<h3>Background</h3> Systemic lupus erythematosus (SLE) is a disease with multisystem involvement. Throughout history, different activity indices have been developed trying to identify patients who have the flare of the disease. These indexes measure different aspects of the disease. Among the most recognised score is SLEDAI 2 K. Others that had been evaluated is the SLEDAI MEX and the ECLAM. The performance of the measurement of the SLEDAI 2 K is more expensive because of the number of variables evaluated. ECLAM score and the SLEDAI MEX have less number of variables and therefore costs are minor. ^{1, 2, 3} <h3>Objectives</h3> To compare the predictive capacity of mortality of three different scores of disease activity (SLEDAI 2 K, SLEDAI MEX, and ECLAM) in a Colombian population with SLE. To compare the predictive capacity of mortality of three different scores of disease activity (SLEDAI 2 K, SLEDAI MEX, and ECLAM) in a Colombian population with SLE. <h3>Methods</h3> Cross-sectional study, in which descriptive analysis with measures of frequency, central tendency and dispersion were made. Subsequently, mortality prediction analysis of the three scales was performed through the evaluation of the ROC curve. Analysis of classification statistics was done. <h3>Results</h3> A total of 200 patients with SLE were included, with mortality of 11%. The averages of disease activity were: for SLEDAI 2 K was 14.5 with standard deviation (SD) of 9.7, for SLEDAI MEX 9.26 with SD of 5.93 and for ECLAM 4.39 with SD of 2, 28. The area under the curve of the ROC curves was 0.9082, 0.9206 and 0.8917 for the scales SLEDAI 2 K, SLEDAI MEX and ECLAM respectively. Regarding classification statistics, a sensitivity of 36.3% was found for the SLEDAI 2 K scale, specificity was 97.7%, positive predictive value 66.6, negative predictive value 92.5% and correct classification of 91%. For the SLEDAI MEX scale were: Sensitivity 50%, specificity 96.6%, positive predictive value 64.7%, negative predictive value 93.9% and correct classification of 91.5%. Finally, for the ECLAM scale, it was obtained the following results: sensitivity 9.09%, specificity 98.88%, positive predictive value 50%, negative predictive value 89.8% and correct classification in 89%. <h3>Conclusions</h3> It can be observed that the predictive capacity for mortality in the patients evaluated is good with the three different scales. The sensitivity found for the three scales is not optimal for making a promptly medical decision, so later it will be necessary the formulation of a new index in which higher number of patients with SLE can be detected with death risk. An additional relevant result is that the SLEDAI MEX activity index has a similar performance than the SLEDAI 2 K activity index for predicting mortality, with the advantage of being a practical index easy to apply and a lower cost of the evaluation. <h3>References</h3> [1] Castrejón I, et al. Índices compuestos para evaluar la actividad de la enfermedad y el daño estructural en pacientes con lupus eritematoso: Revisión sistemática de la literatura. Reumatol Clin2014;10(5):309–320. [2] Castrejon I, Tani C, Jolly M, Huang A, Mosca M. Indices to assess patients with systemic lupus erythematosus in clinical trials, long-term observational stuies and clinical care. Clin Exp Rheumatol2014;32(suppl. 85):S85–S95. <h3>Disclosure of Interest</h3> None declared