Diagnostic Efficacy of Classification Criteria for Systemic Lupus Erythematosus Compared

The diagnostic efficacy of 3 different classification criteria – The American College of Rheumatology (ACR)-1997, Systemic Lupus International Collaborating Clinics (SLICC)-2012, and European Alliance of Associations for Rheumatology (EULAR)/ACR-2019 – for systemic lupus erythematosus (SLE) were compared in a study published in Lupus Science & Medicine. Overall, the SLICC-2012 and EULAR/ACR-2019 diagnostic criteria performed well and showed better early diagnostic ability.

Despite the widespread use of the ACR-1997, SLICC-2012, AND EULAR/ACR-2019 classification criteria, data on their diagnostic performance are limited.

The retrospective cohort study enrolled patients with and without established SLE between January 2016 and December 2020. Demographic and clinical data were collected from medical records. The ACR-1997, SLICC-2012, and EULAR/ACR-2019 scores were calculated. The relative sensitivity and specificity of each score was calculated using area under the receiver operating characteristic curve (AUC).

The study cohort included 352 patients with SLE and 385 individuals without SLE. The majority of both the SLE group (91.5%) and control group (72.5%) were women. Patients with SLE had a significantly younger median age than those without SLE (36.0 vs 54.0 years, respectively; P <.001).

Of the total cohort, 289 (82.1%), 345 (98.3%), and 343 (97.4%) reached the threshold for SLE diagnosis, according to the ACR-1997, SLICC-2012, and EULAR/ACR-2019, respectively. Overall, 287 patients met the diagnostic threshold of all 3 sets of classification criteria. All 3 criteria had excellent classification ability, with AUC values of 0.986 (95% CI, 0.975-0.993) for SLICC-2012, 0.983 (95% CI, 0.970-0.991) for EULAR/ACR-2019, and 0.972 (95% CI, 0.957-0.983) for ACR-1997. Of the 3 criteria, ACR-1997 had the highest specificity (96.4%) but the lowest sensitivity (82.1%). The sensitivity and specificity values for SLICC-2012 were 92.2% and 98.0%, respectively, and for EULAR/ACR-2019, the values were 91.4% and 97.4%.

Among both men and women, SLICC-2012 and EULAR/ACR-2019 vs ACR-1997 had greater sensitivity and lower specificity (among men, 100.0% and 90.0% vs 89.1% and 96.2%, respectively, and 96.2% vs 100.0%, respectively; among women, 98.1% and 98.1% vs 82.0%, respectively, and 90.7% and 89.6% vs 95.0%, respectively). Similarly, across age categories and disease duration strata, ACR-1997 had the highest specificity and lowest sensitivity. In analyses of the median time between symptom onset and fulfillment of the 3 sets of criteria, SLICC-2012 and EULAR/ACR-2019 vs ACR-1997 achieved earlier diagnosis (0.5 and 0.13 vs 1.0 months). The researchers also observed that adjusting the threshold of the EULAR/ACR-2019 classification criteria from 10 to 12 resulted in significantly increased sensitivity and specificity.

As study limitations, the researchers cited the single-center retrospective design, which may have reduced data generalizability.

“In conclusion, both the SLICC-2012 and EULAR/ ACR-2019 had optimal diagnostic efficacy in identifying Chinese patients with SLE, whether in the overall patients or the subgroup stratified by age, [sex] and course of disease,” the study authors said.

Reference

Lu W, Zhong Y, Weng C, et al. Utility of the ACR-1997, SLICC-2012 and EULAR/ACR-2019 classification criteria for systemic lupus erythematosus: a single-centre retrospective study. Lupus Sci Med. Published online September 7, 2022. doi:10.1136/lupus-2022-000718