Optimizing Value in the Evaluation of Chronic Spontaneous Urticaria: A Cost-effectiveness Analysis

Abstract Background Chronic spontaneous urticaria (CSU) affects approximately 1% of the general population. The cost-effectiveness of routine laboratory testing for secondary causes of CSU has not been formally evaluated. Objective To characterize the cost-effectiveness of routine laboratory screening in adults with CSU. Methods A Markov model using cohort analysis and microsimulations was created for adult patients aged 20 years, over a 10-year time horizon, randomized to receive screening laboratory testing or a no-testing approach. Laboratory results were derived from a previously published retrospective analysis of adult CSU patients. Cost-effectiveness was evaluated at a Willingness to Pay (WTP) threshold of $100,000/quality-adjusted life-year (QALY) using the incremental cost-effectiveness ratio (ICER) in patients with untreated CSU, and patients treated with anti-histamines, cyclosporine, or omalizumab. Results Average laboratory costs per simulated CSU patient were $572.97 (SD, $41.11), with only 0.16% (SD, 3.99%) of tests resulting in improved clinical outcomes. Testing costs per laboratory-associated positive outcome were $358,052 (no therapy), $357,576 (anti-histamine therapy), $354,115 (cyclosporine), and $262,121 (omalizumab). Screening tests were not cost-effective, with ICERs of $856,905 (no therapy), $855,764 (anti-histamine therapy), $847,483 (cyclosporine), and $627,318 (omalizumab). In the omalizumab-treated subgroup, testing could be cost-effective below $220 or if it resulted in a 0.73% rate of CSU resolution. From a simulated US population perspective, nation-wide screening costs could reach $941,750,741 - $1,833,501,483. Conclusions In CSU the likelihood of clinical improvement from laboratory testing is very low, and testing not cost-effective. These data support recommendations to not routinely perform laboratory testing in CSU patients with otherwise normal histories and physical evaluations.