GITNUXREPORT 2026

Clinical Trial Participation Statistics

Clinical trial participation shows varied representation with persistent gaps despite improvement efforts.

Rajesh Patel

Rajesh Patel

Team Lead & Senior Researcher with over 15 years of experience in market research and data analytics.

First published: Feb 13, 2026

Our Commitment to Accuracy

Rigorous fact-checking · Reputable sources · Regular updatesLearn more

Key Statistics

Statistic 1

55% of participants cite lack of awareness as primary barrier to trial participation.

Statistic 2

Transportation issues prevent 27% of rural patients from enrolling in trials.

Statistic 3

Fear of side effects deters 41% of potential participants, per CISCRP surveys.

Statistic 4

Only 14% of physicians discuss trials with eligible patients routinely.

Statistic 5

Mistrust in medical research affects 23% of Black participants' willingness.

Statistic 6

Time commitment cited by 36% of working-age adults as top barrier.

Statistic 7

Lack of compensation discourages 19% of low-income eligible patients.

Statistic 8

Language barriers impact 15% of non-English speakers in US trials.

Statistic 9

62% of caregivers report childcare as a barrier to participation.

Statistic 10

Insurance concerns deter 28% from Phase I trials fearing non-coverage.

Statistic 11

Digital divide excludes 22% of older adults from remote trial apps.

Statistic 12

Stigma around mental health trials reduces enrollment by 31%.

Statistic 13

Regulatory paperwork delays site activation by 4-6 months for 45% of trials.

Statistic 14

17% of patients unaware of local trials despite eligibility.

Statistic 15

Cost of participation (travel, lodging) barriers 24% of participants.

Statistic 16

COVID-19 fears reduced in-person trial enrollment by 38% in 2020.

Statistic 17

Lack of diverse investigators cited by 29% as trust barrier.

Statistic 18

Work policy restrictions prevent 21% of employees from participating.

Statistic 19

35% of potential participants fear experimental treatment risks over benefits.

Statistic 20

Black participants in trials increased 14% from 2018-2022 due to targeted outreach.

Statistic 21

FDA's 2022 diversity action plan led to 22% more Hispanic enrollment in oncology trials.

Statistic 22

Trials with diverse principal investigators enroll 30% more minorities.

Statistic 23

NIH's INCLUDE project boosted Native American participation by 18% in 2023.

Statistic 24

Community advisory boards improve retention among Latinos by 25%.

Statistic 25

Decentralized trials increase access for underserved by 40%.

Statistic 26

Asian subgroup data requirements enhanced enrollment 12% in cardio trials.

Statistic 27

Pediatric sickle cell trials saw 35% Black youth increase post-equity programs.

Statistic 28

Women's health trials post-2020 mandates enrolled 28% more females.

Statistic 29

Rural diversity grants led to 19% non-urban enrollment rise.

Statistic 30

LGBTQ+ inclusive protocols boosted enrollment 21% in HIV studies.

Statistic 31

Elderly-specific diversity efforts raised 65+ participation 16%.

Statistic 32

Multilingual consent forms increased non-English enrollment 27%.

Statistic 33

Faith-based partnerships improved minority trust, +24% enrollment.

Statistic 34

Equity training for coordinators raised diverse retention 20%.

Statistic 35

Trial matching apps for minorities saw 33% usage increase.

Statistic 36

Post-COVID equity focus: 17% overall diversity gain in US trials.

Statistic 37

Veteran-focused diversity in psych trials: 25% increase.

Statistic 38

Immigrant health equity programs: 15% enrollment boost.

Statistic 39

Obesity trials with equity focus: 23% diverse participants more.

Statistic 40

In 2022, global clinical trials enrolled 1.2 million participants, with 45% from North America.

Statistic 41

US Phase III trials had an average enrollment of 1,247 participants per trial in 2021.

Statistic 42

Retention rate in oncology trials averages 82%, dropping to 71% in multi-year studies.

Statistic 43

Community-based trials in the US achieve 25% higher enrollment rates than academic sites.

Statistic 44

Pediatric trial enrollment grew 15% from 2019-2022, reaching 45,000 participants annually.

Statistic 45

In COVID-19 vaccine trials, global enrollment hit 150,000 participants across 40 trials.

Statistic 46

Average time to enroll 80% of target in Phase II trials is 9 months, per IQVIA data.

Statistic 47

Decentralized trials increased enrollment by 33% in 2022, with 28% participant retention boost.

Statistic 48

Rare disease trials enroll median 45 participants, with 60% failing full recruitment.

Statistic 49

In Europe, adaptive design trials enroll 20% faster, averaging 6 months to full cohort.

Statistic 50

US oncology trials under-enroll by 30% on average, extending timelines by 2.5 years.

Statistic 51

Virtual screening boosted enrollment by 47% in neurology trials during 2020-2022.

Statistic 52

Phase I trials in healthy volunteers enroll 95% of target within 4 weeks globally.

Statistic 53

Low-enrolling sites (<5 patients) comprise 40% of US trial sites, per Tufts CSDD.

Statistic 54

Biosimilar trials enroll 1.8 times faster than originator drug trials.

Statistic 55

In 2023, 72% of trials met enrollment goals on time, up from 59% in 2018.

Statistic 56

Cell and gene therapy trials enroll median 22 participants, 85% retention.

Statistic 57

Diversity-focused trials enroll 18% slower but retain 12% better.

Statistic 58

Altruism motivates 78% of trial participants to enroll.

Statistic 59

Financial reimbursement increases enrollment by 52% in Phase I healthy volunteer trials.

Statistic 60

Access to novel therapies drives 65% of oncology patient participation.

Statistic 61

Physician recommendation influences 89% of decisions to join trials.

Statistic 62

Free medical care and monitoring attract 44% of uninsured participants.

Statistic 63

Family support boosts participation likelihood by 37%.

Statistic 64

Travel reimbursement offered in 68% of trials increases rural enrollment 29%.

Statistic 65

Educational resources on trials raise willingness by 25%.

Statistic 66

Success stories from prior participants motivate 51%.

Statistic 67

Flexible scheduling (telehealth) incentivizes 43% more working participants.

Statistic 68

Community outreach events lead to 22% higher enrollment rates.

Statistic 69

Personalized risk-benefit counseling increases consent rates by 34%.

Statistic 70

Lottery-style incentives (e.g., gift cards) boost retention 15%.

Statistic 71

Hope for personal benefit cited by 72% of rare disease participants.

Statistic 72

Peer support groups facilitate 28% of referrals to trials.

Statistic 73

Tax deductions for trial expenses motivate 12% more middle-income.

Statistic 74

Digital apps for tracking progress retain 19% more participants.

Statistic 75

Matching donations to charities per visit incentivize 26%.

Statistic 76

In diversity initiatives, cultural competency training raises trust 41%.

Statistic 77

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.

Statistic 78

Among US clinical trial participants aged 65 and older, 25% report participating in oncology trials, higher than the 18% national average for all ages.

Statistic 79

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.

Statistic 80

In pediatric clinical trials (ages 0-17), only 12% of participants are from underrepresented racial minorities, compared to 41% in the general child population.

Statistic 81

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.

Statistic 82

Asian Americans account for 4.2% of participants in cardiovascular clinical trials, despite comprising 6% of the US population.

Statistic 83

Patients with multiple comorbidities participate at a rate of 15% in chronic disease trials, influencing 22% higher dropout rates.

Statistic 84

In 2021, 28% of US clinical trial participants had a college degree or higher, correlating with 35% higher enrollment in Phase III trials.

Statistic 85

Low-income participants (below 200% federal poverty level) represent 22% of enrollees in community-based trials but only 11% in academic centers.

Statistic 86

Veterans comprise 8% of clinical trial participants in mental health studies, with 45% aged 55+

Statistic 87

In oncology trials, patients aged 18-39 years represent just 3% of participants, despite 12% incidence in that age group.

Statistic 88

Native American/Alaska Native individuals are 0.4% of clinical trial participants, versus 1.3% population share.

Statistic 89

Employed full-time individuals participate at 62% rate in trials allowing flexible scheduling, compared to 41% for unemployed.

Statistic 90

In rare disease trials, 67% of participants are female, attributed to higher diagnosis rates in women for certain conditions.

Statistic 91

LGBTQ+ individuals report 14% participation in HIV trials but only 5% in general population health trials.

Statistic 92

In 2023, 31% of Phase II trial participants in Europe were over 70 years old, up from 24% in 2018.

Statistic 93

African immigrants represent 2.1% of participants in infectious disease trials in the US.

Statistic 94

Caregivers participate 18% more in trials offering childcare support, with 55% being female.

Statistic 95

In neurology trials, participants with family history of disease enroll at 42% rate versus 28% without.

Statistic 96

Obese participants (BMI >30) make up 39% of diabetes trial enrollees, matching prevalence.

Trusted by 500+ publications
Harvard Business ReviewThe GuardianFortune+497
Uncovering who actually gets a chance to try tomorrow's medical breakthroughs reveals a stark and often overlooked truth: the opportunity to participate in a clinical trial, and thus shape the future of medicine, is far from equal across different communities in the United States.

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

Clinical trial participation is like a labyrinth designed by committee, where potential participants are told the treasure at the center is vital for humanity, only to find every other turn blocked by a mundane, solvable real-world obstacle that nobody with a key seems particularly motivated to remove.

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

The numbers paint a clear and hopeful picture: when clinical trials intentionally meet people where they are—in their communities, languages, and lived experiences—science becomes more robust and medicine more just.

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

While North America dominates global enrollment and innovative trial designs are showing real promise in boosting speed and diversity, the sobering reality is that many studies—especially in oncology and rare diseases—still struggle with slow recruitment, high dropout rates, and a persistent reliance on underperforming sites, creating a costly tug-of-war between scientific ambition and practical execution.

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

While altruism may light the spark for many, the engine of clinical trial enrollment is pragmatically fueled by a complex blend of trust, access, support, and strategic incentives.

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

Clinical trial participation paints a portrait of an America where the path to medical advancement is paved with good intentions but littered with disparities, revealing that who gets a seat at the research table still depends too much on who you are, where you live, and what you can afford.

Sources & References