Validation of the LupusQoL in Venezuela: A Specific Measurement of Quality of Life in Patients with Systemic Lupus Erythematosus.

BACKGROUND AND OBJECTIVES: Traditionally, the health-related quality of life (HRQoL) of patients with systemic lupus erythematosus (SLE) has been assessed using instruments that neglect the specific characteristics of the disease. This study determines the validity of the Lupus Quality of Life (LupusQoL) questionnaire as a psychometrically stable instrument to measure the HRQoL of patients with SLE in Venezuela and establishes the cutoff points of the questionnaire for the Venezuelan population.

PATIENTS AND METHODS: A cross-sectional study was conducted that included patients with SLE from April to July 2018. Patients completed the LupusQoL and the Generalitat de Catalunya (GENCAT) scale; sociodemographic data, activity index (SLEDAI) and accumulated damage (SLICC), were obtained. Reliability was evaluated by internal consistency and the convergent validity of the LupusQoL was determined with the GENCAT scale.

RESULTS: Of the 100 patients, 93% were women, the mean age was 42years old (SD: 13) and the mean duration of the disease was 11years (SD: 9); the mean of SLEDAI and SLICC was 3 and 1, respectively. The cutoff point that defined a "better" or "worse" HRQoL for LupusQoL was 64.55 points. A moderate convergence was found after grouping, according to the cutoff points, of the LupusQoL with the GENCAT scale (Cohen's kappa coefficient=.556; p=.000).

CONCLUSIONS: The LupusQoL is a valid psychometrically stable instrument to measure the HRQoL of patients with SLE in Venezuela. Cutoff points were established to stratify the HRQoL in the Venezuelan population with LES, being useful to complement a comprehensive evaluation.