Study designs of evaluations included in the review
For the review of intervention studies, randomised controlled trials (RCTs) were eligible. Studies of other designs were included if no RCTs of a particular intervention were available.
Eligible study designs were not specified for the diagnostic accuracy part of the review; all patients had to have completed an appropriate reference standard.
Specific interventions included in the review
Studies of interventions to reduce headache and backache at the time of LP were eligible for inclusion. The included studies assessed the use of atraumatic versus standard needles, reinsertion of the stylet before removing the needle, bed rest after the procedure and use of supplementary fluids.
For the diagnostic accuracy part of the review, studies of biochemical analysis of CSF were eligible. The included studies assessed cerebrospinal Gram staining, white blood cell count, glucose level, blood glucose ratio and/or lactate level.
Reference standard test against which the new test was compared
For the diagnostic accuracy component of the review, the authors stated that studies were required to use an appropriate reference standard (e.g. CSF culture or bacterial antigen) in all patients. The included studies used one of these or both interchangeably.
Participants included in the review
Studies of adults undergoing diagnostic LP were eligible for inclusion. Studies of patients undergoing LP during spinal anaesthesia or myelography were excluded.
For the diagnostic accuracy part of the review, eligible studies involved predominantly adult patients with suspected acute bacterial meningitis.
Outcomes assessed in the review
For the review of intervention studies, the specified outcome of interest was headache occurring up to 7 days after LP. Studies of backache and possibly other adverse events were also eligible.
Inclusion criteria for the outcomes were not specified for the diagnostic accuracy part of the review. The outcomes reported were the sensitivity and specificity of Gram staining and the positive and negative likelihood ratios (LRs) for other biochemical tests.
How were decisions on the relevance of primary studies made?
Two independent reviewers assessed the studies for relevance. Any differences were resolved by discussion, with arbitration by a third reviewer if required.