A case-control study of lifestyle risk factors associated with tuberculosis in Liverpool, North-West England.

The aim of this study was to identify the subtle influences of exposure and individual lifestyles on the risk of developing tuberculosis. A retrospective case-control study (with matching by sex, age, postcode and ethnicity) of all tuberculosis cases notified over a 7-yr period in Liverpool, UK, was carried out. Multiple logistic regression showed that, before diagnosis, cases were 7.4 times more likely to have had visitors from abroad; 4.0 times more likely to have been born abroad; and 3.8 times more likely to have lived with someone with tuberculosis. Subtle socioeconomic factors were also evident with cases 4.0 times less likely to have additional bathrooms. Lifestyle factors emerged with cases 2.3 times more likely to have smoked for at least 30 yrs, 3.8 times less likely to eat dairy products every week and 2.6 times less likely to have had high blood pressure. At interview, these factors were still evident, but cases, unlike controls, had reduced their smoking and alcohol consumption and were less likely to go out of the home or exercise than before their illness. Within individuals, lifestyle consequences of tuberculosis lead to a "healthier" lifestyle on the one hand (less smoking and alcohol consumption), but a reduced quality of life (social activity) on the other.