Results of the base-case analysis and sensitivity analyses
| Bootstrapped estimates | ||||
| Analysis | Difference mean QALYs (95% CI)* | Difference mean costs (US$) (95% CI)* | ICER (95% CI) | Probability internet-CBT cost-effective† $80 000/QALY (%) |
| 1. Base-case analysis (societal perspective)‡ | 0.0031 (0.0003 to 0.0061) | 170.24 (63.14 to 315.04) | 54 916 | 74 |
| 2. Complete cases | 0.0038 (0.0001 to 0.0075) | 164.01 (55.92 to 301.37) | 42 945 | 81 |
| 3. Healthcare perspective | 0.0031 (0.0003 to 0.0061) | 149.99 (100.39 to 219.74) | 48 384 | 81 |
| 4. 20% increase in treatment cost | 0.0031 (0.0003 to 0.0061) | 194.38 (85.69 to 343.16) | 62 703 | 68 |
| 5. All resources | 0.0031 (0.0003 to 0.0061) | 184.45 (69.52 to 344.26) | 59 500 | 71 |
*Bootstrapped estimates and CI.
†Probability of internet-CBT being cost-effective estimated by non-parametric bootstrapping.
‡Cost and outcome variables imputed using multiple imputation by chained equations.
ICER, incremental cost-effectiveness ratio; internet-CBT, internet-delivered cognitive–behavioural therapy; QALY, quality-adjusted life-year.