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

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 patients with CSU. Cost-effectiveness was evaluated at a willingness to pay threshold of $100,000/quality-adjusted life-year using the incremental cost-effectiveness ratio (ICER) in patients with untreated CSU, and patients treated with antihistamines, cyclosporine, or omalizumab. RESULTS: Average laboratory costs per simulated patient with CSU were $573 (standard deviation [SD], $41), 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 (antihistamine therapy), $354,115 (cyclosporine), and $262,121 (omalizumab). Screening tests were not cost-effective, with ICERs of $856,905 (no therapy), $855,764 (antihistamine 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 to $1,833,501,483. CONCLUSIONS: In CSU, the likelihood of clinical improvement from laboratory testing is very low, and testing is not cost-effective. These data support recommendations to not routinely perform laboratory testing in patients with CSU with otherwise normal histories and physical evaluations. (C) 2019 American Academy of Allergy, Asthma & Immunology.