Table 1.

Model Parameters

Epidemiological Data Point	Value, Rio de Janeiro (age 15–59)	Model Output	Matched Model Parameter	Parameter Value (Fit to Data)	Sensitivity Analysis Range	Reference
TB incidence, per 100,000/yr	122	122	Number of TB transmissions per infectious person-year	6.54	5.13–7.50	City of Rio de Janeiro27
TB prevalence, per 100,000	132	132	Rate of TB diagnosis and treatment	0.87/year	0.78–1.00	World Health Organization28
TB mortality, per 100,000/yr	6.5	6.5	Pre-diagnosis TB mortality rate (HIV-negative)	0.038/year	0.023–0.054	City of Rio de Janeiro20
TB incidence in PLHIV, per 100,000 pop/yr	15.7	15.7	Proportion of new TB infections resulting in rapid progression (HIV-positive)	1.0a	0.09–1.0	City of Rio de Janeiro20
			Rate of slow TB progression after remote infection (HIV-positive)	0.10/yeara	0.04–0.31	Gilks et al29 Horsburgh et al30
TB mortality in PLHIV, per 100,000/yr	1.54	1.54	Pre-diagnosis TB mortality rate (HIV, CD4 ≤350)	0.087/yearb	0.048–0.130	City of Rio de Janeiro20
ART coverage, CD4 ≤350	80%	80.0%	Rate of ART initiation	1.04/year	0.77–1.47	UNAIDS31
			Rate of ART discontinuation	0.2/year	0.12–0.29	Assumption
HIV prevalence, per 100,000	600	600	HIV incidence	3.8x10−4/year	1.7–5.9x10−4	City of Rio de Janeiro20
HIV mortality, per 100,000/yr	24.6	24.6	HIV mortality rate (CD4 ≤350, non-TB)	0.061/yearb	0.030–0.100	City of Rio de Janeiro20
Proportion of retreatment cases	0.274	0.274	TB relapse rate	0.013/year	0.006–0.030	City of Rio de Janeiro20
Proportion of TB that is MDR	0.019	0.019	Relative infectiousness of MDR-TB	0.65	0.33–0.85	World Health Organization28
Proportion of MDR-TB that is retreatment	0.52	0.52	Proportion of recoveries ending in new MDR-TB	0.005	0.002–0.007	World Health Organization28
			Literature-Based Model Parameter	Value (from Literature)	Sensitivity Range	Reference
			Relative infectiousness of TB in PLHIV, per person-day	0.75	0.4–1.0	Golub et al32
			Partial immunity to TB re- infection if latently infected	0.56	0.0–1.0	Cohen et al23 Sutherland et al33 Vynnycky et al34
			Proportion of infections that progress rapidly to active TB	0.087	0.066–0.100	Vynnycky et al34
			Rate of slow progression from remote TB infection (HIV-negative)	0.0005/year	0.0002–0.0011	Horsburgh et al30
			Protective efficacy of IPT against reactivation TBc	0.67	0.5–1.0	Ferebee3 Akolo et al5
			Rate of CD4 progression to ≤350 cells/mm3	0.2	0.0–0.4	Sanders et al35
			Non-HIV, non-TB mortality	0.004/year	0.0–0.008	City of Rio de Janeiro20

^aInitial estimates were that 25% of TB infections would result in rapid progression, and the rate of slow progression after remote infection was 0.026/year.³⁰ However, these estimates resulted in substantial underestimates of the burden of HIV/TB. Reasoning that this was more likely due to underestimation of recent, rather than remote, infection (e.g., clustering of recent infection), we allowed the ratio between these two parameters to remain constant, even though this ultimately resulted in an estimated proportion of rapid TB progression equal to 1.0. This provides a maximally conservative estimate of the impact of IPT, which has no benefit against reinfection TB in the model. We also performed sensitivity analysis around a protective effect of antiretroviral therapy (ART) against TB infection of 0.0–1.0.

^bWe assumed that HIV-infected populations with either CD4 nadir >350 cells/mm³ or use of ART would experience mortality rates at the mean of the rates listed for HIV-infected (CD4 ≤350) and -uninfected populations in the Table.

^cIPT was assumed to have a duration of effect of at least five years (the duration of the analysis); in a sensitivity analysis, this duration of effect was reduced to six months, as described in the text.