1. Frequency of surgical treatment and related hospital procedures in the UK: a national ecological study using hospital episode statistics 
T.E.F. Abbott, A.J. Fowler, T.D. Dobbs, E.M. Harrison, M.A. Gillies, R.M. Pearse 
British Journal of Anaesthesia 
Volume 119, Issue 2, Pages (August 2017)
DOI: /bja/aex137
Copyright © 2017 The Author(s) Terms and Conditions

2. Fig 2
Crude 90 day post-procedure mortality for England, Scotland and Wales during the period April 1, 2009–March 31, 2014, stratified by inclusive, intermediate and restrictive categories of surgery and shown in % on the left axis. Procedure frequency using the inclusive category shown on the right axis in multiples of procedures. It is unclear whether the observed reduction in mortality rates between 2009 and 2014 reflect improvements in perioperative care or are an artefact of the increasing frequency of procedures.
British Journal of Anaesthesia  , DOI: ( /bja/aex137)
Copyright © 2017 The Author(s) Terms and Conditions

3. Fig 1
Flow diagram showing Office of Population Censuses and Surveys version 4 (OPCS4) codes included in each category of surgery (inclusive, intermediate or restrictive).
British Journal of Anaesthesia  , DOI: ( /bja/aex137)
Copyright © 2017 The Author(s) Terms and Conditions