Table 1 Key model input parameters

Latent phase

Proportion of latent disease that is binned into latent fast

Range used in calibration

This parameter is calibrated [73,74,98-102]

Adults: 0.05-0.35

Children: set to 1/3 of adult value

Time to progress from latent fast to presymptomatic active disease

Exponentially distributed

[51,52]

Mean: 0.5 year

Time to progress from latent slow to active presymptomatic disease

Exponentially distributed

This parameter is calibrated [51,52,55,74,99]

Range: 5-10% of latent slow reactivate in their lifetime

Relative reduction in susceptibility to reinfection due to prior exposure to TB

0.65

[74,76,103]

Active phase

Time to progress from active presymptomatic to active symptomatic

Exponentially distributed

[53-59]

Mean: 1 year

Proportion of incident active symptomatic TB that is smear positive

Children: 0.15

[48,60,61]

Adult: 0.585

Proportion of incident active symptomatic TB that is smear negative

Children: 0.55

[48,60,61]

Adult: 0.315

Proportion of incident active symptomatic TB that is extrapulmonary

Children: 0.40

[60,104-107]

Adult: 0.1

Duration of active symptomatic disease (until disease resolution) if no treatment is available

Mean 5.5 years

[65]

Disease resolution in smear-positive patients, proportion self-cure

0.3

[65]

Disease resolution in smear-positive patients, proportion death

0.7

[65]

Disease resolution in smear-negative and extrapulmonary patients, proportion self-cure

0.8

[65]

Disease resolution in smear-negative and extrapulmonary patients, proportion mortality

0.2

[65]

Infectiousness

Infectiousness during latent phase

0

[50]

Infectiousness of active presymptomatic TB, relative to smear positive

0.1

[53-59]

Infectiousness of extrapulmonary TB, relative to smear positive

0

[108]

Infectiousness of smear-negative TB, relative to smear positive

0.15

[62-64]

Infectiousness during active symptomatic, smear-positive (contact rate) number of new infections per year

Range used in calibration: 1–7.5

This parameter is calibrated [47,82,103,109]

Relative fitness of MDR strain

1

[66-70]

Treatment seeking

Rate of seeking treatment

Exponentially distributed

[24-28,71]

Mean: 4 months

Rate of seeking retreatment (hospital)

Exponentially distributed

Assumption informed by expert opinion from Chinese CDC

Mean: 22 months

Rate of seeking retreatment (CDC)

Exponentially distributed

Assumption informed by expert opinion from Chinese CDC

Mean: 4 months

Relapsers - time from completion of treatment until relapse

Exponentially distributed

[76]

Mean: 9 months