Recruiting older people to a randomised controlled dietary intervention trial - how hard can it be?

Sarah E Forster,Elizabeth A Williams,A Graham Pockley,Laura Jones,John M Saxton,Gemma Foulds,Daniel J Flower,Stuart G Parker,Hilary J Powers

doi:10.1186/1471-2288-10-17

Abstract

BackgroundThe success of a human intervention trial depends upon the ability to recruit eligible volunteers. Many trials fail because of unrealistic recruitment targets and flawed recruitment strategies. In order to predict recruitment rates accurately, researchers need information on the relative success of various recruitment strategies. Few published trials include such information and the number of participants screened or approached is not always cited.MethodsThis paper will describe in detail the recruitment strategies employed to identify older adults for recruitment to a 6-month randomised controlled dietary intervention trial which aimed to explore the relationship between diet and immune function (The FIT study). The number of people approached and recruited, and the reasons for exclusion, will be discussed.ResultsTwo hundred and seventeen participants were recruited to the trial. A total of 7,482 letters were sent to potential recruits using names and addresses that had been supplied by local Family (General) Practices. Eight hundred and forty three potential recruits replied to all methods of recruitment (528 from GP letters and 315 from other methods). The eligibility of those who replied was determined using a screening telephone interview, 217 of whom were found to be suitable and agreed to take part in the study.ConclusionThe study demonstrates the application of multiple recruitment methods to successfully recruit older people to a randomised controlled trial. The most successful recruitment method was by contacting potential recruits by letter on NHS headed note paper using contacts provided from General Practices. Ninety percent of recruitment was achieved using this method. Adequate recruitment is fundamental to the success of a research project, and appropriate strategies must therefore be adopted in order to identify eligible individuals and achieve recruitment targets.Trial registration numberISRCTN45031464.

Highlights

The success of a human intervention trial depends upon the ability to recruit eligible volunteers
Some of the difficulties associated with recruiting participants to research studies have been well documented [1,2]
Many reasons have been reported by potential participants for their unwillingness to participate in research, including the demands of the research, the time commitment, treatment preferences, not wanting to give a blood sample and distrust of the research process [3,4]

Summary

Introduction

The success of a human intervention trial depends upon the ability to recruit eligible volunteers. In order to predict recruitment rates accurately, researchers need information on the relative success of various recruitment strategies. Some of the difficulties associated with recruiting participants to research studies have been well documented [1,2]. Effective strategies to recruit participants should be sought, and the findings shared. A US study recently reported that positive media coverage increases ‘volunteerism’, whereas negative coverage does not appear to adversely affect recruitment [6]. This finding may not be readily extrapolated to other societies. Older people provide additional research challenges, and poor recruitment and retention rates are often reported as a consequence [7]. Recruiting elderly people from the community can be timeconsuming, often involving large screening samples

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Results

Discussion

Conclusion