Table A16:

Sensitivity Scenario Analysis Results: iCBT Followed by In-Person CBT in a Stepped-Care Model^a

Parameter/Assumption:	Guided iCBT With Individual CBT vs. Guided iCBT With Group CBT, ICER ($/QALY)	Guided iCBT With Individual CBT vs. Usual Care, ICER ($/QALY)	Guided iCBT With Group CBT vs. Usual Care, ICER ($/QALY)
1. Efficacy of CBT: decreased by 25%
a. Base case	1,098	Cost saving	Cost saving
b. Scenario: 0.25 × RR_iCBT & RR_CBT	Dominant	Cost saving	Cost saving
2. Dropout: increased 2 times in CBT
a. Base case: 19% (iCBT) and 16% (CBT)	1,098	Cost saving	Cost saving
b. Scenarios: 2 × base case probability	Dominant	846	Dominated
3. Utility of health states in which iCBT/CBT was provided: 10% lower
a. Base case: 0.85 at 12 months	1,098	Cost saving	Cost saving
b. Scenarios: 10% lower	560	Cost saving	Cost saving
4. Medication costs
a. Base case	1,098	Cost saving	Cost saving
b. Scenario: Increased 2x (all strategies)	1,097	Cost saving	Cost saving
5. Time horizon
a. Base case: lifetime	1,098	Cost saving	Cost saving
b. Scenario: 5 years	6,088	Cost saving	Cost saving

Abbreviations: CBT, cognitive behavioural therapy; iCBT, internet-delivered cognitive behavioural therapy; ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life-year; RR, relative risk.

^aAll costs in 2018 Canadian dollars, discounted at 1.5%.