Table 3.

Sets of Maximum-Likelihood (ML) Estimates for 22 Epidemiological Parameters, With a Time-Invariant, a Gamma, or an Exponential Incidence Curve

Parameters	Time Invariant	Gamma	Exponential
Vertical Transmission Rate (%)	38.5	38.5	38.5
Early-Selection Fertility  Coefficient	1.431	1.672	1.707
Duration-Specific Fertility  Impairment Coefficients
0–4	1.000	0.848	0.758
5–9	0.478	0.357	0.303
10 and above	0.332	0.293	0.238
Female Age-Specific Relative  Incidence Ratio
15–19	0.789	0.594	0.480
20–24	1.486	1.325	1.114
25–29	1.000	1.000	1.000
30–34	0.744	0.752	0.718
35–39	0.617	0.635	0.534
40–44	0.684	0.551	0.549
45–49	0.272	0.356	0.266
50–54	0.323	0.295	0.375
55–59	0.275	0.246	0.314
Male Age-Specific Relative  Incidence Ratio
15–19	0.075	0.059	0.054
20–24	0.735	0.583	0.499
25–29	1.318	1.149	0.975
30–34	1.077	0.963	0.983
35–39	0.731	0.759	0.682
40–44	0.678	0.769	0.619
45–49	0.733	0.622	0.558
50–54	0.437	0.417	0.468
55–59	0.152	0.168	0.168
Number of Observations	46,387	46,387	46,387
Log-Likelihood	‒587.2	‒566.8	‒675.8
Degrees of Freedom	33	33	33

Note: Figures that are shaded are those outside the confidence interval for the ML estimates when the gamma curve is used. In addition to the 22 parameters shown in the table, the degrees of freedom include 11 parameters for the scale of the epidemic in each of the 11 populations.