| Methods |
Double‐blind parallel‐group randomised controlled trial |
| Participants |
242 adults with GBS diagnosed according to the criteria of Asbury 1990. Unable to run. Disease onset < 15 days |
| Interventions |
Intravenous methylprednisolone 500 mg daily for 5 days or placebo infusions |
| Outcomes |
Primary: 0.5 disability grade (Hughes 1978) difference after 4 weeks. Secondary: 0.5 disability grade difference after 12 weeks, reduction of times to cease artificial ventilation, and to recover ability to walk unaided. After 4 weeks, mean (SD) disability grade improvement in corticosteroid group was 0.73 (1.21) grade compared with 0.8 (1.14) grade in the placebo group; difference 0.06 grade (95% CI ‐0.23 to 0.36) |
| Funding |
Funded by the British Medical Research Council |
| Conflicts of interest among primary investigators |
Not stated in the paper but none known |
| Notes |
International multicentre
Plasma exchange permitted at the discretion of the participating neurologist |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
"A telephone call to the trial office led to allocation of a random code number for a patient, stratified in blocks of 12 for each centre" |
| Allocation concealment (selection bias) |
Low risk |
"A telephone call to the trial office led to allocation of a random code number for a patient, stratified in blocks of 12 for each centre. The number led to the pharmacy preparing a coded 100 ml bag of either 5% dextrose with 500 mg methylprednisolone or normal saline alone (placebo). The seals on the bags that contained no methylprednisolone were punctured so that the bags could not be distinguished" |
| Blinding of participants and personnel (performance bias)
All outcomes except death |
Low risk |
See above |
| Blinding of participants and personnel (performance bias)
Death |
Low risk |
See above |
| Blinding of outcome assessment (detection bias)
All outcomes except death |
Low risk |
See above |
| Blinding of outcome assessment (detection bias)
Death |
Low risk |
See above |
| Incomplete outcome data (attrition bias)
All outcomes except death |
Low risk |
2 participants were withdrawn because of incorrect diagnosis (botulism). All other participants (of 240) remained in the trial for 48 weeks and all outcomes were reported |
| Incomplete outcome data (attrition bias)
Death |
Low risk |
See above |
| Selective reporting (reporting bias) |
Low risk |
See above. All outcomes were reported |
| Other bias |
High risk |
"The proportion of patients for whom plasma exchange was stated as possible at randomisation and who then went on to have the procedure was significantly lower in the intravenous methylprednisolone group than in the placebo group (8/45 vs 15/32, p = 0.0125). Therefore it is possible that the patients on placebo were considered by their neurologists to be faring worse than those receiving IVMP and were therefore given plasma exchange; this would have had a beneficial effect and biased the analysis of the trial against detecting an effect of IVMP." |
