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Table 6 Total hip replacement economic results

From: Local anaesthetic wound infiltration in addition to standard anaesthetic regimen in total hip and knee replacement: long-term cost-effectiveness analyses alongside the APEX randomised controlled trials

  Difference (intervention – control) a
  N Mean (95 % CI) P value
MAIN ANALYSIS: NHS and personal social services (PSS) perspective     
Mean QALY gain 322 0.052 (0.017 to 0.087) 0.004
Mean NHS+PSS cost difference 322 –£86 (£–571 to £399) 0.730
Incremental net monetary benefit – lambda £10,000 322 £606 (£–55 to £1,266) 0.072
Incremental net monetary benefit – lambda £20,000 322 £1,125 (£183 to £2,067) 0.019
Incremental net monetary benefit – lambda £30,000 322 £1,645 (£385 to £2,905) 0.011
SECONDARY ANALYSIS: NHS perspective only     
Mean NHS cost difference 322 £78 (£–347 to £502) 0.720
Incremental net monetary benefit – lambda £20,000 322 £961 (£50 to £1,873) 0.039
Incremental Cost per point in WOMAC pain decrease b 322 £16 (£–16,591 to £16,622)c 0.999
SENSITIVITY ANALYSIS: Using macro-costed prescribed medications     
Prescribed medications b 322 –£24 (£–28 to £–20)  
Mean QALY gain 322 0.052 (0.017 to 0.087) 0.004
Mean NHS+PSS cost difference 322 –£107 (£–590 to £376) 0.660
Incremental Net Monetary Benefit – lambda £20,000 322 £1,666 (£406 to £2,925) 0.010
SENSITIVITY ANALYSIS: 50 % higher local inpatient costs     
Initial inpatient stay b 322 –£50 (£–156 to £56)  
Mean QALY gain 322 0.052 (0.017 to 0.088) 0.004
Mean NHS+PSS cost difference 322 –£106 (£–697 to £485) 0.730
Incremental net monetary benefit – lambda £20,000 322 £1,151 (£121 to £2,181) 0.028
SENSITIVITY ANALYSIS: 50 % lower local inpatient costs     
Initial inpatient stay b 322 –£8 (£–44 to £27)  
Mean QALY gain 322 0.050 (0.015 to 0.086) 0.006
Mean NHS+PSS cost difference 322 –£44 (£–445 to £358) 0.830
Incremental net monetary benefit – lambda £20,000 322 £1,051 (£164 to £1,938) 0.020
SENSITIVITY ANALYSIS: dropping high cost patients     
Mean QALY gain 320 0.052 (0.016 to 0.088) 0.004
Mean NHS+PSS cost difference 320 –£73 (£–449 to £302) 0.70
Incremental net monetary benefit – lambda £20,000 320 £1,121 (£ 215 to £2,026) 0.015
  1. a All results are adjusted for minimisation variables, and baseline utility for QALYs, M=20 multiple imputation sets, bootstrapped confidence intervals with 1000 replications, except results noted with b
  2. b Unadjusted estimates with imputed data using M=20 multiple imputation sets
  3. c This confidence interval includes negative ICER values. These negative values indicate that the intervention is dominant