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Obstacles to recruitment in paediatric studies focusing on mental health in a physical health context: the experiences of clinical gatekeepers in an observational cohort study



Studies in both paediatric and psychiatric settings often experience problems in recruitment. This can compromise the ability of the study to recruit to target, meaning studies are potentially underpowered. It can also result in a biased sample if a non-representative group are selectively recruited. Recruitment to studies in health contexts often depends on healthcare professionals, who act as gatekeepers by screening patients for eligibility and obtaining consent for the research team to contact them. The experience of health professionals as gatekeepers in paediatric studies is poorly understood and may affect whether recruitment is successful or not.


Six out of seven eligible healthcare professionals from a specialist paediatric chronic fatigue syndrome (CFS) team were interviewed. All participants were undertaking initial clinical assessments within which they were asked to identify eligible patients for an observational study of co-morbid mental health problems in adolescents with confirmed CFS/ME. This study had experienced particular recruitment problems, more so than other studies in the same service. Interview questions were designed to explore perceptions of research, and barriers and facilitators of recruitment. Interviews were audio recorded and transcribed verbatim. Thematic analysis was used.


Participants espoused their commitment to the value of research. However, they perceived there to be a number of barriers to recruitment. Barriers within the clinical context included time pressures and the emotional nature of initial clinical assessments. Barriers posed by the wider research context included recruiting to multiple studies at the same time. Factors specific to the observational study of mental health in CFS/ME included aspects of the study design, such as the name and nature of the study, as well as the focus of the study itself. Participants made a number of recommendations about how recruitment barriers could be overcome.


The current study highlights the need to carefully consider, at design stage, how to overcome potential barriers to recruitment. Gatekeepers should be actively involved at this stage to ensure that the study is set up in such a way to best enable recruitment activities within the clinical setting.

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In clinical studies, healthcare professionals often act as gatekeepers who facilitate access to potential participants by introducing the study to them and gaining their consent to share their contact details with researchers [1]. Gatekeepers also appear to influence willingness to participate; patients approached about research by their usual doctor are more likely to participate than those who were approached by someone unfamiliar to them or who saw advertisements about the research [2]. Universally, recruitment problems in the context of clinical studies are commonly experienced across settings and patient groups [3,4,5], including in paediatric settings [4, 6] and in psychiatric research [7,8,9]. Recruitment issues pose 2 problems for researchers, firstly that a study may fail to recruit sufficient participants to have the power required to detect an effect, and secondly, that the sample recruited may not be representative of the wider population to which inferences are made, affecting the validity of the conclusions drawn due to selection bias [7, 10].

A number of factors are known to influence a gatekeeper’s decision to inform a potential participant about a study. The gatekeeper needs to assess the potential participant as being eligible for the study, and then to decide to inform them about it. The health status of the patient, the gatekeeper’s engagement with the patient, and their own attitude towards research are likely to affect this decision [8]. The gatekeeper is likely to inform the patient of the study only if they perceive the potential benefits of doing so to outweigh the potential risks.

Although recruitment to studies often depends on healthcare professionals acting as gatekeepers, the views of these professionals, including barriers to recruitment and potential solutions, are poorly understood. Therefore, in the context of an observational study of mental health problems in adolescents with paediatric Chronic Fatigue Syndrome (CFS/ME) presenting to a specialist paediatric CFS team, we undertook a qualitative study to explore healthcare professionals’ views. We did this because we noticed that rates of healthcare professionals failing to undertake eligibility assessments to this study were considerably higher than for other studies in the clinic; approximately 15% of patients were not assessed for eligibility for this study as compared to < 4% in the SMILE trial [11], conducted in the same service. The aim of the current study was to further understand the barriers to recruitment to mental health studies in paediatric health populations, and to generate recommendations for how these can be addressed.



The context was a multidisciplinary team providing specialist assessment and intervention for paediatric CFS/ME within the National Health Service (NHS) in the South West of England. This team had been recruiting for the past 20 months to an observational study screening a clinical cohort of adolescents (age 12–18 with a confirmed diagnosis of CFS/ME at initial assessment) to determine the prevalence of mental health problems. Healthcare professionals who had conducted initial assessments within the team within the prior year were eligible to participate (N = 7). Of these, 1 healthcare professional opted not to participate as they are also a member of the research team. Thus, 6 participants (3 medical doctors and 3 allied healthcare professionals) were interviewed. The participants were a diverse sample in terms of age, gender and years of post-qualification experience.

Procedure and materials

Potentially eligible participants were invited to take part in an interview by email, and a participant information sheet was attached to this invitation. The study was also briefly introduced at a clinical team meeting. Interested parties were asked to contact the research team directly. Participants were asked to complete a consent form, and were subsequently interviewed via Skype (N = 1), over the phone (N = 4), or face-to-face (N = 1). A semi-structured topic guide exploring healthcare professionals’ views of recruiting to studies, including the facilitators and barriers to recruitment to this study specifically, was used to structure the interviews. Interviews were conducted by the principal investigator (ML), and were audio-recorded. Interviews were transcribed into Microsoft Word and anonymised at the point of transcription.

Data analysis

Thematic analysis is a method by which patterns within a set of data can be identified and analysed [12]. We used a combination of a deductive (based on existing literature) and inductive (based on emergent data) approach. We adopted a realist perspective (i.e. that a truth exists independent of our conceptualisation of it), and identified themes at a semantic level (i.e. at the level of words and phrases). Data collection and analysis were conducted concurrently. ML conducted the interviews and subsequently read the transcripts several times as data familiarisation. ML generated initial codes and themes from the first 4 transcripts. These were reviewed and discussed with EC, DK and PS. Subsequently, this was repeated for the remaining 2 transcripts, with revisions and additions made to the initial codes by ML, which were reviewed and discussed with EC.


Three specific themes were identified: the value of research, barriers to recruitment at gatekeeping stage, and what can be done to help to overcome these barriers. Each theme (and concomitant subthemes) is summarised below, with illustrative quotes in Table 1. Individual participants are referred to by number (e.g. P1, P2, etc.).

Table 1 Themes and subthemes with illustrative quotes

The value of research

Participants expressed their interest in and commitment to research (subtheme 1); “it’s very positive because we’re making change to help the whole population” (P4). Working in a research active team was viewed as part of the role; “my job is to make sure that if there is anybody eligible that I recognise that and I offer them the opportunity to take part” (P6). Research activity was even a reason why participants had chosen to work in this particular team, who found it “really exciting…to be involved-to have that link” (P1). Participants highlighted the importance of developing the evidence base through research (subtheme 2) as a way to “answer unanswered questions” (P5), which gives them “added confidence” (P1) when conveying information to patients seen in the service. However, although participants valued research, they did not see it as their primary focus or role (subtheme 4), with their priority being clinical care; “[research] is not the emphasis of my assessment…because I’m here for clinical end of things” (P2).

Barriers to recruitment

A number of barriers to recruitment were highlighted by participants, which clustered into 3 subthemes.

The clinical context of the recruitment activity (subtheme 1), which in this study was the initial clinical assessment, raised barriers. The first barrier (subtheme 1a) was “limited time to get all the information out” (P4), which meant that participants had to prioritise what to spend time on and research studies might not be prioritised. Another contextual barrier was more complex, demanding and emotional initial assessments (Subtheme 1b), where participants may not discuss research “if the patient is struggling to take on information about their diagnosis let alone an additional bit of work around research” (P4). Participants recognised that this meant that some patients were more likely to be recruited than others, which results in “bias” (P6), despite the participants recognising how important it is to offer all patients the option of participating in research studies.

The wider research context (subtheme 2) also presented barriers, including other studies being conducted concurrently in the same service which created research recruitment burden, “research overload” (P5). It also created confusion as “there were around four or five research projects, seem to be, seemingly on the go at any one time…and that is confusing” (P2).

Factors specific to the study including study design and focus were also highlighted as barriers (subtheme 3). This included the name of the study (subtheme 3a), which participants perceived as being off-putting to potential participants (the ‘Depression Diagnosis Study’, although as a prevalence study, the aim was to recruit a clinical cohort of patients with CFS/ME, not just those with co-morbid depression). This meant that more explanation was needed to clarify that “by inviting them to take part I’m not suggesting that they are depressed…” (P1). The name of the study also meant that it didn’t occur to participants to recruit participants for whom depression did not seem to be an issue, “…if you’ve got a patient who clearly isn’t depressed at all is coping extremely well it doesn’t even cross your mind to enter them into something called the depression study” (P5).

The focus of the study on mental health (subtheme 3b) raised further barriers, the first of which was patient and family’s perceptions of mental health in CFS/ME which “can meet some resistance” (P1) and the sensitivity of the topics discussed in the research interviews (e.g. sex, substance use) which is “too intrusive” (P5).The second barrier raised by the focus of the study was the participants’ own training, and their perceived lack of qualifications and/or resources to address mental health problems, in the context of a physical health setting where staff “don’t feel as though I am up-to-date [with] mental health” (P1). The nature of the study as an observational study rather than an intervention study (subtheme 3c) was also seen as a barrier, as participation was not necessarily viewed as generating a beneficial outcome for the specific patient making it a “harder sell” (P6), despite the recognition of the wider value of research.

Recommendations for promoting recruitment

Participants shared their ideas about how to support recruitment. These included ensuring that the gatekeepers understand that content of the study as part of study familiarisation (subtheme 1); “…understanding why the research is useful…I need to understand the content, otherwise I-I wouldn’t feel confident in consenting actually” (P2). Tools to support recruitment included making it as easy as possible for the gatekeeping healthcare professional to recruit including enclosing printed copies of the study materials in each set of patient notes (subtheme 2); “I really, really find it helpful that all the research packs are done so you know the information sheets are printed and ready for a clinician to give” (P3). Use of reminders which are both generic and linked to specific potentially eligible patients was suggested by some participants (subtheme 3); “reminders, keep this study on your radar, we’re still recruiting that’s been hugely helpful” (P3), although other participants found these less helpful as “I get the emails but I get such a load of emails” (P2) and the reminders may even be “irritating” (P6), especially when faced with multiple clinical pressures. More flexibility in the timing of the recruitment activity so that patients can be recruited at the first follow-up appointment if time pressures or the emotional context of the initial assessment precludes recruitment as “someone might in time want to enter the study but it’s not appropriate in the initial consultation” (P5) was suggested (subtheme 4). Highlighting the positive outcomes of the study and its value on a case-by-case basis (subtheme 5), with participants valuing the feedback from individual interviews and identifying “learning points” (P6).


Multidisciplinary healthcare professionals who were actively acting as gatekeepers for the initial stage of recruitment to an observational study of mental health in adolescents with CFS/ME all valued research, but perceived there to be a number of contextual and study specific factors which acted as barriers to recruitment. The clinical context of the recruitment activity, including a lack of time, and the emotionally demanding nature of the initial clinical assessment, as well as the wider research context of competing studies were apparent barriers. The name of the specific study, which was experienced as off-putting and misleading to patients, the sensitive nature of the questions asked in the study, participants’ own lack of training and resources to manage emergent mental health problems, and the lack of a direct beneficial outcome for the patients, were also cited as barriers. Recruitment activities could be supported by study familiarisation, regular reminders, greater flexibility about the point of recruitment, promoting the value of the case specific information gained from participating in the study and thinking carefully about the name of the study.

The clinical context, in this study, was perceived to be a barrier to recruitment; participants talked about the pressures of time within the initial clinical assessment as the recruitment point. Contextual barriers have been reported in previous studies [13] which have recommended making it as easy as possible for clinical gatekeepers to assess for eligibility and seek consent to contact from the research team [14, 15]. Providing easily accessible study information such as printed study recruitment packs is critically important. In interventional studies, recruiting and potentially randomising participants prior to their having received any interventions is an important part of study design; therefore, the initial clinical assessment is a key recruitment point. In an observational study, determining a consistent point of recruitment is important, but it may be worth having some flexibility (for example, to recruit at the first follow-up) or recruiting at a subsequent point in a patient’s journey through a specialist service where this is possible within the requirements of the study design. However, the gatekeeping activities within this study did not differ from that of previous studies within the same clinical context, although the rates of assessment for eligibility did. Therefore, it may be that factors specific to this study hampered gatekeeping activities beyond that which would be accounted for by the clinical context.

Recruitment problems in paediatric studies specifically are compounded by added complexity of requiring parental consent and requiring time out of school for children and potentially out of work for parents; across 181 Principal Investigators on paediatric trials at the Boston Children’s Hospital, 46% of studies were reported to have experienced delays in recruitment [6]. Our finding that gatekeepers may assume that patients and families may find it too overwhelming to be invited to participate in research at the end of an emotional session might be the result of paternalism, which has also been found in previous research [8, 13] and it may be that further education of healthcare professionals about the potential benefits to patients of participating in research is indicated. However, further work with patients and their families would be important to ensure that research is introduced in the most sensitive manner possible, and at the most appropriate time, and it is possible that there may be risks associated with participation in psychiatric studies, such as a potential worsening of mental state as a result of the research procedures which may potentially elicit distress or discomfort [9].

Furthermore, the wider research context can create barriers to recruitment. Previous studies also found that have numerous competing studies recruiting in parallel within one clinical location can serve as a barrier to recruitment. Fenlon et al. [1] found that clinical staff are reluctant to recruit to more than 1 study at a time; in the current study, the patient eligibility criteria for the studies open to recruitment meant that each patient could only be recruited to 1 study, although they were potentially eligible for more than 1 study. Studies have also found that clinicians feel bombarded with too much research [13]. Therefore, carefully considering the timeframes of recruitment for all the research activities within a clinical setting, and having a clinical team member who leads on overseeing research could enable better management of research demands arising from multiple studies recruiting in parallel. Having a clinical team member who champions research has also been recommended elsewhere [1, 14], with the added benefit that these individuals can be involved from design stage [13]. Prompts for the gatekeepers to remind them about the research, both generic and patient-specific, can be helpful.

Study design also seems to be very important as the nature of the research may also affect the views of gatekeepers. The current study was an observational study, and participants commented that they did not perceive there to be a direct benefit to patients of participating in the study, which discouraged them from undertaking study related gatekeeping activities. It may be that the research team could have further highlighted potential benefits of participating to the clinical gatekeepers, particularly at study initiation stage. Prior studies have found that drug studies are more likely to be given priority over epidemiological studies [1], although clinicians recruiting to research studies have also reported that clinical trials are harder to recruit to as they demand greater commitment from participants, both with regard to time and risk [2].

Another barrier in the current study was the gatekeepers’ perceptions of a lack of training and resources to deal with any mental health issues that emerged as an outcome from the research assessments. This may have led to selection bias, with gatekeepers being less likely to introduce the study to patients who were more distressed.

Importantly, the current study found that the name of the study is important to consider, particularly in the context of stigmatised conditions such as mental health, where patients may be reluctant to participate by association [8]. Whilst the study name needs to be appealing, it should not be misleading. Involving key stakeholders, including patients and clinical gatekeepers, at design stage to generate a meaningful and appropriate study name could prevent the name from subsequently posing a barrier to recruitment.

Arguably, due to these barriers, in this study, patients were denied access to taking part in research. All potential participants should be given the option of participating in studies. The NHS constitution commits to informing all patients of research studies that they are eligible to participate in [16], consistent with the ethos of ‘No decision about me without me’ [17]. Participating in research may be therapeutic and empowering, giving patients an additional opportunity to talk about their experiences [9, 18].

Strengths and limitations

We had good rates of study update, with 6 of 7 potentially eligible healthcare professionals participating in the interviews. However, this was a small sample in the context of one specialist paediatric service within the National Health Service, which limits the generalisability of these findings. Nevertheless, many of the themes are widely applicable and are consistent with those in other paediatric and mental health studies. Some interviews were conducted remotely and others in person, but we do not think that this unduly influenced the respondents’ narratives. The topic of recruitment to paediatric studies would benefit from further investigations in a variety of settings, and from different stakeholder perspectives.


Gatekeeping professionals generally valued research, but highlighted a number of barriers to recruiting, related to both the wider research and clinical contexts, and to the design of a study specifically. The current study highlights the need to carefully consider, at design stage, how to overcome potential barriers to recruitment where it is possible to do so (see Table 2). Gatekeepers should be actively involved at this stage to ensure that the study is set up in such a way to best enable recruitment activities within the clinical setting. It is also worth spending time educating busy clinical gatekeepers about the study to ensure that they understand its relevance and importance.

Table 2 Recommendations for how to support recruitment



Chronic Fatigue Syndrome/Myalgic Encephalomyelitis


National Health Service


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The authors would like to thank all those who took part in this study.


Prof Crawley is funded by the NIHR (Senior Research Fellowship, SRF-2013-06-013). Dr. Loades is funded by the NIHR (Doctoral Research Fellowship, DRF-2016-09-021). This report is independent research. The views expressed in this publication are those of the authors(s) and not necessarily those of the NHS, The National Institute for Health Research or the Department of Health. Miss Beasant is funded by the Medical Research Council (MRC) ConDuCT-II Hub (Collaboration and innovation for Difficult and Complex randomised controlled Trials In Invasive procedures - MR/K025643/1).

Availability of data and materials

The datasets generated and/or analysed during the current study are not publicly available due to the nature of the data (i.e. qualitative interview transcripts) which precludes sharing this publically in order to preserve participant confidentiality and anonymity but are available from the corresponding author on reasonable request.

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Authors and Affiliations



ML and EC conceived the study, with input from LB. ML conducted the interviews, and led on the analysis and interpretation of the data, with input from all the authors, including DK and PS. NH-S and LS transcribed the interviews. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Maria E. Loades.

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Ethics approval and consent to participate

Ethical approval was granted by the South West-Frenchay NHS Research Ethics Committee (16/SW/036) and by the University of Bath Department of Psychology Research Ethics Committee (16–203). Written consent was obtained from all participants.

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Not applicable.

Competing interests

EC acts as a medical advisor for the Sussex and Kent ME society. The other authors declare that there is no conflict of interest.

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Loades, M.E., Smith, L., Higson-Sweeney, N. et al. Obstacles to recruitment in paediatric studies focusing on mental health in a physical health context: the experiences of clinical gatekeepers in an observational cohort study. BMC Med Res Methodol 19, 89 (2019).

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  • Recruitment
  • Paediatric
  • CFS
  • Cohort study
  • Gatekeeping