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Table 5 Total knee replacement: differences in costs and outcomes between APEX randomised groups

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)
  N Mean (95 % CI)
OUTCOMES    
QALYs    
QALY gain – available cases a 201 0.010 (−0.039 to 0.060)
QALY gain – imputed data b 316 0.009 (−0.040 to 0.057)
Primary clinical outcome    
WOMAC pain score improvement – available cases c 273 3.83 (−0.83 to 8.49)
WOMAC pain score improvement – imputed data d 316 3.33 (−1.21 to 7.88)
COST    
Initial inpatient stay    
Total of inpatient stay – available cases a 268 £89 (£–194 to £371)
Total of inpatient stay – imputed data b 316 £152 (£–140 to £444)
Secondary care after initial discharge    
Inpatient admissions – available cases a 213 -£170 (£–365 to £24)
Inpatient admissions – imputed data b 316 -£239 (£–489 to £11)
Outpatient visits – available cases a 265 £2 (£–47 to £52)
Outpatient visits with – imputed data b 316 £13 (£–43 to £70)
Total secondary care cost – available cases a 203 -£165 (£–391 to £61)
Total secondary care cost – imputed data b 316 -£226 (£–485 to £34)
Community-based resources    
Total community based costs – available cases a 170 -£56 (£–142 to £31)
Total community based costs – imputed data b 316 £0 (£–99 to £99)
Total NHS cost – complete NHS cost cases a 148 -£343 (£–822 to £137)
Total NHS cost – imputed data b 316 -£74 (£–490 to £343)
Personal social services (PSS)    
Total personal social services – available cases a 259 -£4 (£–95 to £87)
Total personal social services – imputed data b 316 -£4 (£–89 to £82)
Total NHS + PSS cost – complete NHS+PSS cost cases a 145 -£404 (£–924 to £117)
Total NHS + PSS cost – imputed data b 316 -£77 (£–528 to £374)
  1. a Adjusted for minimisation variables (baseline WOMAC c pain score and surgical approach) and baseline utility for QALYs, robust standard errors
  2. b Adjusted for minimisation variables (and baseline utility for QALYs), robust standard errors, M=20 multiple imputation sets, bootstrapped confidence intervals with 1000 replications
  3. c Adjusted for minimisation variables (baseline WOMAC pain score and surgical approach) and baseline utility for QALYs
  4. d Adjusted for minimisation variables, M=20 multiple imputation sets from main statistical analysis