Anemia burden in tuberculosis patients across Southeast Asia: a systematic review and meta-analysis

Anemia represents a significant comorbidity in tuberculosis (TB) patients, affecting treatment outcomes and mortality. Despite Southeast Asia accounting for 46% of global TB cases, no comprehensive regional synthesis of anemia burden exists, limiting evidence-based policy development.

This systematic review and meta-analysis aimed to estimate the pooled prevalence of anemia among tuberculosis patients across Southeast Asia and to examine variations in prevalence by geographic, demographic, and clinical characteristics.

We searched PubMed, Embase, Scopus, and Web of Science for observational studies published from 2000 onwards that reported anemia prevalence in drug-susceptible TB patients from Southeast Asian countries. Random-effects meta-analysis was performed to calculate pooled prevalence estimates with 95% confidence intervals. Subgroup analyses were conducted by country, HIV co-infection status, treatment status, study setting, COVID-19 period, and World Bank income classification. Publication bias was assessed using Egger's and Begg's tests.

Twenty-one studies comprising 6,090 TB patients from five Southeast Asian countries were included. The pooled prevalence of anemia was 72% (95% CI: 68%-76%), with substantial heterogeneity (I²=89.9%). These regional prevalence estimates are higher than the global pooled estimate of 53.9% reported by Barzegari et al. (2019), reflecting the distinct epidemiological context of Southeast Asia. Subgroup analysis revealed significantly higher prevalence in HIV-positive patients (88%, 95% CI: 78%-94%) compared to HIV-negative patients (70%, 95% CI: 65%-74%). Studies conducted during COVID-19 showed elevated prevalence (84%, 95% CI: 75%-90%) compared to pre-COVID (72%, 95% CI: 70%-73%) and post-COVID periods (72%, 95% CI: 68%-83%, p = 0.03). Lower-middle income countries showed higher prevalence (73%, 95% CI: 69%-77%) than upper-middle income countries (67%, 95% CI: 63%-70%). No significant publication bias was detected (Egger's p = 0.721, Begg's p = 0.537).

This first regional synthesis demonstrates that anemia affects three-quarters of TB patients in Southeast Asia, with significant variation by HIV status, income level, and pandemic period. Unlike previous global estimates (53.9%), our region-specific findings (72%) and documentation of COVID-19 impact (84% during pandemic) provide actionable evidence for Southeast Asian TB programs to integrate anemia screening and management, particularly for vulnerable populations during health system disruptions.