Table 5

 Sample calculations based on data in tables 3 and 4

Case typeAnnual risk of TB disease/100 000TB risk adjusted ×5 for anti-TNF effectRisks of prophylaxis /100 000 (table 6)Risk/benefit conclusion
The weighted average risk for prophylaxis with isoniazid (6H) is 278/100 000 which is used for these calculations. The weighted average risk for rifampicin/isoniazid (3RH is higher at 1766/100 000, but this regimen may need to be considered if a shorter duration of chemoprophylaxis is needed on clinical grounds (see section 4.6).
Age 55–74
UK born
Age >35
In UK 3 years
Black African168840278Prophylaxis
Age 35–54
Other ethnic39195278Observation
Age 35+
In UK >5 years