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Data from: Computer-aided X-ray screening for tuberculosis and HIV testing among adults with cough in Malawi (the PROSPECT study): a randomized trial and cost-effectiveness analysis

Citation

MacPherson, Peter (2021), Data from: Computer-aided X-ray screening for tuberculosis and HIV testing among adults with cough in Malawi (the PROSPECT study): a randomized trial and cost-effectiveness analysis, Dryad, Dataset, https://doi.org/10.5061/dryad.ffbg79ctb

Abstract

Suboptimal tuberculosis (TB) diagnostics and HIV contribute to the high global burden of TB. We investigated costs and yield from systematic HIV-TB screening, including computer-aided digital chest X-ray (DCXR-CAD). Suboptimal tuberculosis (TB) diagnostics and HIV contribute to the high global burden of TB. We investigated costs and yield from systematic HIV-TB screening, including computer-aided digital chest X-ray (DCXR-CAD).

In this open, three-arm randomised trial, adults (≥18 years) with cough attending acute primary services in Malawi were randomised (1:1:1) to standard-of-care (SOC); oral HIV testing (HIV screening) and linkage to care; or HIV testing and linkage to care plus DCXR-CAD with sputum Xpert for high CAD4TBv5 scores (HIV-TB screening). Participants and study staff were not blinded to intervention allocation, but investigator blinding was maintained until final analysis. The primary outcome was time to TB treatment. Secondary outcomes included proportion with same-day TB treatment; prevalence of undiagnosed/untreated bacteriologically-confirmed TB on day 56; and undiagnosed/untreated HIV. Analysis was done on an intention to treat basis. Cost-effectiveness analysis used a health-provider perspective. Between 15/11/2018-27/11/2019, 8236 were screened for eligibility, with 473, 492, and 497 randomly allocated to SOC, HIV, and HIV-TB screening arms; 53 (11%), 52 (9%), and 47 (9%) were lost to follow-up, respectively. At 56 days, TB treatment had been started in 5 (1.1%) SOC, 8 (1.6%) HIV-screening, and 15 (3.0%) HIV-TB screening participants. Median (IQR) time to TB treatment was 11 (6.5-38), 6 (1-22) and 1 (0-3) days (hazard ratio for HIV-TB vs. SOC: 2.86, 1.04-7.87), with same-day treatment of 0/5 (0%) SOC, 1/8 (12.5%) HIV, and 6/15 (40.0%) HIV-TB screening arm TB patients (p=0.03). At day 56, 2 SOC (0.5%), 4 HIV (1.0%), and 2 HIV-TB (0.5%) participants had undiagnosed microbiologically-confirmed TB. HIV screening reduced the proportion with undiagnosed or untreated HIV from 10 (2.7%) in the SOC arm to 2 (0.5%) in the HIV-screening arm (risk ratio [RR]: 0.18, 0.04-0.83), and 1 (0.2%) in the HIV-TB screening arm (RR: 0.09, 0.01-0.71). Incremental costs were US$3.58 and US$19.92 per participant screened for HIV and HIV-TB; the probability of cost-effectiveness at a US$1200/quality-adjusted life-year (QALY) threshold were 83.9% and 0%. Main limitations were the lower than anticipated prevalence of tuberculosis and short participant follow-up period; cost and quality of life benefits of this screening approach may accrue over a longer time horizon.

DCXR-CAD with universal HIV screening significantly increased the timeliness and completeness of HIV and TB diagnosis. If implemented at scale this has potential to rapidly and efficiently improve TB and HIV diagnosis and treatment.

Methods

Adults aged 18 years attending acute primary care services with symptoms of tuberculosis (cough of any duration) and who provided informed consent were recruited to the trial and underwent baseline questionnaire, and were randomly allocated to one of three trial arms: standard of care; HIV testing; or HIV testing plus digital chest x-ray screening using CAD4TBv5 (DCXR-CAD), with TB confirmatory testing by sputum Xpert. Participants were followed for 56 days after recruitment for outcome assessment. The primary outcome was time to TB treatment. Secondary outcomes were proportion with same-day TB treatment; prevalence of undiagnosed/untreated bacteriologically-confirmed TB on day 56; and undiagnosed/untreated HIV.

Usage Notes

This dataset contains individual-level data for participants who took part in the PROSPECT Study (clinicaltrials.gov: NCT03519425 https://clinicaltrials.gov/ct2/show/NCT03519425), a three-arm randomised trial of computer-aided chest-xray screening and HIV testing in primary care in Malawi.

The dataset is in .csv file format.

There are a total of 1462 records, each containing data on an individual trial participant.

There are a total of 21 variables, which are defined below.

  • group: trial arm participant was randomly allocated to: SOC: standard of care; HIV: HIV testing; HIV-TB: HIV testing plus DCXR-CAD
  • cough: did participant report cough at recruitment? yes; no
  • duration_of_cough_weeks: duration of cough in weeks
  • night_sweats: did participant report night sweats? yes; no
  • weight_loss: did participant report weight loss? yes; no
  • fever: did participant report fever? yes; n0
  • reported_hiv_status: participant's self-reported HIV status at baseline: HIV-positive; HIV-negative; never tested
  • taking_antiretoviral_therapy: was participant was taking antiretroviral therapy for treatment of HIV? yes; no
  • euro_qol_5q_5d_3l_zimbabwe_tariff: EuroQol EQ5D3L score (Zimbabwe tariff), measured at baseline
  • cxr_done: among participants allocated to the HIV-TB arm, was a chest x-ray done? yes; no
  • cad4tbv5_score: CAD4TBv5 score on digital chest x-ray (range 0-100, with higher score indicating greater probability of pulmonary TB)
  • cad4tbv5_above_threshold: was the CAD4TBv5 score on chest x-ray above the threshold for sputum testing (greater than or equal to 45); yes; no
  • sputum_xpert_done: for participants with CAD4TBv5 scores above the threshold, was a sputum Xpert test done? yes; no
  • sputum_xpert_result: for participants where a sputum Xpert test was done, what was the result of the Xpert test (mtb detected: Xpert showed presence of Mycobaterium tuberculosis)
  • primary_outcome_tb_treatment_initiation: primary trial outcome. Was TB treatment initiated within 56 days of recruitment? 1=yes, 0=no
  • primary_outcome_days_to_tb_initiation: primary trial outcome. Days from recruitment to initiation of TB treatment, or completion of follow-up/censoring if didn't initiate TB treatment
  • secondary_outcome_undiagnsed_tb: secondary trial outcome. Did participant have undiagnosed/untreated microbiologically-confirmed TB on sputum smear, culture or Xpert on sample taken at Day 56 outcome assessment? yes; no
  • secondary_outcome_same_day_tb_treatment: Secondary trial outcome. Did participant initiate TB treatment on the same day as recruitment? yes; no
  • secondary_outcome_undiagnosed_hiv: Secondary outcome. Did participant have undiagnosed or untreated HIV at Day 56 outcome assessment? yes; no
  • secondary_outcome_mortality: did participant die during follow-up period? yes; no
  • secondary_outcome_eq5d: EuroQol EQ5D3L score (Zimbabwe tariff), measured at Day 56 outcome assessment visit

Funding

Wellcome, Award: 206575/Z/17/Z