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Development and Validation of the Lupus Impact Tracker: A Patient‐Completed Tool for Clinical Practice to Assess and Monitor the Impact of Systemic Lupus Erythematosus
Author(s) -
Jolly Meenakshi,
Garris Cindy P.,
Mikolaitis Rachel A.,
Jhingran Priti M.,
Dennis Greg,
Wallace Daniel J.,
Clarke Ann,
Dooley Mary Anne,
Parke Ann,
Strand Vibeke,
Alárcon Graciela S.,
Kosinski Mark
Publication year - 2014
Publication title -
arthritis care and research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.032
H-Index - 163
eISSN - 2151-4658
pISSN - 2151-464X
DOI - 10.1002/acr.22349
Subject(s) - discriminant validity , stepwise regression , medicine , convergent validity , confirmatory factor analysis , physical therapy , criterion validity , clinical psychology , psychology , psychometrics , construct validity , internal consistency , statistics , structural equation modeling , mathematics
Objective To derive and validate a brief patient‐completed instrument, the Lupus Impact Tracker (LIT), to assess and monitor the impact of systemic lupus erythematosus (SLE). Methods Items for the LIT were selected from the LupusPRO, a validated patient‐reported outcomes measure, using 3 approaches: confirmatory factor analysis (CFA), stepwise regression, and patient focus groups. CFA was conducted to find items from the LupusPRO that fit a unidimensional structure to allow scoring as a single index. Stepwise regression methods identified items with the strongest relationship (convergent validity) with disease activity measures and patient health rating. Focus groups (n = 26 patients) identified the most important items describing SLE impact. Selected items were evaluated for reliability and validity. Results CFA found 21 items that fit a unidimensional structure. Stepwise regressions identified 15 of 21 items having good convergent validity with clinical measures. Patient focus groups identified 9 of 15 items as best capturing the impact of SLE. Overall, 7 items were selected across all 3 approaches (CFA, stepwise regression, and focus groups). Another 15 items were selected across 2 approaches. Through consensus with rheumatology clinician experts, a final set of 10 items was selected for the LIT. The LIT items showed good internal consistency (0.89) and test–retest reliabilities (0.87). Mean LIT scores differed significantly ( P < 0.05) across criterion groups in the hypothesized direction, providing evidence of discriminant validity and responsiveness. Conclusion The LIT is reliable and valid in SLE patients and offers a practical way for physicians and patients to assess and monitor the impact of SLE.