8.4.1.1. Example correction for control mortality


 

Tb

number of live test bees before treatment

10

Ta

number of live test bees after treatment

5

Cb         

number of live control bees before treatment      

10

Ca

number of live control bees after treatment

9

b

ratio not corrected test mortality

0.50      

k

ratio control mortality

0.10

 

correction
formulas for
control mortality

not
corrected mortality
ratio

formula

corrected mortality
ratio

percentage (*100)

Abbott's formula

0.50

( (Ca - Ta) / Ca) )

0.44

44.44%

Schneider-Orelli  

0.50

( (b-k) / (1 - k) )

0.44

44.44%

Henderson-Tilton        

0.50

1 - ( (Ta / Ca) * (Cb / Tb) )

0.44

44.44%