Smear-positive pulmonary tuberculosis patients with previously abnormal chest radiographs: missed opportunities for early diagnosis.

Introduction: It is vital to diagnose and treat pulmonary tuberculosis (PTB) early, in the interests of the patient and public health. At the Singapore Tuberculosis Control Unit (TBCU), it was not uncommon to discover abnormal chest radiographs (CXRs) predating their PTB diagnosis by months to years in the electronic medical records (EMRs) of sputum acid-fast bacilli smear-positive patients. Our study explored this observation.