Franek 2011.

Methods	Design: 6‐week prospective randomised controlled study
Participants	Health condition: people with pressure ulcers Sample size: Randomisation: at participant level (one ulcer per participant)§ Randomised (participants, n; ulcers, n): 58; 58 Experimental: 29; 29 Control: 29; 29 Analysed (participants, n; ulcers, n): 58; 58 Experimental: 29; 29 Control: 29; 29 Setting, country: Traumatic Surgery Hospital (1 site), Poland Inclusion criteria: participants with stage I, II and III pressure ulcers Exclusion criteria: participants with spinal cord injury or other loss of sensitivity (paresis or paralysis), chronic venous insufficiency, arteriosclerosis (ABPI < 0.9), diabetes, ventricular arrhythmia and cardiac pacemakers and metal implants pregnancy participants on poststeroid therapy Characteristics of pressure ulcer: Experimental Ulcer aetiology (n): poorly fitting footwear (3), poorly fitted artificial limbs (3), plaster cast usage (6), unhealed postoperative wounds (2), internal pressure from implanted plates and screws (3), prolonged immobilisation (4), mechanical soft tissue injuries (8) Ulcer duration, mean (SD): 3.2 months (8.9) Ulcer location (n): lower leg (16), foot (8), gluteal/ischial (2), ankle (2) and hand (1) Ulcer stage (n): stage I (7), stage II (13), stage III (9) Control Ulcer aetiology (n): poorly fitting footwear (1), poorly fitted artificial limbs (3), plaster cast usage (2), unhealed postoperative wounds (3), internal pressure from implanted plates and screws (3), prolonged immobilisation (7), mechanical soft tissue injuries (10) Ulcer duration, mean (SD): 2.8 months (2.3) Ulcer location (n): lower leg (13), foot (6), gluteal/ischial (4), ankle (2) and hand (4) Ulcer stage (n): stage I (8), stage II (13), stage III (8) Mean age (SD): Experimental: 60 years (9) Control: 60 years (10) Gender: Overall: 52% male Experimental: 66% male Control: 38% male §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: Group A ‐ High Voltage Monophasic Stimulation (HVMS) and pharmacologic agents Duration: 50 minutes per session; 1 session per day; 5 days per week; total 6 weeks Electrode placement: one over the ulcer (active electrode) and the other over the intact skin around the ulcer Device, manufacturer: Monophasic Pulsed Current Generator, Ionoson™, Physiomed Electromedizin AG, Germany Intensity of ES: submotor stimulation that caused mild tingling sensation Frequency: 100 Hz Type of current: pulsed Polarity: cathode (active electrode) over ulcer for 2 weeks then anode over ulcer for next 4weeks Control: Group B‐ Pharmacologic agents Pharmacologic agents for both groups This included ulcers cleansing with potassium permanganate. The ulcer base was covered with compresses of fibrolan, colistin, iruxol and wet dressing containing 10% sodium chloride.
Outcomes	Outcomes included in this review: presented as [name of outcome in review] – [name of outcome in study] Proportion of pressure ulcers healed‐ ulcers healed (expressed as numbers) Surface area of pressure ulcers‐ wound area (expressed as cm2) Complications/adverse events‐ adverse events (expressed in descriptive format)† Rate of pressure ulcer healing‐ change in surface area(expressed as % )† Other outcomes not included in this review: (1) volume, (2) length, (3) width, (4) pus‐covered area, (5) granulation area, and (6) Gilman index Time point included in this review: week 6 (end of intervention) Other time points: baseline †These data were taken from Franek 2012.
Notes	Withdrawals, (n; reason): Experimental: none Control: none Funding source: insufficient detail reported in the study but an author of this study confirmed that this study did not receive any kind of financial support or funding from any source (email dated: 27 January 2017) Trial registration or published protocol: insufficient detail reported in the study but an author of this study confirmed that they did not publish a study protocol in a journal or on a trial registry (email dated: 27 January 2017)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "…computer generated randomisation numbers…" p16
Allocation concealment (selection bias)	Low risk	Quote: “…numbers were sealed in sequentially numbered envelopes." p16
Blinding of participants (performance bias) All outcomes	High risk	Comment: not possible to blind participants
Blinding of personnel (performance bias) All outcomes	High risk	Comment: not possible to blind therapists
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Measurements of area (the total surface area and isolated areas covered with pus or granulation) and volume were performed in each person before…." p19 Comment: insufficient detail reported in the study but an author confirmed that the assessors were blinded (email dated: 27‐Jan‐2017)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no dropouts
Selective reporting (reporting bias)	Low risk	Comment: all pre stated outcomes were reported
Other bias	Unclear risk	Comment: one of the authors (GDG) was the Vice President and Medical Director of Staodyn, Inc. (medical equipment company)