Table 1.

Hair and saliva collection methods and reasons for missing data

	Total (N = 97)	Intervention (n = 43)	Control (n = 54)	P value
	N (%)	N (%)	N (%)
Hair collected and valid laboratory result received
Yes	80 (83)	35 (81)	45 (83)	0.49a
No	17 (18)	8 (19)	9 (17)
Reasons for missing hair valuec
Hair too short	9 (53)	3 (38)	6 (67)
Mother refused	2 (12)	1 (13)	1 (11)
Child refused	2 (12)	0 (0)	2 (22)
Unknown	4 (24)	4 (50)	0 (0)
Saliva collected and valid laboratory result received
Yes	91 (94)	39 (91)	52 (96)	0.45b
No	6 (6.2)	4 (9.3)	2 (3.7)
Reasons for missing saliva valuec
Mother refused	1 (17)	0	1 (50)
Child refused	1 (17)	1 (25)	0
Quantity not sufficient	2 (33)	1 (25)	1 (50)
Unknown	2 (33)	2 (50)	0
Saliva collection method
Passive drool	80 (88)	34 (87)	46 (89)	0.99b
Cotton swab	11 (12)	5 (13)	6 (12)

^aChi-square test

^bFisher’s exact test

^cGroup differences not tested due to small cell sizes