To examine trends in patient-reported outcome (PRO) measure use in clinical trials (2008-2023) and analyze adoption patterns of common PRO measures across geographic regions, disease categories, and age groups.
We identified PRO measures from PROQOLID and health technology assessment recommendations, including generic instruments (EuroQol 5-Dimension [EQ-5D], SF-36/12/8/6D, Patient-Reported Outcomes Measurement Information System [PROMIS]), condition-specific measures (EORTC QLQ-C30/QLU-C10D, Functional Assessment of Chronic Illness Therapy), and pediatric instruments (Pediatric Quality of Life Inventory [PedsQL], EQ-5D-Y, PROMIS Pediatric, Child Health Questionnaire, Child Health Utility 9D). Using a custom Python algorithm (96% sensitivity, 97% specificity), we searched for interventional studies incorporating PRO measures.
Among 475 844 registered trials, PRO measure usage increased substantially. Adult trials incorporating PROs grew from 12.7% (n = 1783) in 2008 to 23.5% (n = 7808) in 2023; pediatric trials increased from 8.0% (n = 231) to 17.7% (n = 1118). EQ-5D surpassed SF measures as the most widely used generic instrument in 2017 (2023: EQ-5D n = 1023, SF n = 781), growing at a compound annual growth rate of 16.2%, whereas PROMIS demonstrated the most rapid expansion with a compound annual growth rate of 51.9%. PRO measures were most frequently implemented in trials studying pathological conditions, nervous system diseases, and neoplasms, with distinct regional preferences: EQ-5D predominated in Europe, whereas SF and PROMIS measures were more common in North America.
By 2023, nearly one-quarter of adult trials included PRO measures, with growing pediatric implementation. PRO integration continues expanding, driven by regulatory and health technology assessment requirements. EQ-5D’s emergence as the leading measure may reflect widespread health technology assessment endorsement. These findings inform PRO selection strategies and identify opportunities for greater pediatric implementation and regional adoption.
What is it about?
Patient-reported outcome measures (PROMs) are questionnaires completed by patients to capture their health status, symptoms, and quality of life from their own perspective. These measures have become increasingly important in healthcare as they provide unique insights into treatment effects that clinical tests and laboratory results do not fully capture. This study aimed to understand how the use of PROMs in clinical trials has changed over time, addressing the gap in knowledge about recent adoption patterns across different regions, diseases, and age groups. The study proposed to examine trends in PROM usage from 2008 to 2023 by analyzing data from ClinicalTrials.gov, the world's largest clinical trial registry. This research makes a significant contribution by providing comprehensive evidence of how patient perspectives are increasingly being integrated into clinical research across diverse disease areas.
How was the research conducted?
The researchers developed a systematic approach to identify and analyze PROM usage in clinical trials over a 16-year period. They created a comprehensive list of measures from the Patient-Reported Outcome and Quality of Life Instruments Database and health technology assessment recommendations, focusing on widely used generic instruments like the EQ-5D and the SF-36, as well as disease-specific and pediatric measures. Using a custom-built Python algorithm with high accuracy (correctly identifying 96% of trials that used these measures and correctly excluding 97% of those that did not), the researchers searched ClinicalTrials.gov for interventional studies that incorporated these PROMs between 2008 and 2023. The analysis included calculating the proportion of trials using PROMs each year, examining growth rates for specific instruments, and conducting comparisons by geographic region, disease category, and age group. This methodology allowed for a thorough examination of 475,844 registered clinical trials to identify patterns in how researchers are incorporating patient perspectives into their studies.
What were the results?
The most striking finding was the substantial increase in PROM usage across clinical trials over the study period. Among adult trials, the proportion incorporating PROMs nearly doubled from 12.7% in 2008 to 23.5% in 2023, while pediatric trials showed similar growth from 8.0% to 17.7%. EQ-5D surpassed the SF health survey family as the most widely used generic PROM in 2017, growing at an average yearly rate of 16.2%. The Patient-Reported Outcomes Measurement Information System (PROMIS), a flexible set of health surveys developed in the United States, demonstrated the most rapid expansion with a 51.9% average yearly growth rate. Notable regional differences emerged, with EQ-5D predominating in European trials while SF measures and PROMIS were more common in North America. Perhaps most unexpectedly, the Health Utilities Index, despite being endorsed by 9 health technology assessment agencies worldwide, was the only measure that showed no growth over the study period. PROMs were most frequently implemented in trials studying conditions involving symptoms and pain, nervous system diseases, and cancer.
Why are the results important?
These findings have significant implications for how treatment effectiveness is evaluated in healthcare by highlighting the growing recognition of patient perspectives in clinical research. The results suggest that regulatory requirements, health technology assessment guidelines, and the broader shift toward patient-centered care are successfully driving greater inclusion of patient-reported outcomes in clinical evidence. For clinical practice, this trend means more treatment decisions can be informed by data on how interventions affect patients' daily functioning and quality of life, not just clinical markers. Patients benefit from having their experiences systematically captured and considered in treatment development and approval processes, while researchers and pharmaceutical companies gain clearer guidance on which PROMs are becoming standard in different regions and disease areas. Long-term, this shift toward patient-centered outcomes may lead to treatments that better address what matters most to patients.
What are the strengths and weaknesses of this study?
The study's primary strength is its comprehensive scope, analyzing nearly half a million clinical trials over 16 years to provide a robust picture of PROM adoption trends across different regions and disease areas. However, a notable limitation is that ClinicalTrials.gov data relies on self-reporting by trial sponsors, which may result in incomplete or inconsistent information, particularly for trials not subject to US Food and Drug Administration registration requirements. Additionally, while the study identifies which PROMs were included in trial registrations, it cannot determine whether these measures were successfully implemented or how their results influenced regulatory decisions or clinical practice. Future research could examine how patient-reported outcomes data from these trials impacts regulatory approvals, evaluate the quality of patient-reported outcomes implementation across different trial phases, and assess whether increased patient-reported outcomes inclusion translates to improved incorporation of patient perspectives in clinical guidelines and decision making.
Note: This content was created with assistance from artificial intelligence (AI) and has been reviewed and edited by ISPOR staff. For more information or for inquiries on ISPOR’s AI policy, click here or contact us at info@ispor.org.