Nain 2011.

Methods	2‐arm RCT undertaken in India
Participants	30 participants Inclusion criteria: age group 20–75 years, ulcer area 50–200 cm², diagnosis of DM made by American Diabetes Association Criteria Exclusion criteria: aged < 20 years or > 75 years; obvious septicaemia; osteomyelitis; wounds resulting from venous insufficiency; malignant disease in a wound; people being treated with corticosteroids, immunosuppressive drugs or chemotherapy; any other serious pre‐existing cardiovascular, pulmonary and immunological disease. Key baselines covariates: not reported
Interventions	Group A: negative‐pressure dressing therapy. Foam‐based dressing covered with adhesive drape. An evacuation tube embedded in the foam was connected to a fluid collection canister contained within a portable vacuum/suction machine. ​Subatmospheric (negative) pressure was applied within a range of –50 mmHg to –125 mmHg intermittently 3 times a day. NPWT dressings were changed when required. Subsequently, the control group received twice daily saline‐moistened gauze dressings. Group B: twice daily dressing changes with saline‐moistened gauze Cointerventions: wounds underwent initial sharp debridement to remove necrotic tissue and slough as far as possible. Standard antibiotic regimens were administered to all participants which consisted of broad‐spectrum antibiotics initially and later according to the culture sensitivity report.
Outcomes	Primary review outcomes: number of wounds completely healed (complete healing defined as 100% wound closure with re‐epithelialisation or scab with no wound drainage present and no dressing required; complete responders: complete healing of lower limb ulcers) Secondary review outcomes: no review relevant outcome reported
Notes	Follow‐up: 8 weeks Funding: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "patients were randomly divided into two groups – study group and control group." Comments: not reported how sequence for randomisation was generated.
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not possible to blind participants and investigators to whether or not they receive NPWT.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "the patients who underwent below knee amputation were excluded from this analysis." Comment: surely this is attrition bias. We do not know how many people underwent amputation (it was unclear what the 80% vs 60% refer to. In the text it said that 9 wounds in the A group as 60% at 4 weeks).
Other bias	Unclear risk	Not reported