Optimising recruitment into a study of physical activity in older people: a randomised controlled trial of different approaches.
BACKGROUND
physical activity studies in older people often have poor recruitment. Including a questionnaire with the invitation would provide information about non-participants and selection bias, but could reduce recruitment. Telephone contact might encourage participation.


OBJECTIVE
to test the effects of different strategies for recruitment into a study of physical activity in older people.


METHODS
factorial randomised controlled trial. Randomisation by household into four groups: telephone contact plus questionnaire, telephone contact only, questionnaire only, neither.


METHODS
primary care, Oxfordshire, United Kingdom.


METHODS
560 patients > or = 65 years randomly selected after exclusions.


METHODS
questionnaire to assess health, functional ability and physical activity. Telephone contact by the research nurse a week after sending study information.


METHODS
recruitment into physical activity study.


RESULTS
telephone contact increased recruitment: contact 47.9% (134/280), no contact 37.9% (106/280), difference (adjusted for the clustering effect of household) 10.0% (95% CI 0.2-19.8). Questionnaire inclusion did not significantly reduce recruitment: no questionnaire 44.3% (124/280) questionnaire 41.4% (116/280) difference -2.9% (95% CI -12.7-7.0).


CONCLUSIONS
telephone contact significantly increased recruitment and should be considered in studies where recruitment may be low. While inclusion of a questionnaire provided valuable information on non-participants and did not significantly reduce recruitment, an adverse recruitment effect could not be excluded.
Harris
Tess J
TJ
Division of Community Health Sciences, St George's, University of London, Cranmer Terrace, Tooting, London, SW17ORE, UK. tharris@sgul.ac.uk
Carey
Iain M
IM
Victor
Christina R
CR
Adams
Rika
R
Cook
Derek G
DG
D000368:Aged; D055812:Community-Based Participatory Research; D005260:Female; D006306:Health Surveys; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D009043:Motor Activity; D010358:Patient Participation; D018579:Patient Selection; D010865:Pilot Projects; D011320:Primary Health Care; D015983:Selection Bias; D006113:United Kingdom