Table 4

Frequency of rationales, study designs and recommendations from non-randomised studies describing recruitment experiences involving one or more host RCTs (ie, Category C studies)

Recruitment study characteristicDescriptionFrequency in Category C recruitment studies (n=24)*
RationalePatients too unwell to provide IC18
Limited time for IC in host RCT due to the clinical condition requiring urgent treatment13
Host RCT not meeting recruitment targets (at one or more sites) or terminated due to poor recruitment3
To better understand the impact of altering eligibility criteria on recruitment2
To better understand the impact of availability of SDMs on recruitment2
To better understand the recruitment process in a host RCT1
To better understand clinicians reasons for refusing patient participation in host RCT1
Recruitment study designObservational study of recruitment14
Qualitative studies of host participants/SDMs or PIS5
Survey of host RCT participants2
Survey of clinical staff involved in host RCT1
Simulation study evaluating the effect of altering eligibility criteria in multiple host RCTs1
Meta-analysis of recruitment data in host RCTs1
Recommendations for optimising recruitment in future RCTs or areas for further research into recruitment†To provide RCT information verbally and allow a verbal consent process10
To use a screening log can to provide insight into recruitment difficulties8
Patients or SDM were unable to recall key RCT information after providing IC†5
To use a ‘waiver of consent’/‘deferred consent’/‘EFIC’4
To perform regular site visits3
To use a broad eligibility criteria/broad therapeutic window2
To use SDMs2
Novel methods for obtaining IC are required†2
To replace poorly recruiting centres1
To approach more eligible patients1
To survey staff involved with host RCT to provide insight into recruitment difficulties1
  • *Each study may appear more than once in the relevant characteristics section (eg, if it described >1 rationale or produced >1 finding/recommendation).

  • †Items for further research and not recommendations for optimising recruitment.

  • EFIC, exception from informed consent; IC, informed consent; PIS, patient information sheet; RCT, randomised controlled trial; SDM, surrogate decision-maker.