Integrated health checks as a person-centred approach to systematic screening of household tuberculosis contacts: A realist-informed mixed-methods study.

Globally, tuberculosis incidence and mortality is driven by syndemic interactions of tuberculosis with other chronic conditions including HIV, diabetes and undernutrition in a deleterious social and structural context, often characterised by poverty. Systematic screening for tuberculosis among household contacts is a core element of the WHO tuberculosis strategy but is hampered in high-tuberculosis incidence settings by health system constraints and low participation by household members of people with tuberculosis. Reframing screening as a health check, informed by the syndemic framework, could improve uptake and address proximate determinants of tuberculosis. Within a larger research study aimed at evaluating new tuberculosis diagnostic tests we developed and, using mixed methods, evaluated an integrated health check in a prospective cohort of tuberculosis household contacts in Zimbabwe. This included screening for a range of health conditions, health education and counselling, and on-site treatment or referral. Of 836 identified household contacts, 700 (84%) participated in tuberculosis screening. Of those, 467 people (67% women, median age 28 years) were invited to the health check; all participated in the intervention. One percent (n = 5/459) were diagnosed with tuberculosis. Almost two thirds (n = 288) had at least one unmet health need (either undiagnosed or uncontrolled diabetes, hypertension, HIV, anaemia, undernutrition, common mental health disorders, vision impairment, or tuberculosis). Of those referred following the health check, 66% accessed care for at least one condition, with variation across conditions. In-depth interviews with participants (n = 28), informed development of a refined explanatory theory, illustrating the benefits of a syndemic theory-based approach to tuberculosis screening for household contacts. Members of tuberculosis affected households have multiple, intersecting and unmet health needs. A holistic approach to systematic screening of household contacts guided by the syndemic framework could improve the health of these vulnerable people, advancing progress towards both tuberculosis and sustainable development goals.