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&nbsp;formula for (excess) risk is:
  
 +
<br>P(dose) = 1 - exp [-alfao +alfa1 *
  
A more simple&nbsp;
+
<br>dose1 +...alfak * dose]
 
 
 
 
the formula for (excess) risk is:
 
 
 
 
 
P(dose) = 1 - exp [-alfao +alfa1 *
 
 
 
 
 
dose1 +...alfak * dose]
 
  
 
(alfa=dose-response)
 
(alfa=dose-response)
  
 +
<br>
  
 +
<br>At
  
 
+
<br>risk levels (&lt;10-2) the following linear formula can be used for the upper bound (95%) risk
At
 
 
 
 
 
risk levels (&lt;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)
Line 31: Line 23:
 
q1=cancer slope factor, upper 95% confidence limit,
 
q1=cancer slope factor, upper 95% confidence limit,
  
 +
<br>calculated from 10% point of departure (POD)
  
calculated from 10% point of departure (POD)
+
<br>from experimental data
 
 
 
 
from experimental data
 
 
 
 
 
See e.g. Casarett &amp; Doull's Toxicology
 
 
 
  
&nbsp;, 6th ed. 2001, p. 95-97.
+
<br>See e.g. Casarett &amp; Doull's Toxicology&nbsp;, 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.