Surgical site infection
: development and evaluation of methods for improved outcome assessment

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)


Surgical site infections (SSI) are common and can cause substantial patient morbidity and burden to health services. SSI outcome assessment is important for routine follow-up, research and audit but accurate assessment is challenging, particularly after hospital discharge. Existing tools for SSI assessment are limited. They are designed for healthcare professional completion in hospital, are complex to apply and do not identify SSI consistently. Patient-centred tools are lacking. This PhD set out to address the limitations of current methods for SSI assessment with two studies.

Study 1 developed and validated a new SSI outcome measure, suitable for patient and/or healthcare professional completion after the patient has left hospital. An analysis of existing SSI tools and stakeholder interviews were undertaken to ensure content validity. Cognitive interviews were conducted to pre-test the measure. Finally, a large field-testing study was undertaken. Findings demonstrated that the measure was acceptable, reliable and valid for SSI assessment post-discharge.

Study 2 developed and evaluated a method for remote wound assessment using patient-generated digital images. A review of wound-photography literature informed the development of photography instructions for patients. A process for patients to transmit images using their own mobile device was developed by adapting existing software. Pre-testing was undertaken with cognitive interviews and observations to study acceptability to patients. Evaluation of the method was performed with a further group of patients testing the method remotely. Findings demonstrated that the method was feasible, usable and acceptable, producing high quality images to supplement data from the SSI measure to identify SSI.

The complementary methods developed in this work provide novel contributions to SSI outcome assessment, particularly for use when patients have left hospital. Future work is directed towards implementation and evaluation of these methods in routine follow-up, research and audit to enhance SSI outcome assessment, thereby improving surgical practice and patient outcomes.
Date of Award29 Sep 2020
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorKerry N L Avery (Supervisor) & Jane Blazeby (Supervisor)

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