Use of instrumented lumbar spinal surgery for degenerative conditions: trends and costs over time in Ontario, Canada
Bibliographic record
Abstract
Background: Instrumented lumbar surgeries, such as lumbar fusion and lumbar disc replacement, are increasingly being used in the United States for low back pain, with utilization rates approaching those of total joint arthroplasty. It is unknown whether there is a similar pattern in Canada. We sought to determine utilization rates and total medical costs of instrumented lumbar surgeries in a single-payer system and to compare these with the rates and costs of total hip and knee replacements. Methods: We included Ontarians aged 20 years and older who underwent instrumented lumbar surgery or total knee or total hip replacement between April 1993 and March 2012. Utilization and medical cost of the procedures were evaluated and compared using linear regression in a time-series analysis. Instrumented lumbar surgical procedures were stratified by age and main indication for surgery. Results: Utilization of instrumented lumbar surgeries rose from 6.2 to 14.2 procedures per 100 000 population between 1993 and 2012 (p < 0.001), well below the utilization of knee and hip arthroplasties. Patients were younger than 50 years for 29.2% of all instrumented lumbar surgery cases; annual procedure rates among those older than 80 years rose 7.6-fold. Direct medical costs of instrumented lumbar surgeries from 2002 to 2012 totaled $176 million. Spinal stenosis and spondylolisthesis were the most common indications for instrumented lumbar surgeries. Conclusion: Use of instrumented lumbar surgeries in Ontario’s single-payer system has increased rapidly, especially among patients older than 80 years. In contrast to the situation in the United States, these rates were well below those of total joint arthroplasties. These data provide useful insights about resource allocation for surgical treatment of lumbar degenerative disorders.
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.006 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
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".