Data collection and items
Both authors independently extracted data using a standardised proforma
with data entered to a Microsoft excel spreadsheet and final approval
ratified by consensus of the first two authors.
Data items included: patient demographics, smoking history, diagnostic
interventions performed prior to therapeutic ND, pathological nodal and
p16 status. Further data items to reflect the primary and secondary
outcomes were collected and are detailed in the table 1 and 2 below.