Table 4.

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.