Table 2. Log-likelihoods (I) for risk-of-infection models.

Model	Parameters	Description of model	I
1	12	Full model, schedule effect and unspecified dose—response	-13.75
2	5	Cumulative model (no schedule effect), unspecified dose—response	-22.70
3	7	Independent-challenges model, unspecified dose—response	-14.09
4a	6	Schedule and dose effects plus interaction, logistic dose—response	-17.85
4b	4	Schedule effect, logistic dose—response (common slope)	-19.24
5	2	Cumulative model (no schedule effect), logistic dose—response	-25.25
6	4	Independent-challenges model, logistic dose—response	-14.84
7	3	Schedule effect, independent dose—response	-21.68
8	1	Cumulative model, independent dose—response	-25.46
9	4	Independent challenges model, independent dose—response	-20.57