211. The Cost of Ankylosing Spondylitis to the UK NHS

Background: There are limited data about the direct costs of AS for the NHS. We estimated the direct NHS costs of AS using a combination of patient-reported and linked routine data.

Methods: Participants in the existing Population-based AS cohort (n = 512) were invited to complete a cost questionnaire, based on their recall of the past 3 months. These patients were also tracked through different healthcare settings using routinely collected NHS datasets. The routine data were linked and compared with the patient-reported data. Where there were discrepancies, the dataset that was most representative of the true situation was used to calculate costs. Direct healthcare costs were calculated using a bottom-up micro-costing approach, at 2010 prices, and reported from the healthcare provider perspective. Logistic regression was used to account for explanatory variables as correlates of cost. Multivariate Ordinary Least Squares regression was used to report the marginal effects of variables on healthcare costs.