THE 6 TH NATIONAL SCIENTIFIC CONFERENCE ON HIV/AIDS Yield and impact of repeated screening for tuberculosis and isoniazid preventive therapy among patients

THE 6TH NATIONAL SCIENTIFIC CONFERENCE ON HIV/AIDS

Yield and impact of repeated screening for tuberculosis

and isoniazid preventive therapy among patients with HIV in Vietnam

Duong BD1, Thai LH2, Cowger T2, Nhung NV3, Nhan DT1, Thoa CK1, Khanh VT4, Thinh T5, Dung NH6, Yen NTB6, Ngoc DV5, McConnell M2, Whitehead S2, Pevzner ES2.

Presenter: Duong BD

1 Vietnam Authority for HIV/AIDS Control;2 U.S. Centers for Disease Control and Prevention;3 National Lung Hospital; 4 VAAC-U.S. CDC Cooperative-agreement Project; 5 Ho Chi Minh City

Provincial AIDS Committee; 6 Pham Ngoc Thach Hospital.

The 6th National Scientific Conference on HIV/AIDS

Background Tuberculosis leading infection and cause of death in

people living with HIV (PLHIV) Diagnosis challenging

Previously, no evidence-based algorithm to screen/diagnose TB in PLHIV

2007: CDC with Vietnam, Cambodia, Thai HIV and TB programs conducted ID-TB/HIV study to identify algorithm to screen for, diagnose and rule out TB

Identified algorithm screens for 3 symptoms: 1) cough of any duration; 2) fever of any duration; 3) night sweats >3 weeks

2010- 2011: CDC and Vietnam HIV-TB programs conducted study to evaluate algorithm in programmatic conditions


Study objectives To evaluatethe diagnostic yield of screening for TB and using the diagnostic algorithm at baselinethe diagnostic yield of TB screening and diagnosis algorithm during follow-up

the outcomes of PLHIV screening negative and starting IPTthe impact of ART and IPT on risk for TB among PLHIV during follow-up

the impact of routine screening for TB using the algorithm on mortality among PLHIV


Methods: Study sites and subjects

One-year longitudinal cohort study

Study sites: 3 HIV outpatient clinics (OPC) in Hanoi and

HCMC

Subjects Eligible: HIV+ patients aged >15 years and not yet receiving ART

At each clinical encounter screened using TB algorithm

Ineligible for follow-up if diagnosed with TB or currently

receiving anti-TB treatment


Methods: Data collection At enrollment:

‒ Eligibility and demographic data

‒ Physical exam findings

‒ Medical history

‒ TB-related medications

‒ Date and screening results At each clinical encounter:

‒ Date and screening results

‒ Deviations from the diagnostic algorithm

‒ Dates of ART and/or IPT initiation

‒ CD4 values

‒ Dates of death, LTFU, TB diagnosis


Data analysis

• Bivariable and multivariable analysis of relationships between predictors and screening results during follow-up

• Time-to-event analyses of incident TB and death


Yield of Repeated TB Screenings


Yield of Repeated TB Screenings


Incidence of TB at enrollment and follow-up screenings

*An additional 16 cases of TB diagnosed at non-study sites during follow-up

1-year period prevalence was 12,421 per 100,000 persons*


Time to incident TB

Time to TB: •Median: 88 days•IQR: 64-142 days

29 Cases of incident TB•Incidence: 4,966 per 100,000


ART and IPT initiation during follow-upAt 1 year, 85% of participants were on ART and/or IPT & 33% were on both ART and IPT


IPT and TB Risk

aHR: 7.7 (2.0, 33.3)

Not on IPT

On IPT

aHR: adjusted hazard ratio. HR adjusted for gender, age, baseline BMI, CD4 count at enrollment, ART, previous TB, smoking


ART and TB risk

ART <3 months v. ART >3 monthsaHR: 16.9 (4.2, 68.2)

ART <3 months

No ART

No ART v. ART >3 monthsaHR: 12.1 (2.5, 59.0)

ART >3 months


Impact of regular TB screening on mortality

Regular follow-up screenings <120 days:•aHR: 1.56 (0.34, 7.1) Regular follow-up

screenings >120 days:•aHR: 10.0 (2.5, 100)

aHR: adjusted hazard ratio. Hazard ratio adjusted for gender, age, baseline BMI, CD4 count at enrollment, ART, Injection drug use, and smoking


Main findingsDiagnosing TBHigh incidence of TB observed at enrollment and follow-upDeclining proportion of persons screening TB positiveDeclining proportion of persons diagnosed with TB

Preventing TBHigh uptake of ART and IPT among participantsLower TB incidence among participants prescribed IPT Higher TB incidence among participants not on ART or <3 months ART

Program impactLower mortality among PLHIV screened regularly for TB


Limitations• Observational data - participants not randomized to receive

repeated screenings

• No external comparison group

• Small number of events (TB & death) limited ability to statistically assess more complicated models. Couldn’t assess the joint effect of ART & IPT

• Purposeful selection of study sites so conclusions may not be generalizable to other sites in Viet Nam

• Gold standard diagnostic results not available for all participants so could not calculate sensitivity and specificity


Conclusions

Benefits of Repeated Screening Opportunities for initiation of ART and IPT

Additional opportunities to diagnose TB for PLHIV with missed or incomplete diagnostic evaluations

Treatment or referral for other health services


Recommendations

• Routine screening for TB in every visit, using TB screening and diagnosis algorithm in line with national guidelines

• Facilitating PLHIV’s access to new TB diagnostics such as Xpert MTB/RIF


Acknowledgements

• CDC (Atlanta and Vietnam)• VAAC• National Lung Hospital /National TB Program• Hanoi PAC• HCMC PAC• Pham Ngoc Thach Hospital • Participating OPCs


Thank you !

Documents

THE 6 TH NATIONAL SCIENTIFIC CONFERENCE ON HIV/AIDS Yield and impact of repeated screening for tuberculosis and isoniazid preventive therapy among patients