Outcomes
Primary outcome: Tracheostomy use in critical care patients. Use of a
tracheostomy was recorded if the Office of Population Censuses and
Surveys Classification of Interventions and Procedures version 4
(OPCS-4) code E42- was used anywhere in the HES record of procedures.
Secondary outcomes: In-hospital mortality, length of hospital stay,
length of critical care stay and tracheostomy malfunction. In these
analyses, tracheostomy use was treated as the primary exposure variable.
Mortality was taken from the Office for National Statistics (ONS) date
linked to HES data at a patient level. An in-hospital death was recorded
if the date of death was the same as or +/- one day of the date of
hospital discharge recorded in HES. Tracheostomy malfunction was
recorded where the ICD-10 code J950 was used.