Adegoke 2001.

Methods	Design: 4‐week single‐centred, parallel randomised controlled study
Participants	Health condition: people with spinal cord injury Sample size: Randomisation: at participant level (1 ulcer per participant)§ Randomised (participants, n; ulcers, n): 7; 7 Experimental: 4; 4 Control: 3; 3 Analysed (participants, n; ulcers, n): 6; 6 Experimental: 3; 3 Control: 3; 3 Setting, country: neurology wards at the University College Hospital (1 site), Nigeria Inclusion criteria: inpatients with spinal cord injury stage IV pressure ulcers (DeLisa classification) pressure ulcers on the pelvic region Exclusion criteria: not reported Characteristics of pressure ulcer: Experimental Ulcer duration, mean (SD): 12 weeks (2) Ulcer location (n): greater trochanter (2), sacrum (1) Ulcer stage (%): stage IV (100) Control Ulcer duration, mean (SD): 8 weeks (2) Ulcer location (n): greater trochanter (1), sacrum (2) Ulcer stage (%): stage IV (100) Mean age (SD): Overall: 44 years (14) Experimental: 53 years (8) Control: 35 years (14) Gender: not reported §It is not clearly stated whether participants or pressure ulcers were randomised but the number of pressure ulcers equals the number of participants.
Interventions	Total groups in this study: two Experimental: interrupted direct current and standard nursing care Duration: 45 minutes per session; 3 sessions per week; total 4 weeks Electrode placement: one over the ulcer and the other over any suitable part of the body Device, manufacturer: Interrupted Direct Current machine, Duffield Medical Equipment Ltd. UK Intensity of ES: gradually increased until a minimal perceptible contraction was seen Frequency: 30 Hz Type of current: direct Polarity: not reported Control: placebo interrupted direct current and standard nursing care Same settings and duration as experimental group, but without current Standard nursing care for both groups Not reported
Outcomes	Outcomes included in this review: presented as [name of outcome in review]‐ [name of outcome in study] Surface area of pressure ulcers‐ surface area (expressed as mm2)* Not useable data: presented as [name of outcome in review]‐ [name of outcome in study] Rate of pressure ulcer healing‐ percentage change in surface area (expressed as percentage per 2 week)† Time point included in this review: week 4 (end of intervention) Other time points: baseline and week 2 *converted to cm2 for the purpose of analyses †SD not provided
Notes	Withdrawals, (n; reason): Experimental: 1; early discharge from the hospital Control: none Funding source: no information about funding source provided Trial registration or published protocol: no information about trial registration or published protocol provided
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Subjects were then randomly assigned to either group A (IDC plus nursing care) or group B (placebo IDC plus nursing care)." p195 Comment: insufficient detail reported
Allocation concealment (selection bias)	Low risk	Quote: "The assignment to groups was done by an individual with no knowledge of the treatment modality as a way of reducing investigator bias." p195
Blinding of participants (performance bias) All outcomes	Low risk	Comment: control participants received placebo interrupted direct currents
Blinding of personnel (performance bias) All outcomes	High risk	Comment: not possible to blind personnel
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "All measurements were taken by the same therapist (BKA) to ensure reliability." p196 Comment: insufficient detail reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "One of the patient[s] requested to be discharged from the hospital before the end of the study hence was not regarded as being part of the study leaving three subjects each in both groups….." p196 Comment: 1/7 (14%) dropouts
Selective reporting (reporting bias)	Low risk	Comment: all pre stated outcomes were reported
Other bias	Low risk	Comment: appears free of other bias