Study subject characteristics
2,351 MTB/HIV co-infections were confirmed among 42,205 TB registered cases in 2011, and thus HIV prevalence among those with TB was 5.6% (2,351/42,205); a total of 2,579.7 years was provided for the TBC group at the follow-up assessment, 4,872.8 years for the TBCR group, and 913.5 years for the TBFMA group over the 60-month follow-up period (Fig.1). The median (M) time participants were tracked at follow-up for the TBC group was 5.0 person-years (PYs), and the inter-quartile range (IQR) was 2.2-5.0; the M (IQR) for TBCR and TBFMA groups was 5.0 PYs (2.1-5.0) and 1.1 (0.3-5.0), respectively (Supplemental Fig.1). The male-to-female ratio among participants was 1.88:1; those who reported that they were farmers (75.1%) and were of Han ethnicity (58.2%) were in the majority.
Mortality trend, hazard risk of mortality
In the TBC, TBCR, and TCFMA groups, the CD4 count (IQR) was 223 cells/μL (53.0–417.0), 184 cells/μL (56.0–367.0), and 105 cells/μL (25.50–268.50), respectively. The percentage of patients by group on ART were 53.2%, 53.5%, and 33.3%; and the M (IQR) of age was 45.0 (31.0–58.0), 48.0 (32.5–62.0), and 53.0 (9.0–67.0), respectively. Finally, differences in the distributions of age, gender, ART initiation, and CD4 count were statistically significant among TBC, TBCR, and TCFMA groups (Table 1).
Table 1 Demographic characteristics of HIV/MTB co-infection patients by treatment outcomes in Guangxi, Southern China
|
Characteristics
|
TB cure n (%)
|
TB complete treatment n (%)
|
TB treatment failure, patient missing, adverse events
n (%)
|
P value
|
All patients
|
680(28.92)
|
1289(54.83)
|
382(16.25)
|
|
Age (year)
|
|
|
|
|
Median
|
45.00
|
48.00
|
53.00
|
<0.0001
|
IRQ
|
31.00-58.00
|
32.50-62.00
|
39.00-67.00
|
|
Gender
|
|
|
|
<0.0001
|
Male
|
455(66.91)
|
796(61.75)
|
284(74.35)
|
|
Female
|
225(33.09)
|
493(38.25)
|
98(25.65)
|
|
Ethnicity
|
|
|
|
0.30
|
Han
|
403(59.26)
|
734(56.95)
|
231(60.47)
|
|
Zhuang
|
253(37.22)
|
523(40.57)
|
136(35.60)
|
|
Yao
|
12(1.76)
|
21(1.63)
|
10(2.62)
|
|
Others
|
12(1.76)
|
11(0.85)
|
5(1.31)
|
|
Occupation
|
|
|
|
<0.0001
|
Farmer
|
538(79.12)
|
929(72.07)
|
306(80.10)
|
|
Government employee
|
19(2.79)
|
91(7.05)
|
16(4.19)
|
|
Worker
|
15(2.21)
|
38(2.95)
|
9(2.36)
|
|
House nursing
|
44(6.47)
|
74(5.74)
|
29(7.59)
|
|
Farmer worker
|
21(3.09)
|
25(1.94)
|
4(1.05)
|
|
Student
|
12(1.76)
|
31(2.40)
|
0(0.00)
|
|
Others
|
31(4.56)
|
101(7.85)
|
18(4.71)
|
|
Infection route
|
|
|
|
0.73
|
Heterosexual
|
547(80.44)
|
1004(77.89)
|
282(73.82)
|
|
Homosexual
|
11(1.62)
|
22(1.71)
|
3(0.79)
|
|
IDU
|
35(5.15)
|
61(4.73)
|
14(3.66)
|
|
Blood transfusion
|
13(1.91)
|
17(1.32)
|
3(0.79)
|
|
Others
|
74(10.88)
|
185(134.35)
|
80(20.94)
|
|
ART
|
|
|
|
<0.0001
|
Initiated ART
|
362(53.24)
|
689(53.45)
|
127(33.25)
|
|
ART naïve
|
255(37.50)
|
450(34.91)
|
182(47.64)
|
|
Unknown
|
63(9.26)
|
150(11.64)
|
73(19.11)
|
|
CD4 Count
|
|
|
|
|
Median
|
223
|
184
|
105
|
0.002
|
IRQ
|
53.0-417.0
|
56.0-367.0
|
25.50-268.50
|
|
Abbreviation: IRQ, Interquartile Range; IDU, Injection drugs users; ART, antiretroviral therapy.
|
At the end point of the 60-month follow-up, a total of 859 HIV/MTB co-infected individuals had died, for a mortality of 36.5%; crude mortality in TBFMA, TBRC, and TBC groups was 60.0% (229/382), 32.0% (413/1,289), and 31.9% (217/680). Compared to the TBC group (χ2 = 78.9, P < 0.0001) and TBCR group (χ2 = 97.0, P < 0.0001), the crude mortality in the TBFMA group was significantly higher (see Table 2). In the initial 6 months of anti-tubercular treatment, mortality in the TBFMA group was 41.1% (157/382), while mortality in TBC and TBCR groups was 12.5% (85/680) and 11.6% (150/1,289). There was no statistically significant difference between mortality in TBC and TBCR groups, whether at the 6-month or 60-month observation (χ26m = 0.60, P = 0.44; χ260m = 0.003, P = 0.95) (Table 2). However, the initial 6-month mortality in the TBFMA group was significantly higher than in TBC and TBCR groups (χ2 = 118.9, P < 0.0001). As mortality was calculated by PYs, a declining trend was observed among all groups from 6-month to 60-month, mortality in those with TBFMA was significant higher than it was with TBC and TBCR at all time-points (Fig. 2) (Supplemental Fig.2).
Table 2 Crude mortality of HIV/MTB co-infection across 60 months by treatment outcomes
|
|
|
Treatment outcomes
|
Case number (%)
|
Mortality in 6 months (%)
|
Mortality in 12 months (%)
|
Mortality in 24 months (%)
|
Mortality in 36 months (%)
|
Mortality in 48 months (%)
|
Mortality in 60 months (%)
|
c2
|
P value
|
Adverse events, failure, missing
|
382 (16.25)
|
157 (41.10)
|
187 (48.95)
|
212 (55.50)
|
222 (58.12)
|
227 (59.42)
|
229 (59.95)
|
107.8
|
<0.0001
|
Complete treatment
|
1289 (54.83)
|
150 (11.64)
|
242 (18.77)
|
315 (24.44)
|
379 (29.4)
|
404 (31.34)
|
413 (32.04)
|
--
|
--
|
Cure
|
680 (28.92)
|
85 (12.50)
|
126 (18.53)
|
164 (24.12)
|
192 (28.24)
|
206 (30.29)
|
217 (31.91)
|
--
|
--
|
Abbreviation: IRQ, Interquartile Range; IDU, Injection drugs users; ART, antiretroviral therapy.
Mortality density analysis showed that the majority of mortality in the TBFMA group occurred during the first 6 months and mortality density was higher than those in TBC and TBCR group during the same period. On the contrary, the majority of mortality in both TBC and TBCR groups happened in the last year of follow-up (Fig. 3).
The HR value of mortality was calculated for TBC, TBCR, and TBFMA groups using Cox regression models. At the 60-month follow-up, the crude HR of mortality in the TBFMA group was 2.5 (95% CI: 2.1–3.1) times higher than that of the TBC group, and 2.6 (95% CI: 2.2–3.0) times higher than that of the TBCR group. A Wald chi-square test showed that the HR for mortality in the TBFMA group was significantly higher than those in the TBC and TBCR groups (χ2cure = 95.4, P < 0.0001; χ2comp = 131.8, P < 0.0001).
HR adjusted by stratification variables
We adjusted the HR by deleting those who died within the initial 6 months of the study. The adjusted HR of mortality in the TBFMA group was 1.6 (95% CI: 1.2-2.0) times higher than the TBC group and 1.3 (95% CI: 1.0-1.7) times higher than the TBCR group, while the adjusted HR of the TBFMA group was significantly higher than the HR of TBC and TBCR groups (χ2cure = 9.95, P = 0.0002; χ2comp = 5.1, P = 0.024) (Fig. 4-1, 4-2).
Based upon preliminary analyses (see Table 1), ART, gender, age, occupation, and CD4 count were selected to compare the OR values in subgroups between TBFMA and the combination of TBC and TBCR. Results indicated that these selected factors were independent and unique factors that caused significant mortality across all groups except the group with CD4 count ≤200 μL (OR=1.5, 95% CI:0.8-3.1,χ2=1.36, P=0.24). Mantel-Haenszel stratified analysis results showed that TBFMA among males (OR=3.9, 95% CI:3.0-5.1) , those <50 years old (OR=3.5, 95% CI:2.5-4.9), and with CD4 count >200 μL (OR=3.4, 95% CI:2.6-4.6)were the top three hazard risks for death, compared to the HR of these subgroups in the control group (Table 3, Fig.4-3,4-4).
Table 3 Cox regression on Mortality risk of HIV/MTB co-infection
in different stratification by TB treatment outcome
|
Stratification
|
TB Treatment outcome
|
β
|
SE
|
Wald
|
df
|
P value
|
Exp (β)
|
1-Exp (β) (%)
|
95.0% Exp(β) Confidential Interval
|
lower limit
|
Upper limit
|
ART and ART naïve
|
Adverse events, failure, missing
|
|
|
26.19
|
2.00
|
<0.0001
|
|
|
|
|
Complete treatment
|
-.548
|
0.12
|
20.00
|
1.00
|
<0.0001
|
0.58
|
42.18
|
0.45
|
0.74
|
Cure
|
-.665
|
0.14
|
23.75
|
1.00
|
<0.0001
|
0.51
|
48.55
|
0.39
|
0.67
|
Gender
|
Adverse events, failure, missing
|
|
|
21.38
|
2.00
|
<0.0001
|
|
|
|
|
Complete treatment
|
-.521
|
0.12
|
18.16
|
1.00
|
<0.0001
|
0.59
|
40.63
|
0.47
|
0.75
|
Cure
|
-.575
|
0.14
|
17.83
|
1.00
|
<0.0001
|
0.56
|
43.70
|
0.43
|
0.74
|
Age group
|
Adverse events, failure, missing
|
|
|
14.49
|
2.00
|
0.0007
|
|
|
|
|
Complete treatment
|
-.449
|
0.12
|
13.23
|
1.00
|
0.0003
|
0.64
|
36.17
|
0.50
|
0.81
|
Cure
|
-.458
|
0.14
|
11.02
|
1.00
|
0.0009
|
0.63
|
36.75
|
0.48
|
0.83
|
CD4 group
|
Adverse events, failure, missing
|
|
|
17.87
|
2.00
|
0.0001
|
|
|
|
|
Complete treatment
|
-.486
|
0.13
|
14.35
|
1.00
|
0.0002
|
0.62
|
38.47
|
0.48
|
0.79
|
Cure
|
-.567
|
0.14
|
16.07
|
1.00
|
0.0001
|
0.57
|
43.28
|
0.43
|
0.75
|