The impact of adherence to guidelines on the health care expenditures of COPD patients

OBJECTIVES: This study proposes to investigate the association among adherence to guidelines, patients characteristics, and health care expenditures using methods for handling endogeneity and selection bias.;METHODS: The study population consists of the random 5% COPD cohort in Medicare for the time period between 2006 and 2008. Patients are classified in 4 groups based on the percentage of use of appropriate therapy based on the GOLD guidelines among the quarters: Group I) 0% - 25%; Group II) 25% - 50%; Group III) 50% - 75%; and Group IV) 75% - 100%. In the dynamic panel data, the time unit of the panel model is set to three months (quarter). The two part model computes the probability of a patient surviving at a given time period and then computes the expected health care expenditures of that patient, given that he/she has survived.;RESULTS: The unadjusted difference in cost between Group I and Group IV is ;CONCLUSIONS: Different approaches are used to control for endogeneity and selection bias, which show that the results of the benefits of appropriate therapy are consistent. Our findings suggest that the treatment recommended by the GOLD guidelines for moderate-to-severe COPD patients leads to a significant reduction in health care expenditures.