Screening for Latent Tuberculosis Infection in Migrants With CKD: A Cost-effectiveness Analysis

Abstract

Rationale & objective: In countries with a low tuberculosis (TB) incidence, TB disproportionately affects populations born abroad. TB persists in these populations through reactivation of latent TB infection (LTBI) acquired before immigration. Those with chronic kidney disease (CKD) are at increased risk for reactivation and may benefit from LTBI screening and treatment.

Study design: Health administrative data from British Columbia, Canada, were used to inform a cost-effectiveness analysis evaluating LTBI screening in those diagnosed with stage 4 or 5 CKD not requiring dialysis (late-stage CKD) and those who began dialysis therapy.

Setting & population: Permanent residents establishing residency in British Columbia, Canada, between 1985 and 2012 who had late-stage CKD diagnosed or began dialysis therapy.

Interventions: Screening with the tuberculin skin test or interferon-gamma release assay (IGRA) compared to no LTBI screening at the time of late-stage CKD diagnosis and time of dialysis therapy initiation. Treatment for those who tested positive was isoniazid for 9 months.

Outcomes: Costs (2016 Can $), TB cases, and quality-adjusted life-years (QALYs). The incremental cost-effectiveness ratio for QALYs gained was calculated.

Model, perspective, & timeframe: Discrete event simulation model using a health care system perspective, 1.5% discount rate, and 5-year time horizon.

Results: Screening with IGRA was superior to the tuberculin skin test in all situations. Screening with IGRA was less expensive and resulted in better outcomes compared to no screening in those initiating dialysis therapy from countries with an elevated TB incidence. In individuals with late-stage CKD, screening with IGRA was only cost-effective in those 60 years or older (cost per QALY gained, <$48,000) from countries with an elevated TB incidence.

Limitations: This study has limitations in generalizability to different epidemiologic settings and in modeling complicated clinical decisions.

Conclusions: LTBI screening should be considered in non-Canadian-born residents initiating dialysis therapy and those with late stage CKD who are older.

Keywords: Canada; Tuberculosis (TB); chronic kidney disease (CKD); cost-effectiveness analysis; dialysis; economic analysis; immigration; latent tuberculosis infection (LTBI); migrants; prevention; quality-adjusted life-year (QALY); reactivation; renal failure; screening.