Development and psychometric analysis of the systemic lupus erythematosus needs questionnaire (SLENQ).

This study aims to develop a self-administered needs assessment questionnaire for people with systemic lupus erythematosus (SLE), assess its face, content and construct validity and test the reliability of the instrument. Eighty-four people with SLE, registered with a Lupus Resource Centre in New South Wales, Australia participated in a series of focus groups and pre and pilot testing phases in the development of a needs instrument and 594 people from a SLE support association were sent the SLE needs questionnaire (SLENQ) and the MOS-SF-36 and asked to complete both. Face and content validity were found to be high following pre and pilot testing. Principal components analysis identified seven factors with eigenvalues greater than 1, which together accounted for 53% of the total variance (psychological/spiritual/existential, health services, health information, physical, social, daily living and employment/financial needs). Internal reliability coefficients (Cronbach's alpha) of all seven factor-based scales were found to be substantial, ranging from 0.77 to 0.96. Moderately significant correlation between the domains of the SLENQ and the MOS SF-36 were supportive in ascertaining concurrent validity. These findings suggest that the SLENQ provides a reliable and valid index of the global needs of people with SLE.