Table 2 Self-reported acute respiratory tract infection and influenza-like illness rate ratios by hand-washing habits with 95% confidence intervals

2-4 times daily

1 (reference)

1 (reference)

1 (reference)

1 (reference)

5-9 times daily

1.14 (0.93-1.40)

1.08 (0.87-1.33)

1.10 (0.75-1.59)

0.98 (0.66-1.46)

10-19 times daily

1.37 (1.11-1.69)

1.22 (0.97-1.53)

1.48 (1.01-2.16)

1.25 (0.82-1.90)

≥20 times daily

1.16 (0.93-1.45)

1.03 (0.81-1.32)

1.23 (0.82-1.85)

1.06 (0.68-1.67)