Risk factors for low back pain increase in rheumatoid arthritis: Analysis of a 7-year follow-up study

Several studies have demonstrated that low back pain (LBP) is related to disease activity in patients with rheumatoid arthritis (RA). However, there is no longitudinal research. This study aimed to determine the impacts and risk factors for LBP increase in RA in a longitudinal cohort study.The study evaluated 113 patients with RA who completed the secondary survey. LBP increase was defined as ≥1 standard deviation of mean change in visual analogue scale (VAS) between the baseline and secondary surveys. The impacts of LBP increase on quality of life (QOL) and psychological status were evaluated. Risk factors were assessed among patient demographic characteristics and radiological changes.Mean change in VAS for LBP was -0.8 ± 30.4 mm during a mean 7-year follow-up. LBP increase was defined as ≥30-mm increase in VAS for LBP. Patients with LBP increase had significantly lower QOL and worse mental status than patients without it. Poor control of RA was identified as an independent risk factor for LBP increase (odds ratio, 9.82, p = .001).Patients with poor control of RA were likely to experience LBP increase in the long term. Control of RA disease activity is important for control of LBP, QOL, and mental status.