available to the public. The database is currently a working database; however, after the Committee's work has been completed further quality control checks would be performed and more definite plans would be formulated for making the database available to the public.