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Table 1 Model input parameters and outputs

From: Estimating the magnitude and direction of bias in tuberculosis drug resistance surveys conducted only in the public sector: a simulation study

Parameter

Meaning

Notes on values; (allowable ranges)

Inputs

Λ

TB incidence rate (new cases)

Fixed incidence (value irrelevant)

k FN

Fraction of new cases that go to the public sector

(0-1)

k RN

Fraction of retreatment cases that go to the public sector

(0-1)

y t

Fraction of new cases that are sensitive

1-qC Where q is the relative transmissibility of resistant compared with sensitive strains (range of q from 0-1; assumes no resistant "superbugs") and C (range of C from 0-1) is the proportion of all incident cases with MDR

x S

Fraction of new sensitive cases that go to the public sector

(0-1)

x R

Fraction of new resistant cases that go to the public sector

(0-1)

f R , f S

f •N , f •P

Fraction failing treatment among drug resistant and sensitive

Fraction failing treatment in public and private sectors

f S f R Failure more likely for resistant

and

f •N f •P Failure as or more likely in private sector

a N ,a P

Fraction of TB cases in the public and private sectors who acquire resistance

(0-1) a N a P Acquired resistance as or more likely in private sector

l

Fraction that are lost to follow-up or die

(0-1)

r N

Fraction in the public sector that return to the public sector for next treatment episode

Retreatment cases more likely to present in public sector

r P

Fraction in the private sector that return to the private sector for next treatment episode

Retreatment cases more likely to present in public sector

Outputs

A

Proportion of new cases with resistant TB

A N

Proportion of new cases in public sector with resistant TB

A P

Proportion of new cases in private sector with resistant TB

B

Proportion of retreatment cases with resistant TB

B N

Proportion of retreatment cases in public sector with resistant TB

B P

Proportion of retreatment cases in private sector with resistant TB

C

Proportion of all cases with resistant TB

C N

Proportion of all cases in public sector with resistant TB

C P

Proportion of all cases in private sector with resistant TB