This study found that YMCA wellness instructors can be trained to deliver a group-based DPP lifestyle intervention and achieve changes in body mass after 6 and 12 months that are comparable to the DPP study. This level of effectiveness was observed even in the context of a modest (57%) overall attendance level. This is the first study to demonstrate that the YMCA is a promising vehicle for the dissemination of the DPP lifestyle intervention into the community. In the DPP, 5 kg (about 5%) of weight loss was associated with a 58% reduction in incident diabetes.31
In this pilot study, people at high risk for developing diabetes achieved and maintained a mean 6% reduction in baseline body weight and significant reductions in total cholesterol. Given these results, delivery of the DPP via the YMCA warrants further study as a model for the wide-scale dissemination of an evidence-based strategy to lower diabetes and cardiometabolic risk for millions of Americans with prediabetes.
This was a small pilot feasibility study, and it has some notable limitations. First, the study involved only two matched YMCA facilities and allocated participants by randomizing these sites to deliver a group-based DPP intervention or to offer only brief counseling and information about existing YMCA programs. This study design was chosen for two reasons: (1) the YMCA did not feel comfortable declining program access to some participants at a single site when others (possibly a neighbor or close friend) would receive the program free of charge, and (2) it was desirable not to inform control participants that other individuals might receive a more-intensive lifestyle intervention. This minimized treatment contamination and some potential bias attributable to treatment awareness. However, group allocation may have increased the possibility of unmeasured confounding because it increased the probability of baseline differences between individual participants in the two treatment groups. In addition, it is possible that weight loss and other outcomes are correlated within neighborhoods (or YMCAs), and this could increase the probability that treatment differences were significant. Sensitivity analyses found that outcomes did not differ significantly with statistical adjustment for baseline differences in potential confounders such as gender and race. However, it was not possible to adjust for all potential confounders in this study or to control for the correlation of weight-loss outcomes within YMCA sites because this small pilot study involved only one site in each treatment group. Because the differences in weight outcomes were strongly significant (p<0.001 at 6 months), these findings clearly warrant further study of the group-based delivery of the DPP lifestyle intervention by trained YMCA wellness instructors.
Another interesting finding was the modest but significant weight loss observed by control participants. One explanation for this finding is that the study recruited and retained motivated people with an increased likelihood of achieving short-term weight loss with brief advice alone. Because 16% of the participants did not complete data collection at 6 months for the primary weight-loss outcome, the effectiveness of the intervention may have been over-estimated if weight loss was lower in nonrespondents. It is also possible that a community-marketing approach, followed by the formal testing of diabetes risk, brief activation by trained professionals, and follow-up for retesting after 6 and 12 months, may be sufficient to help some individuals with prediabetes to lose and maintain modest weight loss. Although brief counseling with limited follow-up alone is not typically sufficient as a strategy to maintain weight loss even in motivated volunteers,29
it is possible that the knowledge of prediabetes risk is particularly activating, and that formal advice supplemented by NDEP materials can support lifestyle change in select individuals. Because even modest weight reduction translates into meaningful reductions in diabetes risk,31
further research is needed to understand the impact of diabetes-risk perceptions on individuals’ receptivity to brief lifestyle counseling.
Despite the clear effectiveness of an intensive lifestyle intervention to prevent the development of diabetes, there are no existing models for delivering such an intervention to a large and growing population of American adults with prediabetes. This study provides evidence that the YMCA could offer one solution for how to deliver a DPP lifestyle intervention in community settings and to achieve weight-loss levels that translate into considerable reductions in diabetes risk. The YMCA may also offer additional benefits for successful DPP translation because it is accessible to broad segments of the population and it sets fees for program access that are based on cost-recovery alone. Much of the difficulty in disseminating the original DPP lifestyle intervention has been the relatively high cost of one-on-one delivery by behavioral experts.32
In this study, the hourly wage of YMCA group instructors was approximately one half that of behavioral experts in the DPP. Moreover, the group-delivery approach reduces overall personnel costs by an additional 50% by offering sessions to 8–12 participants simultaneously. Finally, the YMCA has a national policy to turn no person away due to inability to pay for membership or program access. Under this policy, the YMCA uses charitable donations to subsidize access to programs by people in underserved areas and low-income households.
This study was not designed to compare different approaches for optimizing enrollment in a YMCA-based diabetes prevention intervention. However, the relatively low level of participation with community-based diabetes risk screening events verifies the findings from the DPP and other studies33
that a household mailing approach alone may engage only a limited subset of people who are at risk for diabetes. Future research should assess and compare the use of multiple recruitment channels, in both healthcare and nonhealthcare sectors, to optimize the reach of DPP translation activities in conjunction with low-cost intervention delivery by a community partner such as the YMCA.
By lowering the cost of and expanding the accessibility to diabetes-prevention services, the YMCA may serve not only to increase the number of individuals with prediabetes who have access to and can pay for evidence-based diabetes prevention; it may also provide a compelling model for health-plan reimbursement. This provides yet another compelling reason to develop and test novel strategies that link community-based program delivery with existing clinical services that could help to identify and activate more adults with prediabetes. Some health plans already pay for fitness facility access and other community wellness benefits, but short-term cost recovery and uncertainty about health benefits from these policies limits their sustainability.34–36
If the YMCA can continue to develop and support a model for the formal training of program group instructors and can ensure the quality and consistency of the program as it has with other national lifestyle programs,37
health plans may be more willing to pay the fees associated with a DPP intervention delivered at the YMCA for enrollees with prediabetes. In one prior prediction model, a health plan could pay 100% of the costs of the group lifestyle intervention as delivered in this study and recover all costs within 3 years (after which the plan would save costs each year from avoided health outcomes).15
In this context, the costs and cost effectiveness of community-based models for DPP translation should be a primary focus of future studies.
There are currently more than 2500 YMCA facilities serving more than 10,000 rural, suburban, and inner-city communities in the U.S. alone. Given the encouraging benefits of group-based diabetes prevention in the YMCA on body weight and total cholesterol, combined with a potential for broad reach and cost effectiveness, the national dissemination of the DPP intervention in partnership with the YMCA provides hope in the battle against a growing national diabetes epidemic.