This analysis was aimed at assessing the associations of acupuncture use with mortality, readmission and reoperation rates in hip fracture patients using a longitudinal population-based database. A retrospective matched cohort study was conducted using data for the years 1996-2012 from Taiwan’s National Health Insurance Research Database. Hip fracture patients were divided into:
- an acupuncture group consisting of 292 subjects who received at least 6 acupuncture treatments within 183 days of hip fracture,
- and a propensity score matched “no acupuncture” group of 876 subjects who did not receive any acupuncture treatment and who functioned as controls.
The two groups were compared using survival analysis and competing risk analysis.
Compared to non-treated subjects, subjects treated with acupuncture had
- a lower risk of overall death (hazard ratio (HR): 0.41, 95% confidence interval (CI): 0.24-0.73, p = 0.002),
- a lower risk of readmission due to medical complications (subdistribution HR (sHR): 0.64, 95% CI: 0.44-0.93, p = 0.019)
- and a lower risk of reoperation due to surgical complications (sHR: 0.62, 95% CI: 0.40-0.96, p = 0.034).
The authors concluded that postoperative acupuncture in hip fracture patients is associated with significantly lower mortality, readmission and reoperation rates compared with those of matched controls.
That’s a clear and neat finding; the question is, what does it mean?
Here are a few possibilities for consideration:
- As a result of having at least 6 acupuncture sessions, patients had lower rates of mortality, readmission and reoperation.
- As a result of having lower rates of mortality, readmission and reoperation, patients used acupuncture.
- As a result of some other factor, patients had both lower rates of mortality, readmission and reoperation and at least 6 sessions of acupuncture.
Which of the three possibilities is the most likely?
- Some enthusiasts might think that acupuncture makes you live longer. But does anyone truly believe it reduces the likelihood of needing a reoperation? Seriously? Well, I don’t see even a hint of a mechanism by which acupuncture might achieve this. Therefore, I would categorise this possibility as highly unlikely.
- It stands to reason that patients who are alive and well use more acupuncture than those who are dead or in need of surgery. So, this possibility is not entirely inconceivable.
- It seems very likely that people who are more health conscious might use acupuncture and live longer, need less readmissions or surgery. No doubt, this possibility is by far the best explanation of the findings of this retrospective matched cohort study.
If that is so, does this paper tell us anything useful at all?
Not really (that’s why it was published in an acupuncture journal which few people would read)
On second thought, perhaps it does tell us something valuable: retrospective matched cohort studies are hopeless when it comes to establishing cause and effect!