Objective: To evaluate the responsiveness of Lupus Impact Tracker (LIT) to changes in physician and patient disease activity assessments over time.
Methods: Available longitudinal data from routine patient care visits on LIT, physician assessed disease activity (physician global assessment (PGA), SELENA-SLEDAI score, SELENA Flare Index (SFI)), and patient-reported changes in systemic lupus erythematosus (SLE) health status were analyzed. Significant, clinically important change (worsening or improvement) in physician disease activity assessment or patient-reported SLE health status were judged using the following criteria: change of 0.3 on PGA, 4 on SELENA-SLEDAI, change in SFI status over time, and change of 2 in either direction in patient-reported SLE health status. Mixed model regression analysis was used to compare changes in LIT using the above criteria.
Results: There were 1184 observations with significant changes in physician disease activity or patient-reported measure for 182 patients' data across 1364 visits. Patients' mean (SD) age and SELENA-SLEDAI were 43.5 (13.2) years and 6.4 (7.3) respectively. LIT mean scores decreased by more than 3 with improvement in PGA (standardized response mean -0.26, p < 0.05), while it increased by more than 5 with worsening in SELENA-SLEDAI (standardized response mean 0.42, p = 0.01). Mean change in LIT of greater than ±3 was noted with change in SFI status (p < 0.05). Mean LIT score decreased by greater than 4 and increased by greater than 2 with patient-reported improvement and worsening in SLE health status respectively (p < 0.05).
Conclusions: LIT is responsive to physician-assessed and patient-assessed changes in disease status. A mean LIT change of 2-4 may represent a significant clinical change in LIT. It is an effective tool that may be used by patients and physicians in tracking disease impact in SLE patients.
Keywords: Systemic lupus erythematosus; disease activity; outcomes research.
© The Author(s) 2015.