HLA-B27 detection test for individuals with suspected axial spondyloarthritis to Brazilian public health system: accuracy, cost-effectiveness, and budget impact analysis

Objective: the aim of this study is to assess the accuracy, cost-effectiveness, and budget impact of the HLA-B27 test in diagnosis of axial spondyloarthritis to Brazilian Public Health System (SUS). Methods: A systematic review was conducted to assess the sensitivity and specificity of HLA-B27 compared to test ASAS or New York diagnostic criteria. Additionally, a cost-effectiveness analysis (a decision tree model coupled with a Markov model and effectiveness outcome of quality-adjusted life year (QALY)) and budget impact analysis were also developed. Costs were obtained in Brazilian currency and converted to dollars considering the PPP conversion factor. Results: Twenty-nine studies have shown that the sensitivity of the HLA-B27 test was 68% (95% CI: 67-69%) and the specificity was 88% (95% CI: 87-88%) (very low certainty of evidence to both outcomes) when compared with any comparator. The analysis of two studies showed that the combination of HLA-B27+clinical parameters still achieved sensitivity and specificity comparable to or greater than the combination of imaging and clinical parameters, or clinical parameters alone. When compared with clinical evaluation and clinical evaluation±imaging, the HLA-B27 test+clinical evaluation was close to the cost-effectiveness threshold ($17,628 per QALY) and dominated the comparator, respectively. Furthermore, incorporating HLA-B27 into the SUS would result in an increase in costs of $530,393 in 5-years of analysis (mean of six thousands/year eligible patients to HLA-B27). Conclusion: The findings supported the coverage of the HLA-B27 test in SUS, considering that test increases accuracy when associated with other diagnostic strategies and has the potential to be cost-effective or dominant.