Ford 2002.

Study characteristics
Methods	2‐arm RCT Single‐centred, conducted in hospital settings at Boston Medical in the USA Duration of follow‐up unclear – stated as ranging from 3 to 10 months not clear if it different between trial groups
Participants	28 participants with 41 wounds enrolled: stated that 22 participants with 35 wounds completed the study Inclusion criteria listed: presence of stage III or IV ulcer for ≥ 4 weeks; albumin ≥ 2.0; age 21–80 years; ulcer volume after debridement = 10 mL–150 mL Exclusion criteria listed: fistulas to organs or body cavities; malignancy in the wound; pregnant or lactating women; Hashimoto thyroiditis; Graves' disease; iodine allergy; systemic sepsis; electrical burns; radiation exposure; chemical exposure; cancer; connective tissue disease; chronic renal or pulmonary disease; uncontrolled diabetes; corticosteroids or immunosuppressive agents; cardiac pacemaker; ferromagnetic clamps; recent placement of orthopaedic hardware
Interventions	Group A: NPWT (number of participants in the trial group not reported; n = 20 ulcers). The report suggests using the KCI VAC product. The duration of treatment was 6 weeks. "NPWT dressings were changed Mondays, Wednesdays, and Fridays (manufacturer recommends dressing changes every 48 hours)." Group B: Healthpoint System (which consists of three gel products: Accuzyme®, Iodosorb®, and Panafil®). The study reports that of the choice of three treatments available ‐ participants whose wounds showed substantial exudate received Iodosorb® or Iodoflex®; those patients whose ulcers were clean and granulating received Panafil®. Because all wounds were debrided surgically as appropriate, Accuzyme® was not used. The number of participants in the trial groups was not reported; n = 15 ulcers. The duration of treatment was 6 weeks. "HP [Healthpoint] dressings were changed once or twice daily, depending on the degree of wound drainage."
Outcomes	Primary outcomes: Complete wound healing (% ulcers healed) Adverse events Secondary outcomes: not reported
Notes	Some participants had more than one ulcers: potential unit of analysis issue Funding source: the Plastic Surgery Education Foundation and Kinetic Concepts, San Antonio, TX
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients underwent ulcer debridement as necessary, followed by random assignment to 6 weeks of treatment with either VAC or HP. Randomization was based on a table of random letters, V or H, generated before the trial began." Comment: method of generation of random schedule not clear
Allocation concealment (selection bias)	Unclear risk	Comment: method of allocation not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Wound healing Quote: "Blinded clinic staff, including nurses, medical students, and interns, measured wounds and obtained plaster impressions." Comment: blinding of key study personnel used Adverse events Comment: not blinded
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "28 participants with 41 wounds were enrolled; 22 participants with 35 wounds completed the study." Comment: report suggest 6 participants with 1 wound each were lost to follow‐up. It is not clear which trial group these participants were from. The paper also reports that the average patient age was 41.7 years in Group A and 54.4 years in Group B. It is not clear if this was before or after the loss of 6 participants, but there seems to be imbalance
Selective reporting (reporting bias)	Low risk	Comment: based on paper only, protocol not obtained
Other bias	High risk	Comment: possible unit of analysis issue is due to participants with multiple wounds in the trial with data being reported at the wound rather than participant level. No information on the number of participants randomised to each group. Duration of follow‐up and any differences in trial groups of follow‐up times were not clear