Telephone reminders are effective in recruiting nonresponding patients to randomized controlled trials.
OBJECTIVE
Studies investigating means of recruiting participants to randomized controlled trials (RCTs) are sparse. We investigated the effects of telephone reminders as a recruitment strategy.


METHODS
Sick-listed employees received a written invitation to participate in a study comparing standard treatments with a solution-focused follow-up and were randomly allocated to an intervention or control group (n=703). Those who did not respond within 2 weeks received either 'no reminder' (n=242) or 'attempted telephone reminder' (n=256). Outcome was enrollment to the RCT.


RESULTS
An intention to recruit analysis revealed no significant differences between the groups (P=.229). An intention to phone analysis among nonresponders revealed significant differences between 'no reminder' (recruited 4.5%) and 'attempted telephone reminder' (recruited 12.1%) (P=.003, odds ratio 2.89, 95% confidence interval [CI] 1.42-5.90). An analysis of numbers needed to phone showed that to recruit one more person in this group of nonresponders, we needed to phone 13 persons (95% CI=8-33).


CONCLUSIONS
Systematic use of telephone calls can increase the recruitment rate among nonresponders in RCTs.
Norwegian Directorate for Health and Social Welfare, Department of Social Services Research, PO Box 8054 dep., Oslo N-0031, Norway. pny@shdir.no
Pål
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Nystuen
Kåre B
KB
Hagen
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016272:Occupational Health; D010349:Patient Compliance; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D017010:Reminder Systems; D012107:Research Design; D018582:Sick Leave; D013689:Telephone