Healthcare Service Usage and Costs for Elderly Patients with Obstructive Lung Disease.

Background: The worldwide prevalence of obstructive lung disease (OLD) is increasing, especially among people >65 years old, and nearly three in four adults with OLD have two or more comorbid conditions. This study describes the impact of such comorbidities on the healthcare service usage and related costs in a country with universal health coverage, basing on a large cohort of elderly patients with OLD and employing real-world data. Methods: We carried out a retrospective cohort study on a large population of elderly (age >64 years) patients with OLD served by a Local Health Unit in northern Italy. Their comorbidities were assessed using the clinical diagnoses assigned by the Adjusted Clinical Group (ACG) system to individual patients by combining different information flows. Correlations between number of comorbidities and total annual healthcare service usage and costs were examined with Spearman's test. Regression models were applied to analyze the associations between the above-mentioned variables, adjusting for age and sex. Results: All types of healthcare service usage (access to emergency care; number of outpatient visits; number of hospital admissions) and pharmacy costs increased significantly with the number of comorbidities. Average total annual costs increased steadily with the number of comorbidities, ranging from € 1158.84 with no comorbidities up to € 9666.60 with 6 comorbidities or more. Poisson regression analyses showed an independent association between the number of comorbidities and the use of every type of healthcare service. Conclusion: These results based on real-world data provide evidence that the burden of care for OLD patients related to their comorbidities is independent of and in addition to the burden related to OLD alone and is strongly dependent on the number of comorbidities, suggesting a holistic approach to multimorbid patients with OLD is the most sound public health strategy.