A Randomized, Double‐Blind, Crossover Comparison of the Efficacy and Safety of Oral Controlled‐Release Tramadol and Placebo in Patients with Painful Osteoarthritis
Bibliographic record
Abstract
OBJECTIVE: To compare the efficacy and safety of controlled-release (CR) tramadol (Zytram XL, Purdue Pharma, Canada) and placebo in patients with painful osteoarthritis. METHODS: Patients underwent analgesic washout for two to seven days before random assignment to 150 mg daily of CR tramadol or placebo, and were titrated weekly to 200 mg, 300 mg or a maximum of 400 mg once daily. After four weeks, patients crossed over to the alternate treatment for another four weeks. Plain acetaminophen was provided as a rescue analgesic. All patients who completed the crossover study were eligible to receive open label CR tramadol for six months. RESULTS: Seventy-seven of 100 randomly assigned patients were evaluable for efficacy. CR tramadol resulted in significantly lower visual analogue scale pain intensity scores (37.4+/-23.9 versus 45.1+/-24.3, P=0.0009). Western Ontario and McMaster Universities osteoarthritis index subscale scores for pain (189.0+/-105.0 versus 230.0+/-115.4; P=0.0001) and physical function (632.4+/-361.3 versus 727.4+/-383.4; P=0.0205) were significantly better with CR tramadol. Total pain and disability (22.8+/-14.5 versus 27.2+/-14.8; P=0.0004), and overall pain and sleep (104.7+/-98.0 versus 141.0+/-108.2; P=0.0005) scores in the Pain and Sleep Questionnaire were significantly lower for CR tramadol. Short-form 36 Health Survey scores were significantly better during CR tramadol treatment for the pain index (38.8+/-10.8 versus 35.6+/-9.0; P=0.0100), general health perception (46.5+/-11.2 versus 44.4+/-11.6; P=0.0262), vitality (43.1+/-13.2 versus 40.2+/-13.7; P=0.0255) and overall physical components (40.8+/-8.9 versus 37.8+/-7.7; P=0.0002). CR tramadol treatment was preferred by 55.8% of patients (P=0.0005) versus 20.8% and 23.4% of patients who chose placebo or had no preference, respectively. These improvements were sustained for up to six months, and 86.5% of patients reported at least moderate benefit from CR tramadol during long-term treatment. CONCLUSION: CR tramadol is effective for the management of painful osteoarthritis.
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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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.004 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.008 | 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".