Using Propensity Score Methods to Create Target Populations in Observational Clinical Research

In a propensity score–matched cohort study published in the March 12, 2019, issue of JAMA, Zeng et al¹ found that prescription tramadol was associated with significantly greater 1-year mortality compared with nonsteroidal anti-inflammatory alternatives in adults with osteoarthritis. At baseline, patients receiving tramadol were different than those who received other analgesics in terms of demographics, medical comorbidities, medications, and prior hospital resource utilization. Zeng et al¹ used propensity score matching in an effort to account for differences between groups.² This matched sample corresponds to a unique target population.