Table 4. Factors associated with risk for JHR among 79 cases of tick-borne relapsing fever, Spain*.

Variable	Value			p value†	Adjusted OR (95% CI)	p value‡
Sex				0.13		NS
F	1 (1.3)
M	7 (8.9)
Median age, y (IQR)				0.86		NS
Y	28.6 (17.3–46.3)
N	25.5 (18.9–48.7)
Rural environment				0.57		NS
Y	7 (8.9)
N	1 (1.3)
Contact with rodents				0.11		NS
Y	3 (3.8)
N	5 (6.3)
Hepatomegaly				0.46		NS
Y	0
N	8 (10.1)
Splenomegaly				0.49		NS
Y	1 (1.3)
N	7 (8.9)
Jaundice				0.9		NS
Y	0
N	8 (10.1)
Petechiae				0.9		NS
Y	0
N	8 (10.1)
Meningeal signs				0.9		NS
Y	0
N	8 (10.1)
Exanthema				0.28		NS
Y	1 (1.3)
N	7 (8.9)
Tick bite				0.17		NS
Y	3 (3.8)
N	5 (6.3)
Tetracycline				0.54		NS
Y	7 (8.9)
N	1 (1.3)
Cephalosporin				0.31		NS
Y	2 (2.5)
N	6 (7.6)
Macrolides				0.35		NS
Y	1 (1.3)
N	7 (8.9)
Median length of clinical signs, d (IQR)§				0.36		NS
Y	3 (2–5.8)
N	3 (1.3–4)
Median length of hospital admission, d (IQR)				0.004	0.56 (0.29–1.02)	0.057
Y	5 (4–7)
N	3 (3–3.3)
Median duration of antimicrobial therapy, d (IQR)				0.55		NS
Y	10 (8–14)
N	10 (9–11.8)
*Values are no. (%) patients with JHR except as indicated. IQR, interquartile range; JHR, Jarisch-Herxheimer reaction; NS, not statistically significant; OR, odds ratio. †Univariant analysis calculated by using χ2 or Fisher exact test. ‡Multivariant analysis calculated by using Student t-test or Mann-Whitney U-test. §Values represent findings from 36 patients with known length of clinical signs.