Is there an advantage over SF-36 with a quality of life measure that is specific to systemic lupus erythematosus?
OBJECTIVE
To assess whether the Lupus Quality of Life (LupusQoL) questionnaire contributed additional information not obtained using the Medical Outcomes Study Short-Form 36 questionnaire (SF-36) in a cohort of patients with systemic lupus erythematosus (SLE).


METHODS
Forty-one patients seen at a single center were followed at monthly intervals for 12 months. The LupusQoL and the SF-36 questionnaires were coadministered monthly. Disease activity was determined by the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) every 30 days. We determined the correlation of the 4 comparable domains of both questionnaires. For the 4 noncomparable domains of the LupusQoL we determined the correlation between each domain with the Physical Component Summary scores (PCS) and the Mental Component Summary scores (MCS) of the SF-36. The effect size (ES) and the standardized response mean (SRM) were used to compare the responsiveness of both questionnaires when a clinically significant change in disease activity occurred as determined by SLEDAI-2K.


RESULTS
Three hundred seventy-six patient visits were recorded. There was a strong correlation between comparable domains in both questionnaires. For the 4 noncomparable domains of the LupusQoL, there was a correlation with the MCS and PCS of SF-36. The mean scores for comparable domains in both questionnaires were similar. Both questionnaires displayed responsiveness, as determined by ES and SRM among patients who flared and improved, but not among patients in remission, when compared to the previous visit.


CONCLUSION
LupusQoL and SF-36 were equivalent in assessing quality of life over time in this group of patients. Both questionnaires are responsive measures of quality of life in patients with SLE flares and improvement.