Social Determinants of Health and Informed Consent Comprehension for Pediatric Cancer Clinical Trials.

Importance: Ensuring valid informed consent (IC) prior to enrollment in clinical trials is a fundamental ethical right. Objective: To assess whether social determinants of health (SDOH) and related sociocontextual factors are associated with parental IC comprehension in therapeutic childhood cancer clinical trials. Design, Setting, and Participants: This cross-sectional study prospectively enrolled 223 parents of children with newly diagnosed cancer at Rady Children's Hospital San Diego, a large quaternary academic center in California, from October 1, 2014, to March 31, 2021. Linear mixed effects models were used to assess whether IC comprehension overall and by domain (purpose, procedures, and randomization; risks and benefits; alternatives; and voluntariness) were associated with SDOH and sociocontextual factors. Data were analyzed from January 1, 2022, to July 31, 2023. Exposures: Informed consent for a therapeutic childhood cancer clinical trial. Main Outcomes and Measures: The primary outcome of interest was IC comprehension and its associations with SDOH (marital status, language, educational attainment, employment, insurance type, socioeconomic status, and health literacy) and sociocontextual factors (ethnicity, satisfaction with informed consent, and cancer type). Results: Of 223 parents, 172 (77.1%) were aged 18 to 44 years, 111 (49.8%) were Hispanic, 152 (68.2%) were women, and 163 (73.1%) were married. In terms of race, 2 (0.9%) were American Indian or Alaska Native, 22 (9.9%) were Asian or Pacific Islander, 8 (3.6%) were Black, 149 (66.8%) were White, and 42 (18.8%) were more than 1 race. In multivariable linear mixed-effects analyses, limited vs adequate health literacy was associated with lower comprehension of informed consent overall (mean [SD], 68.28 [11.81] vs 79.24 [11.77]; β estimate, -9.02 [95% CI, -12.0 to -6.07]; P < .001) and with lower comprehension of the purpose, procedures, and randomization (mean [SD], 65.00 [12.64] vs 76.14 [11.53]; β estimate, -7.87 [95% CI, -10.9 to -4.85]; P < .001); risks and benefits (mean [SD], 62.84 [20.24] vs 73.14 [20.86]; β estimate, -10.1 [95% CI, -15.6 to -4.59]; P < .001); alternatives (mean [SD], 54.27 [43.18] vs 82.98 [34.24]; β estimate, -14.3 [95% CI, -26.1 to -2.62]; P  .02); and voluntariness (mean [SD], 76.52 [24.33] vs 95.39 [13.89]; β estimate, -9.14 [95% CI, -14.9 to -3.44]; P = .002) domains. Use of Spanish vs English language for medical communication was associated with lower comprehension overall (mean [SD], 66.45 [12.32] vs 77.25 [12.18]; β estimate, -5.30 [95% CI, -9.27 to -1.34]; P = .01) and with lower comprehension of the purpose, procedures, and randomization (mean [SD], 63.33 [11.98] vs 74.07 [12.52]; β estimate, -4.33 [95% CI, -8.43 to -0.23]; P = .04) and voluntariness (mean [SD], 70.83 [24.02] vs 92.54 [17.27]; β estimate, -9.69 [95% CI, -16.8 to -2.56]; P = .009) domains. Conclusions and Relevance: In this cross-sectional study including parents of children with newly diagnosed cancer who provided IC for their child's participation in a therapeutic clinical trial, limited health literacy and use of Spanish language for medical communication were associated with lower comprehension of IC. These findings suggest that, in this setting, parents with limited health literacy or those who use Spanish language for medical communication may not fully comprehend IC and therefore may not make truly informed decisions. These findings support the investigation of interventions, across pediatric disciplines, tailored to the participant's language and health literacy level to improve IC comprehension, particularly in racial and ethnic minority populations.