Lamb 2002.

Study characteristics
Methods	Randomised trial: use of sequentially‐numbered, sealed, opaque envelopes; stratified by pre‐injury mobility
Participants	John Radcliffe Nuffield Orthopaedic Hospital, Oxford, UK Period of study: not stated, earliest report located 1998 27 female participants Inclusion: women aged ≥ 75 years who had surgical fixation (not total hip replacement) of a hip fracture, living in own home or a relative's home or in sheltered housing before their injury. Written informed consent Exclusion: history of stroke or Parkinson's disease, clinical depression or acute mental illness, cognitive impairment: 6 or lower on the Hodkinson Mental Test Score. Other fracture, respiratory or cardiac failure sufficient to prevent walking 50 feet (15.25 m), systolic blood pressure > 200 mmHg or diastolic blood pressure > 100 mmHg, surgical complications, pathological fracture. At medication assessment at day 6: on hypnotics, sedatives, muscle relaxant or medications likely to affect muscular function during postoperative period. Age: mean 84 years (range: not stated) % male: none Number lost to follow‐up: 3 excluded. One had myasthenia gravis (confirmed independently as not related to trial), one a severe chest infection and the third participant withdrew consent after a few days.
Interventions	Early postoperative rehabilitation, started at 7 days after surgery. 1. Patterned neuromuscular (electrical) stimulation of the quadriceps muscle for 3 hours a day for 6 weeks. Stimulus intensity was the minimum required for visible muscle contraction. Each stimulus delivered 0.3 micro coulomb of charge. versus 2. Placebo stimulation for same time period. Interventions started in hospital 1 week after surgery and continued at participants' homes after hospital discharge at 10 to 14 days. A trained assistant, who was independent of the study, showed the participants how to apply the stimulator.
Outcomes	Length of follow‐up: 12 weeks after randomisation (13 weeks after surgery) Recovery of mobility Walking velocity Leg extensor power Compliance Pain (1: no pain to 6: severe pain) Side effects (none)
Notes	Patterned neuromuscular (electrical) stimulation is "a variable frequency stimulus (mean frequency 8.9 Hz) derived from the discharge of a fatiguing motor unit of the quadriceps". The stimulator was designed for home use, being portable and independent of an electric supply. Difficulties found by the participants in changing the batteries meant that weekly visits were required by study personnel. Funding: Research into Ageing and the PPP Healthcare Charitable Trust. Conflict of interest: nil
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“Randomization lists were prepared in advance of the study with a random number table.”
Allocation concealment (selection bias)	Low risk	“Assignments were placed in sealed, numbered, opaque envelopes that were opened in a strict sequence after eligibility had been established and consent obtained.”
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Good attempt made to blind participants with placebo stimulation.
Blinding of outcome assessment (detection bias) Observer‐reported outcomes, some judgement	Low risk	“The investigator responsible for measuring outcomes and all participants were blind to the treatment assignment."
Blinding of outcome assessment (detection bias) Observer‐reported outcomes, no judgement	Low risk	Only complications reported, blinding indicated, and assessment of this outcome is unlikely to be influenced by knowledge of group allocation.
Incomplete outcome data (attrition bias) Observer‐reported outcomes, some judgement	Unclear risk	No data, including group allocation, presented for the 3 people who did not complete the study
Incomplete outcome data (attrition bias) Death, re‐admission, re‐operation, surgical complications, return to living at home	Unclear risk	Only complications reported
Selective reporting (reporting bias)	Unclear risk	Probably, but no trial protocol or trial registration available
Free from baseline imbalance bias?	Unclear risk	Incomplete report of baseline data as those for the 3 post‐randomisation exclusions were not available. No major differences in the available data for those followed up.
Free from performance bias due to non‐trial interventions?	Low risk	No obvious differences. Both arms included similar usual care.