Development of a predictive model for temporal artery biopsies

Abstract

Objective: Temporal 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.

Design: A prospective case series PARTICIPANTS: A consecutive case series of patients referred to the Ophthalmology service for temporal artery biopsy.

Methods: All subjects underwent standardized serum testing, and signs and symptoms assessment. Predictive models were created and evaluated.

Results: 119 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.

Conclusions: Utilizing 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.