Study designs of evaluations included in the review
The inclusion criteria for study design were not explicitly stated. The included study designs were placebo comparison randomised controlled trials (RCTs), a longitudinal cohort comparison, and a longitudinal cohort study with no comparison group.
Specific interventions included in the review
Studies of PST were eligible for inclusion. The frequencies used in the included studies were 50 Hz (1 study), 2 to 60 Hz (1 study), 1 to 30 Hz (1 study) and 5 to 12 Hz applied stepwise (1 study). In two studies the patients received nine 1-hour treatment sessions (during 9 consecutive days in one study, and daily with a maximum of 48 hours between treatments in the other study); in one study there were 18 30-minute treatment sessions over a 1-month period; and in one there were daily sessions of 30 minutes/day for 4 weeks in the open phase of the trial and for 3 weeks for a subgroup of patients. Placebo involved simulation of the treatment using the same type of device in the inactive mode.
Participants included in the review
Patients with osteoarthritis were eligible for inclusion. Participants in two of the included studies had osteoarthritis of the knee; in one study patients with osteoarthritis of the cervical spine were included; and in another, patients with cervical and lumbar spondylosis were included. One study was excluded partly because it included patients in the treatment group with different affected joints to those in the control group.
Outcomes assessed in the review
The inclusion criteria for outcomes were not explicitly specified. The included studies used a range of outcome measures including spontaneous pain, pain at rest, pain on motion, and global assessment by patient and physician.
How were decisions on the relevance of primary studies made?
The author does not state how the papers were selected for the review, or how many of the reviewers performed the selection.