Stratification on the propensity score has been used to identify heterogeneity of treatment effect (HTE) and may be an indicator of clinically meaningful differences between subgroups. The RiGOR study, an AHRQ-funded prospective observational study of the comparative effectiveness of open angle glaucoma treatments, incorporates analysis of HTE across pre-specified minority subgroups. Recruitment and baseline data collection for RiGOR is complete. Follow-up for clinical outcomes over 12 months is ongoing. Results of estimation of propensity scores indicative of treatment preference and heterogeneity in the propensity score between two or more minority subgroups in RiGOR will be presented. Implications for the final analyses comparing clinical outcomes according to treatment will be explored.