Method

Cost per dose

Cost per vaccination

Test


Arm A

Arm B

Arm A

Arm C


Method 1

$0.24

$0.36

–

–

–

Method 1

–

–

$4.55

$5.40

–

Method 2

$0.32

$0.47

–

–

t = −2.5, df = 51, p = 0.017

Method 2

–

–

$5.65

$6.32

t = −1, df = 56, p = 0.32

 The cost per deworming dose and per rabies vaccination for each Arm of the study as calculated by the two different calculation methods is given. Method 1 has calculated the average of a ratio, whilst Method 2 has calculated the ratio of averages (or totals). Method 1 is useful as an aggregate measure over all clinics, but cannot be used to test for statistical differences across clinic categories because it is not calculated on a per clinic basis. Method 2 allows testing for statistical differences across clinic types, but represents a summary statistic for cliniclevel cost per dose measure rather than an aggregate measure. The result of the statistical analysis of Method 2 is given