Deaths from pulmonary tuberculosis in a low-incidence country

Abstract

Objectives: To study the validity of official mortality statistics regarding deaths from pulmonary tuberculosis, and to identify factors contributing to death.

Design: A retrospective study.

Setting: Cases were enrolled from the data of the Central Bureau of Statistics from where the official mortality statistics are issued, the National Tuberculosis Register and all Autopsy Registers in the region.

Subjects: Case and autopsy reports from all patients who died from active pulmonary tuberculosis in two Norwegian counties between 1977 and 1989.

Main outcome measures: Patients identified from all three registers with active pulmonary tuberculosis, concomitant diseases/risk-factors, chest X-rays, symptoms, number of patients investigated and treated for tuberculosis, duration from hospital admission until start of treatment and/or death.

Results: Ninety-six patients, median age 75 years, died from pulmonary tuberculosis, 51 without treatment. Thirty-four patients had not been registered at the Central Bureau of Statistics. Thirty-nine patients had cough on admission. Weight loss and generalized malaise occurred just as frequently. Forty-two patients had infiltrates on chest X-ray located elsewhere than in the apical region. In 42 patients, no diagnostic tests for tuberculosis were performed. The median length of stay in hospital was 24 days before death in the untreated group, and 21 days before start of treatment in the treated group.

Conclusion: Reliable figures of patients who died from pulmonary tuberculosis could not be obtained from the official statistics because of under-notification and erroneous codification of diseases. Deaths occurred mainly because the diagnosis was established too late: in half of the patients at autopsy. Eighty-one patients had concomitant diseases known to lower resistance against tuberculosis. Lack of diagnostic suspicion may have been caused by nonspecific symptoms and atypical chest X-ray findings.