Background Sleep quality is an important aspect of health and well-being and the Outcome Measures in Rheumatology Clinical Trials group has identified sleep quality as a key concern for rheumatoid arthritis (RA) patients1. Patient reported sleep-disturbance is included in the RAID (RA Impact of Disease) score, but not in many other core patient reported outcomes (PROs) and is seldom reported in clinical trials.

Objectives To assess self-reported sleep disturbance in a large sample of patients from a population based RA registry and identify factors associated with self-reported sleep disturbance.

Methods In a population based RA registry in Oslo, Norway, 868 patients aged 20-79 years (mean (SD) age 59.9 (12.3) years, disease duration 13.0 (10.8) years, 77.1% females) responded in 2009 to a mailed questionnaire (response rate 60.6%). 844 patients answered the numeric rating scale (NRS) on sleep disturbance due to RA (part of the RAID questionnaire) within the last week, and use of benzodiazepine like sleeping drugs (zopiclone/zolpidem = z-hypnotics) and other medications used in the treatment of RA. Other PROs included 100mm visual analogue scales (VAS) for pain, fatigue and global disease activity (patglob), HAQ (0-3, 3 worst), SF-36 with physical (PCS) and mental (MCS) component scores (0-100, 0=worst), RA Disease Activity Index (RADAI, 0-10, 10 worst) and RAID score (0-10, 10=extreme/very poor). Use of z-hypnotics was significantly associated with MCS, PCS, HAQ, RADAI, RAID, NRS sleep disturbance, VAS pain/fatigue/patglob (all p<0.001), and with disease duration (p=0.03). Linear regression analyses were used to identify factors independently associated with sleep disturbance (0-10 NRS, 10=extreme sleep disturbance) and adjusted for age, gender and disease duration.

Results

Females used z-hypnotics more frequently than males (10.2% vs. 3.5%, p=0.01), but no significant gender differences were seen for age, VAS pain, VAS patglob, MCS, RADAI, or use of sDMARDs, biologics or prednisolone. Adjusted linear regression analyses with sleep disturbance assessed by NRS identified significant associations with gender (B=0.40, 95% CI 0.06, 0.74), HAQ (B=0.40, 95% CI 0.13, 0.67), RADAI (B=0.42, 95% CI 0.27, 0.57) and 10unit increase in VAS pain (B=0.15, 95% CI 0.04, 0.27), VAS fatigue (B=0.18, 95% CI 0.11, 0.25) and MCS (B= -0.51, 95% CI -0.65, -0.38).

Conclusions Sleep disturbance is to a higher degree reported by females and is independently associated with increased pain, fatigue and worse mental and physical function. Improving sleep quality may reduce RA impact of disease and should be addressed in daily clinical practice when treating patients with RA.

1. Kirwan JR, Newman S, Tugwell PS, Wells GA. Patient Perspective on Outcomes in Rheumatology A Position Paper for OMERACT 9. J Rheumatol 2009;36(9):2067-70.

Disclosure of Interest None Declared