Difference between revisions of "Multistage model"
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P(Response|Dose)= background +(1-background)*(1-exp(-q1*Dose -q2*Dose^2 -q3*Dose^3...)) | P(Response|Dose)= background +(1-background)*(1-exp(-q1*Dose -q2*Dose^2 -q3*Dose^3...)) | ||
+ | <br> | ||
+ | <br>A more simple formula for (excess) risk is: | ||
+ | <br>P(dose) = 1 - exp [-alfao +alfa1 * | ||
− | + | <br>dose1 +...alfak * dose] | |
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− | dose1 +...alfak * dose] | ||
(alfa=dose-response) | (alfa=dose-response) | ||
+ | <br> | ||
+ | <br>At | ||
− | + | <br>risk levels (<10-2) the following linear formula can be used for the upper bound (95%) risk | |
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− | risk levels (<10-2) the following linear formula can be used for the upper bound (95%) risk | ||
Risk = exposure (mg/kg/day) * q1 (risk per mg/kg/day) | Risk = exposure (mg/kg/day) * q1 (risk per mg/kg/day) | ||
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q1=cancer slope factor, upper 95% confidence limit, | q1=cancer slope factor, upper 95% confidence limit, | ||
+ | <br>calculated from 10% point of departure (POD) | ||
− | + | <br>from experimental data | |
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− | from experimental data | ||
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− | , 6th ed. 2001, p. 95-97. | + | <br>See e.g. Casarett & Doull's Toxicology , 6th ed. 2001, p. 95-97. |
[[Category:Health_effects]] [[Category:Needs_editing]] | [[Category:Health_effects]] [[Category:Needs_editing]] |
Revision as of 07:31, 27 March 2008
The multistage model is a dose-response model that attempts to reflect the biological process of carcinogenesis.
P(Response|Dose)= background +(1-background)*(1-exp(-q1*Dose -q2*Dose^2 -q3*Dose^3...))
A more simple formula for (excess) risk is:
P(dose) = 1 - exp [-alfao +alfa1 *
dose1 +...alfak * dose]
(alfa=dose-response)
At
risk levels (<10-2) the following linear formula can be used for the upper bound (95%) risk
Risk = exposure (mg/kg/day) * q1 (risk per mg/kg/day)
q1=cancer slope factor, upper 95% confidence limit,
calculated from 10% point of departure (POD)
from experimental data
See e.g. Casarett & Doull's Toxicology , 6th ed. 2001, p. 95-97.