The Bluebelle study: a feasibility study of three wound dressing strategies in elective and unplanned surgery

Background: Surgicalsite infection (SSI) affects up to 20% of people with a primary closed woundafter surgery. Wound dressings may reduce SSI.

Objective(s): Assess the feasibility of a multi-centre randomised controlledtrial (RCT) to evaluate the effectiveness and cost-effectiveness of dressingtypes or no dressing to reduce SSI in primary surgical wounds.

Design:
Phase A: semi-structured interviews; outcome measure development; practicesurvey; literature reviews; value-of-information analysis.
Phase B: pilot RCT with qualitative research; questionnaire validation.Patients and public were involved.

Setting: Usual NHS care.

Participants: Patients undergoing elective/non-elective abdominal surgeryincluding caesarean section.

Interventions:
Phase A: none.
Phase B: simple dressing; glue-as-a-dressing (tissue-adhesive); ‘no dressing’.

Main outcome measures:
Phase A: pilot RCT design; SSI, patient experience and wound managementquestionnaires; dressing practices; value-of-information of a RCT.
Phase B: participants screened, proportions consented/randomised; acceptabilityof interventions; adherence; retention; validity and reliability of SSImeasure; cost drivers.

Data sources:
Phase A: Interviews with patients and health care professionals (HCPs);narrative data from published RCTs; data about dressing practices.
Phase B: participants and HCPs in five hospitals.

Results:
Phase A: We interviewed 102 participants. HCPs interpreted ‘dressing’ variably,and reported using available products. HCPs suggested practical/clinicalreasons for dressing use, acknowledged the weak evidence base, and felt an RCTincluding a ‘no dressing’ group was acceptable. A survey showed that 68% of1769 wounds (727 participants) had simple dressings and 27% hadglue-as-a-dressing. Dressings were used similarly in elective and non-electivesurgery. The SSI questionnaire was developed from content analysis of existingSSI tools and interviews, yielding 19 domains and 16 items. A main RCT would bevaluable to the NHS at a willingness-to-pay of £20,000/QALY.
Phase B: From 04/03/2016-30/11/2016 we approached 862 patients for the pilotRCT; 81.1% were eligible, 59.4% consented and 394 were randomised (simple=133;glue=129; no dressing=132); non-adherence was 3/133, 8/129 and 20/132respectively. SSI occurred in 51/281. We interviewed 55 participants. Alldressing strategies were acceptable to stakeholders, with no indication thatadherence was problematic. Adherence aids and patients’ understanding of theirallocated dressing appeared key. SSI questionnaire response rate overall was67.2%. Items in the SSI questionnaire fitted a single scale, which had good reliability(test-retest and Cronbach’s alpha > 0.7) and diagnostic accuracy(c-statistic=0.906). Key cost drivers were: hospital appointments; dressingsand re-dressings; use of new medicines; primary care appointments.

Limitations: Multiple activities, often in parallel, were challenging tocoordinate. An amendment took four months, restricting recruitment to the pilotRCT. Only 67% of participants completed the SSI questionnaire. We could notimplement photography in theatres.

Conclusions: A main RCT of dressing strategies is feasible and would bevaluable to the NHS. The SSI questionnaire is sufficiently accurate to use asthe primary outcome.

Future work: A main trial with three groups (as in the pilot) would be valuableto the NHS, using a primary outcome of SSI at discharge and patient-reportedSSI symptoms at 4-8 weeks.

Registration:
Phase A: ISRCTN06792113
Phase B: ISRCTN49328913

Funding details: NIHR HTA programme, 12/200/04. MRC ConDuCT-II Hub,MR/K025643/1.