Introduction New immigrant GP registration databases maybe an important tool for identifying recent immigrants to the UK at high risk of latent infection with M tuberculosis (LTBI), who may benefit from screening and treatment to prevent tuberculosis (TB). However, effectiveness of this strategy is determined by the proportion of immigrants that register and the time after UK entry that registration occurs.

Aims To evaluate whether differences exist in the pattern of GP registration onto the new immigrant registration database for Leicestershire (Flag-4), between immigrants stratified by age group (<16, 16–35 or =36 years) and ethnicity (Indian sub-continent [ISC] or Black African).

Methods A retrospective analysis was performed of all immigrants entering the UK after 1999 that were Flag-4 registered between 2000 and 2010 (N=29186) and collated with data for all TB notifications over the same period (N=884). Comparisons were made between immigrants developing TB and staying healthy; and between TB cases occurring in foreign born persons captured or missed by the new immigrant database. Among captured cases, the proportion with a notification date at least 12 months after UK entry and 4 months after GP registration were considered preventable.

Results There was a significant and inverse relationship for the proportions of cases captured and missed by the Flag-4 system in black Africans and ISC immigrants (Abstract P59 table 1, p<0.001). The higher proportion of missed cases in black Africans was evident for both adult age groups but not children. Among registered immigrants, those developing TB had a significantly longer delay to registration (mean difference [95% CI] 420 [259 to 580] days, p<0.001). Compared with age stratified ISC immigrants, time to registration was significantly longer for black Africans aged 16–35 years (mean difference 832 days, p<0.001). However, the proportion of preventable cases in registered immigrants was similar between ISC and black Africans (83.3% and 90.2%).

Conclusions Strategies to encourage early registration by new immigrants with a GP may improve utility of this resource for screening. However, greater emphasis on complementary strategies, including engagement of third sector organisations is needed, particularly for identifying black African immigrants at risk of TB.