Spondyloarthritis und Lebensqualität

Validity and reliability of EQ-5D-5L among patients with axial spondyloarthritis in Singapore

OBJECTIVE

This study aims to evaluate the reliability and validity of EuroQOL-5 Dimensions-5 Levels (EQ-5D-5L) among patients with axial spondyloarthritis (SpA) in Singapore.

METHODS

A cross-sectional study was conducted involving patients with axial SpA in an Asian tertiary hospital from 2017 to 2018. This study followed the COnsensus-based Standards for selection of health Measurement Instruments framework. Construct validity was evaluated by testing 22 a priori hypotheses with other patient-reported outcomes measures. Cronbach's alpha was used to estimate the internal consistency of the EQ-5D-5L, while its test-retest reliability was assessed using weighted kappa and the intraclass correlation coefficient (ICC). The measurement error was assessed by analyzing minimal detectable change (MDC).

RESULTS

The median age of included patients (n=118) was 35 years (interquartile range: 28, 49). Ninety-six (81.4%) patients were male, while 112 (94.9%) patients were of Chinese ethnicity. The EQ-5D-5L demonstrated good internal consistency with a Cronbach's alpha of 0.79. The test-retest reliability of the EQ-5D-5L was good with a weighted kappa of ≥0.61 for mobility, self-care, usual activities, and anxiety/depression; the ICC was 0.92 and 0.99 for the EQ-5D-5L index and visual analog scale (VAS) scores, respectively. The weighted kappa for the EQ-5D-5L pain/discomfort was moderate [0.53, 95% confidence interval: 0.41-0.60]. The MDC for EQ-5D-5L index and VAS scores was 0.06 and 4.5, respectively. Convergent validity was supported as all hypotheses were confirmed in the results.

CONCLUSION

This study supports EQ-5D-5L as a valid and reliable instrument for assessing health-related quality of life among patients with axial SpA in Singapore.

The burden of non-radiographic axial spondyloarthritis

OBJECTIVES

To identify patients earlier, new classification criteria have been introduced for axial spondyloarthritis (axSpA). Patients who satisfy the clinical or imaging criteria for axSpA in the absence of definite sacroiliac joint changes on pelvic x-rays are classified as having non-radiographic axSpA. Although the burden associated with radiographic axSpA (i.e., ankylosing spondylitis) has been extensively studied, the impact of non-radiographic disease is not well understood. The purpose of this review is to provide an overview of the burden of illness in non-radiographic axSpA, including epidemiology and effects on patients׳ functioning and health-related quality of life (HR-QoL).

METHODS

A PubMed search was performed using relevant key words (e.g., "spondyloarthritis," "ankylosing spondylitis," "epidemiology," and "quality of life") to examine literature published from 2003 to 2013.

RESULTS

Studies conducted to date suggest that radiographic progression is detected in approximately 10% of patients with non-radiographic axSpA over 2 years. Differences between patients with non-radiographic and radiographic axSpA were found in age, symptom duration, and gender distribution. Although less inflammation (i.e., lower C-reactive protein levels and less spinal inflammation on MRI) and less impairment in spinal mobility are observed in non-radiographic than in radiographic axSpA, the 2 conditions pose a similar burden in terms of disease activity, physical function, HR-QoL impairment.

CONCLUSIONS

Patients with non-radiographic axSpA are more frequently female. Although patients with non-radiographic axSpA have shorter disease duration and lack radiological changes, they demonstrate a substantial burden of illness, with self-reported disease activity and functional impairments comparable to those found in patients with radiographic disease.

Sleep quality and associated factors in ankylosing spondylitis: relationship with disease parameters, psychological status and quality of life

The aim of this study is to investigate sleep quality in patients with ankylosing spondylitis (AS) and to evaluate the relationship of the disease parameters with sleep disturbance. Eighty AS patients (60 males and 20 females) fulfilling the modified New York criteria, and 52 age- and gender-matched controls (33 males and 19 females) were enrolled in the study. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Pain was measured by visual analogue scale. The disease activity and functional status were assessed by the Bath AS disease Activity Index and the Bath AS Functional Index. The Bath AS Metrology Index was used to evaluate mobility restrictions, and the Bath AS Radiology Index was employed to evaluate the radiological damage. The psychological status and quality of life were assessed with the hospital anxiety-depression scale and AS quality of life scale. The patients with AS had significantly more unfavourable scores in the subjective sleep quality, habitual sleep efficiency domains (p < 0.001) and the total PSQI score (p < 0.05). Poor sleep quality (total PSQI score) was positively correlated with increased pain, poor quality of life, higher depressed mood, higher disease activity and mobility restrictions. Pain was also an independent contributor to poorer sleep quality (p = 0.002). The sleep quality is disturbed in patients with AS. The lower quality of sleep is greatly associated with the pain, disease activity, depression, quality of life and increased limitation of mobility.