Experiment ID
297 & 298
Pathogen
Contains Preferred Model
Yes
Reference
Lawin-Brüssel, C. A., Refojo, M. F., Leong, F. L., Hanninen, L. ., & Kenyon, K. R. (1993). Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis. Cornea, 12, 1.
Exposure Route
contact lens
Response
corneal ulceration
Host type
white rabbit
# of Doses
10.00
Dose Units
CFU
Μodel
beta-Poisson
a
1.9E-01
N50
1.85E+04
LD50/ID50
1.85E+04
Description
Pooled data of White rabbit /  Pseudomonas aeruginosa 
Dose Corneal Ulceration

Not Corneal Ulceration

Total
63.2 0 5 5
63.2 0 5 5
2220 2 3 5
2220 2 3 5
13200 3 2 5
13200 1 4 5
78000 3 2 5
78000 1 4 5
462000 5 0 5
462000 4 1 5

 

Goodness of fit and model selection
Model Deviance Δ Degrees 
of freedom
χ20.95,1 
p-value
χ20.95,m-k 
p-value
Exponential

30.9

20.8 9 3.84 
5.11e-06 
16.9 
0.000312
Beta Poisson

10.1

8 15.5 
0.26
Beta-Poisson fits better than exponential; cannot reject good fit for beta-Poisson.

 

Optimized parameters for the beta-Poisson model, from 10000 bootstrap iterations
Parameter MLE estimate Percentiles
0.5% 2.5% 5% 95% 97.5% 99.5%
α 1.9E-01 9.63E-02 1.15E-01 1.24E-01 3.86E-01 5.51E-01 2.50E+00
N50 1.85E+04 3.18E+03 4.73E+03 6.01E+03 7.05E+04 8.98E+04 1.97E+05

 

Parameter histogram for exponential model (uncertainty of the parameter)

Exponential model plot, with confidence bounds around optimized model

References