Table 2.

Comparison of SAA levels in different groups.

Comparison	n	Median (Q1, Q3) of SAA level (mg/L)	U value	P value
HC vs. AAU	18 vs. 108	0 (0, 0) vs. 3.83 (2.22, 6.83)	159	<0.0001
Active vs. inactive AAU	57 vs. 51	5.42 (3.25, 9.83) vs. 2.81 (1.78, 4.98)	794.5	<0.0001
HLA-B27− vs. HLA B27+	25 vs. 83	2.83 (1.63, 5.67) vs. 4.19 (2.59, 7.87)	703	0.014
AS− vs. AS+	61 vs. 47	3.51 (1.92, 6.20) vs. 4.31 (2.81, 10.87)	1071	0.024

Calculated using Mann–Whitney U-test; Median (Q1, Q3) Median (25% percentile, 75% percentile)

n number