Assessment of the Construct Validity of the Lupus Low Disease Activity State (LLDAS) – an Expert Opinion Case Study

Vera Golder¹, Molla Huq², Kate Franklyn³, Alicia Calderone⁴, Aisha Lateef⁵, Chak Sing Lau⁶, Sandra V. Navarra⁷, Timothy Godfrey^4,8, Shereen Oon⁴, Alberta Y. Hoi³, Eric F Morand³, Mandana Nikpour⁹ and Asia Pacific Lupus Collaboration, ¹Southern Clinical School, Centre for Inflammatory Diseases, Monash University, Melbourne, Australia, ²Department of Medicine (Rheumatology), Melbourne University, Melbourne, Australia, ³Centre for Inflammatory Diseases, Monash University, Melbourne, Australia, ⁴St. Vincent’s Hospital, Melbourne, Australia, ⁵Medicine/Rheumatology, National University Health System, Singapore, Singapore, ⁶Univ Dept of Medicine, Queen Mary Hospital, Hong Kong, Hong Kong, ⁷Rheumatology, University of Santo Tomas Hospital, Manila, Philippines, ⁸63 Sutton Street, St. Vincent’s Hospital, Melbourne, Australia, ⁹Melbourne University, Melbourne, Australia

Meeting: 2016 ACR/ARHP Annual Meeting

Date of first publication: September 28, 2016

Keywords: Disease Activity and systemic lupus erythematosus (SLE)

Session Information

Date: Sunday, November 13, 2016

Title: Systemic Lupus Erythematosus – Clinical Aspects and Treatment - Poster I: Clinical Trial Design and Current Therapies

Session Type: ACR Poster Session A

Session Time: 9:00AM-11:00AM

Background/Purpose: Systemic lupus erythematosus (SLE) has historically lacked clear treat-to-target definitions. The recently reported Lupus Low Disease Activity State (LLDAS) definition, combining disease activity and treatment domains, was shown to be associated with protection from damage accrual in a longitudinal cohort study. Before acceptance in clinical practice and research, any new measure should undergo rigorous validation including face, content, construct and criterion validity. The objective of this study was to assess the construct validity of LLDAS by testing the operational definition against SLE expert opinion.

Methods: Fifty SLE case summaries based on real patients and without manipulation were prepared by experts in 4 countries in the Asia Pacific. Each case detailed past history, current disease features, current treatment and investigation results. Fifty rheumatologists with expertise in SLE, from multiple centres and countries, but with no prior involvement in the LLDAS project, responded to a survey in which they were asked to categorise the current disease activity state of each case as either remission, low, moderate or high, without reference to the operational definition. Two investigators independently assessed whether each case met the operational definition of LLDAS. Agreement between expert opinion and the operational definition of LLDAS was assessed using Cohen’s Kappa.

Results: In total, 2500 unique responses were collected. Overall agreement between expert opinion and the operational definition of LLDAS was 77.96% (95% CI 76.34 – 79.58%), with a Cohen’s Kappa of 0.57 (95% CI 0.55 – 0.61). Of the cases (22 of 50) that fulfilled the operational definition of LLDAS, only 5.34% of responders classified the cases as moderate/high activity. In contrast, of the cases that did not fulfill the operational definition of LLDAS (28 of 50), 35.14% of responders classified the cases as remission/low activity. Common reasons for this discordance were assignment to remission/low activity of cases with higher corticosteroid doses than defined in LLDAS (prednisolone ≤ 7.5mg) or serological activity (high anti-dsDNA antibody and /or low complement).

Conclusion: LLDAS has good construct validity with high overall agreement between the operational definition of LLDAS and expert opinion. Discordance of results suggests that the operational definition of LLDAS is more stringent than expert opinion at defining a low disease activity state, and that expert definition of acceptable corticosteroid dose in SLE varies.

Disclosure: V. Golder, None; M. Huq, None; K. Franklyn, None; A. Calderone, None; A. Lateef, None; C. S. Lau, None; S. V. Navarra, None; T. Godfrey, None; S. Oon, None; A. Y. Hoi, None; E. F. Morand, None; M. Nikpour, None.

To cite this abstract in AMA style:

Golder V, Huq M, Franklyn K, Calderone A, Lateef A, Lau CS, Navarra SV, Godfrey T, Oon S, Hoi AY, Morand EF, Nikpour M. Assessment of the Construct Validity of the Lupus Low Disease Activity State (LLDAS) – an Expert Opinion Case Study [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/assessment-of-the-construct-validity-of-the-lupus-low-disease-activity-state-lldas-an-expert-opinion-case-study/. Accessed .

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