Study designs of evaluations included in the review
No inclusion criteria relating to the study design were specified. Non-clinical studies, expert opinion, or clear therapeutic studies were excluded. The included studies were prospective cohort studies, prospective and retrospective studies, prospective and retrospective case series, and randomised controlled trials.
Specific interventions included in the review
Studies of selective nerve root injections performed under fluoroscopic guidance were eligible for inclusion. Studies of non-selective nerve injections, with the route of administration not specifically described were excluded. The specific interventions evaluated in the included studies were: nerve block with magnetic resonance imaging and surgical correlation; cervical nerve root mechanical stimulation; selective nerve root injections; selective nerve root block (SNRB) post laminectomy with surgical re-exploration; SNRB prior to surgery; mechanical stimulation with needle and SNRB compared with surgical exploration or myelogram and surgical exploration; mechanical stimulation followed by SNRB with marcaine; spinal blocks of the facets, sciatic nerve, medial branch blocks, and trigger point blocks; and SNRB and radiculography with surgery.
Reference standard test against which the new test was compared
No inclusion criteria relating to the reference standard were specified. The studies appear to have used surgical confirmation and clinical results as the reference standard, although this was unclear from the data presented.
Participants included in the review
Studies of patients with pain of spinal origin were eligible for inclusion.
Outcomes assessed in the review
The specific outcomes assessed in the review were pain relief following nerve root block, surgical outcome, and sensitivity and specificity.
How were decisions on the relevance of primary studies made?
Titles and abstracts were printed and reviewed for exclusion criteria. The authors did not state how many reviewers were involved in this process. Full journal articles of potentially relevant studies were ordered. These were reviewed by three reviewers.