Placebo Group
Because the placebo group were to have a different anaesthetic regime and therefore may not have amnesia the surgeon did a similar arthroscopic debridement operation. The placebo operation went ahead, the knee was prepped and draped, three, 1cm incisions were made in the skin, the surgeon asked for instruments and manipulated the knee just as if the arthroscopy was performed. Saline was splashed about to simulate the sounds of lavage yet no instruments entered the knee. The patient spent the same time in the theatre as a true operation and also spent a night in hospital after the procedure.
Staff and Regimes
The nurses who cared for all the groups after surgery were unaware of which groups the patients were assigned to. The good thing about the design was that the external evidence of an operation was there to be seen in all groups including the placebo group. The patients can see that something is being done and so can the carers, meaning the carers won’t act differently with patients depending on their allocation. The post-op regime was the same for all the patients, walking aids, same graded exercises and analgesia. The use of analgesia after surgery was monitor for two years and found to be “very similar” in all groups.
Outcome Analysis
The post operative outcomes were assessed by people unaware of group allocations and the surgeon had no involvement post-operatively. Data was collected at 2 weeks, 6 weeks, 3 months, 6 months, 12 months, 18 months and 14 months. At each follow up the patients were asked to guess which procedure they had and “patients in the placebo group were statistically no more likely that the other two groups to state they believed they had the placebo operation”. Consider that.
At 12 weeks 13.8% of patients in the placebo group guessed correctly that they had undergone the placebo group. However, 13.2% of people who underwent the lavage and debridement procedures also did! Consider this too! Patients were assessed on pain, function, 30 metre walking test and timed stair climbing.
Findings
- “At no point did either the intervention group have a greater pain relief than the placebo group”.
- “At no time did either of the intervention groups have significantly greater improvement in function than the placebo group”.
- “Indeed, objectively measured walking and stair climbing were POORER in the debridement group than the placebo group at 2 weeks, one year and 2 years”.
Much more to follow!