Related Experiment Videos
Recruitment of participants for the multiple risk factor intervention trial (MRFIT)
Insights
The Multiple Risk Factor Intervention Trial (MRFIT) successfully recruited over 12,000 men for heart disease prevention research. Key strategies included experienced staff and dedicated recruitment personnel, ensuring trial success.
Area of Science:
- Cardiovascular disease prevention
- Clinical trial methodology
- Public health research
Background:
- The Multiple Risk Factor Intervention Trial (MRFIT) aimed to reduce coronary heart disease mortality.
- Primary prevention trials require robust participant recruitment and retention strategies.
Purpose of the Study:
- To detail the recruitment process and challenges of the MRFIT trial.
- To identify factors contributing to the successful recruitment of a large cohort for cardiovascular risk intervention.
Main Methods:
- Screening 361,662 men across 20 clinics to randomize 12,866 participants.
- Monitoring eligibility and dropout rates, analyzing variations among clinics.
- Implementing strategies to overcome recruitment barriers.
Main Results:
- Exceeded recruitment goal by 866 men, completing recruitment in 44 months.
- Observed significant variability in eligibility and dropout rates across clinics.
- Identified subjective eligibility interpretation and participant characteristics (smokers, Black men) as factors influencing retention.
Conclusions:
- MRFIT's recruitment success stemmed from experienced investigators and dedicated recruitment staff.
- Phased clinic entry, central monitoring, and regular problem-solving meetings were crucial.
- Lessons learned inform future large-scale primary prevention trial recruitment strategies.
Abstract:
The Multiple Risk Factor Intervention Trial (MRFIT) was a randomized primary prevention trial designed to test the effect of multifactor intervention on mortality from coronary heart disease. Before randomization, men were seen at three screening visits to establish eligibility. A total of 361,662 men were screened, and 12,866 men were randomized, 866 more than the goal of 12,000. The total time required for planning and recruitment was 44 months. Eligibility rates and dropout or refusal rates between screening visits varied considerably among the 20 clinics that took part in MRFIT. The variation in eligibility rates resulted largely from subjective interpretation by the staff of the willingness of the men to participate in the study and to make risk factor changes. Cigarette smokers and blacks were more likely to discontinue their participation between screening exams. The ultimate success of the MRFIT recruitment is attributed to (1) the previous experience of investigators in screening large numbers of participants for clinical trials and similar epidemiologic investigations, (2) the identification at each clinic of one or more persons whose specific responsibility was recruitment, (3) the phased entry of clinics into the study, (4) routine monitoring and reporting of recruitment rates by the coordinating center, (5) regular discussion of recruitment successes and problems at the Steering Committee meetings, and (6) site visits to examine in detail recruitment problems.