Evidence of tuberculosis treatment outcomes among people experiencing homelessness: a scoping review.

Background: Tuberculosis is an infectious, preventable and treatable disease that is socially determined. People experiencing homelessness represent a group that is highly vulnerable to this disease, presenting a challenge for its control and elimination. The aim of this review was to synthesize the existing scientific evidence on the outcomes of tuberculosis treatment in the context of the population experiencing homelessness.

Methods: This scoping review was conducted following JBI guidelines. Six databases were consulted: MEDLINE, Web of Science, Scopus, LILACS, CINAHL and EMBASE. Scientific literature with quantitative or mixed-method approaches may be included, published from 2015 onward, in English, Portuguese and Spanish, involving participants aged 15 years or older. The Rayyan application was used to facilitate the selection process, and a descriptive analysis of the findings was performed.

Results: Fourteen articles were included, comprising primarily cohort studies (n= 6) and cross-sectional studies (n= 5), along with two ecological studies and a systematic review. Eight articles were from South America (seven from Brazil), three from Europe and three from Asia. The rates of treatment success outcomes ranged from 89.7% to less than 30%, with nine studies reporting rates under 45%. The highest proportion of accumulated unsuccessful treatment outcomes was nearly 70%, with four studies indicating rates between 60% and 66%. Loss to follow-up was the most frequently reported negative outcome (n= 9), reaching rates of 53.6%. The "failed" treatment outcome was reported in low proportions, often less than 1% (n= 5) and "not evaluated" outcome was reported in half of the studies (n= 7). The proportions observed in the systematic review were consistent with these findings. Furthermore, the results revealed significant differences compared with those of the global general population. While both groups exhibited low proportions of treatment failures, other outcomes for the homeless population were markedly poorer.

Conclusions: The homeless population experiences low success rates in tuberculosis treatment, with no study in this review meeting the international treatment success rate target. A comprehensive, collaborative and patient-centered care approach that addresses social determination of health is essential to improve outcomes and enhance health, social care, and educational services tailored to the needs of this population.