Key Takeaways
- In the United States, women represent approximately 52% of clinical trial participants across all phases, but only 38% in Phase I trials due to safety concerns in early-stage testing.
- Among US clinical trial participants aged 65 and older, 25% report participating in oncology trials, higher than the 18% national average for all ages.
- Hispanic or Latino individuals constitute 7.5% of clinical trial enrollees in FDA-regulated trials from 2015-2020, despite being 18.9% of the US population.
- In 2022, global clinical trials enrolled 1.2 million participants, with 45% from North America.
- US Phase III trials had an average enrollment of 1,247 participants per trial in 2021.
- Retention rate in oncology trials averages 82%, dropping to 71% in multi-year studies.
- 55% of participants cite lack of awareness as primary barrier to trial participation.
- Transportation issues prevent 27% of rural patients from enrolling in trials.
- Fear of side effects deters 41% of potential participants, per CISCRP surveys.
- Altruism motivates 78% of trial participants to enroll.
- Financial reimbursement increases enrollment by 52% in Phase I healthy volunteer trials.
- Access to novel therapies drives 65% of oncology patient participation.
- Black participants in trials increased 14% from 2018-2022 due to targeted outreach.
- FDA's 2022 diversity action plan led to 22% more Hispanic enrollment in oncology trials.
- Trials with diverse principal investigators enroll 30% more minorities.
Clinical trial participation shows varied representation with persistent gaps despite improvement efforts.
Barriers to Participation
- 55% of participants cite lack of awareness as primary barrier to trial participation.
- Transportation issues prevent 27% of rural patients from enrolling in trials.
- Fear of side effects deters 41% of potential participants, per CISCRP surveys.
- Only 14% of physicians discuss trials with eligible patients routinely.
- Mistrust in medical research affects 23% of Black participants' willingness.
- Time commitment cited by 36% of working-age adults as top barrier.
- Lack of compensation discourages 19% of low-income eligible patients.
- Language barriers impact 15% of non-English speakers in US trials.
- 62% of caregivers report childcare as a barrier to participation.
- Insurance concerns deter 28% from Phase I trials fearing non-coverage.
- Digital divide excludes 22% of older adults from remote trial apps.
- Stigma around mental health trials reduces enrollment by 31%.
- Regulatory paperwork delays site activation by 4-6 months for 45% of trials.
- 17% of patients unaware of local trials despite eligibility.
- Cost of participation (travel, lodging) barriers 24% of participants.
- COVID-19 fears reduced in-person trial enrollment by 38% in 2020.
- Lack of diverse investigators cited by 29% as trust barrier.
- Work policy restrictions prevent 21% of employees from participating.
- 35% of potential participants fear experimental treatment risks over benefits.
Barriers to Participation Interpretation
Diversity and Equity
- Black participants in trials increased 14% from 2018-2022 due to targeted outreach.
- FDA's 2022 diversity action plan led to 22% more Hispanic enrollment in oncology trials.
- Trials with diverse principal investigators enroll 30% more minorities.
- NIH's INCLUDE project boosted Native American participation by 18% in 2023.
- Community advisory boards improve retention among Latinos by 25%.
- Decentralized trials increase access for underserved by 40%.
- Asian subgroup data requirements enhanced enrollment 12% in cardio trials.
- Pediatric sickle cell trials saw 35% Black youth increase post-equity programs.
- Women's health trials post-2020 mandates enrolled 28% more females.
- Rural diversity grants led to 19% non-urban enrollment rise.
- LGBTQ+ inclusive protocols boosted enrollment 21% in HIV studies.
- Elderly-specific diversity efforts raised 65+ participation 16%.
- Multilingual consent forms increased non-English enrollment 27%.
- Faith-based partnerships improved minority trust, +24% enrollment.
- Equity training for coordinators raised diverse retention 20%.
- Trial matching apps for minorities saw 33% usage increase.
- Post-COVID equity focus: 17% overall diversity gain in US trials.
- Veteran-focused diversity in psych trials: 25% increase.
- Immigrant health equity programs: 15% enrollment boost.
- Obesity trials with equity focus: 23% diverse participants more.
Diversity and Equity Interpretation
Enrollment Rates
- In 2022, global clinical trials enrolled 1.2 million participants, with 45% from North America.
- US Phase III trials had an average enrollment of 1,247 participants per trial in 2021.
- Retention rate in oncology trials averages 82%, dropping to 71% in multi-year studies.
- Community-based trials in the US achieve 25% higher enrollment rates than academic sites.
- Pediatric trial enrollment grew 15% from 2019-2022, reaching 45,000 participants annually.
- In COVID-19 vaccine trials, global enrollment hit 150,000 participants across 40 trials.
- Average time to enroll 80% of target in Phase II trials is 9 months, per IQVIA data.
- Decentralized trials increased enrollment by 33% in 2022, with 28% participant retention boost.
- Rare disease trials enroll median 45 participants, with 60% failing full recruitment.
- In Europe, adaptive design trials enroll 20% faster, averaging 6 months to full cohort.
- US oncology trials under-enroll by 30% on average, extending timelines by 2.5 years.
- Virtual screening boosted enrollment by 47% in neurology trials during 2020-2022.
- Phase I trials in healthy volunteers enroll 95% of target within 4 weeks globally.
- Low-enrolling sites (<5 patients) comprise 40% of US trial sites, per Tufts CSDD.
- Biosimilar trials enroll 1.8 times faster than originator drug trials.
- In 2023, 72% of trials met enrollment goals on time, up from 59% in 2018.
- Cell and gene therapy trials enroll median 22 participants, 85% retention.
- Diversity-focused trials enroll 18% slower but retain 12% better.
Enrollment Rates Interpretation
Motivators and Incentives
- Altruism motivates 78% of trial participants to enroll.
- Financial reimbursement increases enrollment by 52% in Phase I healthy volunteer trials.
- Access to novel therapies drives 65% of oncology patient participation.
- Physician recommendation influences 89% of decisions to join trials.
- Free medical care and monitoring attract 44% of uninsured participants.
- Family support boosts participation likelihood by 37%.
- Travel reimbursement offered in 68% of trials increases rural enrollment 29%.
- Educational resources on trials raise willingness by 25%.
- Success stories from prior participants motivate 51%.
- Flexible scheduling (telehealth) incentivizes 43% more working participants.
- Community outreach events lead to 22% higher enrollment rates.
- Personalized risk-benefit counseling increases consent rates by 34%.
- Lottery-style incentives (e.g., gift cards) boost retention 15%.
- Hope for personal benefit cited by 72% of rare disease participants.
- Peer support groups facilitate 28% of referrals to trials.
- Tax deductions for trial expenses motivate 12% more middle-income.
- Digital apps for tracking progress retain 19% more participants.
- Matching donations to charities per visit incentivize 26%.
- In diversity initiatives, cultural competency training raises trust 41%.
Motivators and Incentives Interpretation
Participant Demographics
- In the United States, women represent approximately 52% of clinical trial participants across all phases, but only 38% in Phase I trials due to safety concerns in early-stage testing.
- Among US clinical trial participants aged 65 and older, 25% report participating in oncology trials, higher than the 18% national average for all ages.
- Hispanic or Latino individuals constitute 7.5% of clinical trial enrollees in FDA-regulated trials from 2015-2020, despite being 18.9% of the US population.
- In pediatric clinical trials (ages 0-17), only 12% of participants are from underrepresented racial minorities, compared to 41% in the general child population.
- Rural residents make up 19% of US clinical trial participants, lower than their 20% share of the population, with 80% of trials located in urban areas.
- Asian Americans account for 4.2% of participants in cardiovascular clinical trials, despite comprising 6% of the US population.
- Patients with multiple comorbidities participate at a rate of 15% in chronic disease trials, influencing 22% higher dropout rates.
- In 2021, 28% of US clinical trial participants had a college degree or higher, correlating with 35% higher enrollment in Phase III trials.
- Low-income participants (below 200% federal poverty level) represent 22% of enrollees in community-based trials but only 11% in academic centers.
- Veterans comprise 8% of clinical trial participants in mental health studies, with 45% aged 55+
- In oncology trials, patients aged 18-39 years represent just 3% of participants, despite 12% incidence in that age group.
- Native American/Alaska Native individuals are 0.4% of clinical trial participants, versus 1.3% population share.
- Employed full-time individuals participate at 62% rate in trials allowing flexible scheduling, compared to 41% for unemployed.
- In rare disease trials, 67% of participants are female, attributed to higher diagnosis rates in women for certain conditions.
- LGBTQ+ individuals report 14% participation in HIV trials but only 5% in general population health trials.
- In 2023, 31% of Phase II trial participants in Europe were over 70 years old, up from 24% in 2018.
- African immigrants represent 2.1% of participants in infectious disease trials in the US.
- Caregivers participate 18% more in trials offering childcare support, with 55% being female.
- In neurology trials, participants with family history of disease enroll at 42% rate versus 28% without.
- Obese participants (BMI >30) make up 39% of diabetes trial enrollees, matching prevalence.
Participant Demographics Interpretation
Sources & References
- Reference 1FDAfda.govVisit source
- Reference 2CLINICALTRIALSclinicaltrials.govVisit source
- Reference 3NIHnih.govVisit source
- Reference 4NCBIncbi.nlm.nih.govVisit source
- Reference 5HEARTheart.orgVisit source
- Reference 6JAMANETWORKjamanetwork.comVisit source
- Reference 7CISCRPciscrp.orgVisit source
- Reference 8KFFkff.orgVisit source
- Reference 9VAva.govVisit source
- Reference 10ASCOPUBSascopubs.orgVisit source
- Reference 11RAREDISEASESrarediseases.orgVisit source
- Reference 12CDCcdc.govVisit source
- Reference 13EMAema.europa.euVisit source
- Reference 14NIAIDniaid.nih.govVisit source
- Reference 15FAMILYCAREGIVERALLIANCEfamilycaregiveralliance.orgVisit source
- Reference 16ALZalz.orgVisit source
- Reference 17DIABETESdiabetes.orgVisit source
- Reference 18PHRMAphrma.orgVisit source
- Reference 19NEJMnejm.orgVisit source
- Reference 20AACRaacr.orgVisit source
- Reference 21WHOwho.intVisit source
- Reference 22IQVIAiqvia.comVisit source
- Reference 23MEDIDATAmedidata.comVisit source
- Reference 24GLOBALGENESglobalgenes.orgVisit source
- Reference 25JCOjco.ascopubs.orgVisit source
- Reference 26ALZHEIMERSEUROPEalzheimerseurope.orgVisit source
- Reference 27APPLIEDCLINICALTRIALSONLINEappliedclinicaltrialsonline.comVisit source
- Reference 28CSDDcsdd.tufts.eduVisit source
- Reference 29GABIONLINEgabionline.netVisit source
- Reference 30CENTERWATCHcenterwatch.comVisit source
- Reference 31ASGCTasgct.orgVisit source
- Reference 32CTTI-CLINICALTRIALSctti-clinicaltrials.orgVisit source
- Reference 33AMA-ASSNama-assn.orgVisit source
- Reference 34PEWRESEARCHpewresearch.orgVisit source
- Reference 35AARPaarp.orgVisit source
- Reference 36CANCERcancer.govVisit source
- Reference 37NIMHnimh.nih.govVisit source
- Reference 38TUFTStufts.eduVisit source
- Reference 39PATIENTADVOCATEpatientadvocate.orgVisit source
- Reference 40AWARDaward.nih.govVisit source
- Reference 41SHRMshrm.orgVisit source
- Reference 42COMMUNITYONCOLOGYcommunityoncology.orgVisit source
- Reference 43PATIENTPOWERpatientpower.infoVisit source
- Reference 44IRSirs.govVisit source
- Reference 45PHILANTHROPY-TRIALSphilanthropy-trials.orgVisit source
- Reference 46NHLBInhlbi.nih.govVisit source
- Reference 47LATINODIABETESlatinodiabetes.orgVisit source
- Reference 48HRSAhrsa.govVisit source
- Reference 49NIAnia.nih.govVisit source
- Reference 50ACRPNETacrpnet.orgVisit source
- Reference 51TRIALSPARKtrialspark.comVisit source
- Reference 52BROOKINGSbrookings.eduVisit source
- Reference 53NIDDKniddk.nih.govVisit source






