Delay from symptom onset to treatment start among tuberculosis patients in England, 2012–2015

Abstract

Improving access to tuberculosis (TB) care and ensuring early diagnosis are two major aims of the WHO End TB strategy and the Collaborative TB Strategy for England. This study describes risk factors associated with diagnostic delay among TB cases in England. We conducted a retrospective cohort study of TB cases notified to the Enhanced TB Surveillance System in England between 2012 and 2015. Diagnostic delay was defined as more than 4 months between symptom onset and treatment start date. Multivariable logistic regression was used to identify demographic and clinical factors associated with diagnostic delay. Between 2012 and 2015, 22 422 TB cases were notified in England and included in the study. A third (7612) of TB cases had a diagnostic delay of more than 4 months. Being female, aged 45 years and older, residing outside of London and having extra-pulmonary TB disease were significantly associated with a diagnostic delay in the multivariable model (aOR = 1.2, 1.2, 1.2, 1.3, 1.8, respectively). This study identifies demographic and clinical factors associated with diagnostic delay, which will inform targeted interventions to improve access to care and early diagnosis among these groups, with the ultimate aim of helping reduce transmission and improve treatment outcomes for TB cases in England.

Factors associated with delay in treatment initiation for pulmonary tuberculosis

“…Delays are probably due to diagnostic challenges of a negative first-line investigation, but also because positive smear is associated with more severe and clinically and radiologically obvious disease [15][16][17]. Consistent with previous observational data from the UK or United States examining healthcare delay or total delay, we found longer delays in females [8,18,19], native-born cases [9,10,[18][19][20], cases with longer time since migration [19] and cases referred by general practitioners [10]. One explanation for the above populations experiencing longer delays would be a low index of clinical suspicion in the examining clinician for cases whom they perceive as being at low risk of TB.…”

“…This may be further compounded for people with extrapulmonary sites of disease. Shorter delays to diagnosis have been noted in London compared to the lowest incidence areas of England, including the South East [19]; our findings are most generalisable to low-incidence settings with relatively low ethnic diversity, and similar referral pathways. Improving awareness of TB in such populations remains a significant challenge.…”

“…In people with multiple social risk factors (but not a single social risk factor), we found weak evidence of shorter presentation delay, and strong evidence of shorter healthcare delay. Shorter total delay has been observed in groups with social risk factors by researchers in the UK [18] and USA [20], but not consistently by others [8,19]. Shorter delays for those with multiple social risk factors could be due to case finding and specific referral pathways in what is likely to be a high-risk group, and greater awareness of increased risk by clinicians, but effects may be specific to presentation delay/healthcare delay and differ by region.…”

“…Older age has been associated with longer total delay [9,10,19], increased delays being most pronounced when comparing adults with children [9,19], and thought to be due to difficulties in recognising TB symptoms among other comorbidities, or less typical TB presentation. Similarly, we observed shorter presentation delay in children, and weak evidence of trends to longer healthcare delay with older age; we may have detected a significant effect with a larger cohort giving greater statistical power.…”

Determination of related factors about diagnostic and treatment delays in patients with smear-positive pulmonary tuberculosis in Turkey

“…We found that the diagnosis delay was longer in women (median = 27 days) than in men (median = 19 days). In a study performed in England, the diagnostic delay was found to be associated with being female [24]. In China, female sex was related with a risk of diagnostic delay [25,26].…”