Table 2.
Cost effectiveness, cost per QALY (£, year 2016 values): non-invasive vs. invasive weaning
| Cost perspective | Mean incremental cost/QALY | Probability of cost effectiveness | INMB | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Incremental cost | Incremental QALYs | ICERa | pb | p | pd | INMBb | INMBc | INMBd | |
| Base case (NHS/PSS perspective) | |||||||||
| Imputed attributable costs and QALYs (fixed baseline), adjusted for covariates | − 302 (− 5489 to 4761) | 0.01589 (− 0.01262 to 0.0465) | NIV dominant | 0.57 | 0.58 | 0.59 | 541(− 4598 to 5833) | 620 (− 4545 to 5928) | 779 (− 4470 to 6162) |
| Sensitivity analyses | |||||||||
| 1. Imputed societal attributable costs and QALYs (fixed baseline), adjusted for covariates | − 339 (− 5422 to 4645) | 0.01631 (− 0.01271 to 0.04714) | NIV dominant | 0.57 | 0.58 | 0.60 | 584 (− 4509 to 5733) | 665 (− 4473 to 5862) | 828 (− 4369 to 6075) |
| 2. Complete cases (NHS/PSS) attributable costs and QALYs (fixed baseline), adjusted for covariates | − 739.5 (− 7139 to 5641) | 0.01605 (− 0.0211 to 0.0557) | NIV dominant | 0.59 | 0.60 | 0.62 | 980 (− 5539 to 7442) | 1060 (− 5505 to 7559) | 1220 (− 5456 to 7833) |
| 3. Imputed attributable costs and QALYs (fixed baseline using SF-6D utility score), covariates adjusted | − 330 (− 540 to 4692) | 0.0295 (− 0.1367 to 0.1762) | NIV dominant | 0.58 | 0.60 | 0.62 | 774 (− 5033 to 6521) | 922 (− 5357 to 7025) | 1218 (− 6163 to 8267) |
| 4. Imputed attributable costs and QALYs (fixed baseline), adjusted for covariates and pre-admission EQ-5D-3L covariate | − 445 (− 5305 to 4486) | 0.0156 (− 0.0151 to 0.0479) | NIV dominant | 0.59 | 0.60 | 0.61 | 625 (− 4809 to 5114) | 735 (− 4914 to 5044) | 894 (− 5182 to 4962) |
| Subgroup analyses (COPD and operative status) | |||||||||
| COPD: Presence of COPD: Imputed attributable costs and QALYs (fixed baseline), covariates adjusted EQ-5D-3L utility score | − 5322 (− 17,899 to 6431) | 0.1169 (0.0353 to 0.215) | NIV dominant | 0.82 | 0.84 | 0.87 | 7076 (− 4817 to 19,814) | 7660 (− 4308 to 20,451) | 8829 (− 3368 to 21,731) |
| COPD: Absence of COPD: Imputed attributable costs and QALYs (fixed baseline), covariates adjusted EQ-5D-3L utility score | 756 (− 4768 to 6380) | − 0.0050 (− 0.0352 to 0.0258) | NIV dominated | 0.40 | 0.40 | 0.39 | − 831 (− 6588 to 4793) | − 856 (− 6629 to 4801) | − 906 (− 6745 to 4863) |
| Operative status: Non-operative: Imputed attributable costs and QALYs (fixed baseline), covariates adjusted EQ-5D-3L utility score | -1915 (− 7955 to 3932) | 0.03743 (0.00105 to 0.0766) | NIV dominant | 0.75 | 0.76 | 0.79 | 2477 (− 3491 to 8559) | 2664 (− 3394 to 8806) | 3038 (− 3134 to 9264) |
| Operative status: Operative: Imputed attributable costs and QALYs (fixed baseline), covariates adjusted EQ-5D-3L utility score | 3266 (− 6808 to 13,041) | − 0.0311 (− 0.0747 to 0.0135) | NIV dominated | 0.27 | 0.26 | 0.25 | − 3733 (− 13,560 to 6415) | − 3888 (− 13,736 to 6284) | − 4200 (− 14,063 to 6042) |
ICER dominant: indicates average costs were lower and average benefit greater for the non-intensive treatment group. Figures in parentheses are 95% confidence intervals
COPD chronic obstructive pulmonary disease, EQ-5D-3L three-level EuroQoL 5-Dimensions instrument, ICER incremental cost-effectiveness ratio, INMB incremental net monetary benefit (QALY at thresholds £15,000, £20,000 and £30,000), NHS UK national health service, NIV non-invasive, P probability, QALY quality-adjusted life-year, PSS personal social services, SF-6D 6-Dimension Short-Form survey
aConfidence intervals based on 10,000 simulations
bProbability cost effective or net monetary benefit if cost-effectiveness threshold is £15,000/QALY
cProbability cost effective or net monetary benefit if cost-effectiveness threshold is £20,000/QALY
dProbability cost effective or net monetary benefit if cost-effectiveness threshold is £30,000/QALY