GH1 and hypopituitarism: For adults over 25 years old, the prescribing of GH treatment is based on NICE criteria that requires patients to: a) have severe GHD, defined as peak GH response of less than 9 mU/litre during a GH stimulation test; b) have a perceived impairment of quality of life (QoL), as demonstrated by a score of at least 11 in the ‘Quality of Life - Adult Growth Hormone Deficiency Assessment’ (QoL-AGHDA) questionnaire; c) be receiving appropriate treatment for any other pituitary hormone deficiencies.