Table 3

Samples sizes required for condition level scores to achieve 90% confidence intervals of ±10 points on estimated pass rates

No of cases with the condition requiredNo of cases with applicable indicators requiredNo of randomly selected cases requiredMultiplication factor for PCT level scores*
URTI = upper respiratory tract infections; UTI = urinary tract infections; HRT = hormone replacement therapy; PCT = Primary Care Trust.
*The sample sizes (in the preceding three columns) can be multiplied by this value to obtain the samples required to derive quality scores at the PCT level.
†Not computed as sample too small.
Chronic conditions
    Allergic rhinitis3041713526
    Coronary artery disease882331.3
Acute conditions
    Acute childhood diarrhoea19195111.4
    Acute low back pain103487741.6
    Otitis media14143341.6
    URTI – bronchitis217415514
    URTI – rhinitis624133085
    URTI – tonsillitis33333701.5
Preventive care
    Cervical screening119401.6
    Family planning20203571.9
    Influenza immunisation62623072.9
    Pneumococcal immunisation37372318.3
    Hepatitis B immunisation373711851