Availability and Use of Social Determinants of Health Data in Alliance Gastrointestinal Cancer Clinical Trials

Social determinants of health (SDOH) shape cancer treatment access, adherence, and outcomes, yet their collection and use within National Clinical Trials Network (NCTN) studies remain poorly defined. This study examined how demographic and SDOH-related variables were historically collected and published to identify gaps that constrain the study of social context within NCTN trials.

Participant-level data from completed phase III trials for gastrointestinal (GI) cancers conducted by the Alliance for Clinical Trials in Oncology (Alliance) or its legacy groups from 1999 to 2018 were pooled. Thirteen measures were assessed: four demographic and nine SDOH-related. The proportion of individual participants with data collected for each measure was evaluated. Data utilization was evaluated for all primary articles and via targeted review of related publications using the number either reporting subgroups or publishing analyses for each measure.

A total of 12,701 participants across 11 trials were included. All trials collected demographic measures (<2% of patients missing), insurance status (1% missing), and ZIP code (3% missing). Education level was collected in two trials (28% missing) with marital and employment status collected in one trial (41% missing for both). No trials collected data on other SDOH-related measures. Education level was the only SDOH-related measure reported in primary articles, and none reported analysis of SDOH-related measures. Of the 149 related publications, <2% reported or analyzed any SDOH-related measure.

Across Alliance and NCTN legacy group phase III trials for GI cancers, demographic variables have been consistently collected and frequently reported or analyzed, whereas SDOH-related measures are inconsistently collected and rarely published in the literature. These findings demonstrate a historical absence of routine SDOH data capture and utilization within NCTN trials.