Table 2 Study eligibility criteria
From: Occipital nerve stimulation for non-migrainous chronic headaches: a systematic review protocol
Inclusion criteria | -Randomized controlled trials, quasi-randomized trials, retrospective, and prospective observational studies -Chronic setting -At least one group of patients suffering from chronic headache -At least one group of adult patients (≥ 18 years old) -Any sample sizes -Clinical trials with at least one group of patients treated by occipital nerve stimulation -Studies including before and after internal control or a separate control group |
Exclusion criteria | -Sample of patients with migraine only -Combination of ONS and other forms of nerve stimulation |