Intended for healthcare professionals


Overcoming barriers to recruitment in health research: Concerns of potential participants need to be dealt with

BMJ 2006; 333 doi: (Published 17 August 2006) Cite this as: BMJ 2006;333:398
  1. Iain K Crombie, professor of public health (i.k.crombie{at},
  2. Marion E T McMurdo, head, section of ageing and health,
  3. Linda Irvine, research fellow,
  4. Brian Williams, senior lecturer in behavioural sciences
  1. Ninewells Hospital and Medical School, Dundee DD1 9SY
  2. Ninewells Hospital and Medical School, Dundee DD1 9SY
  3. Section of Public Health, Division of Community Health Sciences, University of Dundee, Dundee DD2 4BF

    EDITOR—Hewison and Haines discuss recruitment procedures as barriers to participation in research on health.1 We explored this as part of a survey of the attitudes of older people to physical activity.2

    Altogether 887 people aged 65-84 were invited by a letter from their general practitioner to participate in a home interview study. They also received an information leaflet and a postcard to return to decline participation. Overall 54% refused, most (384) by returning the postcard; the remainder (91) refused when visited or telephoned. Ethics permission was obtained to investigate the reasons for refusal to participate.

    After general practitioners excluded patients deemed ineligible, 417 people were sent an eight item questionnaire. Overall, 60% of those who initially refused to participate in the survey returned a questionnaire giving reasons for not taking part. The commonest reason (given by 56%) was that participants thought that they did not do enough activities to be of interest to the study. The other main concern was being visited at home by a research nurse (45%). Only 28% said they were not interested in research.

    This study confirms the importance of investigating attitudes to participation. The high response rate among people who initially refused indicates a willingness to participate in research. The finding that many of those who refused did so because they thought they were not sufficiently interesting, implies that it was misperception rather than antipathy to the study that prompted refusal.

    Tackling low response, and the bias it may create, requires understanding and addressing the concerns of potential participants. The requirement for opt-in systems, as Hewison and Haines point out, exacerbates low response rates. Research should be undertaken only when there is a high likelihood of producing valid findings. Ethics requirements which result in invalid research may themselves be unethical.


    • Competing interests None declared.


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