Abstract 261: Where Clinical Practice, Emerging Medical Technology, And Evaluation Intersect In A Healthcare System Based On Equal Access: The Example Of Transcatheter Aortic Valve Replacement
Bibliographic record
Abstract
BACKGROUND: Transcatheter aortic valve replacement (TAVR) is an emerging treatment for frequently elderly patients with severe symptomatic aortic stenosis considered at too high risk for conventional surgery. However, this less invasive treatment has important implications in a universal public payer healthcare system with limited resources. In early 2011, the province of Quebec’s Ministry of Health requested an evaluation of TAVR by INESSS, a government-funded independent body that assists evidence-based policy-making with literature reviews, field evaluations and outcomes research. The Ministry also asked INESSS to be involved in the creation of a provincial registry. At the time of the request, 4 centers were already performing TAVR and others were developing programs. METHODS: We conducted a systematic literature review (2008-2011) on effectiveness, safety, economic, and ethical issues, in collaboration with a committee of independent clinical experts (4 interventional cardiologists, 4 cardiac surgeons). The committee’s role was to help interpret and contextualize existing evidence and to collaborate in the development of a provincial registry. We proposed clinical, process of care and economic variables for a registry based on the literature review and the clinicians’ perspectives. RESULTS: According to the literature, outcomes of TAVR are promising for carefully selected patients with respect to 1-year survival, functional improvement, and quality of life. Limitations in the evidence base include uncertain longer-term benefits and device durability due to a lack of studies with lengthy follow-up; an important risk of stroke and high rates of hospitalization post-intervention in the one available randomized controlled trial; lack of standardization of data definitions across studies; and insufficient evidence on cost-effectiveness and cost-utility. We recommended that: (1) TAVR be offered only to patients declined for surgery and who would likely have improved quality of life as a result of the procedure; (2) patients be fully informed of the relative novelty of the procedure and uncertainty about associated risks and longer-term benefits; (3) selection of patients involve a multi-disciplinary team and be uniform in terms of criteria and process across centers to ensure equal access; (4) the patient selection process be documented; (5) TAVR programs receive specific funding that includes financing of a registry; (6) a mandatory registry be used to collect data on baseline patient characteristics, procedures, outcomes, and costs, to inform both participating centres and the Ministry; and (7) TAVR be performed by a limited number of expert centers to maintain a sufficient volume of procedures. CONCLUSIONS: The practice of TAVR in the province of Quebec will be guided by the results of a systematic review of existing evidence and future evidence from a provincial registry developed by an independent body in collaboration with clinical experts. We believe that this evaluation model will meet the challenges posed by the introduction of innovative technology in a universal healthcare system with limited resources.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.177 | 0.222 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.003 |
| Bibliometrics | 0.009 | 0.012 |
| Science and technology studies | 0.004 | 0.013 |
| Scholarly communication | 0.012 | 0.009 |
| Open science | 0.002 | 0.007 |
| Research integrity | 0.007 | 0.005 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".