Table 2. Risk for infection with avian influenza A (H7N7) with different levels of oseltamivir use, on the basis of combined conjunctivitis and serology-based case definition, the Netherlands, 2003*.

Oseltamivir use	Risk† (95% CI)
Not used	0.145 (0.078–0.233)
Not prescribed	0.161 (0.052–0.336)
Prescribed but not used during visit	0.138 (0.061–0.246)
Used	0.031 (0.008–0.073)
Prescribed and used consistently	0.015 (0.0008–0.0630)
Prescribed and used inconsistently	0.049 (0.004–0.157)
Prescribed and consistency of use unknown	0.068 (0.004–0.258)
Unknown	0.019 (0.001–0.080)
Prescribed but period of use unknown	0.020 (0.001–0.080)

*CI, confidence interval.
†Probability of infection per visit.