External adjustment for unmeasured confounders improved drug-outcome association estimates based on health care utilization data

摘要

Objectives: Health care utilization (HCU) databases are widespread sources of data for pharmacoepidemiologic investigations. Possible confounders are typically not measured in such databases. We show how to assess the impact of confounders in a study aimed at comparing cardiovascular (CV) risk according to drug regimen prescribed at starting antihypertensive therapy, nominally one agent (monotherapy) or a combination of agents in a unique tablet (fixed-dose combination) or in at least two distinct tablets (extemporaneous combination).