Health Care Costs attributable to Hospital-diagnosed Back Pain: A Longitudinal Register-based Study of the Danish Population

Background: Back pain is one of most frequent musculoskeletal conditions with enormous impact to health care systems and society. Analytical studies that guide the management of this disease are strongly needed, but there is a lack of cost estimates for the attributable cost of severe or chronic back pain in particular. Objective: The objective of this study was to estimate the health care costs attributable to hospitaldiagnosed back pain across strata of age-, gender- and diagnostic entity. Methods: All adult Danes (N=4.3 million) were included in this longitudinal, controlled register-based study. One-year prevalence was defined according to a previously published and validated algorithm, which was applied to the Danish national patient registry. Data from other relevant health service use registries was appended along with data from the national cause of death registry in order to calculate cost rates per life year (2011 price year). The attributable health care cost was defined as the absolute difference in cost rates between individuals with versus individuals without hospital-diagnosed back pain, whereas the ratio between the two groups was used for the reporting of reference values. Results: The health care costs attributable to hospital-diagnosed back pain were estimated at Danish Crowns (DKK) 22,700 per year for the youngest age strata (16-24 years) and increased up to DKK 72,700 per year for the oldest age strata of males (>85 years). Hospital admissions and outpatient visits accounted for the majority of these costs. The ratio of health care costs for individuals with versus individuals without the condition ranged from less than 1 to almost 6, depending on the type of service use, age and gender. Conclusion: At the disease stage where back pain leads to contact with specialised health care, diseased individuals appear to use on average three times more health care than non-diseased individuals. This study provides detailed reference values, which can be used to inform health economic models.