Skip to main content

Table 3 Power calculations assuming 50 clusters allocated in a 1:1 ratio between treatment and controls to achieve power of 80%

From: The TIRS trial: protocol for a cluster randomized controlled trial assessing the efficacy of preventive targeted indoor residual spraying to reduce Aedes-borne viral illnesses in Merida, Mexico

TIRS efficacy

No. events

Total effective sample size

No. per cluster, unadjusted

No. per cluster, adjusted*

Total sample size, adjusted*

70%

28

1038

74

92

4600

75%

22

870

43

54

2700

80%

18

734

30

37

1850

90%

12

534

17

21

1050

  1. *Adjusted for a 20% loss to follow-up