Corticosteroid use is common, with 8.4 million UK prescriptions issued for oral preparations in 2018 [1]. They are prescribed as replacements for deficiency as well as therapeutically for a range of conditions. There is no question that those on replacement corticosteroids (eg for pituitary or adrenal disease) need additional peri-operative dosing, but there are uncertainties as to which patients on therapeutic corticosteroids (eg for chronic obstructive pulmonary disease or inflammatory arthritides) should receive supplementation, as well as the optimal dose. Up to one-third of patients on therapeutic corticosteroids show evidence of adrenal suppression when well [2]; in theory, these patients could be unable to increase endogenous production to cover surgical stress. No robust evidencebased guidelines exist currently; recently-published national consensus guidance is based on little class A and B evidence [3].

We hypothesised that UK clinical practice was extremely variable before publication of the guidance and this insight would help optimise future study designs to address the most important uncertainties. We conducted an electronic survey (SurveyMonkey©) of the peri-operative prescribing practices of the Royal College of Anaesthetists (RCoA) Fellows and Members for patients taking therapeutic corticosteroids. The survey was open between 23 September and 23 October 2019. We received 1415 out of 18,203 (8%) fully or partially completed questionnaires. Most respondents were consultant anaesthetists (1012/1415; 71.5%) from 13 NHS regions. Table 1 shows the initial approach to prescribing. More detailed prescribing practices can be found in the supplementary material [4]. Most (1266 out of 1329; 95%) prescribed peri-operative steroids and the majority (675 out of 1226; 55%) used 10 mg prednisolone daily as their prescribing threshold. Few stated they would prescribe additional steroids to