Table 3

Rationale and types of recruitment interventions reported in Category A or B studies (ie, prospectively nested within RCTs)

Author and yearRationale(s)Descriptive summary of recruitment intervention(s)Classification of recruitment interventionTiming of information provision regarding host RCTTiming of informed consent for host RCTTiming of randomisation for host RCT
Prospectively designed RCTs of interventions to optimise recruitment nested within one or more host RCTs (Category A studies)
Leira et al 21
2009*
Limited time for IC in host RCT due to the clinical condition requiring urgent treatmentIntervention group:
‘advance notification’ about host RCT using phone and fax prior to meeting prehospital team
Control group:
no information prior to meeting prehospital team
Advance notification using phone and faxIntervention group:
‘advance notification’ prior to face-to-face meeting with prehospital team
Control group:
during face-to-face meeting with prehospital team
Intervention group: during face-to-face meeting with prehospital team
Control group:
during face-to-face meeting with prehospital team
Intervention group: while patient in prehospital setting
Control group:
while patient in prehospital setting
Prospectively designed, non-randomised studies of interventions to optimise recruitment to one or more host RCTs (Category B studies)
Chow et al 23
2011
Recruitment team would be overwhelmed by covering multiple sites over a wide geographical areaAn automated service notified recruitment team in real time when a potentially eligible participant was identified across multiple centresAutomated service to facilitate real-time notifications to recruitment team covering multiple sitesDuring face-to-face meeting with recruitment staff
(once eligibility confirmed)
During face-to-face meeting with recruitment teamWhile patient in hospital
Shaw et al 24
2014
Limited time for IC in host RCT due to the clinical condition requiring urgent treatment
Prehospital staff have limited experience of RCTs
Standardised verbal information was provided by prehospital staff before a simple capacity assessment, verbal consent and delivery of emergency treatment
Host RCT procedures were tailored towards prehospital staff, who also attended a 1-day training event
Optimising information provision in prehospital setting
Allowing verbal consent from patient or SDM
Training of prehospital staff
Simple verbal information provided in prehospital setting
Further full information provided in hospital
Initial verbal consent given in prehospital setting
Written informed consent gained in hospital
While patient in prehospital setting
Beshansky et al 22
2014
Limited time for IC in host RCT due to the clinical condition requiring urgent treatmentStandardised verbal information was provided by prehospital staff before a simple capacity assessment, verbal consent and delivery of emergency treatmentOptimising information provision in prehospital setting
Allowing verbal consent from patient
Simple verbal information provided in prehospital setting
Further full information provided in hospital
Initial verbal consent in prehospital setting
Written informed consent in hospital
While patient in prehospital setting
  • *Leira et al—patients were randomised to the recruitment intervention or control group prior to the recruitment team seeing the patient, and without consent from the participant.

  • IC, informed consent; RCT, randomised controlled trial; SDM, surrogate decision-maker.