Table 3

Summary of included qualitative studies

	Title	Study method and aims	Recruitment to RCT?
Hales et al (2001)31	The conflicting roles of clinicians versus investigators in HIV randomised clinical trials	Semistructured interviews One theme investigated was recruitment.	Yes Clinical drug trial Primary care and secondary care
Caldwell et al (2002)32	Paediatricians' attitudes towards RCTs involving children	Focus groups To examine doctors attitudes towards children's participation in RCTs and to identify barriers to participation.	Yes RCTs involving children Secondary care (Teaching hospital in Australia)
Jones et al (2003)33	Building research capacity: an exploratory model of GPs' training needs and barriers to research involvement	Semistructured interviews Investigation of GPs research training needs, and barriers to involvement in research.	Not specified
McIntosh et al (2005)34	Recruitment of physician offices for an office-based adolescent smoking cessation study.	Focus groups To elicit perceptions of facilitators and barriers to initial engagement of physician practices.	Yes Adolescent smoking cessation study
Mason et al (2007)35	GPs' experiences of primary care mental health research: a qualitative study of the barriers to recruitment	Semistructured interviews To investigate the perceived barriers among GPs to introducing participation in RCTs to patients with depression.	Yes Primary care mental health research
Ziebland et al (2007)36	Does it matter if clinicians recruiting for a trial do not understand what the trial is really about? Qualitative study of surgeons' experiences of participation in a pragmatic multicentre RCT	In-depth interviews To explore physicians understanding of the trial purpose and how this understanding had influenced their recruitment.	Yes Multicentre pragmatic RCT Spinal surgery
Bill-Axelson et al (2008)37	Experiences of randomisation interviews with patients and clinicians in the SPG-IV trial	Semistructured interviews Investigation of patients' and clinicians' experiences of randomisation with the aim of facilitating future trial participation.	Yes Prostate cancer RCT
Potter et al (2009)38	A qualitative study exploring practice nurses' experience of participating in a primary care-based RCT	Semistructured interviews To explore the views of practice nurses' recruiting into a primary care-based RCT and to investigate factors that influence the success of trial recruitment.	Yes. Primary care-based RCT to promote adherence to treatment of people with type 2 diabetes.
Howard et al (2009)39	Why is recruitment to trials difficult? An investigation into recruitment difficulties in an RCT of supported employment in patients with severe mental illness	Interviews To evaluate reasons for under-recruitment in an RCT. Trial staff and recruiting physicians were interviewed.	Yes. RCT of supported employment in patients with severe mental illness.
Patterson et al (2010)40	The great divide: a qualitative investigation of factors influencing researcher access to potential RCT participants in mental health settings	Interviews Using Grounded Theory process evaluation of a multicentre trial to investigate factors influencing referral to potential RCTs in mental health settings.	Yes Potential RCTs in mental health setting
Paramasivan et al (2011)41	Key issues in recruitment to RCTs with very different interventions: a qualitative investigation of recruitment to the SPARE trial	Interviews; content analysis of RCT documents; conversation analysis of recruitment appointments To explore reasons for low recruitment and attempt to improve recruitment rate by implementing changes suggested by qualitative findings.	Yes Bladder cancer treatment trial—feasibility study

RCT, randomised controlled trials.