Table 6.
Evidence quality of included studies.
| Author (date) | Interventions vs comparisons | Outcomes (number of studies) | Risk of bias | Inconsistency | Indirection | Imprecision | Publication bias | Quality of evidence |
|---|---|---|---|---|---|---|---|---|
| Gao (2011) | Acupuncture vs sham acupuncture | Effective rate at the end of treatment (8) | 0 | 0 | 0 | −1① | 0 | Moderate |
| Effective rate at the end of follow-up (4) | 0 | −1② | 0 | −1① | 0 | Low | ||
| Zheng (2012) | Acupuncture vs western medicine | Effective rate (8) | 0 | −1② | 0 | 0 | 0 | Low |
| Acupuncture vs Chinese medicine therapy | Effective rate (3) | 0 | 0 | 0 | −1① | −1③ | Low | |
| Acupuncture vs sham acupuncture | Effective rate (3) | 0 | 0 | 0 | −1① | −1③ | Low | |
| Chen (2014) | Acupuncture vs western medicine | Effective rate (13) | 0 | 0 | 0 | 0 | 0 | High |
| Yang (2014) | Acupuncture vs western medicine | Short-term effective rate (9) | 0 | −1② | 0 | 0 | 0 | Low |
| Long-term effective rate (4) | 0 | −1② | 0 | —1① | 0 | Very low | ||
| Zhao (2014) | Acupuncture vs Western medicine | Effective rate (11) | 0 | 0 | 0 | 0 | 0 | High |
| Dai (2014) | Acupuncture vs western medicine | Effective rate (2) | 0 | −1② | 0 | −1① | −1③ | Very low |
| Pu (2016) | Acupuncture vs western medicine | Effective rate after 3–4 months follow-up (4) | 0 | −1② | 0 | −1① | −1③ | Very low |
| Effective rate after 5–6 months follow-up (2) | 0 | 0 | 0 | −1① | −1③ | Low | ||
| Song (2016) | Acupuncture vs western medicine | Short-term effective rate (15) | 0 | 0 | 0 | 0 | 0 | High |
| Long-term effective rate (7) | 0 | 0 | 0 | 0 | 0 | High | ||
| Long-term headache times (2) | 0 | −1② | 0 | 0 | −1③ | Low | ||
| Xian (2016) | Acupuncture vs sham acupuncture | Effective rate at 1–2 months follow-up (5) | 0 | 0 | 0 | −1① | 0 | Moderate |
| Effective rate at 3–4 months follow-up (6) | 0 | 0 | 0 | −1① | 0 | Moderate | ||
| Effective rate at 5–6 months follow-up (5) | 0 | −1② | 0 | −1① | 0 | Low | ||
| Effective rate of more than 6 months follow-up (2) | 0 | −1② | 0 | 0 | −1③ | Low | ||
| Acupuncture vs western medicine | Effective rate at 1–2 months follow-up (4) | 0 | −1② | 0 | 0 | −1③ | Low | |
| Effective rate at 3–4 months follow-up (2) | 0 | −1② | 0 | 0 | −1③ | Very low | ||
| Effective rate at 5–6 months follow-up (5) | 0 | −1② | 0 | −1① | −1③ | Very low | ||
| Effective rate of 0–1 months follow-up (2) | 0 | −1② | 0 | −1① | −1③ | Very low | ||
| Zhao (2016) | Acupuncture vs western medicine | Effective rate (8) | 0 | −1② | 0 | 0 | 0 | Moderate |
| Xu (2018) | Acupuncture vs western medicine | Effective rate (6) | 0 | 0 | 0 | −1① | 0 | Moderate |
①The optimal information size was not enough. ②I2 value of the combined results was large, and/or confidence intervals overlapped difference. ③Suspicion of publishing bias.