Prevalence and types of anemia among people with tuberculosis in Africa: a systematic review and meta-analysis

Globally, tuberculosis (TB) and anemia are public health problems related with high morbidity and mortality. Furthermore, anemia is frequently manifested among people with TB in Africa, prevalence ranging from 25 to 99%. The presence of anemia is associated with an increase in individuals' susceptibility to TB and poor treatment outcomes. Studies have reported heterogeneous estimate of prevalence of anemia among people with TB in Africa. This review aimed to estimate the prevalence of anemia among newly diagnosed people with TB n Africa. We searched studies in Medline/PubMed, Cochrane library, ScienceDirect, JBI database, the Web of Science, Google Scholar, WorldCat, Open Grey, Scopus, Agency for Healthcare Research and Quality, ProQuest, and African Journals Online that reported the prevalence of anemia at TB diagnosis. Two reviewers performed data extraction with pre-defined inclusion criteria. A random-effects logistic regression model was used to pool the prevalence of anemia and levels of anemia with a 95% confidence interval (CI) in STATA version 14. Heterogeneity and publication biases were explored. A total of 1408 studies were initially identified, and seventeen studies with 4555 people with TB were included in the analysis. The prevalence of anemia among people with TB in Africa was 69% (95% CI 60.57-77.51). The pooled prevalence of anemia of chronic disease was 48% (95% CI 13.31-82.75) and normocytic normochromic anemia was 32% (95% CI 13.74-50.94) while mild anemia was 34% (95% CI 20.44-46.86). Females were more anemic than males at TB diagnosis in Africa (74% vs. 66%). The finding indicates that anemia is a common co-morbidity present among people with TB, especially among females. Mild anemia and normocytic normochromic anemia were more common at TB diagnosis. The finding indicates that anemia is a common co-morbidity present among people with TB in Africa region. Hence, it is recommended to instigate a routine anemia screening at TB diagnosis to improve treatment outcomes.