The preventable proportion of TB according to primary care registration status
| % Preventable FB-TB cases (N preventable/N total) | Flag-4 registration | Primary care registration (PRDS) | RR* (95% CI) | Sig (p-value)† |
|---|---|---|---|---|
| Overall | 29.1 (250/857) | 59.6 (511/857) | 0.49 (0.43 to 0.55) | <0.0001 |
| WHO TB incidence in country of origin/100 000 | ||||
| <150 | 16.7 (9/54) | 51.9 (28/54) | 0.32 (0.17–0.62) | 0.0002 |
| 150–499 | 31.9 (227/711) | 61.9 (440/711) | 0.52 (0.46 to 0.58) | <0.0001 |
| 500+ | 15.2 (14/92) | 46.7 (43/92) | 0.33 (0.19 to 0.64) | <0.0001 |
| Age at primary care registration‡ | ||||
| <16 years | 31.2 (15/48) | 83.3 (40/48) | 0.38 (0.24 to 0.58) | <0.0001 |
| 16–35 years | 32.3 (175/542) | 63.7 (345/542) | 0.51 (0.44 to 0.58) | <0.0001 |
| >35 years | 27.3 (60/220) | 57.3 (126/220) | 0.48 (0.37 to 0.61) | <0.0001 |
The preventable proportion was calculated in subgroups of the foreign-born (FB)-TB cohort, stratified according to WHO TB incidence region of origin and age at primary care registration.
*RR, rate ratio of the preventable proportion of TB in Flag-4 registered immigrants as a fraction of the total preventable proportion in our FB-TB cohort. A higher RR indicates greater representation of primary care registered preventable cases on the Flag-4 registry.
†Statistical significance measured for differences between Flag-4 registration and NHS patient registration data system (PRDS) registration using χ2 test for proportions.
‡This subgroup analysis was confined to foreign-born TB with primary care registration (N=810).