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Table 4 Adjusted (adjusted for baseline differences (age, gender, stage of CKD, baseline EQ-5D health utility score and baseline cost)) mean incremental costs, incremental QALYs/outcomes and incremental cost-effectiveness ratio between sodium bicarbonate vs placebo

From: Clinical and cost-effectiveness of oral sodium bicarbonate therapy for older patients with chronic kidney disease and low-grade acidosis (BiCARB): a pragmatic randomised, double-blind, placebo-controlled trial

AnalysisIncremental mean costs, £ (95% CI)a, b, cIncremental mean QALYs/outcomes (95% CI)a, b, cMean incremental cost-effectiveness ratio (£/QALY/outcome)
Complete cases over 12-month follow-up (n = 176)563.74 (88.18 to 1154.18)−0.047 (− 0.078 to − 0.015)Dominated
 Sensitivity analysis: lower sodium bicarbonate costd352.76 (− 154.37 to 957.45)− 0.047 (− 0.078 to − 0.015)Dominated
 Sensitivity analysis: lower inpatient stay coste539.03 (109.13 to 1050.45)− 0.046 (− 0.078 to − 0.015)Dominated
 Sensitivity analysis: using ICECAP valuef636.20 (187.59 to 1189.24)− 0.017 (− 0.032 to 0.0001)Dominated
 Sensitivity analysis: using life satisfaction valueg580.19 (143.38 to 1130.11)− 0.396 (− 0.733 to − 0.059)Dominated
Complete cases over 24-month follow-up (n = 114)h591.00 (166.29 to 1078.36)− 0.083 (− 0.166 to − 0.005)Dominated
 Sensitivity analysis: lower sodium bicarbonate costd242.59 (− 179.63 to 720.27)− 0.083 (− 0.166 to − 0.005)Dominated
 Sensitivity analysis: lower inpatient stay coste593.74 (191.37 to 1072.07)− 0.083 (− 0.166 to − 0.005)Dominated
 Sensitivity analysis: using ICECAP valuef598.87 (215.69 to 1052.43)−0.051 (− 0.095 to − 0.010)Dominated
 Sensitivity analysis: using life satisfaction valueg682.44 (257.28 to 1142.63)− 0.974 (− 1.762 to − 0.190)Dominated
Complete cases over 24-month follow-up and all participants starting renal replacement therapy during the trial (n = 161)h808.93 (− 4124.71 to 5411.89)− 0.074 (− 0.151 to − 0.003)Dominated
 Sensitivity analysis: lower sodium bicarbonate costd534.61 (− 4385.90 to 5149.69)− 0.074 (− 0.150 to − 0.003)Dominated
 Sensitivity analysis: lower inpatient stay coste817.21 (− 4097.90 to 5415.22)− 0.073 (− 0.151 to − 0.001)Dominated
 Sensitivity analysis: using ICECAP valuef, i422.08 (− 4091.74 to 4629.60)− 0.046 (− 0.090 to − 0.002)Dominated
 Sensitivity analysis: lower dialysis costj600.26 (− 3560.78 to 4379.06)− 0.075 (− 0.154 to − 0.001)Dominated
 Sensitivity analysis: higher dialysis costk899.41 (− 4327.11 to 5714.04)− 0.074 (− 0.156 to 0.002)Dominated
 Sensitivity analysis: using life satisfaction valueg, l928.18 (− 4373.23 to 5729.68)− 0.072 (− 1.366 to 0.002)Dominated
  1. aBootstrapped non-parametric 95% confidence interval (2.5th/97.5th percentile)
  2. bGeneralised linear model with γ distribution and power 0.65 link function to estimate incremental costs and ordinary least squares regression to estimate incremental QALYs (complete cases)
  3. cGeneralised linear model with Gaussian distribution and power 0.5 link function to estimate incremental costs and ordinary least squares regression to estimate incremental QALYs (114 complete cases + 47 participants starting renal replacement therapy during the trial with baseline EQ-5D). For incomplete cases, missing cost data were assumed to be zero and missing EQ-5D data were imputed by carrying forward the last observation
  4. dApplied average cost of three generic sodium bicarbonate 500 mg with the lowest price, £0.14/day
  5. eApplied average of lower quartile unit cost for non-elective inpatient and elective inpatient bed days, £287/day
  6. fAdjusted for baseline differences (age, gender, stage of CKD, baseline ICECAP value and baseline cost)
  7. gAdjusted for baseline differences (age, gender, stage of CKD, baseline life satisfaction value and baseline cost)
  8. hDiscounted at 3.5% per year
  9. iTwo participants from the bicarbonate group without any ICECAP data were excluded from the analysis, n = 159
  10. jApplied average of lower quartile unit cost for haemodialysis (£134/visit) and peritoneal dialysis (£66/visit)
  11. kApplied average of upper quartile unit cost for haemodialysis (£180/visit) and peritoneal dialysis (£77/visit)
  12. lTwo participants (1 from each group) without any life satisfaction data were excluded from the analysis, n = 159
  13. Abbreviations: QALYs quality-adjusted life years, ICER incremental cost-effectiveness ratio, SA sensitivity analysis, ICECAP Investigating Choice Experiments for the preferences of older people CAPability tool, CKD chronic kidney disease