Sample size and statistical methods
For the prospective observational study, univariable and multivariable logistic mixed‐effects models with institution as a random effect were used to explore factors associated with potential trial eligibility. These factors included sociodemographic characteristics (race, age, education, income, health literacy) and perceived health status.For the prospective intervention study, the planned study sample size was 16 patients per physician and 24 physicians (i.e., 384 patients) using the person‐level multi‐site/block trial design within Optimal Design,