Effects of Intensity of Electroacupuncture on Chronic Pain in Patients With Knee Osteoarthritis

A Randomized Controlled Trial

Zheng-tao Lv; Lin-lin Shen; Bing Zhu; Zhao-qing Zhang; Chao-yang Ma; Guo-fu Huang; Jing Yin, Ling-ling Yu; Si-yi Yu; Ming-qiao Ding; Jing Li; Xiao-cui Yuan; Wei He; Xiang-hong Jing; Man Li


Arthritis Res Ther. 2019;21(120) 

In This Article


Participants and Baseline Characteristics

Between September 2014 and March 2016, we screened 805 participants for eligibility among the 5 hospitals, of whom 301 were randomly assigned. Among the randomized participants, 271 (90.0%) completed the study. Multiple imputations were used for the missing data in 21 participants (9 in the strong EA group, 8 in the weak EA group, and 4 in the sham EA group). Dropouts at each stage and the number assessed for the primary end point are presented in Figure 1. The baseline characteristics of the participants are shown in Table 1. They were comparable across the 3 groups.

Figure 1.

Trial flow chart

Primary and Secondary Outcomes

For the primary outcome, the mean of CPM function score was 9.49 at baseline and 24.34 at week 2 in the strong EA group, 9.86 at baseline and 14.61 at week 2 in the weak EA group, and 9.46 at baseline and 10.89 at week 2 in the sham EA group (Additional file 1: Table S1). The change in CPM function score differed significantly among the three groups at 2 weeks after randomization (Table 2). The CPM function score increased in the strong EA group by 14.85, in the weak EA group by 4.75, and in the sham EA by 1.43; a greater increment of CPM function score was observed in the strong EA group than in the sham EA group (between-group difference 13.54; 95% CI 13.23 to 13.85; P < .01) and in the weak EA vs. sham EA group (3.80; 95% CI 3.45 to 4.15; P < .01). In addition, the strong EA group was also statistically different from the weak EA group (9.73; 95% CI 9.44 to 10.02; P < .01) (Table 2). As shown in Figure 2, the mean CPM scores were similar among the three groups before treatment, with differences between true EA (strong and weak EA) and sham EA, and strong and weak EA becoming apparent after 2 weeks treatment. Moreover, at the end of week 2, VAS value, WOMAC, and all secondary outcomes (NPRS, ES, and PPI) were significantly lower in the two true EA groups than in the sham EA group (P < .01 for all comparisons), and strong EA was more effective in improving VAS, NPRS, and ES than weak EA (Table 2). Results of per-protocol analyses were included in the supporting information (Additional file 2: Table S2).

Figure 2.

Mean CPM scores in sham, weak, and strong EA groups over 2 weeks treatment

During the treatment course (the first week), there was no significant difference among the three groups in the CPM value (P > .05 for all comparisons) (Table 2). On the other hand, compared with the sham EA group, both strong and weak EA groups showed a significant improvement in all pain-related scores of VAS, WOMAC, NPRS, ES, and PPI (P < .01 for all comparisons). Furthermore, no differences were observed between the strong EA group and the weak EA group in the WOMAC, NPRS, or PPI scores (P > .05 for all comparisons) except for the VAS and ES scores at week 1.


During the 2-week trial, 10 participants experienced serious AEs (5 coronary heart disease, 1 stroke, 1 fracture, 1 pulmonary embolism, 1 lung infection, and 1 nephritis). All individuals were admitted to a hospital, and their conditions were considered unrelated to the study or intervention. Among 145 participants (15.2%) who received at least 1 week of strong EA treatment, 22 AEs were recorded (15 subcutaneous hemorrhage or bleeding, 7 needling pain and nausea); 72 participants (13.9%) receiving weak EA reported 10 side effects (7 subcutaneous hemorrhage and 3 needling pain or nausea); and in 75 participants (14.7%) who underwent sham EA treatment, 11 side effects were recorded (7 subcutaneous hemorrhage or bleeding and 4 needling pain).