At What Cost to Clinical Trial Enrollment? A Retrospective Study of Patient Travel Burden in Cancer Clinical Trials

Hala T. Borno, Li Zhang, Adam Siegel, Emily Chang, Charles J. Ryan

Research output: Contribution to journalArticlepeer-review

65 Scopus citations


Background: Recent literature suggests that living in a rural setting may be associated with adverse cancer outcomes. This study examines the burden of travel from home to cancer center for clinical trial (CT) enrollees. Materials and Methods: Patients from the University of California San Francisco Clinical Trial Management System database who enrolled in a cancer CT for a breast, genitourinary, or gastrointestinal malignancy between 1993 and 2014 were included. Cancer type, household zip code, race/ethnicity, phase of study, study sponsor, and year of signed consent were exported. Distance traveled from home to center was calculated using a GoogleMaps application programming interface. The relationships of distance with phase of CT, household income, and race/ethnicity were examined. Results: A total of 1,600 patients were enrolled in breast (55.8%), genitourinary (29.4%), or gastrointestinal (14.9%) cancer CTs. The overall median unidirectional distance traveled from home to study site was 25.8 miles (interquartile range [IQR] 11.5–75.3). Of the trial sponsors examined, principal investigator (56.4%), industry (22.2%), cooperative group (11.6%), and National Institutes of Health (NIH; 9.8%), the longest distance traveled was for NIH-sponsored trials, with a median of 39.4 miles (p <.001). Phase I (8.4%) studies had the longest distance traveled, with a median of 41.2 miles (IQR 14.5–101.0 miles; p =.001). White patients (83%) traveled longer compared with black patients (4.4%), with median distances of 29.9 and 13.9 miles, respectively (p <.001). Patients from lower-income areas (n = 799) traveled longer distances compared with patients from higher-income areas (n = 773; 58.3 vs. 17.8 miles, respectively; p <.001). A multivariable linear model where log10 (distance) was the outcome and adjusting for the exported variables and income revealed that cancer type, year of consent, race/ethnicity, and income were significantly associated with distance traveled. Conclusion: This study found that the burden of travel is highest among patients enrolled in NIH-sponsored trials, phase I studies, or living in low-income areas. These data suggest that travel burden for cancer CT participants may be significant. Implications for Practice: This study is one of the first to measure travel distance for patients in cancer clinical trials using a real-world GoogleMaps calculator. Out-of-pocket expenses such as travel are not typically covered by health care payers; therefore, patients may face considerable cost to attend each study visit. Using a single-center clinical trials enrollment database, this study found that the burden of travel is highest for patients enrolled in National Institutes of Health-sponsored trials and phase I studies, as well as for patients living in low-income areas. Results suggest that a significant proportion of patients enrolled in clinical trials face a substantial travel burden.

Original languageEnglish (US)
Pages (from-to)1242-1249
Number of pages8
Issue number10
StatePublished - Oct 1 2018

Bibliographical note

Funding Information:
Other variables examined included patient racial/ethnic background, study sponsor type, phase of study, year that consent was signed by participant, and census-reported median income for home zip code. The category of sponsor type was determined based on the UCSF cancer center’s standard definitions. Studies categorized as National Institutes of Health (NIH) trials were publicly funded clinical trials supported by the NIH. Cooperative group trials were supported by external clinical research study organizations that tend to be collaborative. Principal investigator or institutional in-house clinical research studies were coauthored by the cancer center’s investigators with a variable payer source. Lastly, industry trials were financially sponsored by a pharmaceutical company and influenced the design and implementation of the clinical research study. The median household income data were derived from census data from 2006 to 2010 [12]. The patients were grouped in high-and low-income subgroups based on whether their income lay above or below the median ($77,483), respectively. Additionally, the patients were also categorized into high/middle/low income groups based on income <$65,462, between $65,462 and $101,094, and >$101,094, respectively. These income cut-points were informed by research from Dickman et al. and are derived from 361% ($65,462) and 558% ($101,094) of the 2012 federal poverty level for a family of three, or two adults and one child [13].

Publisher Copyright:
© AlphaMed Press 2018


  • Cancer clinical trial disparities
  • Health care costs
  • Recruitment science
  • Representativeness in clinical trials
  • Travel distance


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