Table 1.

Variables registered in the NTSR with definitions

Variable	Definition
Date of birth Date of surgery
Indication of surgery
Airway obstruction/snoring/hypertrophic tonsils	Tonsils cause breathing disorder during sleep (parent reported)
Recurrent tonsillitis	At least three episodes of acute tonsillitis during last 12 months
Peritonsillar abscess	Peritonsillar abscess or peritonsillitis warranting emergency operation, or history of peritonsillar abscesses/peritonsillitis
Chronic tonsillitis	Prolonged inflammation of the tonsils (at least 3 months) affecting daily activities
Other	Free field to register other indications
Surgical Unit
Day case surgery	No admission overnight
Overnight surgery	Prearranged overnight admission
Type of surgery
Primary surgery	No previous tonsil surgery performed
Revision surgery	Tonsillectomy or tonsillotomy performed previously
Extent of surgery
Tonsillectomy only	Extracapsular removal of tonsils
Tonsillectomy and adenoidectomy	Extracapsular removal of tonsils and removal of adenoid
Tonsillotomy only	Partial removal of tonsils
Tonsillotomy and adenoidectomy	Partial removal of tonsils and removal of adenoid
Surgical technique
Cold steel	Procedure performed with cold instruments only, for example knife, scissors or elevator
Radiofrequency	Radiofrequency energy is used for cutting and coagulation
Diathermy scissors	Procedure performed with bipolar diathermy scissors, which can simultaneously cut and coagulate
Ultracision	Procedure performed with instrument, which simultaneously cuts and coagulates using ultrasonic vibration
Dissection with bipolar diathermy	Tonsils are dissected using bipolar diathermy
Other	Free field to register other techniques
Technique for haemostasis
Infiltration with local anaesthetic and adrenalin	Haemostasis achieved with adrenaline vasopressor effect
Monopolar diathermy	Heat coagulation of the vessels using monopolar diathermy
Bipolar diathermy	Heat coagulation of the vessels using bipolar diathermy
Ligature	Suture used to stop haemorrhage
Suture ligature	Suture with needle used to stop haemorrhage
Radiofrequency	Haemostasis achieved using radiofrequency instruments
None	Haemostasis achieved with compression only
Other	Free field to register other techniques
Primary haemorrhage requiring intervention (Yes/No)	Any haemorrhage requiring intervention and occurring after extubation during initial hospital stay