A comparison of patients’ and physicians’ assessments of disease activity using the Swedish version of the Systemic Lupus Activity Questionnaire

Abstract

Objectives: We compared patients’ assessments of systemic lupus erythematosus (SLE) disease activity by a Swedish version of the Systemic Lupus Activity Questionnaire (SLAQ) with physicians’ assessments by the Systemic Lupus Activity Measure (SLAM) and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K). We also explored the performance of the SLAQ in patients with short (< 1 year) versus long (≥ 1 year) disease duration.

Method: Patients filled out the SLAQ before physicians’ assessments. Correlations between SLAQ total, subscales (Symptom score, Flares, Patients global) and SLAM and SLEDAI-2K, as well as between the corresponding items in SLAQ and SLAM, were evaluated using Spearman’s ρ. Comparisons between patients with different disease durations were performed with Mann–Whitney U or chi-squared tests.

Results: We included 203 patients (79% women), with a median age of 45 years [interquartile range (IQR) 33–57 years] and disease duration of 5 years (IQR 0–14 years). Correlations between physicians‘ SLAM without laboratory items (SLAM-nolab) and patients’ assessments were: SLAQ total, ρ = 0.685, Symptom score, ρ = 0.651, Flares, ρ = 0.547, and Patients global, ρ = 0.600. Of the symptom items, fatigue (ρ = 0.640), seizures (ρ = 0.635), and headache (ρ = 0.604) correlated most closely. Neurology/stroke syndrome, skin, and lymphadenopathy correlated less well (ρ < 0.24). Patients’ and physicians’ assessments were notably more discordant for patients with short disease durations.

Conclusion: We confirm that the SLAQ can be used to monitor disease activity. However, the discrepancy between patients’ and physicians’ assessments was greater for patients with short versus long disease duration. We encourage further use of the SLAQ, but would like to develop a shorter version which would be valuable in modern, partly web-based, clinical care.

Acknowledgements

We are most grateful to all the patients who contributed in responding to the questions, and registered nurses Birgitta Fogelfors Mannerstedt and Eva Waldheim for assisting in the data collection.

This work was supported by the Swedish Rheumatism Association, a grant from King Gustaf V’s 80th Birthday Fund, and through the regional agreement on medical training and clinical research between Stockholm County Council and Karolinska Institutet and the Swedish Society of Nursing. The Associations of Swedish Rheumatology Nurses in collaboration with Merck Sharp and Dohme (Sweden), the Swedish Research Council, and the Swedish Heart–Lung Foundation.

Supporting Information

Additional Supporting Information may be found in the online version of this article.

Supplementary Table S1.The Swedish version of the SLAQ (Systemic Lupus Activity Questionnaire).

Supplementary Table S2. Disease activity scores of patients with SLE, mean (sd) and comparison to Karlson et al (12).

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