Skip to main content

Table 2 Growth constants, doubling times and Reff for each stage

From: The impact of three progressively introduced interventions on second wave daily COVID-19 case numbers in Melbourne, Australia

Control level

Growth constant per day

p > 0

p kn − kn−1 > 0

Doubling/halving time (95% CI) days

Serial interval 3.96

Serial interval 6.49

Reff (95% C.I.)

Successive reduction

Reff (95% C.I.)

Successive reduction

Pre-Stage 3

0.133 (s.e. 0.005)

< 0.001

5.22 (4.87 to 5.61)

1.39 (1.37 to 1.40)

2.02 (1.93 to 2.1)

Stage 3

0.033 (s.e. 0.006)

< 0.001

< 0.001

21.21 (15.75 to 32.49)

1.12 (1.08 to 1.16)

18.5%

1.22 (1.14 to 1.3)

35.4%

Stage 3 + masks

− 0.036 (s.e. 0.012)

0.003

< 0.001

− 19.47 (− 54.63 to − 11.84)

0.86 (0.76 to 0.95)

25.9%

0.78 (0.65 to 0.92)

39.0%

Stage 4

− 0.069 (s.e. 0.004)

< 0.001

0.019

− 10 (− 11.19 to − 9.03)

0.72 (0.69 to 0.75)

14.7%

0.59 (0.56 to 0.63)

22.6%

  1. Intercept: 1.86 s.e. 0.086; Residual standard error: 0.24 on 88 degrees of freedom; Multiple R-squared: 0.959 Adjusted R-squared: 0.957; F-statistic: 509 on 4 and 88 DF, p-value: < 0.001. Doubling/halving time calculated as ln(2)/k (see text)