The Long Term Effects of Consumer-Directed Health Plans (CDHPs) on Use of Preventive Care
Objective: To investigate the effects of CDHPs on the use of recommended preventive care including childhood immunization, cancer screening (breast, cervical and colorectal), and hemoglobin (A1C) testing.
Data: We use a unique dataset of 5 years of enrollment and claims data for 60 large U.S. firms (about 17 million, person-years of data) half of which began offering a CDHP during the study period.
Methods: We start with firm level difference-in-difference models to compare trends in use of preventive services in firms that offered CDHPs to firms that never offered CDHPs. To control for possible differences in treatment and control firm composition, we use a rich set of control variables to balance observables including use of preventive care prior to CDHP offer. We distinguish between effects in the first year of offer, second year of offer and third year of offer. We also estimate how effects differed with take-up of CDHP plans.
In an alternate set of analyses, we stratify the sample into those who did or did not receive the preventive service in a base year. We then follow these families over time to see if use of preventive services in future years is influenced by enrollment in CDHPs. The stratification will address concerns that families who are about to transition into a high-deductible plan will try to obtain care that they anticipate needing before the transitions; that is, they will try to “stock up” on care. Preliminary evidence indicates that CDHPs reduce use of preventive care.