Association of Patients' Characteristics with Acupuncture Treatment Outcomes in Treating Bell's Palsy: Results from a Randomised Controlled Trial

BACKGROUND: Acupuncture has been found to be effective for treating Bell's palsy (BP). However, which class of BP patients will have a better response to acupuncture remains uncertain and requires investigation. METHODS: We performed a secondary analysis of a multicenter, randomized, controlled trial. BP patients were randomly divided into five acupuncture treatment groups. The degree of facial nerve recovery was assessed according to the House–Brackmann grading system (HB grade). Grade I was defined as complete recovery (CR), and grades II–VI were defined as incomplete recovery (IR). The relevant patient characteristics were collected and compared between CR and IR groups by univariate and logistic regression analyses. RESULTS: Eight-hundred twenty-six subjects were analyzed. Among these, 698 (85%) subjects had a good prognosis. No significant difference in the effectiveness of the five treatments was observed (all P > 0.05). The likelihood of IR increased by 2.2% with each one-year increase in age (odds ratio (OR) 1.022, 95% confidence interval (CI) 1.005–1.038; P=0.009). The likelihood of IR increased by 9% with each kg/m2 increase in BMI (OR 1.090, 95% CI 1.019–1.165; P=0.012). The likelihood of IR at the recovery stage was higher than that at the acute stage (OR 7.996, 95% CI 4.570–13.991; P < 0.001), and the likelihood of IR of patients with lesions at or above the chorda tympani was higher than that of patients with lesions below the chorda tympani (OR 1.989, 95% CI 1.256–3.150; P=0.003). The likelihood of IR increased by 281.7% with each unit increase in the HB grade (OR 2.817, 95% CI 2.113–3.756; P < 0.001). CONCLUSIONS: Younger patients at the acute stage of the disease with low BMIs, low initial HB grades, and lesions below the chorda tympani were more likely to respond to acupuncture.