Table A5:
Assessment of the Limitations of Studies Assessing the Cost-Effectiveness of iCBT for Anxiety Disorders
| Author, Year, Country | Does the model structure adequately reflect the nature of the health condition under evaluation? | Is the time horizon sufficiently long to reflect all important differences in costs and outcomes? | Are all important and relevant health outcomes included? | Are the estimates of relative treatment effects obtained from best available sources? | Do the estimates of relative treatment effect match the estimates contained in the clinical report? | Are all important and relevant (direct) costs included in the analysis? | Are the estimates of resource use obtained from best available sources? |
|---|---|---|---|---|---|---|---|
| Kumar et al, 2018,63 United States | Partially | Yes, lifetime (assumption made on 5-yr efficacy of iCBT) | Partially, no recurrence | Partially | No | Yes | Unclear |
| El Alaoui et al, 2017,61 Sweden | NA | No | NA | NA | No | Yes | Unclear |
| Hedman et al, 2016,60 Sweden | NA | No | Unclear | Partially | No | Yes | Unclear |
| Dear et al, 2015,62 Australia | NA | No | Partially, no relapse | Unclear | No | Yes | Yes |
| Nordgren et al, 2014,56 Sweden | NA | No | No | Unclear | No | Yes | Unclear |
| Hedman et al, 2014,59 Sweden | NA | Partially | Yes | Unclear | No | Yes | Unclear |
| Hedman et al, 2013,57 Sweden | NA | No | No | Unclear | No | Unclear | Unclear |
| National Collaborating Centre for Mental Health and NICE, 2013,64 United Kingdom | Partially | Yes (assumption made on long-term efficacy of iCBT) | Yes | Partially | Unclear | Yes | Yes |
| Joesch et al, 2012,55 United States | NA | No | Yes | Unclear | No | Yes | Unclear |
| Hedman et al, 2011,58 Sweden | NA | Partially | Yes | Unclear | No | Yes | Unclear |
| National Collaborating Centre for Mental Health and NICE, 2011,9 United Kingdom | Partially | No | No | Unclear | No | Yes | Partially |
| Bergstrom et al, 2010,54 Sweden | NA | No | No | Unclear | No | Partially | Unclear |
| Titov et al, 2009,53 Australia | NA | No | No | No | No | No | No |
| McCrone et al, 2009,52 Sweden | NA | No | No | No | No | No | No |
| Mihalopoulos et al, 2005,51 Australia | NA | No | No | Unclear | No | Unclear | Unclear |
| Kaltenthaler et al, 2006,50 United Kingdom | Partially | No | No | Unclear | No | Partially | Unclear |
| Author, Year | Are the unit costs of resources obtained from best available sources? | Is an appropriate incremental analysis presented or can it be calculated from the reported data? | Are all important and uncertain parameters subjected to appropriate sensitivity analysis? | Is there a potential conflict of interest? | Overall assessment including applicability to the project (Minor limitations/potentially serious limitations/very serious limitations) |
|---|---|---|---|---|---|
| Kumar et al, 2018,63 United States | Unclear | No | No | Unclear | Potentially serious limitations |
| El Alaoui et al, 2017,61 Sweden | Unclear | Yes | Unclear | Unclear | Potentially serious limitations due to CMA design and duplication of data analysis |
| Hedman et al, 2016,60 Sweden | Unclear (self-reported questionnaire) | Yes | No | Unclear | Potentially serious limitations, selected sample, self-reported costs, no sensitivity analysis, no CEAC, no all comparators, no clear influence of medications |
| Dear et al, 2015,62 Australia | Yes | Yes | No | Unclear | Potentially serious limitations |
| Nordgren et al, 2014,56 Sweden | Unclear | Yes | Unclear | Unclear | Potentially serious limitations, selected population, only TAU, Unclear estimation of QALYs, very large increment as compared to other studies |
| Hedman et al, 2014,59 Sweden | Unclear | Yes | Unclear | Unclear | Potentially serious limitations, selected population, not clear cost calculations, only group CBT, drug comparator probably not used for this condition |
| Hedman et al, 2013,57 Sweden | Yes | Unclear | Partially | Unclear | Potentially serious limitations, short duration, estimates not presented well |
| National Collaborating Centre for Mental Health and NICE, 2013,64 United Kingdom | Partially | Partially | Partially | Unclear | Minor limitations, large modeling assumptions, but all strategies are modeled, results for year 1 are not presented, but are discussed as cost-effective, uncertainty analysis not presented |
| Joesch et al, 2012,55 United States | Unclear | Yes | Unclear | Unclear | Potentially serious limitations, study population quite sick, other comparators not well defined, iCBT mixed with other interventions |
| Hedman et al, 2011,58 Sweden | Unclear | Yes | Unclear | Unclear | Potentially serious limitations, selected population, no clear cost calculations, only group CBT, drug comparator probably not used for this condition, not clear quality of this RCT |
| National Collaborating Centre for Mental Health and NICE, 2011,9 United Kingdom | Partly | Yes | Unclear | Unclear | Potentially serious limitations, simple decision tree analysis, short modeling time, costs well estimated but may not be applicable to Ontario, utilities—EQ-5D but change based on assumption and linear extrapolation due to lack of data |
| Bergstrom et al, 2010,54 Sweden | Unclear | No | No | Unclear | Potentially serious limitations, study population selected, no QALY, costs not well estimated, analysis not well done |
| Titov et al, 2009,53 Australia | No | No | No | Unclear | Very serious limitations, selected population, cost estimates not well done |
| McCrone et al, 2009,52 Sweden | No | No | Unclear | Unclear | Very serious limitations, costs not measured, QALYs not estimated, selected population |
| Mihalopoulos et al, 2005,51 Australia | Unclear | No | No | Unclear | Very serious limitations, unclear how costs or outcomes were measured, QALYs not estimated, pilot project |
| Kaltenthaler et al, 2006,50 United Kingdom | Unclear | Partially | No | Unclear | Potentially serious limitations, simple model, 1-yr time horizon, utilities—EQ-5D but changed based on assumption and linear extrapolation due to lack of data from a study in individuals with prior panic disorder |
Abbreviations: CBT, cognitive-behavioural therapy; CEAC, cost-effectiveness acceptability curve; iCBT, internet-delivered CBT; NA, not applicable; NICE, National Institute for Health and Care Excellence; QALY, quality-adjusted life year; RCT, randomized controlled trial; TAU, treatment as usual.