Table 3: Bivariate analysis of continuous variables.

CharacteristicRA with AITDRA without AITDP
Mean ± SDMean ± SD

Age52.26 ± 12.3951.88 ± 12.240.029
Median ± IQRMedian ± IQR
Educational level (y)14 ± 711 ± 90.006
Body mass index25.5 ± 6.323.9 ± 5.90.006

AITD: autoimmune thyroid disease; IQR: interquartile range; RA: rheumatoid arthritis; SD: standard deviation.