Table 4.

Response variable and explanatory variables

Variable	N	%
Response variable
Secondary household transmission
Yes	69	9·2
No	682	90·8
Explanatory variable (qualitative)
Symptoms in STEC-positive daycare centre children
Presence	305	40·6
Absence	446	59·4
STEC type
O26 Stx1-producing STEC	565	75·2
O157 Stx1 and Stx2-producing STEC	186	24·8
Information provided face-to-face (vs. letter or telephone) to families with STEC-positive children (at initial response)
Letter, telephone	68	9·1
Face-to-face contact	683	90·9
Information provided face-to-face (vs. letter or telephone) to families with STEC-negative children (at initial response)
Letter, telephone	551	73·4
Face-to-face contact	200	26·6
Information provided face-to-face (vs. letter or telephone) to families with STEC-negative children (after initial response)
Letter, telephone	197	26·2
Face-to-face contact	554	73·8
Routine handling of families
Education about infection prevention measures: Yes	125	16·6
Education about infection prevention measures: No	626	83·4
Explanatory variable (quantitative)	Min	Median	Max
Lag time (days) between onset and providing information	0	1	11
Age (years) of STEC-positive daycare centre children	1	3	6