Rare diseases: what do you need to know?

This six-part series on rare diseases aims to increase awareness and offer advice on how nurses can help patients. Part 1 uses a case study to illustrate the complexity of caring for people with rare diseases and provides pointers on how the care of this patient group can be improved.

The LupusQoL and associations with demographics and clinical measurements in patients with systemic lupus erythematosus.

OBJECTIVE: Having developed and validated a disease-specific health-related quality of life (HRQOL) measure for patients with systemic lupus erythematosus (SLE), the LupusQoL, we determined its relationship to demographic and clinical measurements in a group of patients with SLE. METHODS: A group of 322 outpatients completed the LupusQoL. Demographic (age, sex, marital status, ethnicity) and clinical variables (disease duration, disease activity, damage) were recorded. Associations between the 8 LupusQoL domains and age, disease duration, disease activity, and damage were explored using Spearman's correlation coefficients. Differences in LupusQoL scores were examined for sex and marital status using the Mann-Whitney U test. Ethnic groups were compared using ANOVA. RESULTS: All domains of LupusQoL were impaired, with fatigue (56.3) being the worst affected and body image (80.0) the least. The correlations between the LupusQoL domain scores and age (r = -0.01 to -0.22) and disease duration (r = 0 to 0.16) were absent or weak. Similarly, there were no significant differences in the LupusQoL scores regarding sex, marital status, or the 3 main ethnic groups (Black-Caribbean, Asian, White). Although there were statistically significant correlations between the scores of the LupusQoL domains and some scores of the British Isles Lupus Assessment Group index (r = -0.22 to 0.09) and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (r = -0.29 to 0.21), these were weak. CONCLUSION: HRQOL was impaired in this cohort of outpatients with SLE as assessed by the validated lupus-specific LupusQoL. There were no clinically important associations between the 8 domains of the LupusQoL and clinical or demographic variables in this group of patients. Thus, the LupusQoL is a relatively independent outcome measure in patients with SLE.

Development and validation of a disease-specific health-related quality of life measure, the LupusQol, for adults with systemic lupus erythematosus.

OBJECTIVE: To develop and validate a disease-specific health-related quality of life (HRQOL) instrument for adults with systemic lupus erythematosus (SLE). METHODS: The work consisted of 6 stages. Stage 1 included item generation for questionnaire content from semistructured interviews with SLE patients. In stage 2 item selection for the draft questionnaire was performed by thematic analysis of the patient interview transcripts and expert panel agreement. In stage 3 the content validity of the draft questionnaire was assessed by patients completing the questionnaire and providing critical feedback. In stages 4 and 5 construct validity and internal reliability of the 3 versions of the LupusQoL were evaluated using principal component analysis with varimax rotation and Cronbach's alpha coefficients, respectively. In stage 6 discriminatory validity, concurrent validity, and test-retest reliability were evaluated. RESULTS: Stages 1, 2, and 3 resulted in a preliminary instrument containing 63 items. In stage 4, 8 domains were identified. This factor structure, accounting for 82% of the variance, was confirmed in stage 5. The domains and Cronbach's alpha coefficients were physical health (0.94), emotional health (0.94), body image (0.89), pain (0.92), planning (0.93), fatigue (0.88), intimate relationships (0.96), and burden to others (0.94). Discriminant validity was demonstrated for different levels of disease activity (British Isles Lupus Assessment Group Index) and damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index). High correlations (r = 0.71-0.79) between comparable domains of the Short Form 36 and the LupusQoL assured acceptable concurrent validity. Good test-retest reliability (r = 0.72-0.93) was demonstrated. CONCLUSION: The LupusQoL is a validated SLE-specific HRQOL instrument with 34 items across 8 domains defined by patients as being important.