Table 1.

Definitions used in systematic review.

Variable	Definition
Barrier	Obstacle preventing TB treatment initiation and treatment access. Includes: cost, infrastructure, and health-seeking behaviors.
Treatment initiation	TB medication start date.
Child (pediatric)	0–18 (UNICEF)[14]
Adolescent	10–19 years (UNICEF, WHO, UNFPA)[14]
Youth	15–24 (WHO, UN, UNESCO, UNICEF)[14]
Patient-level (P)	Individual-level factors and perceptions. Includes patient costs, health-seeking behavior, and internal/external stigma.
System-level (S)	Characteristics of health systems. Includes health system delays, laboratory capacity, geography, health system infrastructure beyond the individual (i.e. information technology systems), and provider attitudes towards TB.
Cost	Direct or indirect economic burden to family, guardian, and/or patient associated with TB care. *Part of the cost was incurred prior to treatment initiation, i.e. costs incurred while obtaining diagnosis or between diagnosis and treatment were included in analysis.
Direct cost	Out-of-pocket expenses for transportation, food, medicine, etc.
Indirect cost	Lost wages due to time spent seeking care or inability to work.
Catastrophic medical expenses	When a household’s total out-of-pocket health payments are equal to or exceed 40% of the household’s capacity to pay [15].
Health-seeking behavior	Navigation of the health system. Includes care pathways of providers (formal and informal healthcare providers, private and public sector, traditional healers, health extension workers, herbalists, nurses, physicians, etc.) sought prior to appropriate TB diagnosis and treatment. Also includes knowledge, attitudes, and beliefs regarding TB.
Infrastructure	The geography and access to care, laboratory capacity, level of care and health policies (centralized versus decentralized care), health system errors (initial default), and quality of health services delivery.
Initial default	If a patient is diagnosed with TB but does not initiate treatment.