Empirical treatment for tuberculosis: survey of cases treated over 2 years in a London area

To determine factors influencing the decision to treat tuberculosis empirically and its outcome.

A retrospective survey was done to assess the factors influencing the decision to treat tuberculosis empirically and the effectiveness of such treatment, within a London area. Data on tuberculosis cases treated during 1995-96 (n = 218) was collected and analysed.

One hundred and fifty-eight (72.5%) cases of tuberculosis were treated empirically, that is, in the absence of positive smear or histology. Factors suggesting tuberculosis were clinical suspicion, abnormal radiology, elevated Erythrocyte Sedimentation Rate (ESR) and/or C-reactive Protein (CRP), grade 3 or 4 Heaf test, contact or family history, and Heaf conversion. Significantly more Asian [79 of 105 (75.2%); p < 0.02] and African patients [61 of 81 (75.3%); p < 0.05] were treated empirically as compared to West European patients [14 of 28 (50%)]. Based on logistic regression, any non-European ethnicity carried a significant risk for being treated empirically [OR: 2.7, CI: 1.7-20.8; p < 0.05]. Patients requiring revision of diagnosis (n = 9) were older [55.7 +/- 10.1 vs 32.8 +/- 16.0 years; p < 0.001]; 6 of them had neoplastic conditions.

In this survey, frequent use of empirical treatment for tuberculosis in non-European patients reflects the physicians' high index of suspicion. Although such therapy is justifiable in selected cases, the proportion requiring revision of diagnosis may be reduced by more thorough investigation, especially in older patients.