Table 4

Cost comparison

Control group
Mean±SD in £
Procedural-refinement group
Mean±SD in £
difference in £
P value
Total29 923±12 16826 343±6399−35800.001
 Fixed costs1324±1070803±454−521<0.001
 Variable18 625±625020 278±4431+16530.004
Costs of special interest
 Procedural costs (implantation)17 308±602319 398±4291+2090<0.001
 Intensive care unit1838±3001200±574−1638<0.001
  • Costs were categorised into fixed, semi-fixed and variable costs based on acute health clinical costing standards28 provided by Healthcare Financial Management Association in the UK ( Fixed costs are not affected by in-year changes in activity such as rent and rates. Semi-fixed costs are fixed for a given level of activity but change in steps when activity levels exceed or fall below these given levels; nursing costs are an example. Variable costs are costs that vary with changes in activity,for example, devices (valve, closure device etc.). Non-parametric test used (Mann-Whitney U test).