# Drug-resistant TB treatment outcomes and factors associated with discontinuation and LTFU in Germany: No1Lost study protocol

## TL;DR

This study will investigate treatment outcomes and factors leading to discontinuation or loss to follow-up for drug-resistant TB patients in Germany.

## Contribution

The study introduces a prospective, multi-center cohort design in a low-incidence TB country to evaluate MDR/RR-TB treatment discontinuation factors.

## Key findings

- The study will describe treatment outcomes for 150 MDR/RR-TB patients in Germany.
- It will identify factors like social determinants associated with treatment discontinuation.
- It will analyze the safety and outcomes of newer MDR/RR-TB regimens.

## Abstract

Treatment discontinuation, including loss to follow-up (LTFU), is an important challenge for TB treatment, particularly for multidrug- or rifampicin-resistant TB (MDR/RR-TB). Evidence from low-incidence countries evaluating risk factors for unsuccessful outcomes is scarce. Our study aims to examine treatment outcomes and factors associated with treatment discontinuation for MDR/RR-TB patients in the German health care setting. This observational prospective, multi-centre cohort study will enrol 150 MDR/RR-TB patients in treatment centres between 2025 and 2027. Primary outcome is the description of treatment results. Exploratory analyses will be performed, including logistic regression to assess demographic, clinical, and important factors like social determinants possibly associated with treatment discontinuation. Secondary outcomes will include the descriptive analysis of outcomes and safety of the recently recommended 6–9 months and longer MDR/RR-TB regimens, barriers for adherence to TB guidelines and the clinical structures for MDR/RR-TB management. The prospective No1Lost MDR/RR-TB cohort study will improve the understanding of risk factors and barriers for treatment discontinuation and LTFU in a low-incidence setting to address high rates of treatment discontinuation in this vulnerable population with targeted interventions.