Table 1 Secondary outcome measures

Number of patients screened

Pre-Trial Screening Assessment Form

Number of patients eligible/ineligible

Pre-Trial Screening Assessment Form

Appropriateness of eligibility criteria and reasons for ineligibility

Pre-Trial Screening Assessment Form

Proportion of eligible patients consenting to participate (and whether type of wound/surgical speciality impacts on this)

Consent Form and Pre-Trial Screening Assessment Form

Time between randomisation and treatment start

Phase 1 Start of Treatment Form

Proportion of patients receiving randomised treatment within 48 h

Phase 1 Start of Treatment Form

Duration of Negative Pressure Wound Therapy (NPWT)

Phase 1 Start of Treatment Form and End of Phase 1 Treatment Form

Factors affecting timely delivery of randomised treatment

Non-immediate Use of NPWT Form

Wound dimensions

Assessment of Weekly Participant Events Form

Quality and completeness of data collected for date of healing

Assessment of Weekly Participant Events Form and Blinded Outcome Assessment Form

Patient-reported health-related quality of life

The Short Form (12) Health Survey (SF-12) [13]

EuroQoL (EQ-5D) [14]

Cointerventions used and rate of treatment change

Investigator Baseline Case Report Form (CRF), Assessment of Weekly Participant Events Form, Phase 1 Start of Treatment Form, Phase 1 End of Treatment Form

Significant events (e.g. rehospitalisation, infection, reoperation)

Assessment of Weekly Participant Events Form

Adverse events

Adverse Event Form, Serious Adverse Event Form, Adverse Event/Serious Adverse Event Follow-up Form

Response rates

Proportion of participant self-report measures returned

Withdrawal rates

Change of Status Form

Treatment change including change from NPWT for intervention participants, reasons for changes and changes to NPWT

Surgical Wounds Dressing Change Form, End of Phase 1 Treatment Form and Assessment of Weekly Participant Events Form

Resource use

Resource Use Questionnaire (3-month Participant CRF)

Missing data rates

Missing responses

Healing rates

Assessment of Weekly Participant Events Form, Blinded Outcome Assessment Form

Blinded outcome assessment

Blinded Outcome Assessment Form

Participant opinion on trial participation

Likert Scales (3-month Participant CRF)

Self-reported wound pain

Weekly text messaging

Visual Analogue Scales (baseline, 2-week, 1-month and 3-month Participant CRFs)

Brief Pain Inventory (BPI) (baseline, 2-week, 1-month and 3-month Participant CRFs) [15]

Wound progress

Photographs Wound tracings

Depth measurements