From symptoms to diagnosis of Urban Tuberculosis, considering individual and contextual factors. What are the determinants and critical points of this delay?

Summary:

 

Tuberculosis (TB) is still a major health problem at a global scale, but in medium-low incidence Western European countries (MLIWEC), a stable or upward trend in TB incidence observed in large cities is contrasting with its decline in the remaining places. Therefore Urban TB is now a challenge: in large cities, TB is mainly confined to known vulnerable groups, but interactions between individuals from all parts of society in urban environments create wide opportunities for TB transmission. In order to contribute to reduce TB transmission, the ground-breaking nature of this proposal is to understand Pulmonary TB (PTB) delay in diagnosis, considering individual and contextual factors, considering the existence of vulnerable groups, with a special focus on large cities in MLIWEC. Facing this dynamic problem, focus on Urban PTB cases, this study aims to understand the delay between onset of symptoms and diagnosis and its impact on one specific final outcome: the success/failure of treatment. Specifically, we aim to identify areas that have higher delays and to characterize delay by its components (onset of symptoms to seeking health care-delay attributable to patients, and seeking health care to diagnosis-attributable to health services ), and associated factors. Critical points (obstacles) on this delay pathway/chain will be identify and several scenarios will be simulated. Additionally we will analyze the impact of the delays on the individual outcome – treatment success/ failure. Mainly as a contextual approach, a nationwide study will be focusing on global delay. These local studies (in Lisbon and Oporto areas – high incidence areas, previously identified) will be based on questionnaires applied to new PTB patients, allowing detailed analyses by components (not possible with Portugal? s National Tuberculosis Control Programme (NTP) information). The national study will be based on data provided by NTP, considering the period 2008-2017.

Some studies were previously published by our team, specifically focused on global delay (from symptoms to diagnosis). Now we want to go further, focusing specifically on Urban PTB, considering patient and health services delays and also vulnerable and less-vulnerable groups. Methods will be based on multivariate analyses, specifically spatiotemporal clustering, temporal and survival analyses, binary logistic regressions and simulations. Identifying critical areas, understanding the whole of delay chain (including the identification of potential obstacles in different settings) and the prediction of scenarios after intervention on those critical points, will allow to establish and promote specific, tailored actions. Expected outcomes: six papers in scientific journals, one PhD and one master thesis, meetings with NTP (to present and discuss the results), international collaborations and final seminar. This project constitutes a joint work between academia and health services. Budget is mainly to research grants.