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Usage and perceived effectiveness of recruitment techniques among clinical trials recruiters

Published online by Cambridge University Press:  13 August 2025

Jewels Watts
Affiliation:
Case Western Reserve University School of Medicine, Cleveland, USA
Lauren Kaiser-Jackson
Affiliation:
Huntsman Cancer Institute, University of Utah, Salt Lake City, USA
Bob Wong
Affiliation:
College of Nursing, University of Utah, Salt Lake City, USA
Azra Helac
Affiliation:
Huntsman Cancer Institute, University of Utah, Salt Lake City, USA
Molly Volkmar
Affiliation:
Huntsman Cancer Institute, University of Utah, Salt Lake City, USA
Jessica W. Berg
Affiliation:
School of Law, University of California Davis, Davis, USA
Aaron J. Goldenberg
Affiliation:
Case Western Reserve University School of Medicine, Cleveland, USA
Eric Kodish
Affiliation:
Case Western Reserve University School of Medicine, Cleveland, USA Department of Pediatrics, Cleveland Clinic Lerner College of Medicine, Cleveland, USA Cleveland Clinic Children’s, Cleveland, USA
Ben Schwan
Affiliation:
Case Western Reserve University School of Medicine, Cleveland, USA The Metro Health System, Cleveland, USA
Cathy Wolfsfeld
Affiliation:
Huntsman Cancer Institute, University of Utah, Salt Lake City, USA
Erin Rothwell
Affiliation:
Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, USA
Maxwell Mehlman
Affiliation:
School of Law, Case Western Reserve University, Cleveland, USA
Kimberly A. Kaphingst*
Affiliation:
Huntsman Cancer Institute, University of Utah, Salt Lake City, USA Department of Communication, University of Utah, Salt Lake City, USA
*
Corresponding author: K.A. Kaphingst; Email: kim.kaphingst@hci.utah.edu
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Abstract

Introduction:

Effective recruitment techniques are essential for researchers to recruit and retain potential participants in studies, particularly as recruitment numbers into clinical trials have decreased. While recruitment techniques have been investigated, there is a gap in understanding the perspectives of clinical trials recruiters. This paper examines recruiters’ usage and perceived effectiveness of various recruitment techniques, as well as their perspectives on related ethical issues.

Methods:

We conducted a cross-sectional survey of 381 clinical trials recruiters. Closed-ended items examined whether recruiters had used 31 pre-defined recruitment techniques and their perceptions of the effectiveness of each technique. For techniques perceived to be highly effective or ineffective, open-ended items examined recruiter reasoning. The multiple methods analysis integrated the closed-ended and open-ended data.

Results:

Recruitment techniques such as reassured potential participants about confidentiality (96.3%) and reassured about data sharing (95.8%) had high usage, while techniques like having the PI approach and enroll had a high average perceived effectiveness (M = 4.23, SD = 0.91). Recruiters often rated techniques as more highly effective when they had prior experience using them. They also identified concerns about professionalism, ethics, and transparency in standard practice recruitment techniques.

Conclusions:

Our findings indicate that there is significant variation in the usage of clinical trial recruitment techniques and how different recruiters view the effectiveness of each technique. The unique perspectives of those who recruit into clinical trials can help inform future decisions regarding which recruitment techniques to utilize, along with how and when to use particular recruitment techniques in an ethical manner.

Information

Type
Research Article
Creative Commons
Creative Common License - CCCreative Common License - BYCreative Common License - NC
This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial licence (https://creativecommons.org/licenses/by-nc/4.0), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original article is properly cited. The written permission of Cambridge University Press must be obtained prior to any commercial use.
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of Association for Clinical and Translational Science

Background

Recruitment techniques are essential tools used by research teams with the aim of enrolling participants in research studies. Identifying effective recruitment techniques is particularly important for clinical trials, which have been facing a trend of decreased recruitment and retention in recent years. Potential reasons for this trend include the COVID-19 pandemic, a general distrust of research and healthcare, lack of awareness of clinical trial research, competition for participants among research studies, and economic and/or communication barriers [Reference Brintnall-Karabelas, Sung, Cadman, Squires, Whorton and Pao1Reference Strujo, Sanders, Fiscella and Thomas4]. Recruitment challenges impact the results of studies as they may be seen as less reliable due to lower numbers of participants enrolled and/or retained [Reference McDonald, Treweek and Shakur5]. A shift to virtual recruitment methods in recent years has also increasingly necessitated an investigation of what recruitment techniques are effective in this new context [Reference Toly, Eliades and Miller6].

A variety of recruitment techniques have been explored and examined to determine how and when they are used in the recruitment process. These include increased emphasis and offering of incentives, economic and marketing techniques, developing stronger relationships with potential participants, better communication between sponsors and investigators, increased participation of a patient’s physician in recruitment, and increasing potential participant awareness of the issues being investigated [Reference Morgan, Harrison, Wright, Jia, Deal and Malova7Reference VanEpps, Volpp and Halpern10]. Some systematic reviews of recruitment into randomized controlled trials suggest that, in general, recruitment techniques that increased potential participants’ understanding, engagement, and awareness of the health problem being studied significantly increased consent rates [Reference Caldwell, Hamilton, Tan and Craig9,Reference Moffat, Shi, Cannon and Sullivan11Reference Treweek, Pitkethly and Cook13]. The most common types of techniques identified in these reviews were differences in recruiter protocol (i.e. differences in training, differences in investigator contact, etc.), participant incentives, and specific methods of providing information [Reference Caldwell, Hamilton, Tan and Craig9,Reference Moffat, Shi, Cannon and Sullivan11Reference Treweek, Pitkethly and Cook13]. Another study found, through interviews of clinical research coordinators and patients who have participated in clinical trials, that for minority populations, the credibility of research coordinators was important for shaping potential participants’ attitudes toward the research [Reference Morgan, Harrison, Wright, Jia, Deal and Malova7]. Parkinson et al. (2019) determined that incentives are often the reason that a participant decides to consent to a clinical trial. Further, in a focus piece, VanEpps et al. (2016) summarized how behavioral economics informs potential participants’ decisions, finding that recruiters’ choices of what information to provide, how to provide it, and what incentives are offered at each stage of the consenting process will affect the consent rate. This prior literature suggests that if recruiters take note of the choice architecture in play for potential participants and decide to alter it, they can influence decision making and potentially improve successful recruitment into clinical trials.

Due to their covert nature and potential impact on decision making, there are ethical considerations related to choosing recruitment techniques, particularly those that alter the choice architecture. The point at which a recruitment technique begins to subject a participant to undue influence and hinder the informed consent process is a gray area. For example, Halpern et al. (2021) investigated the impact of financial incentives on two trials with varying amounts of risk. They found that an increase in financial incentive for the lower risk trial significantly impacted the recruitment success rate, but did not have the same impact on the higher risk trial across demographic groups. Investigators determined that financial incentives were not unjust because they did not preferentially motivate across groups with different income levels or financial health in either trial [Reference Halpern, Chowdhury and Bayes14]. But the study raises questions about the extent to which financial incentives impact decisions to participate in studies and the interplay between financial incentives and trial risk.

Although a number of studies over the last two decades have investigated common recruitment techniques to understand which are effective and why, fewer have investigated how research staff perceive the effectiveness and ethics of recruitment techniques, and those that have called for continuing future research to be done on this topic [Reference Elliott, Husbands, Hamdy, Holmberg and Donovan15Reference Farrar, Elliott and Houghton17]. This leaves a gap in the literature about recruiters’ perceptions regarding the effectiveness and ethics of recruitment techniques. Gaining the perspectives of active clinical trial recruiters on the use and effectiveness of recruitment techniques is important to fill this gap. Their varied experiences recruiting potential participants with unique backgrounds, medical needs, and motivations for participating in research inform our general understanding of recruitment techniques utilized and the ethical issues surrounding them. Our prior qualitative interview study, described further in the Methods section, explored the perspectives of 39 trial recruiters from 2 different university systems on their recruitment process and its perceived effectiveness [Reference Volkmar, Watts and Kaiser-Jackson18], providing a foundation for a larger quantitative examination of these issues.

The goal of this study was to (a) assess the usage and perceived effectiveness of various recruitment techniques, and (b) investigate recruiters reasoning about a technique’s perceived effectiveness or ineffectiveness.

Methods

Study design

Procedures and respondents

This survey study of clinical trial recruiters aimed to collect both closed-ended and open-ended data on the use and perceived effectiveness of recruitment techniques previously identified in a qualitative interview study with recruiters [Reference Volkmar, Watts and Kaiser-Jackson18] and a literature review. For the present survey study, inclusion criteria for respondents included: English speakers, over 18 years of age, and worked as a clinical trial recruiter on at least one active clinical trial in the past year. A University of Utah Clinical and Translational Science Award (CTSA) liaison sent a brief description of the survey, consent cover letter, and survey link to the CTSA hubs for dissemination to the clinical trial recruiters at each site. Eligible respondents returned surveys from 22 different CTSA sites. Respondents received a $20 gift card after completing the survey. The study received Institutional Review Board approval from the University of Utah acting as the single IRB of record.

Survey

The survey was conducted via REDCap. In developing the survey instrument, recruitment techniques were selected to be included based on information gained via in-depth interviews from clinical trial recruiters [Reference Volkmar, Watts and Kaiser-Jackson18] as well as techniques identified by the study team in their review of the literature.

Both closed- and open-ended items were employed to assess respondents’ practices and experiences regarding 31 recruitment techniques (Supplemental Materials Table 1). The recruitment techniques were organized into six categories: Physician/Principal Investigator (PI) Involvement (techniques involving the patient’s physician), Community Engagement (techniques aimed at involving the participant’s community), Behavioral (recruiter behaviors), Benefits (techniques relating to study benefits), Risks (techniques relating to study risks), and Incentives (techniques aimed at incentivizing participation). Cognitive testing of a draft survey instrument was conducted with five clinical trial recruiters at one of the study sites, and minor wording changes were made to the survey for clarity.

Measures

Use

Survey respondents were asked if they had experience using each recruitment technique with a closed-ended item (“Yes,” “No,” or “Unsure”).

Perceived effectiveness

Respondents were asked how effective they perceived each technique to be in recruiting participants on a scale of 1 to 5 (1 = “Not at all effective,” 5 = “Extremely effective”). Respondents were asked to report their perception of how effective each recruitment technique was regardless of whether they had used it or not, but the question stem varied to reflect whether they reported having used the technique. If respondents selected “not at all effective” for an item in a category of recruitment techniques, an open-ended item asked why they found the technique(s) to be not at all effective. If they selected “extremely effective,” an open-ended item asked why they found the technique(s) to be extremely effective.

Participant characteristics

Respondents were asked to self-report their age, gender, race and ethnicity, educational attainment, years of experience as a recruiter, professional title, and the number of studies for which they were currently recruiting.

Data analysis

Quantitative data

For the closed-ended survey items, R and Excel were used to summarize demographic information. Descriptive statistics were examined for use and perceived effectiveness data. The average perceived effectiveness was calculated separately by those that had used the technique before and those that had not. Independent t-tests were used to compare respondents that used the technique versus those that did not. Results with a p-value < 0.05 were considered statistically significant. The difference between the mean perceived effectiveness scores by those who had and those who had not used the techniques was also calculated (Supplemental Materials Table 2).

Qualitative data

The open-ended responses were exported from REDCap, and the data was cleaned in Excel. A qualitative content analysis approach was used. Two independent coders reviewed and coded all responses using inductively derived codes.

The coders met to discuss discrepant codes, and the analysis was based on the consensus codes. The coders presented the emerging themes to the full study team based on the consensus-driven codes and supportive data. The codes were then organized into themes, which are presented below with exemplar quotes.

Results

Participant characteristics

From October 25, 2023, to January 19, 2024, 423 respondents started the survey, and 381 completed it (Table 1). The mean age was 37.0 years (SD = 11.8). The majority of respondents were female (n = 314, 82.4%) and non-Hispanic/non-Latino (n = 337, 88.5%). About half had completed a Bachelor’s degree level of education (n = 177, 46.5%). On average, respondents had 6.6 years of experience in the field (SD = 6.8), and at the time of survey completion, were actively recruiting for an average of 5.7 studies (SD = 8.9).

Table 1. Characteristics of participating clinical trial recruiters

Usage and perceived effectiveness of recruitment techniques

Respondents reported whether they had used each of the recruitment techniques in their time as a recruiter (Table 2). As shown in Table 3, across all techniques in the survey, the most highly used recruitment techniques were reassuring potential participants about confidentiality (n = 367; 96.3%); reassuring potential participants about protections of data during data sharing (n = 365; 95.8%); discussing potential benefits to others (n = 359; 94.2%); reassuring potential participants that their care would not be compromised if their physician was involved in the study (n = 320; 84.0%), and having a physician recommend the research (n = 320; 84.0%). Of all categories, techniques related to presentation of risk information were the most used, with the majority of respondents reporting having used four of the five techniques.

Table 2. Items and response options included on the survey of clinical trial recruiters

Table 3. Mean usage data for each recruitment technique organized by recruitment technique category and by descending usage within category (N = 381)

Respondents also reported the perceived effectiveness of each recruitment technique (Table 4). Across all techniques, the average perceived effectiveness according to those who had never used the technique was lower than among those who had used the technique (Table 4). Techniques in the Physician/PI Involvement category had the highest average perceived effectiveness. Specifically, having the PI approach and enroll potential participants had the highest mean score (mean (M) = 4.23, standard deviation (SD) = 0.91).

Table 4. Mean perceived effectiveness rating for each recruitment technique stratified by whether or not respondents reported having used the technique

Physician/PI involvement

The techniques categorized as Physician/PI Involvement were highly used. Within this category, the most commonly used technique was having the participant’s physician recommend the research study to them (n = 320; 84.0%), and for those who have experience using the technique, the highest perceived effectiveness was having the PI approach and enroll potential participants (M = 4.23, SD = 0.91). For those who did not have experience using techniques in the category, the highest perceived effectiveness was having the physician recommend the research study to a potential participant (M = 3.93, SD = 0.93). The largest difference in perceived effectiveness for those who had and had not used techniques in this category was having the PI approach and enroll potential participants (Δ = 0.65, p < 0.001).

In open-ended comments, respondents reported the effect that a physician/PI being present or involved in recruiting had on their increased recruitment success, pointing to the trust, rapport, and medical authority the physician had with their patients. This type of response was consistent across all of the techniques in this category.

When one of our site PIs is on shift, she will recruit her patients and has lots of success. I think it is because it is coming from someone that the family already trusts, and has medical authority. Additionally knowing that their attending is okay with them enrolling works well for all our recruitment, so I think it works extra well when the attending is also the one enrolling them. (ID117)

Community engagement

The Community Engagement category was the least commonly used category of techniques. The most used technique in this category was encouraging participants to reach out to their friends, with 51.2% (n = 195) of respondents reporting that they had used the technique. In addition, recruitment techniques in the Community Engagement category had the smallest differences in perceived effectiveness between those who had and those who had not used the techniques. For those who had used a technique before, the one most perceived as effective was employing a community member to recruit (M = 3.70, SD = 0.82). The difference between perceived effectiveness scores of those who had and had not used the technique of employing a community member was Δ = 0.43, p < 0.001.

Respondents cited the increased trust and easier communication when using techniques in the Community Engagement category.

Community leaders endorsing the study serves two benefits. It enhances our trust within the community to have a trusted advocate speaking for us. It also helps with distribution of the recruitment message, as the leader acts as a surrogate. Peer connections are extremely effective. They know what motivates their peers and thus are able to communicate the study message in a well-received manner. Additionally, peer connections enhance study retention, as the peer network serves to remind the volunteers of the importance of continued study participation. (ID403)

Some respondents did mention a hesitation to employ community members for fear that this may be unethical or coercive.

It feels unethical to hire a trusted community member to recruit for a study…it might be somewhat effective, but it still feels like a breach of trust. (ID416)

While encouraging participants to reach out to friends was one of the most used techniques in this category, this technique, along with recruiting at a community fair, was ranked lowest on the perceived effectiveness score for the category of Community Engagement. Respondents mentioned that these formats may waste recruiters’ time as they were often inadequate for certain patient populations or had a lack of privacy while recruiting.

In the past, some of our studies have attended fairs…and we end up with 1–2 enrollments for 6–8 hours of work on a Saturday or on off hours. It has just never been fruitful for us, but I think this can highly depend on the population… (ID205)

It is noisy at community events – there is lack of privacy, especially when you could be discussing sensitive health information… (ID281)

Behavioral

The recruitment techniques in the Behavioral category had significant variability in reported usage. The most used behavioral technique was asking personal questions, with 77.7% (n = 296) having reported using it. In this category, the technique perceived to be most effective by respondents who had used it before was offering non-health services (M = 3.83, SD = 0.85). This was the same for those who reported not having used the techniques (Offered non-health services: M = 3.17, SD = 1.18). The difference in perceived effectiveness for the technique of offering non-health services (e.g., childcare, travel) between those who had and those who had not used it before was moderate (Δ = 0.43, p < 0.001). Within this category, respondents emphasized the importance of building rapport and the removal of barriers to research for the potential participant as methods to increase recruitment. However, some were concerned about professionalism in this category and the ethical implications of using these techniques.

…Sharing the effect HIV has had on my community helps internalize any extrinsic motivations, which improves both recruitment and retention success…Removing as many barriers helps interested volunteers actually volunteer, and establishes good rapport. Rapport is of the utmost importance. Our clinic space, clinicians, and support staff are friendly and welcoming, which gives potential volunteers a “good feeling” about participating, rather than a cold, sterile, environment. (ID403)

First, I would like to say that I find all these things very unethical and would not feel comfortable doing them. However, they would work because it makes the participant’s life easier and essentially persuades them to do it. (ID76)

Working in a medical field patients would expect a more professional appearance. If someone dressed in sweatpants and t shirt approached someone about a serious medical issue, it almost seems disrespectful. Looking up their address and touching them also seems like it may give off the wrong impression with stalking and physical harassments. Especially when we work with children, parents may be more wary of these types of things. (ID32)

Risks

The most used technique in the category of communicating about risks was reassuring participants about confidentiality with 96.3% (n = 367) having used it. The perceived effectiveness of techniques in this category was highly variable, both for those who had and had not used the techniques previously. Of those who had experience with a technique, reassuring potential participants that their clinical care would not be compromised by physician involvement in the study (M = 4.02, SD = 0.79) was perceived to be most effective. Those who had no experience with this technique rated it much lower (M = 2.92, SD = 1.22; Δ = 1.10, p < 0.001).

Respondents identified safety, medical and other risks, and privacy as being most important to potential participants, and the corresponding techniques (i.e., Reassured about medical risks, Reassured about data sharing, and Reassured about confidentiality) were seen as beneficial to recruitment. Reassurance regarding any concerns in this area was thought to be a necessary component of the recruitment process to some respondents. Some respondents worried about maintaining professionalism when using these techniques and wanted to ensure they were perceived as honest to the potential participant.

Most of the participants I interact with are concerned with their information will be shared with others or published in a paper. Once I’ve established they are assigned a random ID number, their data is deidentified, and no individual data will ever be published, they tend to relax and are more receptive to learning about the study and enroll. (ID148)

Building trust with potential participants involves being transparent and discussing all of the details of the study including the risks and discomforts participants might experience. Drawing attention away from the informed consent form comes across as suspicious since you are trying to avoid discussing the details of the study, appearing to be hiding information. (ID384)

Benefits

The Benefits category of recruitment techniques included some of the most used techniques across all categories. The most used benefit technique was discussing the benefits of the study to others with 94.2% (n = 359) having used this technique. The technique rated most effective on average in this category was reporting on positive experiences for other participants in the study (M = 3.90, SD = 0.71). The same technique was also rated as the most effective by those who had not used the techniques previously (Reported others’ positive experiences: M = 3.21 and SD = 1.05). Respondents highlighted how altruism and past positive outcomes were often a motivator for potential participants. However, respondents were more hesitant to mention past positive outcomes, believing it could be misleading.

In non-drug trials, where there is “less” risk to participants, explaining what we could learn from a study has actually been really helpful. If people understand that there is little risk to them/their family but that what we learn could potentially help people in the future, they are often very willing to participate. In cases like this where there is little burden on subjects, this is a successful recruiting tactic. This is more difficult to use in studies with higher risk. In that case, people care more about their own health and safety, as they should. It can still be helpful in those situations though. (ID85)

You are allowing the trial/treatment to “sell itself” when you discuss positive outcomes from other subjects who have enrolled. Offering a potential subject to privately talk to an enrolled subject is extremely effective for recruitment and generally building trust. Most of the time after the private conversation with an enrolled subject, the potential subject will agree to enroll; but all of the time the confidence and comfort with the study team will increase… (ID217)

Although this is unethical due to the limited power of such reports, this method would be effective if used. I would not feel comfortable using it because it is misleading. (ID 287)

Incentives

The most used Incentive category technique by the survey respondents was highlighting that the study would pay for treatment with 65.4% (n = 249) having used it. For those with experience with the incentive-related techniques, the highest perceived effectiveness was for highlighting monetary incentives (M = 3.87, SD = 0.83). Alternatively, for those who had not used the techniques, the perceived effectiveness was highest for highlighting payment for treatment (M = 3.49, SD = 1.03).

Respondents stated that the removal of cost and other barriers increased recruitment, some seeing it as a necessity to reimburse participants in some way for their effort and time. Others worried about such techniques being potentially unethical, making it harder for potential participants to turn down a decision to participate.

Especially with rarer conditions, cost barriers are a huge factor. Relieving that burden is an incentive for people. However, we again have to be conscious of ethical concerns to make sure participants know they have options, by coordinating with social workers or assistance programs. (ID343)

Techniques were further grouped based on the results of both their usage and perceived effectiveness ratings (according to those that have used the technique) (Supplemental Table 2). Four categories were produced: high usage and high perceived effectiveness, minimal usage and high perceived effectiveness, high usage and minimal perceived effectiveness, and minimal usage and minimal perceived effectiveness. The techniques were grouped around the mean value across all 31 techniques (3.68); that is, a technique was rated “high usage” if more than 50% of respondents reported using the technique and rated as “high perceived effectiveness” if the mean perceived effectiveness was greater than 3.68. Those techniques in the high usage groups ranged from 51% to 96% used, and those in the high perceived effectiveness groups ranged from a mean perceived effectiveness of 3.69 to 4.23. The Physician/PI, Benefits, Risks, and Incentives categories were all represented with at least one technique in the highly used and highly effective category.

The categories with techniques that fell into the high usage and high perceived effectiveness group were physician/PI involvement in recruitment, communication about risks and benefits, and highlighting incentives. The specific techniques involved included: hope for altruistic outcomes, gain of medical information, physician recommendation, reassurance about risks, and financial incentives. The techniques described as minimal usage but perceived as highly effective included offering services beyond the scope of research, reporting on prior research outcomes and others’ positive experiences to reassure the patient, discussing lack of other options, employing a community member, and drawing attention away from risks in the informed consent process.

Discussion

This survey examined clinical trial recruiters’ usage, perceived effectiveness, and explicated perspectives on 31 recruitment techniques across six categories identified through our prior interview study and literature review: Physician/PI Involvement, Community Engagement, Behavioral, Benefits, Risks, and Incentives. One finding from our survey was that many common recruitment techniques had large differences in perceived effectiveness based on whether recruiters had used the technique in the past. In all cases, perceived effectiveness was higher among those who had used the technique relative to those who had not. This finding suggests that lack of experience may impact perceptions of effectiveness, a result consistent with prior literature looking at experience and perception of effectiveness, albeit in studies outside the specific area of clinical trial recruitment [Reference Bang, Shu and Weber19].

In the comments, survey respondents indicated that some of the techniques which fell into the high usage and high perceived effectiveness category (hope for altruistic outcomes, gain of medical information, physician recommendation, reassurance about risks, and financial incentives) are considered standard practice, and were often a part of research protocols. There was little controversy surrounding their use, and more respondents had experience with these techniques. These “normalized” techniques were also perceived as being effective in the interview study by Volkmar et al. (2025) and were seen as highly impactful [Reference Volkmar, Watts and Kaiser-Jackson18]. Many of these techniques overlap with patient-centered recruitment approaches, techniques requiring active patient participation throughout the recruitment process [Reference Sacristán, Aguarón and Avendaño-Solá20]. They have been shown to be objectively effective in past research, aligning with the perceptions from recruiters in this study [Reference Chhatre, Jefferson and Cook21,Reference Hung, Mohajeri and Almpani22]. However, some studies have shown that the effectiveness of techniques can be heavily dependent on many factors such as study type or topic, staff availability and resources, geographical location, or participant subgroups and may not lend themselves to patient-centered recruitment approaches.

The techniques that were minimally used and perceived as highly effective included offering services beyond the scope of research, reporting on prior research outcomes to reassure the patient, reporting that other participants had a positive experience, employing a community member, discussing the necessity of the research for that patient, and drawing attention from the informed consent document. Similar to the highly used and highly effective category, some recruiters viewed providing certain information as necessary to maintain professional standards. However, others considered these efforts as going beyond their responsibilities or being controversial. As such, there was more onus on the researcher staff to decide whether to use these recruitment techniques and thus more variation. For example, when deciding whether to use techniques recruiters who did not use them commented that potential participants might be suspicious of a discussion of the lack of other options for treatment, or of a recruiter highlighting the benefits of a study first, despite the high perceived effectiveness in using those approaches. Where they were considered the norm by respondents, use was high, and several recruiters speculated that the techniques could be successful in increasing recruitment. In contrast, some of those who had never used a technique in this group, despite the perception of high effectiveness, indicated their fear of being perceived as dishonest.

Some recruitment techniques were regularly used but not thought to be particularly effective, or were neither used nor considered effective, despite literature indicating that their use should be part of best practices. Some of the techniques described in the behavioral and risk-related categories were used much less than other recruitment techniques (e.g., the recruiter physically touching the patient and the recruiter drawing attention away from the informed consent form). The Behavioral category contained the highest volume of “not effective” commentary. Trust building and respect of boundaries have been previously described as especially effective ways to increase recruitment [Reference Morgan, Occa, Mouton and Potter23,Reference Morgan, Occa, Potter, Mouton and Peter24]. Many of these techniques (utilizing body language to better “read” a potential participant, mirroring potential participant behaviors, building rapport, and utilizing non-verbal behaviors such as smiling) have been described as effective in literature [Reference Morgan, Occa, Mouton and Potter23,Reference Morgan, Occa, Potter, Mouton and Peter24]. The low perceived effectiveness could again be due to the lack of experience with these techniques but may also be due to what recruiters perceive they must prioritize given time and or financial constraints [Reference Newington and Metcalfe16,Reference Newington and Metcalfe25]. Similarly, there is extensive literature on the use of community engagement to facilitate recruitment, particularly in specific communities [Reference Kadam, Borde, Madas, Salvi and Limaye26,Reference Otado, Kwagyan, Edwards, Ukaegbu, Rockcliffe and Osafo27], but these were only minimally used by recruiters and were often weighed against study time and resources. Past research has described these sorts of techniques as particularly effective for specific communities, noting that if recruiters do not choose to use these techniques, they may fail to enroll participants from these communities [Reference Goin-Kochel, Lozano and Duhon28,Reference Hanrahan, Gillies and Biesty29].

For many of the techniques, there was a difference between what recruiters in this study perceived as effective and actually used, and what prior literature has identified as effective or best practice in recruiting potential participants. As mentioned earlier, this was sometimes due to a lack of recruiter experience with the technique. Additional attention is needed to explore recruiters’ attitudes and practices. Particularly, further exploration of recruiter perception of behavioral and community engagement-related techniques would be valuable. Understanding the dissonance between recruiter perceived effectiveness and best practices could inform tailoring of techniques to encourage higher utilization by recruiters.

Ethics and maintaining professional standards were the two other significant concerns recruiters had when thinking about technique effectiveness and use. While some studies have already speculated on how to use recruitment techniques in an ethical manner [Reference Halpern, Chowdhury and Bayes14], future research could examine how other stakeholders (potential participants, IRB members, etc.) feel about the use of recruitment techniques, and in what circumstances they are ethical to use. Absent more work in this area, some hesitance toward the use of these techniques is understandable.

Limitations

While this study was able to assess the perspectives of a large group of clinical trial recruiters across multiple sites regarding the effectiveness and usage of recruitment techniques, there were some limitations. First, there were several “Unsure” responses by recruiters regarding if they had used a technique, which may have been due to limited recall or an issue in the wording and interpretation of the survey. Second, we only asked the clinical trial recruiters their perceptions of the effectiveness – a subjective measure. Techniques may be more or less objectively effective (as determined by recruitment and retention numbers) than what was reported here. To measure objective effectiveness, randomized controlled trials may be required. Not only is subjectivity itself a limitation, but whose perception is being measured is another issue. Other stakeholders may view the effectiveness of techniques differently. Further, although we recruited from a large variety of institutions, we focused only on CTSAs, and there is the possibility that clinical trial recruiters from other research networks would have different experiences using these recruitment techniques. We also did not formally ask recruiters the details of what clinical trials they were currently recruiting for; therefore, the perceived effectiveness of the recruitment techniques they were familiar with may be particular to certain populations or with certain types of trials. However, many recruiters in our study did expound on this in the open-ended survey data. We also defined effectiveness in recruitment as a higher number of participants agreeing to participate in a study. There are other possible definitions of “effectiveness,” such as how well potential participants understood the informed consent information.

Conclusion

Overall, survey findings suggest that there is significant variation in the usage of clinical trial recruitment techniques and how different recruiters view the effectiveness of each technique. More information on how the two aspects – use and perception of effectiveness – are related would be helpful. Some techniques presented in this survey are considered standard practice, but are not used very often, or are considered ineffective despite their regular use. Additional work is needed to make recommendations regarding changes to standard practice. There are also techniques that are not often used but perceived to be highly effective such as offering non-health care services to participants, reporting on past participants’ experiences and outcomes, and candidly discussing the participants’ lack of other options. Exploring in more detail the reasons why these perceived effective techniques are not used (and the ethical concerns raised) can help shed light on the scope of appropriate recruitment practices.

There is significant literature regarding techniques for improving clinical trial recruitment and retention. This study explores the unique view of the clinical trial recruiters. Their unique perspectives may help inform future decisions regarding which techniques to utilize while recruiting for trials, along with how and when to use particular recruitment techniques in an ethical manner.

Supplementary material

The supplementary material for this article can be found at https://doi.org/10.1017/cts.2025.10117

Author contributions

Jewels Watts: Conceptualization, Investigation, Methodology, Writing – original draft; Lauren Kaiser-Jackson: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – original draft; Bob Wong: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Writing – review & editing; Azra Helac: Investigation, Writing – review & editing; Molly Volkmar: Data curation, Investigation, Project administration, Writing – review & editing; Jessica W. Berg: Investigation, Writing – review & editing; Aaron J. Goldenberg: Investigation; Eric Kodish: Investigation, Writing – review & editing; Ben Schwan: Investigation, Writing – review & editing; Cathy Wolfsfeld: Investigation; Erin Rothwell: Investigation; Maxwell Mehlman: Funding acquisition, Project administration, Writing – review & editing; Kimberly A. Kaphingst: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Supervision, Writing – review & editing.

Funding statement

Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health, USA, under award number R01TR004245.

Competing interests

Dr Kodish serves as a consultant and external member of the Data Sharing Committee for Incyte.

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Figure 0

Table 1. Characteristics of participating clinical trial recruiters

Figure 1

Table 2. Items and response options included on the survey of clinical trial recruiters

Figure 2

Table 3. Mean usage data for each recruitment technique organized by recruitment technique category and by descending usage within category (N = 381)

Figure 3

Table 4. Mean perceived effectiveness rating for each recruitment technique stratified by whether or not respondents reported having used the technique

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