Tramadol Hydrochloride Extended-Release Once-Daily in the Treatment of Osteoarthritis of the Knee and/or Hip: A Double-Blind, Randomized, Dose-Ranging Trial
Bibliographic record
Abstract
This 12-week, multicenter, randomized, double-blind, placebo-controlled, dose-ranging trial evaluated tramadol ER (extended-release tramadol) in the management of osteoarthritis pain. Adults with knee and/or hip osteoarthritis and baseline pain intensity of ≥40 on a 100-mm visual analog scale (0 = no pain, 100 = extreme pain) received once-daily tramadol ER 100 mg (n = 201), 200 mg (n = 199), or 300 mg (n = 199), celecoxib 200 mg (n = 202; to test model sensitivity), or placebo (n = 200). Coprimary efficacy variables were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale, WOMAC physical function subscale, and patient global assessment of disease activity. Tramadol ER 300 mg significantly improved patient global assessment scores compared with placebo (P ≤ 0.05), but not the other 2 coprimary efficacy variables. Tramadol ER 200 and 100 mg were not significantly different from placebo for the coprimary efficacy variables. Daily diary arthritis pain intensity scores improved significantly for tramadol ER 300 and 200 mg compared with placebo. WOMAC joint stiffness subscale, physician's global assessment, arthritis pain intensity in index and nonindex joints, and overall sleep quality scores improved significantly for tramadol ER 300 mg compared with placebo. Significant differences in efficacy between celecoxib and placebo validated the model sensitivity. Adverse events occurred more frequently with tramadol ER than placebo in the gastrointestinal (nausea, constipation, diarrhea) and central nervous (dizziness, headache) systems. In this study, tramadol ER 300 mg was effective in the management of moderate to severe painful osteoarthritis of the hip or knee. A large, increasing placebo response during the study may have contributed to the lack of statistical separation between tramadol ER 200 or 100 mg and placebo.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.004 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 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".