Stimulated by Lin et al 2020.
LHID – Longitudinal Health Insurance Database (Taiwan)key to acronyms
NHIRD – National Health Insurance Research Database (Taiwan)
PD –Parkinson’s Disease (again!)
This paper from Taiwan is another of the large retrospective observational cohort studies, which I listed in a previous blog: Reducing TKR surgery.
This one is unusual in that it highlights one of the risks associated with acupuncture treatment, and I have focussed this blog on one previous such study: Post-acupuncture pneumothorax incidence.
LHID 2005 includes a random 1 million patient sample of the NHIRD over the period 1997 to 2012. Within this sample 407 802 patients received 6 207 378 acupuncture treatments. The database was interrogated to find those patients who developed cellulitis within 2 weeks of an acupuncture treatment session. Those that had had cellulitis within one month before acupuncture were excluded, as were those who had had an invasive procedure within the month prior to the development of cellulitis. The regional location of acupuncture treatment had to match the location of cellulitis for the case to be included.
The incidence of cellulitis after acupuncture was 64.4 per 100 000 treatment ‘courses’. Over 60% of these were in the leg or foot. I have to assume, as it is not specified in the paper, that a treatment course is 10 sessions, as often described in the Chinese acupuncture literature. A single course is often described as daily treatment for 5 days a week over a 2-week period.
The largest prospective study of adverse events after acupuncture noted ‘local infection’ in 31 cases of a cohort of 229 230 patients having an average of 10 treatments each (in Germany). That is equivalent to 13.5 per 100 000 treatment courses; however, only 24 of the 31 required treatment, which equates to 10.5 per 100 000.
Prospective research is more reliable than retrospective observational research, so that could account for some degree of over estimation, but the other important factor is the possible difference in populations. Unfortunately, the paper from Germany does not give demographic details, so I can only speculate that the patients from Taiwan were likely to be older and suffer more co-morbidities.
On the topic of comorbidities, Lin et al used the entire cohort who received acupuncture and performed propensity score matching of those with cellulitis in a 1:4 ratio with the rest (those without cellulitis). This allowed them to estimate the risk of cellulitis following acupuncture related to a variety of factors and comorbidities.
As might be expected, the risk was increased with age and the number of treatment courses, and decreased with urbanisation and affluence. I was alarmed to see a marked increase in risk associated with being male. All of the comorbidities were associated with an increased risk apart from PD, but I was a little surprised to see varicose veins topping the list of odds ratios at 2.48. Next was liver cirrhosis at 2.05, heart failure at 1.76 and diabetes at 1.71.
In a case control study within a longitudinal cohort based in Australia, severe lower limb cellulitis was associated with several conditions involving lower limb pathology. Varicose veins did not quite top the list this time with an odds ratio of 2.95, but it was slightly above lymphoedema at 2.65. Top of the list was tinea pedis with an adjusted odds ratio of 3.05.
Getting back to East Asia, acupuncture associated infections have been raised as a matter for attention, and Lin et al suggest that patients are interviewed concerning their past medical history prior to acupuncture (I would hope so too!) and high risk patients are closely monitored.
1 Lin S-K, Liu J-M, Wang P-H, et al. Incidence of Cellulitis Following Acupuncture Treatments in Taiwan. Int J Environ Res Public Health 2019;16:3831. doi:10.3390/ijerph16203831
2 Witt CM, Pach D, Brinkhaus B, et al. Safety of Acupuncture: Results of a Prospective Observational Study with 229,230 Patients and Introduction of a Medical Information and Consent Form. Forsch Komplementmed 2009;16:91–7. doi:10.1159/000209315
3 Cannon J, Rajakaruna G, Dyer J, et al. Severe lower limb cellulitis: defining the epidemiology and risk factors for primary episodes in a population-based case-control study. Clin Microbiol Infect Off Publ Eur Soc Clin Microbiol Infect Dis 2018;24:1089–94. doi:10.1016/j.cmi.2018.01.024
4 Zhou P, Chen Y, Chen B, et al. Acupuncture-associated infections: A matter of concern in China. Infect Control Hosp Epidemiol 2019;40:383–4. doi:10.1017/ice.2018.354