Introduction NICE (2011) recommends that patients with latent TB infection who are eligible for but decline treatment are followed up with a chest x-ray (CXR) at 3 and 12 month intervals to assess for TB reactivation. The aim of this study was to assess the effectiveness of this strategy in detecting reactivation of TB.
A retrospective case note analysis of 146 latent TB patients (2006–2011) of all ages.
Mode age range 16–35 (46%).
Follow-up attendance, clinical presentation, CXR appearances and patient demographics were recorded.
47% (n=69) attended for follow-up at 3 and 12 months.
18% DNA at 3 months, 35% DNA at 12 months. 13% moved away.
98.6% of patients showed no evidence of TB reactivation in a 12-month period.
52% of patients were under 35.
2 (1.4%) patients developed active TB within a 12-month period. One was found to have CXR changes at the 3-month follow-up, and was later admitted with TB meningitis. The other was symptomatic (no CXR changes) and was treated empirically for active TB.
63% were new entrants; 41% had been in the UK <1 year.
1 patient was immunosuppressed.
Common risk factors for LTBI were ethnicity (73%) and occupational exposure (19%). Only 12% recalled previous TB contact.
3 and 12-month follow-up had a very low yield of detecting TB reactivation in this sample (1.4%).
It cost £16 000 (based on current PbR tariff) to screen the 69 patients who attended at 3 and 12 months.
Use of limited resources must be justified. Are there better staging intervals for follow-up?
Follow-up is also associated with a high DNA rate, particularly at 12 months, further stretching resources.
However, follow-up allows health promotion regarding TB symptoms and the role of chemoprophylaxis.