Methodological Quality of SCS Cost-Effectiveness Analyses Rui Duarte, MSc, PhD Health Technology Assessment Lead, Liverpool Reviews and Implementation Group, University of Liverpool Rod Taylor, MSc, PhD Chair of Population Health Research, University of Glasgow Professor of Health Services Research & Director of Exeter CTU & NIHR Senior Investigator, University of Exeter Medical School IMMPACT - Research Design Considerations for Randomized Clinical trials of spinal cord stimulation for pain, November 14-16, 2018, Washington DC

Previous SRs of CEAs of SCS

Aim What are the research methods employed, which outcomes are assessed, how are these reported, and what are the results of economic evaluations of SCS?

Methods – study identification Databases: MEDLINE, MEDLINE Epub Ahead of Print & MEDLINE In-Process, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, CEA Registry & hand searches of included studies Added economic specific terms 1. spinal cord stimulat$.ti,ab,kw. 2. dorsal column stimulat$.ti,ab,kw. 3. epidural stimulat$.ti,ab,kw. 4. or/1-3 5. (cost-effectiveness or cost-utility).mp. 6. incremental cost-effectiveness ratio.mp. 7. incremental cost-utility ratio.mp. 8. (QALY or LY or life year$).mp. 9. or/5-8 10. 4 and 9

Methods – study selection Two reviewers (RT & RD) reviewed all titles and abstracts Inclusion/exclusion criteria During review added the criteria that studies had to be based on comparative clinical evidence – either RCT or nonRCT

Methods – study quality Quality of included SCS cost-effectiveness studies assessed using the CHEERS checklist 24-questions assess quality of reporting

Results – included studies 1st author (year) Pop Comparison Type of analysis Primary data source Andrell (2003) RA SCSc vs CABG Trial-based RCT Annemans (2014) FBSS SCSc vs SCS-HF vs reop vs CMM Model-based Non-RCT Dyer (2008) SCSc vs PMR Hollingworth (2011) SCSc vs CMM Kemler (2002) CRPS SCSc vs CMM (PT) Kemler (2010) Klomp (2006) CLI Kumar (2002) Kumar (2013) FBSS/CLI/RA/CRPS North (2007) SCSc vs reop Simpson (2009) FBSS/CRPS SCSc vs CMM vs reop Slangen (2007) DN Taylor (2005) Trial-based (indirect) Taylor (2010)

Results – quality assessment

Results – methodological quality 1st author (year) CHEERS score CHEERS score % issues Andrell (2003) 13/21 62% Rod to complete Annemans (2014) 19/24 79% Dyer (2008) 22/22 100% Hollingworth (2011) 20/21 95% Kemler (2002) 21/22 Kemler (2010) 19/21 90% Klomp (2006) Kumar (2002) Kumar (2013) 23/24 96% North (2007) 19/22 86% Simpson (2009) 24/24 Slangen (2007) Taylor (2005) Taylor (2010)

Conclusions Quality of included SCS CEA studies as assessed by CHEERS quality of reporting checklist was generally high Limitation of this analysis: CHEERS checklist developed as a ‘CONSORT for CEA studies’ assists authors and reviewers to check if those items are described but does not account for the appropriateness of what the authors have done (like the risk of bias tool for RCTs as an example).

Conclusions cont. Recommendations for future SCS CEAs Base model-based analyses effectiveness estimates of (non-biased) RCT evidence And preferably a systematic review/meta-analysis of the literature rather than ‘cherry picking’ studies Improved specific reporting on: perspective/comparator/discount rates/time horizon/exploration of population heterogeneity (subgroups)