medwireNews: Placebo, followed by telephone-based cognitive behavioral therapy (CBT), does not meet noninferiority criteria compared with meloxicam for pain relief in patients with knee osteoarthritis (OA), say US researchers.
However, the investigators emphasize that the differences in pain scores between the placebo/CBT group and those given meloxicam were not “clinically important” and did not translate to “meaningful differences” in patient perceptions of pain or function after 14 weeks.
“Although the results of the trial are negative, they provide clinicians with data to support shared decision-making and reassure patients willing to taper NSAIDs [nonsteroidal anti-inflammatory drugs] and consider self-management approaches, such as CBT,” they write in JAMA Internal Medicine.
The noninferiority randomized withdrawal trial included 364 veterans with knee OA who used an NSAID other than aspirin on most days for at least 3 months prior to enrolment.
All participants swapped their regular NSAID for meloxicam 15 mg once daily during a 2-week run-in period, and were then randomly assigned to switch to placebo or continue with meloxicam for 4 weeks. After this time, participants in the placebo arm took part in a 10-week telephone CBT program delivered by a psychologist using a treatment manual for chronic pain that was adapted for OA, while individuals in the meloxicam arm continued to receive the same treatment.
The investigators found that the average raw WOMAC pain score increased from 5.4 points at the time of randomization to 7.8 points at the 4-week follow-up among patients who switched to placebo, and from 5.9 to 6.7 points in the NSAID continuation group.
These findings translated into an estimated average between-group difference in pain score of 1.4 points after adjustment for baseline pain and study location, and this did not meet the criteria for noninferiority of placebo versus meloxicam, say Liana Fraenkel (Yale University School of Medicine, New Haven, Connecticut) and colleagues.
After completion of the CBT intervention, the adjusted mean difference in WOMAC pain score between the CBT and meloxicam groups was 0.8 points at the 14-week follow-up, which also did not meet noninferiority criteria for CBT versus meloxicam.
Therefore, “[a]mong patients with knee OA, placebo and CBT (after placebo) are inferior to meloxicam,” say the researchers. However, they remark that the between-group differences in WOMAC pain scores were smaller than the minimum clinically important difference of 2.1 points, and there was no meaningful difference in patients’ global impression of change or lower extremity disability scores in the final week of the trial.
Fraenkel et al note that use of other therapies for knee pain was higher among people given placebo followed by CBT compared with those who took meloxicam throughout the study, with people using acetaminophen during 46% and 26% of study weeks, respectively, and other prescribed therapies for knee pain during a corresponding 8% and 5% of weeks.
In the safety analysis, a numerically lower proportion of patients in the placebo/CBT arm experienced gastrointestinal adverse events (AEs) compared with those in the meloxicam group (3 vs 7%), but rates of serious AEs were equivalent, at 2% in each group.
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