The Diabetes Prevention Program

Abstract

The Diabetes Prevention Program (DPP) is a multicenter randomized controlled trial designed to test whether diet and exercise or medication can prevent or delay the onset of type 2 diabetes in persons with impaired glucose tolerance, who are at increased risk of the disease. This paper describes DPP recruitment methods, strategies, performance, and costs. The DPP developed an organizational structure for comprehensive management and continuous monitoring of recruitment efforts. The DPP utilized a variety of recruitment strategies, alone or in combination, and a stepped informed consent procedure leading to randomization. Studywide and clinic-specific recruitment data were monitored, analyzed, and used to modify recruitment approaches. DPP recruitment was completed slightly ahead of schedule, meeting goals for the proportion of women enrolled and nearly meeting goals for the proportion of racial/ethnic minorities. Clinics varied widely in the recruitment strategies they used, and these strategies also varied by participant age, gender, and race/ethnicity. Staff time devoted to recruitment averaged 86.8 hours per week per clinic, with the majority of effort by staff specifically assigned to recruitment. The number of staff hours required to recruit a participant varied by recruitment strategy. Recruitment cost (excluding staff cost) was about 1075 US dollars per randomized participant. The DPP experience offers lessons for those planning similar efforts: (1) a method for ongoing assessment and revision of recruitment strategies is valuable; (2) a range of recruitment strategies may be useful; (3) the most effective methods for recruiting potential subjects may vary according to the gender, age, and race/ethnicity of those individuals; (4) recruitment strategies vary in the amount of staff time required to randomize a participant; and (5) a stepped screening may make it easier to identify and recruit volunteers who understand the requirements of the study.

Exceeding the recruitment target in a primary care paediatric trial: an evaluation of the Choice of Moisturiser for Eczema Treatment (COMET) feasibility randomised controlled trial

“…Therefore, we advise using a number of recruitment strategies to spread the risk, should one strategy prove more challenging or less fruitful than another. This is in agreement with other trial researchers who recommend using a number of strategies [36, 37]. We also emphasise the importance of careful recruitment monitoring because the additional measures we implemented during the trial (such as increasing the upper age limit and recruiting more practices) had an important and positive impact on recruitment and may not necessarily have been identified without monitoring.…”

Impact of Lifestyle and Metformin Interventions on the Risk of Progression to Diabetes and Regression to Normal Glucose Regulation in Overweight or Obese People With Impaired Glucose Regulation

“…For completeness, we also present the multivariable models and predicted probabilities of progression to DM and regression to NGR for the entire DPP population regardless of their adherence (Supplementary Tables 1–3). Because only 2.5% of persons initially screened for the DPP, and approximately one-fourth of those who met 2-h PG eligibility criteria were randomized (7), it is difficult to generalize the results of the DPP to the U.S. population with impaired glucose regulation.…”

Common variation at PPARGC1A/B and change in body composition and metabolic traits following preventive interventions: the Diabetes Prevention Program

“…The DPP study [21, 22] was a multicentre randomised controlled trial in which the effects of metformin and lifestyle modification on the incidence of diabetes were assessed. Non-diabetic persons ( n =3,234) with elevated fasting glucose and impaired glucose tolerance were randomised to placebo, metformin (850 mg twice daily) or lifestyle modification (~7% weight loss and ~150 min physical activity/week).…”