Validation of a disease-specific health-related quality of life measure in adult Italian patients with systemic lupus erythematosus: LupusQoL-IT.

OBJECTIVE: The objective of this paper is to assess the validity of a linguistically validated version of the Lupus Quality of Life (LupusQoL(©)) in Italian patients affected by systemic lupus erythematosus (SLE). METHODS: Consecutive SLE patients completed the Italian version of the LupusQoL(©) and the Short Form (SF)-36. Disease activity was evaluated by the SLE disease activity Index-2000 (SLEDAI-2 K), and chronic damage by the Systemic Lupus International Collaborating Clinics/American College Rheumatology (ACR) Damage Index score (SDI). Internal consistency and test-retest reliability, convergent and discriminant validity were examined. Factor analysis with varimax rotation was performed. RESULTS: A total of 117 Italian SLE patients (M:F 13:104; mean age 40.6 ± 11.6 years, mean disease duration 127.5 ± 94.1 months) were recruited into the study. The Italian version of the LupusQoL(©) demonstrated substantial evidence of convergent validity in these patients when compared with equivalent items of the SF-36. In addition, the LupusQoL(©) discriminated between patients with different degrees of disease activity as measured by the SLEDAI-2 K. SLE patients with higher disease activity (SLEDAI-2K ≥4) showed poor QoL compared with those with lower disease activity (SLEDAI-2K <4), with significant differences in the domains of physical health, planning, burden to others and fatigue (p = 0.001, p = 0.04, p = 0.03, p = 0.04, respectively). The confirmatory factor analysis using the eight domain loadings of the 34 items showed a poor fit (χ(2)/degree of freedom (df) 2.26, χ(2 )= 1128.6 (p < 0.001), root mean square error of approximation (RMSEA) = 0.167; goodness-of-fit index (GFI) = 0.606, comparative fit index (CFI) = 0.649)). Screeplot analysis suggested a five-factor loading structure and confirmatory factor analysis result of which is similar to the eight-factor model. A good internal consistency was observed (Cronbach's α 0.89-0.91). Test-retest reliability was good to excellent between baseline and day 15 (intraclass correlation coefficient (ICC) 0.90-0.98). CONCLUSION: The Italian version of the LupusQoL(©) is a valid tool for adult patients with SLE.

Linguistic validation of the N-QOL (ICIQ), OAB-q (ICIQ), PPBC, OAB-S and ICIQ-MLUTSsex questionnaires in 16 languages.

OBJECTIVE: Overactive bladder (OAB) is a highly prevalent condition with a negative impact on both health-related quality of life and sexual functioning. We aimed to create and validate conceptually equivalent tools to assess OAB for use in diverse cultural and linguistic settings. RESEARCH DESIGN AND METHODS: To evaluate the linguistic validity of harmonised translations of the Nocturia Quality of Life (N-QOL) questionnaire, Overactive Bladder Questionnaire (OAB-q) family, Patient Perception of Bladder Condition (PPBC) questionnaire, Overactive Bladder Satisfaction Questionnaire (OAB-S) and International Consultation on Incontinence Questionnaire (ICIQ) Male Sexual Matters associated with Lower Urinary Tract Symptoms Questionnaire (ICIQ-MLUTSsex), bilingual (target language and English) interviewers cognitively debriefed subjects to assess their ability to paraphrase and understand the instructions, questions and responses within each questionnaire. RESULTS: Overall item comprehension rates were 96% for the N-QOL, 98.9% for the OAB-q, 92% for the PPBC, 98.5% for the OAB-S and 94.3% for the ICIQ-MLUTSsex. DISCUSSION: We found that the translations were well-understood by subjects, although a number of minor changes were made to the N-QOL, OAB-q, OAB-S and ICIQ-MLUTSsex translations in an effort to improve clarity and cultural appropriateness. In a few instances, the majority of subjects in a language were unable to paraphrase a specific term or phrase prior to the revisions. In several cases, problems arose from the wording of the question in the source language. CONCLUSIONS: The translated instruments in this study demonstrated a high level of overall linguistic validity.