Time to diagnosis of tuberculosis is greater in older patients: a retrospective cohort review

Introduction: Age-related immunosenescence influences the presentation of tuberculosis (TB) in older patients. Here, we explore the clinical and radiological presentation of TB in the elderly and the factors associated with time to treatment for TB. Methods: This is a retrospective cohort study comparing the clinical, radiological and demographic characteristics of TB patients aged >= 65 years with TB patients aged 18-64 years in a large cohort of TB patients in the UK. Factors associated with the time to presentation and time to treatment were identified using a multivariable analysis model. Results: 1023 patients were included in the analyses: 679 patients aged 18-64 years and 344 patients aged >= 65 years. Classical symptoms of TB (cough, haemoptysis, fever, nights sweats and weight loss) were less common among older patients with pulmonary TB (PTB) (p<0.05), but dyspnoea was more common among older patients (p=0.001). Time from presenting in secondary care to starting treatment was shorter in younger compared with older patients: 3 versus 15 days (p=0.001). When adjusted for age, factors associated with shorter time to treatment from symptom onset include sex (male versus female) (hazard ratio (HR) 1.23 (95% CI 1.05-1.46)), UK born (HR 1.23 (95% CI 1.05-1.46)) and HIV (HR 2.07 (95% CI 1.30-3.29)). Only age remained an independent predictor of time to treatment in a multivariable model (HR 0.98 (95% CI 0.98-0.99)). For those with PTB, chest radiography findings showed that cavitation and lymphadenopathy were more common among younger patients (p=0.001). Conclusions: Older patients aged >= 65 years with TB had fewer classical clinical and radiological presentations of TB, which may explain longer times to starting treatment from symptom onset compared with younger patients aged <65 years.