Comparative Effectiveness of 2 Diabetes Prevention Lifestyle Programs in the Workplace

The City and County of San Francisco Diabetes Prevention Trial

Assiamira Ferrara, MD, PhD; Julia C. McDonald, MS; Susan D. Brown, PhD; Janet G. Alexander, MS; Jennifer L. Christian-Herman, PhD; Stephanie Fisher, MPH; Charles P. Quesenberry, PhD


Prev Chronic Dis. 2020;17(5):E38 

In This Article

Abstract and Introduction


Introduction: Data on the comparative effectiveness of Diabetes Prevention Programs (DPPs) in the workplace are limited.

Methods: Between September 2015 and July 2016, employees of the City and County of San Francisco who were at risk for type 2 diabetes (N = 158) were randomly assigned to one of 2 DPP-derived programs recognized by the Centers for Disease Control and Prevention: an in-person YMCA-DPP (n = 78) or an online virtual lifestyle management DPP (VLM-DPP) offered through Canary Health (n = 80). The primary outcome was change in body weight assessed at 6 and 12 months. Follow-up ended in August 2017.

Results: Both the YMCA-DPP and VLM-DPP yielded a significant reduction in percentage body weight at 6 months. For the YMCA-DPP, mean percentage change at 6 months was −2.70% (95% confidence interval [CI], −3.91% to −1.48%) and at 12 months was −2.46% (95% CI, −4.24% to −0.68%). For the VLM-DPP, mean percentage change at 6 months was −2.41% (95% CI, −4.07% to −0.77%) and at 12 months was −1.59% (95% CI, −3.51% to 0.33%). The mean between-condition difference at 6 months was −0.25% (95% CI, −2.04% to 1.55%) and at 12 months was −0.84% (95% CI, −3.03% to 1.34%). No significant differences were observed between conditions.

The YMCA-DPP had a slightly higher reduction in waist circumference than VLM-DDP at 6 months (mean between-condition difference −2.00 cm [95% CI, −4.24 to 0.25 cm]). Participant engagement, expressed as mean number of completed core program sessions, was significantly higher for the YMCA-DPP than the VLM-DPP. Participants of the YMCA-DPP completed an average of 10.2 sessions (95% CI, 9.0 to 11.4), and participants of the VLM-DPP completed an average of 5.9 sessions (95% CI, 4.7 to 7.1). The adjusted mean between-condition difference was 4.2 sessions (95% CI, 2.54 to 5.99).

Conclusion: Both the YMCA-DPP and VLM-DPP yielded weight loss at 6 months, which was maintained at 12 months in the YMCA-DPP. The workplace may be an effective setting to offer DPPs.


An estimated 84 million people in the United States have prediabetes.[1,2] The Diabetes Prevention Program (DPP) demonstrated that a lifestyle intervention can reduce the incidence of type 2 diabetes by 58% in high-risk adults.[3] DPP-derived lifestyle interventions thus present an opportunity to improve health and reduce the annual cost of type 2 diabetes, which is estimated at $176 billion in direct medical expenses and $69 billion in indirect costs related to absenteeism, lost productivity, and disability.[4]

The Centers for Diseases Control and Prevention (CDC) developed the National DPP[5] with the goal of implementing a standardized, evidence-based DPP lifestyle program. CDC established the Diabetes Prevention Recognition Program (DPRP)[6] to monitor and support the delivery of the National DPP. CDC offers recognition to organizations delivering a DPP-derived intervention if they use a CDC-approved curriculum and meet intensity and duration requirements.[7]

Given the availability of DPP-derived lifestyle interventions and the high costs of diabetes, employers are increasingly considering offering type 2 diabetes prevention programs to their at-risk employees. Because of its convenience, the workplace holds promise for reaching adults who have barriers (eg, time, transportation), including individuals with fewer socioeconomic resources, that may prevent them from engaging in DPPs.[8–10] However, data on the comparative effectiveness of DPRP-recognized lifestyle programs implemented in workplace settings are limited.[9,10]

Researchers at the Kaiser Permanente Northern California Division of Research collaborated with the City and County of San Francisco (CCSF) Health Service System to conduct a randomized controlled trial comparing the effectiveness on weight loss of 2 DPRP-recognized lifestyle programs implemented in the workplace setting: 1) YMCA-DPP,[11] an in-person program delivered by YMCA-trained staff; and 2) Virtual Lifestyle Management DPP (VLM-DPP),[12] offered through Canary Health, which uses an online platform with supplemental secure email messaging with VLM-trained staff.