Community-acquired pneumonia: pneumonia acquired outside hospital (including residency in a care home or nursing home), or which appears within 48h of admission to hospital.

Hospital-acquired pneumonia: pneumonia that develops 48h or longer after hospital admission, and was not subclinical on admission.

Lower respiratory tract infection: an acute illness with cough and at least one other lower respiratory tract symptom, presumed to be due to infection. The definition includes pneumonia, acute bronchitis and infective exacerbation of chronic obstructive pulmonary disease.