Review: missed tuberculosis cases in India: a systematic analysis of diagnostic, treatment, and reporting gaps.

BACKGROUND: India aims to eliminate tuberculosis (TB) by 2025. Despite ongoing efforts to transform TB care, numerous factors contribute to the persistence of missing cases in India. To gain insight into this issue, we performed a comprehensive review to identify the factors responsible for these missing cases, segregating them into patient- and provider-related factors, with reference to the layers of the onion model.

METHODS: We conducted a comprehensive literature review using relevant search strings in the MEDLINE, Scopus, and Web of Science databases from 2000 to 2024. Given the heterogeneity of the included studies, a qualitative rather than quantitative data analysis approach was considered. For the quality evaluation of studies, we employed a modified version of the Critical Appraisal Skills Program (CASP) checklist.

RESULTS: Of the 253 articles identified, 25 studies that met the criteria for “missing cases” were selected for analysis. Based on the objectives of this review, we identified patient-related factors contributing to missing cases, including geographical displacement due to migration or occupational reasons, alcoholism, illiteracy, personal commitments, side effects to Anti-Tubercular Treatment (ATT), depressive symptoms, perceived social stigma, reluctance to reveal prior treatment history, and no record keeping. Provider-related factors highlighted were inadequate communication and sputum sample collection, exhaustion of pharmaceutical supplies, patient loss to follow-up, ACF versus PCF, inadequacy of diagnostic tests, lack of history taking, misclassification, and issues related to Ni-KSHAY notification. Based on this layer-wise model of missing factors, we discuss pertinent challenges along with plausible strategies and recommendations to stem the rise in missing cases within the Indian context.

CONCLUSION: Our novel findings with reference to the onion model allow for systematic highlighting and addressing of the key patient and provider factors that are fuelling missing cases. The results revealed that provider factors predominantly contributed to the missing case TB scenario. Improved accessibility to services, provider training, and competency building (i.e., handling samples, co-morbid patients, and case notifications), along with improving diagnostic infrastructure, would serve to strengthen the cause of TB elimination.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-025-12967-4.