Relationship between optimism and quality of life in patients with two chronic rheumatic diseases: axial spondyloarthritis and chronic low back pain: a cross sectional study of 288 patients

BACKGROUND Axial Spondyloarthritis (AxSpA) and chronic low back pain are rheumatic diseases that impact patients' health-related quality of life (HRQoL). In other chronic conditions, HRQoL was positively associated with dispositional optimism, a personality trait. The objective was to explore the relationship between optimism and HRQoL in these two diseases. METHOD A cross-sectional study was performed in 2 tertiary care hospitals and 2 private practices in France. Patients had definite AxSpA or chronic low back pain according to the rheumatologist. A generic HRQoL questionnaire (Short Form, SF-12) with physical and mental composite scores (PCS and MCS respectively) and an optimism questionnaire (the Life Orientation Test-revised, LOT-R) were collected. Analyses included non-parametric correlations and multiple regression analyses to study the effect of optimism on PCS and MCS. RESULTS In all, 288 (199 AxSpA and 89 low back pain) patients were included: mean age, 47.3 ± 11.9 years, 48.6 % were males. Pain levels (0-10) were 4.5 ± 2.4 and 4.3 ± 2.4 in AxSpA and LOW BACK PAIN patients, respectively. HRQoL was similarly altered in both diseases, for both physical and mental composite scores (mean PCS: 43.7 ± 8.2 vs. 41.9 ± 7.1; mean MCS 45.9 ± 7.8 vs. 46.7 ± 8.1 for AxSpA and low back pain respectively). Optimism was moderate and similar in both populations. Optimism was positively correlated to MCS in both diseases (rho = 0.54 and 0.58, respectively, both p <0.01) and these relations persisted in multivariate analyses (beta = 1.03 and 1.40, both p <0.0001). CONCLUSIONS Optimism was similar in these 2 chronic diseases and was an explanatory factor of the mental component of HRQoL, but not physical HRQoL. Physical HRQoL may reflect more the disease process than character traits.