Mechanical stretch preconditioned adipose-derived stem cells elicit polarization of anti-inflammatory M2-like macrophages and improve chronic wound healing.

Transplantation of adipose-derived stem cells (ASCs) is a promising option in the field of chronic wounds treatment. However, the effectiveness of ASCs therapies has been hampered by highly inflammatory environment in chronic wound areas. These problems could be partially circumvented using efficient approaches that boost the survival and anti-inflammatory capacity of transplanted ASCs. Here, by application of mechanical stretch (MS), we show that ASCs exhibits increased survival and immunoregulatory properties in vitro. MS triggers the secretion of macrophage colony stimulating factor (M-CSF) from ASCs, a chemokine that is linked to anti-inflammatory M2-like macrophages polarization. When the MS-ASCs were transplanted to chronic wounds, the wound area yields significantly faster closure rate and lower inflammatory mediators, largely due to macrophages polarization driven by transplanted MS-ASCs. Thus, our work shows that mechanical stretch can be harnessed to enhance ASCs transplantation efficiency in chronic wounds treatment.

Precise spatial structure impacts antimicrobial susceptibility of S. aureus in polymicrobial wound infections.

A hallmark of microbial ecology is that interactions between members of a community shape community function. This includes microbial communities in human infections, such as chronic wounds, where interactions can result in more severe diseases. Staphylococcus aureus is the most common organism isolated from human chronic wound infections and has been shown to have both cooperative and competitive interactions with Pseudomonas aeruginosa. Still, despite considerable study, most interactions between these microbes have been characterized using in vitro well-mixed systems, which do not recapitulate the infection environment. Here, we characterized interactions between S. aureus and P. aeruginosa in chronic murine wounds, focusing on the role that both macro- and micro-scale spatial structures play in disease. We discovered that S. aureus and P. aeruginosa coexist at high cell densities in murine wounds. High-resolution imaging revealed that these microbes establish a patchy distribution, only occupying 5 to 25% of the wound volume. Using a quantitative framework, we identified a precise spatial structure at both the macro (mm)- and micro (µm)-scales, which was largely mediated by P. aeruginosa production of the antimicrobial 2-heptyl-4-hydroxyquinoline N-oxide, while the antimicrobial pyocyanin had no impact. Finally, we discovered that this precise spatial structure enhances S. aureus tolerance to aminoglycoside antibiotics but not vancomycin. Our results provide mechanistic insights into the biogeography of S. aureus and P. aeruginosa coinfected wounds and implicate spatial structure as a key determinant of antimicrobial tolerance in wound infections.

Controversies in the pathophysiology of leg ulcers in sickle cell disease.

Patients with sickle cell disease (SCD) often experience painful vaso-occlusive crises and chronic haemolytic anaemia, as well as various acute and chronic complications, such as leg ulcers. Leg ulcers are characterized by their unpredictability, debilitating pain and prolonged healing process. The pathophysiology of SCD leg ulcers is not well defined. Known risk factors include male gender, poor social conditions, malnutrition and a lack of compression therapy when oedema occurs. Leg ulcers typically start with spontaneous pain, followed by induration, hyperpigmentation, blister formation and destruction of the epidermis. SCD is characterized by chronic haemolysis, increased oxidative stress and decreased nitric oxide bioavailability, which promote ischaemia and inflammation and consequently impair vascular function in the skin. This cutaneous vasculopathy, coupled with venostasis around the ankle, creates an ideal environment for local vaso-occlusive crises, which can result in the development of leg ulcers that resemble arterial ulcers. Following the development of the ulcer, healing is hindered as a result of factors commonly observed in venous ulceration, including venous insufficiency, oedema and impaired angiogenesis. All of these factors are modulated by genetic factors. However, our current understanding of these genetic factors remains limited and does not yet enable us to accurately predict ulceration susceptibility.

A Bacterial Responsive Microneedle Dressing with Hydrogel Backing Layer for Chronic Wound Treatment.

The treatment of chronic wounds still presents great challenges due to being infected by biofilms and the damaged healing process. The current treatments do not address the needs of chronic wounds. In this study, a highly effective dressing (Dox-DFO@MN Hy) for the treatment of chronic wounds is described. This dressing combines the advantages of microneedles (MNs) and hydrogels in the treatment of chronic wounds. MNs is employed to debride the biofilms and break down the wound barrier, providing rapid access to therapeutic drugs from hydrogel backing layer. Importantly, to kill the pathogenic bacteria in the biofilms specifically, Doxycycline hydrochloride (Dox) is wrapped into the polycaprolactone (PCL) microspheres that have lipase-responsive properties and loaded into the tips of MNs. At the same time, hydrogel backing layer is used to seal the wound and accelerate wound healing. Benefiting from the combination of two advantages of MNs and hydrogel, the dressing significantly reduces the bacteria in the biofilms and effectively promotes angiogenesis and cell migration in vitro. Overall, Dox-DFO@MN Hy can effectively treat chronic wounds infected with biofilms, providing a new idea for the treatment of chronic wounds.

Effects of mitochondrial transplantation on chronic pressure wound healing in a human patient.

BACKGROUND AIMS: Wound healing is a multistage process that requires a concerted effort of various cell types. The intricate processes involved in the healing of wounds result in high energy requirements. Furthermore, mitochondria play a crucial role in the healing process because of their involvement in neo angiogenesis, growth factor synthesis, and cell differentiation. It is unclear how mitochondria transplantation, a promising new approach, influences wound healing. METHODS: In this study, healthy autologous mitochondria obtained from skeletal muscle were injected into chronic pressure wounds as an intervention to promote wound healing. RESULTS: Mitochondrial transplantation accelerated wound healing by reducing wound size, increasing granulation tissue, and hastening epithelialization. CONCLUSIONS: This study is the first to demonstrate the therapeutic efficacy of mitochondrial transplantation in wound healing.

IL-17 in wound repair: bridging acute and chronic responses.

Chronic wounds, resulting from persistent inflammation, can trigger a cascade of detrimental effects including exacerbating inflammatory cytokines, compromised blood circulation at the wound site, elevation of white blood cell count, increased reactive oxygen species, and the potential risk of bacterial infection. The interleukin-17 (IL-17) signaling pathway, which plays a crucial role in regulating immune responses, has been identified as a promising target for treating inflammatory skin diseases. This review aims to delve deeper into the potential pathological role and molecular mechanisms of the IL-17 family and its pathways in wound repair. The intricate interactions between IL-17 and other cytokines will be discussed in detail, along with the activation of various signaling pathways, to provide a comprehensive understanding of IL-17's involvement in chronic wound inflammation and repair.

Preclinical and Clinical Studies on the Use of Extracellular Vesicles Derived from Mesenchymal Stem Cells in the Treatment of Chronic Wounds.

To date, the widespread implementation of therapeutic strategies for the treatment of chronic wounds, including debridement, infection control, and the use of grafts and various dressings, has been time-consuming and accompanied by many challenges, with definite success not yet achieved. Extensive studies on mesenchymal stem cells (MSCs) have led to suggestions for their use in treating various diseases. Given the existing barriers to utilizing such cells and numerous pieces of evidence indicating the crucial role of the paracrine signaling system in treatments involving MSCs, extracellular vesicles (EVs) derived from these cells have garnered significant attention in treating chronic wounds in recent years. This review begins with a general overview of current methods for chronic wound treatment, followed by an exploration of EV structure, biogenesis, extraction methods, and characterization. Subsequently, utilizing databases such as Google Scholar, PubMed, and ScienceDirect, we have explored the latest findings regarding the role of EVs in the healing of chronic wounds, particularly diabetic and burn wounds. In this context, the role and mode of action of these nanoparticles in healing chronic wounds through mechanisms such as oxygen level elevation, oxidative stress damage reduction, angiogenesis promotion, macrophage polarization assistance, etc., as well as the use of EVs as carriers for engineered nucleic acids, have been investigated. The upcoming challenges in translating EV-based treatments for healing chronic wounds, along with possible approaches to address these challenges, are discussed. Additionally, clinical trial studies in this field are also covered.

What is slough? Defining the proteomic and microbial composition of slough and its implications for wound healing.

Slough is a well-known feature of non-healing wounds. This pilot study aims to determine the proteomic and microbiologic components of slough as well as interrogate the associations between wound slough components and wound healing. Ten subjects with slow-to-heal wounds and visible slough were enrolled. Aetiologies included venous stasis ulcers, post-surgical site infections and pressure ulcers. Patient co-morbidities and wound healing outcome at 3-months post-sample collection was recorded. Debrided slough was analysed microscopically, through untargeted proteomics, and high-throughput bacterial 16S-ribosomal gene sequencing. Microscopic imaging revealed wound slough to be amorphous in structure and highly variable. 16S-profiling found slough microbial communities to associate with wound aetiology and location on the body. Across all subjects, slough largely consisted of proteins involved in skin structure and formation, blood-clot formation and immune processes. To predict variables associated with wound healing, protein, microbial and clinical datasets were integrated into a supervised discriminant analysis. This analysis revealed that healing wounds were enriched for proteins involved in skin barrier development and negative regulation of immune responses. While wounds that deteriorated over time started off with a higher baseline Bates-Jensen Wound Assessment Score and were enriched for anaerobic bacterial taxa and chronic inflammatory proteins. To our knowledge, this is the first study to integrate clinical, microbiome, and proteomic data to systematically characterise wound slough and integrate it into a single assessment to predict wound healing outcome. Collectively, our findings underscore how slough components can help identify wounds at risk of continued impaired healing and serves as an underutilised biomarker.

Racial/ethnic disparities in chronic wounds: Perspectives on linking upstream factors to health outcomes.

This review explores the complex relationship between social determinants of health and the biology of chronic wounds associated with diabetes mellitus, with an emphasis on racial/ethnic disparities. Chronic wounds pose significant healthcare challenges, often leading to severe complications for millions of people in the United States, and disproportionally affect African American, Hispanic, and Native American individuals. Social determinants of health, including economic stability, access to healthcare, education, and environmental conditions, likely influence stress, weathering, and nutrition, collectively shaping vulnerability to chronic diseases, such as obesity and DM, and an elevated risk of chronic wounds and subsequent lower extremity amputations. Here, we review these issues and discuss the urgent need for further research focusing on understanding the mechanisms underlying racial/ethnic disparities in chronic wounds, particularly social deprivation, weathering, and nutrition, to inform interventions to address these disparities.

Further psychometric evaluation of the WOUND-Q: A responsiveness study.

The WOUND-Q is a modular patient-reported outcome measure (PROM) with 13 scales measuring constructs across 4 domains (i.e., wound characteristics, health related quality of life, experience of care and wound treatment). The psychometrics of the WOUND-Q were previously assessed and the 13 scales evidenced good validity and reliability. However, the responsiveness (i.e., ability to detect clinical change) of the WOUND-Q has yet to be assessed. The objective of this study was to evaluate responsiveness for 9 WOUND-Q scales that assess outcomes, in a sample of people 18 years of age or older with chronic wounds that were present for at least 3 months. This study conducted a 4 month follow-up of 421 participants who completed the WOUND-Q as part of a previous psychometric study. Participants completed an online survey answering questions about their current wound state (e.g., number, type, size, smell, drainage), anchor questions about change, as well as the WOUND-Q scales that they had completed in their initial assessment. Pre-defined hypotheses were tested with a 75% acceptance threshold indicating sufficient evidence of responsiveness. Minimally important differences (MIDs) were also calculated using both anchor-based and distribution-based methods. Of 390 invited participants, 320 provided responses, ranging in age from 19 to 84 years. Acceptance of hypotheses ranged from 60% to 100%, with only the Symptom scale not meeting the 75% threshold. The findings of this study provide evidence that the WOUND-Q can validly measure clinical change in patients with chronic wounds.

Patterns of use of advanced wound matrices in the Veterans Administration clinics.

Chronic wounds are a common and costly health issue affecting millions of individuals in the United States, particularly those with underlying conditions such as diabetes, venous insufficiency, and peripheral artery disease. When standard treatments fail, advanced wound care therapies, such as skin substitutes, are often applied. However, the clinical effectiveness, indications, and comparative benefits of these therapies have not been well established. In this study, we report on the usage of both acellular and cellular, single and bilayer, natural and synthetic, dermal, and epidermal skin substitutes in a VA hospital system. We performed a retrospective chart review to understand the ordering and usage patterns of advanced wound therapies for patients with chronic wounds at the VA Northern California Health Care System. We examined types of products being recommended, categories of users recommending the products, indications for orders, and rate of repeated orders. Neuropathic, venous, or pressure ulcers were the main indications for using advanced wound matrices. Only 15.6% of patients for whom the matrices were ordered had supporting laboratory tests. Exactly 34.3% of the ordered matrices were not applied. And the use of wound matrices resulted in increased costs per patient visit of $1018-$3450. Our study sheds light on the usage patterns of these therapies in a VA healthcare facility and highlights the need for more robust evidence-based studies to determine the true benefits, efficacy, and cost-effectiveness of these innovative treatment options.

Temporal and differential proteomic profile of molecular mediators associated with chronic and acute wound healing.

The underlying pathophysiology of nonhealing chronic wounds is poorly understood due to the changes occurring at the gene level and the complexity arising in their proteomic profile. Here, we elucidated the temporal and differential profile of the normal and diabetic wound-healing mediators along with their interactions and associated pathways. Skin tissues corresponding to normal and diabetic wounds were isolated at Days 0, 3, 6, and 9 representing different healing phases. Temporal gene expression was analyzed by quantitative real-time PCR. Concurrently, differential protein patterns in the wound tissues were identified by Nano LC-ESI-TOF mass spectrometry and later confirmed by Western blot analysis. Gene ontology annotation, protein-protein interaction, and protein pathway analysis were performed using DAVID, PANTHER, and STRING bioinformatics resources. Uniquely identified proteins (complement C3, amyloid beta precursor protein, and cytoplasmic linker associated protein 2) in the diabetic wound tissue implied that these proteins are involved in the pathogenesis of diabetic wound. They exhibit enhanced catalytic activity, trigger pathways linked with inflammation, and negatively regulate wound healing. However, in the normal wound tissue, axin 1, chondroitin sulfate proteoglycan 4, and sphingosine-1-phosphate receptor were identified, which are involved in proliferation, angiogenesis, and remodeling. Our findings demonstrate the correlation between elevated gene expression of tumor necrosis factor-α, interleukin (IL)-1ß, and identified mediators: aryl hydrocarbon receptor nuclear translocator, 5'-aminolevulinate synthase 2, and CXC-family, that inflicted an inflammatory response by activating downstream MAPK, JAK-STAT, and NF-κB pathways. Similarly, in normal wound tissue, the upregulated IL-4 and hepatocyte growth factor levels in conjunction with the identified proteins, serine/threonine-protein kinase mTOR and peroxisome proliferator-activated receptor gamma, played a significant role in the cellular response to platelet-derived growth factor stimulus, dermal epithelialization, and cell proliferation, processes associated with the repair mechanism. Furthermore, Western blot analysis indicated elevated levels of inflammatory markers and reduced levels of proliferative and angiogenic factors in the diabetic wound.

A novel conductive microtubule hydrogel for electrical stimulation of chronic wounds based on biological electrical wires.

Electrical stimulation (ES) is considered a promising therapy for chronic wounds via conductive dressing. However, the lack of a clinically suitable conductive dressing is a serious challenge. In this study, a suitable conductive biomaterial with favorable biocompatibility and conductivity was screened by means of an inherent structure derived from the body based on electrical conduction in vivo. Ions condensed around the surface of the microtubules (MTs) derived from the cell's cytoskeleton are allowed to flow in the presence of potential differences, effectively forming a network of biological electrical wires, which is essential to the bioelectrical communication of cells. We hypothesized that MT dressing could improve chronic wound healing via the conductivity of MTs applied by ES. We first developed an MT-MAA hydrogel by a double cross-linking method using UV and calcium chloride to improve chronic wound healing by ES. In vitro studies showed good conductivity, mechanical properties, biocompatibility, and biodegradability of the MT-MAA hydrogel, as well as an elevated secretion of growth factors with enhanced cell proliferation and migration ability in response to ES. The in vivo experimental results from a full-thickness diabetic wound model revealed rapid wound closure within 7d in C57BL/6J mice, and the wound bed dressed by the MT-MAA hydrogel was shown to have promoted re-epithelization, enhanced angiogenesis, accelerated nerve growth, limited inflammation phases, and improved antibacterial effect under the ES treatment. These preclinical findings suggest that the MT-MAA hydrogel may be an ideal conductive dressing for chronic wound healing. Furthermore, biomaterials based on MTs may be also promising for treating other diseases.

Variable effects of exposure to ionic silver in wound-associated bacterial pathogens.

Silver compounds are used in wound dressings to reduce bioburden. Where infection is not rapidly resolved, bacteria may be exposed to sub-therapeutic concentrations of antimicrobials over prolonged periods of time. In this study, a panel of chronic wound bacteria, Pseudomonas aeruginosa (two strains), Staphylococcus aureus, and Escherichia coli, were exposed to silver nitrate on agar. Phenotypic characterization was achieved using broth microdilution sensitivity testing, a crystal violet biofilm assay, and a wax moth pathogenesis model. Repeated exposure to ionic silver did not result in planktonic phenotypic silver resistance in any of the test panels, although S. aureus demonstrated reversible increases in minimum bactericidal concentration. An ulcer-derived P. aeruginosa exhibited marked reductions in biofilm eradication concentration as well as significantly increased biofilm formation and wax moth killing when compared to the same progenitor. These changes were reversible, trending towards baseline measurements following 10 passages on silver-free media. Changes in virulence and biofilm formation in the other test bacteria were generally limited. In summary, phenotypic adaptation following exposure to ionic silver was manifested other than through changes in planktonic susceptibility. Significant changes in pseudomonas biofilm formation and sensitivity could have implications for wound care regimes and therefore warrant further investigation.

Digital Health Interventions for Chronic Wound Management: A Systematic Review and Meta-Analysis.

BACKGROUND: Digital health interventions (DHIs) have shown promising results for the management of chronic wounds. However, its effectiveness compared to usual care and whether variability in the type of intervention affects wound outcomes are unclear. OBJECTIVE: The main objective was to determine the effectiveness of DHIs on wound healing outcomes in adult patients with chronic wounds. The secondary objectives were to assess if there was any variation in wound healing outcomes across the various types of DHIs. METHODS: In total, 9 databases were searched for the literature up to August 1, 2023. Randomized controlled trials (RCTs), cohort studies, and quasi-experimental studies comparing the efficacy of DHIs with controls in improving wound outcomes in adult patients with chronic wounds were included. Study selection, data extraction, and risk of bias assessment were conducted independently by 2 reviewers. We assessed the quality of each RCT, cohort study, and quasi-experimental study separately using the Cochrane risk of bias tool, ROBINS-I, and the Joanna Briggs Institute Critical Appraisal tools checklists. Relative risks (RRs) and 95% CIs were pooled using the random effects model, and heterogeneity was assessed by the I2 statistic. Subgroup analysis and sensitivity analysis were also performed. RESULTS: A total of 25 studies with 8125 patients were included in this systematic review, while only 20 studies with 6535 patients were included in the meta-analysis. Efficacy outcomes in RCTs showed no significant differences between the DHIs and control groups in terms of wound healing (RR 1.02, 95% CI 0.93-1.12; P=.67) and all-cause mortality around 1 year (RR 1.08, 95% CI 0.55-2.12; P=.83). Compared with the control group, the use of DHIs was associated with significant changes in adverse events (RR 0.44, 95% CI 0.22-0.89; P=.02). Subgroup analysis suggested a positive effect of the digital platforms in improving wound healing (RR 2.19, 95% CI 1.35-3.56; P=.002). Although meta-analysis was not possible in terms of wound size, cost analysis, patient satisfaction, and wound reporting rates, most studies still demonstrated that DHIs were not inferior to usual care in managing chronic wounds. CONCLUSIONS: The findings of our study demonstrate the viability of adopting DHIs to manage chronic wounds. However, more prominent, high-quality RCTs are needed to strengthen the evidence, and more detailed clinical efficacy research is required. TRIAL REGISTRATION: PROSPERO CRD42023392415; https://tinyurl.com/4ybz6bs9.

Timolol in the treatment of hard-to-heal wounds: a comprehensive review.

OBJECTIVE: The aims of this study were to ascertain the effectiveness and safety of the off-label use of topical timolol as an adjunct treatment for hard-to-heal (chronic) wounds. Furthermore, to review and analyse the existing literature regarding the use of topical timolol on wounds of varying aetiologies. METHOD: A systematic review of literature in the English language published between May 1961-May 2021 on the application of topical timolol for hard-to-heal wounds in adults was performed. Each research study was evaluated by two reviewers independently. Studies eligible for inclusion in the review were randomised controlled trials (RCTs), clinical trials, observational studies of at least 4 weeks' duration, case series and case studies. Search strategies were performed according to PRISMA guidelines and included MeSH terms and keyword searches. RESULTS: An initial 878 articles were identified from a search of PubMed, Ovid Medline, Embase, Cochrane, and SCOPUS. Of these, 699 were reviewed for eligibility, 19 were read in full-text, and 12 were selected for inclusion in the review. In total, two RCTs and 10 observational studies, including five case studies, were analysed. All studies demonstrated efficacy and safety of topical timolol; however, statistical analysis remained limited by lack of blinding and small sample sizes. CONCLUSION: This review concludes with all currently available evidence that topical timolol may be considered as an effective and safe adjunct treatment for refractory wounds, primarily venous leg ulcers and diabetic foot ulcers. Given the overall safety, low cost and ease of application of topical timolol, this review provides evidence in favour of off-label use and should prompt further, more rigorous studies.

Dehydrated Amnion Chorion Membrane versus standard of care for diabetic foot ulcers: a randomised controlled trial.

OBJECTIVE: Diabetic foot ulcers (DFUs) continue to challenge wound care practitioners. This prospective, multicentre, randomised controlled trial (RCT) evaluated the effectiveness of a dehydrated Amnion Chorion Membrane (dACM) (Organogenesis Inc., US) versus standard of care (SoC) alone in complex DFUs in a challenging patient population. METHOD: Subjects with a DFU extending into dermis, subcutaneous tissue, tendon, capsule, bone or joint were enrolled in a 12-week trial. They were allocated equally to two treatment groups: dACM (plus SoC); or SoC alone. The primary endpoint was frequency of wound closure determined by a Cox analysis that adjusted for duration and wound area. Kaplan-Meier analysis was used to determine median time to complete wound closure (CWC). RESULTS: The cohort comprised 218 patients, and these were split equally between the two treatment groups with 109 patients in each. A Cox analysis showed that the estimated frequency of wound closure for the dACM plus SoC group was statistically superior to the SoC alone group at week 4 (12% versus 8%), week 6 (22% versus 11%), week 8 (31% versus 21%), week 10 (42% versus 27%) and week 12 (50% versus 35%), respectively (p=0.04). The computed hazard ratio (1.48 (confidence interval: 0.95, 2.29) showed a 48% greater probability of wound closure in favour of the dACM group. Median time to wound closure for dACM-treated ulcers was 84 days compared to 'not achieved' in the SoC-treated group (i.e., ≥50% of SoC-treated DFUs failed to heal by week 12; p=0.04). CONCLUSION: In an adequately powered DFU RCT, dACM increased the frequency, decreased the median time, and improved the probability of CWC when compared with SoC alone. dACM demonstrated beneficial effects in DFUs in a complex patient population. DECLARATION OF INTEREST: This study was funded by Organogenesis Inc., US. JC serves as a consultant and speaker for Organogenesis. RDD serves as a speaker for Organogenesis. OMA and MLS serve as consultants for Organogenesis. The authors have no other conflicts of interest to declare.

Artificial intelligence in wound care: diagnosis, assessment and treatment of hard-to-heal wounds: a narrative review.

OBJECTIVE: The effective assessment of wounds, both acute and hard-to-heal, is an important component in the delivery by wound care practitioners of efficacious wound care for patients. Improved wound diagnosis, optimising wound treatment regimens, and enhanced prevention of wounds aid in providing patients with a better quality of life (QoL). There is significant potential for the use of artificial intelligence (AI) in health-related areas such as wound care. However, AI-based systems remain to be developed to a point where they can be used clinically to deliver high-quality wound care. We have carried out a narrative review of the development and use of AI in the diagnosis, assessment and treatment of hard-to-heal wounds. We retrieved 145 articles from several online databases and other online resources, and 81 of them were included in this narrative review. Our review shows that AI application in wound care offers benefits in the assessment/diagnosis, monitoring and treatment of acute and hard-to-heal wounds. As well as offering patients the potential of improved QoL, AI may also enable better use of healthcare resources.

Key performance indicators to inform evaluation of wound care programmes for people with complex wounds: a protocol for systematic review.

OBJECTIVE: The objective of the systematic review is to examine and summarise the available evidence in the literature of the use of key performance indicators (KPIs) to inform evaluation of wound care programmes and services for people with hard-to-heal (complex) wounds. The need for wound care is expected to grow with the continued ageing of the population and the resulting increased development of chronic conditions. This expected increase necessitates improvement of wound care programmes and services and their ability to deliver quality, evidence-based and cost-effective practice. The current literature lacks a systematic assessment of KPIs to inform evaluation of wound care services and programmes across various settings, and how the KPIs are used to improve the quality of wound care and achieve desired outcomes. This protocol sets out how the systemtic review will be undertaken. METHOD: Primary studies will be screened from databases such as MEDLINE, CINAHL and Scopus, with unpublished studies and grey literature retrieved from Google Scholar and ProQuest Dissertations and Theses. The study titles and abstracts will be screened by two independent reviewers, using Covidence systematic review software to ensure they meet the inclusion criteria, who will then proceed with data extraction of the full-text using the standardised data extraction instrument. The reference lists of all studies selected for critical appraisal will be screened for additional publications. The two independent reviewers will critically appraise all studies undergoing full-text data extraction using the appropriate checklist from JBI SUMARI. At all stages, differences between reviewers will be resolved through discussion, with adjudication by a third, independent reviewer. RESULTS: Data points will be analysed with descriptive statistics and grouped, based on programme characteristics and publication status. Grey literature and peer-reviewed publications will form separate analyses. To answer review questions, the data will be summarised in a narrative format. A meta-analysis is not planned. At the time of writing, this protocol has been implemented up to the preliminary literature search. CONCLUSION: This review will address a current literature gap and systematically identify KPIs in wound care, allowing for programmes to evaluate their quality of care and improve their services in a methodical manner.

Identifying health-related quality of life concepts to inform the development of the WOUND-Q.

OBJECTIVE: The impact of hard-to-heal wounds extends beyond traditional clinical metrics, negatively affecting a patient's health-related quality of life (HRQoL). Yet treatment outcomes are seldom measured from the patient's perspective. The purpose of the present study was to perform in-depth qualitative interviews with patients diagnosed with varying types of hard-to-heal wounds to identify outcomes important to them. METHOD: Participants were recruited from wound care clinics in Canada, Denmark, the Netherlands and the US, and were included if they had a hard-to-heal wound (i.e., lasting ≥3 months), were aged ≥18 years, and fluent in English, Dutch or Danish. Qualitative interviews took place between January 2016 and March 2017. An interpretive description qualitative approach guided the data analysis. Interviews were audio-recorded, transcribed and coded line-by-line. Codes were categorised into top-level domains and themes that formed the final conceptual framework. RESULTS: We performed 60 in-depth interviews with patients with a range of wound types in different anatomic locations that had lasted from three months to 25 years. Participants described outcomes that related to three top-level domains and 13 major themes: wound (characteristics, healing); HRQoL (physical, psychological, social); and treatment (cleaning, compression stocking, debridement, dressing, hyperbaric oxygen, medication, suction device, surgery). CONCLUSION: The conceptual framework developed as part of this study represents the outcome domains that mattered the most to the patients with hard-to-heal wounds. Interview quotes were used to generate items that formed the WOUND-Q scales, a patient-reported outcome measure for patients with hard-to-heal wounds.