In a recent study published in the Clinical Journal of Pain, electrical stimulation and a higher baseline pain score were shown to be associated with a higher chance for improved pain relief with acupuncture; however, psychological comorbidities increased the chance for treatment failure.
In this retrospective study, researchers evaluated data collected from the military electronic medical record system from 222 patients who received ≥4 acupuncture treatments and had chronic pain ≥4 on a visual analog scale within 1 week before treatment began (mean age, 46.8; 62.2% men; 56.8% white).
Patients had nociceptive pain (36%), neuropathic pain (13.1%), or both (50.9%). Treatment success was defined as a ≥2-point reduction on a numeric or visual analog scale 12-weeks posttreatment.
Overall, 42.3% of patients had a positive treatment outcome. Patients who had successful treatment had a greater mean decrease in pain score (3.30; P <.001) compared with patients who had unsuccessful treatment (0.14; P =.17). Age, sex, race/ethnicity, education, military status, smoking status, pain duration, pain type, pain location, and obesity were shown to have no significant effect on treatment success.
The use of stimulation needles was significantly associated with treatment success (ρ =0.14; P =.03). Other characteristics of acupuncture treatment, such as the number, length, and frequency of acupuncture sessions, had no significant impact on the treatment outcome.
In a binary logistic regression analysis, baseline pain score (odds ratio [OR], 1.26; P =.02), presence of psychological comorbidity (OR, 0.67; P =.01), and the use of stimulation needles (OR, 2.72; P =.03) significantly predicted treatment success. A model using these 3 factors correctly classified treatment outcomes in 60.6% of the patients.
The researchers noted that the small sample size and retrospective design were limitations of the study, concluding that “baseline pain, number of psychological comorbidities, and use of stimulation…should be considered when determining which patients to initiate treatment for, and in the design of future randomized trials.”
Plunkett A, Beltran T, Haley C, et al. Acupuncture for the treatment of chronic pain in the military population: factors associated with treatment outcomes. Clin J Pain. 2017;33:939-943