Investigating the role of symptom valorisation in tuberculosis patient delay in urban areas in Portugal

Background: Diagnosis delay contributes to increased tuberculosis (TB) transmission and morbimortality. TB incidence has been decreasing in Portugal, but median patient delay (PD) has risen. Symptom valorisation may determine PD by influencing help-seeking behaviour. We aimed to analyse the association between symptom valorisation and PD, while characterising individuals who disregarded their symptoms. Methods: A cross-sectional study was conducted among TB patients in Lisbon and Oporto in 2019 – 2021. Subjects who delayed seeking care because they did not value their symptoms or thought these would go away on their own were considered to have disregarded their symptoms. PD was categorised using a 21-day cut-off, and a 30-day cut-off for sensitivity analysis. We estimated the effect of symptom valorisation on PD through a directed acyclic graph. Then, a multivariable regression analysis characterised patients that disregarded their symptoms, adjusting for relevant variables. We fitted Poisson regression models to estimate crude and adjusted prevalence ratios (PR). Results: The study included 75 patients. Median PD was 25 days (IQR 11.5–63.5), and 56.0% of participants had PD exceeding 21 days. Symptom disregard was reported by 38.7% of patients. Patients who did not value their symptoms had higher prevalence of PD exceeding 21 days compared to those who valued their symptoms [PR 1.59 (95% CI 1.05–2.42)]. The sensitivity analysis showed consistent point estimates but wider confidence intervals [PR 1.39 (95% CI 0.77–2.55)]. Being a smoker was a risk factor for symptom disregard [PR 2.35 (95% CI 1.14–4.82)], while living in Oporto [PR 0.35 (95% CI 0.16–0.75)] and having higher household incomes [PR 0.39 (95% CI 0.17–0.94)] were protective factors. Conclusions: These findings emphasise the importance of symptom valorisation in timely TB diagnosis. Patients who did not value their symptoms had longer PD, indicating a need for interventions to improve symptom recognition. Our findings also corroborate the importance of the socioeconomic determinants of health, highlighting tobacco as a risk factor both for TB and for PD.