Fig. 4

Multivariate logistic regression analyses for predictors of development of new syndesmophytes. ORs reflect a change in one unit for continuous variables. Normal body mass index (BMI) = reference. Exposure data are number of patients exposed or median (interquartile range). Significant ORs are shown in bold typeface. Variables included for total group: baseline syndesmophytes, exposure to bisphosphonates, age, current smoker, sex, time between x-rays, BMI categories, history of uveitis, baseline C-reactive protein (CRP) or time-averaged CRP, non-steroidal anti-inflammatory drug (NSAID)-index and Bath Ankylosing Spondylitis Metrology Index (BASMI), for men: baseline syndesmophytes, current smoker, age, time between x-rays, BMI categories and lateral spinal flexion, for women: exposure to bisphosphonates, BMI categories, BASMI, age and baseline syndesmophytes. CI, confidence interval; OR, odds ratio