Data for 2,596 adult patients enrolled on ART during 2004–2007 were abstracted and analyzed. At ART initiation, median age was 34, 62% were female, and median CD4 count was 153/µL (IQR, 76–231/µL), being lower for males than females (139/µL vs. 159/µL, p<0.01). Prior completed TB treatment was documented for 20% of patients, while 11% of patients (95% CI, 9–13%), had active TB at ART start (prevalent TB) ().
Associations between Patient Characteristics and Prevalence of Active TB at ART Initiation.
Compared with patients not diagnosed as having prevalent TB at ART enrollment, patients with prevalent TB were more likely to be males (48% vs. 37%, p<0.001), have WHO stage III or IV disease (94% vs. 55%, p<0.001) (), have weight <45 kg (34% vs. 16%, p<0.001), have a CD4 count <50/µL (26% vs. 15%, p
0.001), have hemoglobin <8 g/dL (25% vs. 13%, p<0.001), and have been treated for TB prior to the current TB diagnosis (89% vs. 12%, p<0.001).
Efavirenz combined with lamivudine (3TC), and stavudine (d4T) or zidovudine (AZT), was prescribed to 73% of patients with active TB versus only 2% of patients assessed as TB-free (p<0.001) (). In contrast, Nevirapine with 3TC, and d4T/AZT was prescribed to 97% of patients assessed as TB-free versus 22% of active TB patients at baseline (p<0.001).
Among all ART enrollees, 61% (53–69%) had some documentation of TB screening in their medical records (). The most common symptoms screened for were chronic cough (55%) and chronic fever (52%). Only 5% of ART enrollees during 2004–2007 were screened for all six recommended TB symptoms. Proportions of ART patients receiving some form of TB screening increased from 31% in 2004 to 66% in 2007 (p<0.001) ().
Compliance with TB Screening among ART Enrollees.
Proportions of ART enrollees with some documentation of TB screening in the records varied significantly by site, from 2% to 98% (p<0.001) (). Larger sites [>1,000 patients (n
12)] did not differ from smaller sites [<
18)] in TB screening compliance (60% vs. 64%, p
0.647) and rural sites (n
9) did not differ from urban sites (n
21) in TB screening compliance (67% vs. 58%, p
0.188). However, all 30 clinics were supported by one of seven non-Governmental organizations (NGOs), and TB screening compliance was associated with the NGO providing support ().
Compliance with TB Screening at ART Enrollment by Clinic and Supporting Non-Governmental Organization.
Only three patients not taking TB treatment at ART start [0.1% (95% CI, 0.0–0.2%)] were prescribed isoniazid preventive therapy (IPT).
Among the 2,325 patients, who were considered TB-free at ART start by attending clinicians, 72 were diagnosed with pulmonary TB and 14 with extra-pulmonary TB during 3,438 person-years of ART follow-up, with an overall TB incidence rate of 2.32 cases per 100 person-years (95% CI, 1.80–3.05). TB incidence rates did not vary significantly across 3-monhtly ART follow-up intervals ().
Figure 3 TB Incidence Rates during ART Follow-up among Patients Assessed as TB-free at ART Initiation (n=2,325).
Baseline characteristics associated with increased risk of TB incidence included a 10-year age increase [adjusted hazards ratio (AHR) 1.40; 95% CI, 1.23–1.60] (). Compared with employed patients, students had lower TB incidence (AHR 0.20; 95% CI, 0.07–0.55). Compared with patients having a weight >60kg at ART start, patients with a weight of 45–60 kg (AHR 2.52, 95% CI 0.91–7.01, p
0.066) or <45 kg (AHR 3.50, 95% CI 0.84–14.54, p
0.075) tended to have higher incidence of TB diagnosis (). Similarly, compared with patients having a CD4>
200/µL, patients with a CD4<50/µL tended to have higher TB incidence rates (AHR 1.79, 95% CI, 0.94–3.44, p
0.074). Compared with patients assessed as having ART adherence >
95%, patients with adherence <95% had higher TB incidence rates (AHR 2.06, 95% CI, 1.32–3.21) (). Compared with patients for whom no documentation of TB screening at ART initiation was found, patients with documented TB screening at ART start had higher incidence of TB diagnosis during follow-up (AHR 1.60, 95% CI, 1.12–2.28) ().
Cox Proportional Hazards Analysis of Patient Characteristics Associated with TB Incidence during ART Follow-up.
Kaplan Maier Analysis of TB-Free Survival.