Development of a predictive model for temporal artery biopsies

Abstract

ObjectiveTemporal artery biopsy is a critical, relatively safe, and reliable test in the diagnosis of temporal arteritis. Yet, a clarification of the pre-test probabilities may provide clarity on which patients with suspected giant cell arteritis would benefit from this invasive diagnostic procedure. DesignA prospective case series ParticipantsA consecutive case series of patients referred to the Ophthalmology service for temporal artery biopsy. MethodsAll subjects underwent standardized serum testing, and signs and symptoms assessment. Predictive models were created and evaluated. Results119 patients were analyzed. This exploratory study found that a simple model including platelet count, erythrocyte sedimentation rate, and c-reactive protein was able to define a subset of patients with a pre-test probability of a positive biopsy of 0% or 100%. 40% (95% confidence interval 31%-49%) of patients fell into this category. ConclusionsUtilizing a simple clinically applicable predictive model of the pretest probability of a temporal artery biopsy in patients with suspected giant cell arteritis, up to 31%-49% of temporal artery biopsies may be avoided. This study was a single site exploratory study with data-driven thresholds - therefore these results need to be validated with an independent sample prior to clinical use.