Our evidence summaries are underpinned by a PICO question, usually focused on a clinical intervention. This means that our search strategies are based on answering clinical questions that define specific population, intervention of interest, comparison intervention and clinical outcomes. Our evidence summaries usually describe the primary clinical question at the top of the publication, and our experts develop a PICO matrix outlining PICO criteria for more focused clinical questions. Often the evidence summary will include multiple populations (e.g., adults and children), multiple interventions that fall within the primary clinical question (e.g. different types of the same category of therapy), a variety of comparators (e.g., placebo, standard therapy or no comparator) and different ways of measuring a clinical outcome.

ELEMENTS OF A PICO QUESTION

Patient population/ disease
The patient population or disease of interest, for example:
• Demographics: Age/gender/ethnicity
• With specific co-morbidities/clinical conditions
• Cared for in specific clinical settings
Intervention or issue of interest
The intervention or range of interventions of interest, for example:
• Specific wound healing or management interventions
Comparison intervention or issue of interest
What you want to compare the intervention or issue against, for example:
• Alternative therapy, placebo, or no intervention/therapy
Outcome
Outcome of interest, for example:
• Outcome expected from therapy (e.g., wound healing, quality of life)
• Rate of occurrence of adverse outcome (e.g., allergy)

CLINICAL OUTCOMES FOR WOUND HEALING AND MANAGEMENT

Wound prevention

Wound prevention is usually measured as a prevalence or incidence rate. There are a range of difference strategies for measuring and reporting prevalence or incidence of wounds, and this sometimes makes direct comparison of the outcomes reported in the body of evidence more challenging.

Wound healing

Many interventions reported in our evidence summaries focus on healing wounds. There is no standardised method to measure wound healing. Outcomes might be measured objectively (e.g. wound size measured using a ruler) or objectively (e.g. a clinician-rated score on an assessment tool). Commonly reported outcome measures include:

• Complete wound healing: for example, number of wounds completed healed, time to complete healing
• Change in wound size: for example, change in wound surface area, number of wounds achieving 50% reduction in size
• Change in tissue type: for example, percent granulation tissue in wound bed, percent necrosis/slough in a wound bed
• Change in wound-related symptoms: for example, amount of exudate, reduction in wound-related pain

Other important outcome measures

Other relevant outcomes may be the focus or reported in addition to the primary outcomes. Our evidence summaries often note these outcomes in the “Considerations for Use” section of the summary. For example:

• Quality of life or social outcomes
• Cost effectiveness
• Acceptability of the intervention to wound clinicians or patients
• Feasibility and factors influencing the ease of delivering the intervention

LITERATURE SEARCHES

Our evidence summaries report the databases that have been searched. We usually search: Embase, Medline, PubMed, the Cochrane Library and Google Scholar. We often search the CINAHL and Allied Health and Complementary Medicine databases and specific wound journals.

For our low-middle resource community evidence summaries, we usually also search the Hinari database, which was established by the World Health Organisation to index research for low-middle resource health communities. We also search a list of specific wound journals published in low-middle resource countries.

MANAGING THE LITERATURE

All identified literature that meets the PICO inclusion criteria based on a screen of the title and abstract is imported into reference management software. Full texts are then retrieved and reviewed.

For topics for which we identify a large body of evidence, we restrict our inclusion criteria based on study design (e.g. only including systematic reviews or randomised controlled trials). In this way, we can produce a streamlined summary of the best available evidence. If we have restricted the eligible evidence, this is stated in our evidence summary report.

EVALUATING THE EVIDENCE

We follow the methods set out by Joanna Briggs Institute for a rapid evidence summary.

1. Does the evidence source help answer the PICO question?
• Does it answer the evidence summary question?
• Is the study's patient population similar to the defined population (or those we can expect to see in clinical practice)?
2. Are the results valid?
• How strong is the evidence? What is the risk of bias? This is evaluated using the JBI critical appraisal tools that consider internal and external validity.
• What was the study design, and is it most appropriate for the question domain? All studies are assigned a level of evidence, as listed below.

3. Are the results important?
• How large was the treatment effect?
• Are results statistically significant?
• Are the results clinically significant?

We report the level of evidence (see below) for every evidence source in the evidence summary text, and also tabulated in a summary of the primary evidence. Our evidence summaries provide an indication as to the level of bias observed in the body of literature and this informs the Grade of recommendations (see below). To streamline the evidence summaries, specific details of the validity of every study are not reported.

Studies receive a level of evidence based on study design using the following system.

JOANNA BRIGGS INSTITUTE LEVELS OF EVIDENCE FOR EFFECTIVENESS

Level 1 – Experimental Designs
Level 1.a – Systematic review of Randomized Controlled Trials (RCTs)
Level 1.b – Systematic review of RCTs and other study designs
Level 1.c – RCT
Level 1.d – Pseudo-RCTs
Level 2 – Quasi-experimental Designs
Level 2.a – Systematic review of quasi-experimental studies
Level 2.b – Systematic review of quasi-experimental and other lower study designs
Level 2.c – Quasi-experimental prospectively controlled study
Level 2.d – Pre-test – post-test or historic/retrospective control group study
Level 3 – Observational – Analytic Designs
Level 3.a – Systematic review of comparable cohort studies
Level 3.b – Systematic review of comparable cohort and other lower study designs
Level 3.c – Cohort study with control group
Level 3.d – Case – controlled study
Level 3.e – Observational study without a control group
Level 4 – Observational –Descriptive Studies
Level 4.a – Systematic review of descriptive studies
Level 4.b – Cross-sectional study
Level 4.c – Case series
Level 4.d – Case study
Level 5 – Expert Opinion and Bench Research
Level 5.a – Systematic review of expert opinion
Level 5.b – Expert consensus
Level 5.c – Bench research/ single expert opinion

Joanna Briggs Institute Levels of Evidence and Grades of Recommendation Working Party. 2013. JBI Levels of Evidence. Joanna Briggs Institute .

Recommendations are graded using the following system.

JOANNA BRIGGS INSTITUTE GRADES OF RECOMMENDATION

Grade A

A ‘strong’ recommendation for a certain health management strategy where

(1) it is clear that desirable effects outweigh undesirable effects of the strategy;

(2) where there is evidence of adequate quality supporting its use;

(3) there is a benefit or no impact on resource use, and

(4) values, preferences and the patient experience have been taken into account.

Grade B

A ‘weak’ recommendation for a certain health management strategy where

(1) desirable effects appear to outweigh undesirable effects of the strategy, although this is not as clear;

(2) where there is evidence supporting its use, although this may not be of high quality;

(3) there is a benefit, no impact or minimal impact on resource use, and

(4) values, preferences and the patient experience may or may not have been taken into account.

Joanna Briggs Institute Levels of Evidence and Grades of Recommendation Working Party. 2013. JBI Grades of Recommendation. Joanna Briggs Institute.

Find our evidence summaries in:

Wound Practice and Research Journal

World Council of Enterostomal Therapists (WCET) Journal

The Joanna Briggs Institute library