Comparison of the systemic lupus erythematosus activity questionnaire and the systemic lupus erythematosus disease activity index in a black barbadian population

The use of patient-reported outcome measures to classify type 1 and 2 systemic lupus erythematosus activity

OBJECTIVE

We developed a model that categorizes systemic lupus erythematosus (SLE) activity into two dimensions: Type 1 SLE consists of inflammatory activity, including arthritis, nephritis, and rashes; Type 2 SLE includes fatigue, myalgia, mood disturbance, and cognitive dysfunction. Patient-reported outcome (PRO) measures have received attention as a way to capture symptomatology of SLE. The objective of this study was to explore the use of existing PRO measures to classify Type 1 and 2 SLE activity.

METHODS

Systemic lupus erythematosus patients completed three questionnaires: Systemic Lupus Activity Questionnaire (SLAQ), Polysymptomatic Distress Scale (PSD), and Patient Health Questionnaire (PHQ-2). SLE Disease Activity Index (SLEDAI) and physician global assessments (PGA; 0-3) for Type 1 and Type 2 activity were also recorded. High Type 1 SLE activity was defined as cSLEDAI ≥4 (scored without labs), SLEDAI ≥6, active nephritis, or Type 1 PGA ≥1.0. High Type 2 SLE activity was defined as Type 2 PGA ≥1.0. Patients with both high Type 1 and 2 activity were defined as Mixed SLE, and patients with low Type 1 and 2 activity were defined as Minimal SLE. Data were reduced with a factor analysis. Using a reduced set of 13 variables, multinomial logistic regression models estimated the probability of Minimal, Type 1, Type 2, and Mixed SLE classification.

RESULTS

The study included 208 patients with SLE. The model accurately predicted the clinician-based Type 1 and 2 SLE classification in 63% of patients; 73% of patients had their Type 1 SLE activity accurately predicted; and 83% had their Type 2 SLE activity accurately predicted. Performance varied by group: 87% of Minimal patients were correctly predicted to be in the Minimal SLE group, yet only about one-third of patients in the Type 1 group were correctly predicted to be in the Type 1 group.

CONCLUSIONS

Our findings indicate Type 2 SLE activity can be identified by patient-reported data. The use of PROs was not as accurate at predicting Type 1 activity. These findings highlight the challenges of using PROs to categorize and classify SLE symptoms since some manifestations of Type 1 activity (e.g., nephritis) may be essentially clinically silent while other Type 1 manifestations may cause severe symptoms.

Use of Physician Global Assessment in systemic lupus erythematosus: a systematic review of its psychometric properties

OBJECTIVE

The Physician Global Assessment (PGA) is a visual analogue score that reflects the clinician's judgement of overall SLE disease activity. The aim of this systematic literature review is to describe and analyse the psychometric properties of the PGA.

METHODS

This systematic literature review was conducted by two independent reviewers in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. All articles published through 1 July 2019 in PubMed were screened, with no limitation on year of publication, language or patients' age. Psychometric properties data were analysed according to the OMERACT Filter methodology version 2.1.

RESULTS

The literature search identified 91 studies. Face validity was reported in all the articles retrieved in which the PGA was used alone or as part of composite indices (Systemic Responder Index, Safety of Estrogen in Lupus Erythematosus National Assessment Flare Index, Lupus Low Disease Activity State, Definitions of Remission in Systemic Lupus Erythematosus criteria). Content validity was reported in 89 studies. Construct validity was demonstrated by a good correlation (r ≥ 0.50) between the PGA with the SLEDAI (12 studies), SLAM (4 studies), LAI, BILAG and ECLAM (2 studies each). Criterion validity was assessed exploring the PGA correlation with quality of life measurements, biomarker levels and treatment changes in 28 studies, while no study has evaluated correlation with damage. A good responsiveness for PGA was shown in eight studies. A high variability in scales was found, causing a wide range of reliability (intraclass correlation coefficient 0.67-0.98).

CONCLUSION

PGA is a valid, responsive and feasible instrument, though its reliability was impacted by the scale adopted, suggesting the major need for standardization of its scoring.

Translation, cultural adaptation and validation of the Systemic Lupus Erythematosus Activity Questionnaire (SLAQ) in a cohort of Italian systemic lupus erythematosus patients

Introduction The Systemic Lupus Erythematosus Activity Questionnaire (SLAQ) is a patient-reported instrument for the assessment of disease activity in systemic lupus erythematosus (SLE). The aims of the present study are translation, cultural adaptation and validation of an Italian version: the SLAQit. Methods The process of translation and cultural adaptation followed published guidelines. SLAQit was pretested in a group of 35 SLE patients to evaluate acceptability, comprehension and feasibility. Internal consistency, test-retest validity and external validity were tested on consecutive SLE patients attending the clinic. Results In total, 135 SLE patients were enrolled in this study. The pilot test provided a 99.9% response rate and demonstrated feasibility and comprehensibility of the questionnaire. A good internal consistency was found among the three components of the score (SLAQ score, numerical rating scale (NRS), patient global assessment question (PGA); α = 0.79). SLAQit showed very high reliability (test-retest α > 0.8). NRS and PGA showed a strong positive correlation with both Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) ( p = 0.002 and p < 0.001, respectively) and European Consensus Lupus Measurement (ECLAM) scores ( p = 0.01 and p < 0.001, respectively), while the SLAQ score did not. A significant agreement was observed between the physician's intention to treat and both the NRS and PGA scores, while no significant association was reported with the SLAQ score. Conclusions SLAQit was demonstrated to be a reliable and valid instrument for self-assessment of disease activity in SLE patients.

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

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.