Chronic wounds in a multiethnic Asian population: a cost of illness study.

OBJECTIVE: To estimate the 'cost of illness' arising from chronic wounds in Singapore. DESIGN: Incidence-based cost of illness study using evidence from a range of sources. SETTING: Singapore health services. PARTICIPANTS: We consider 3.49 million Singapore citizens and permanent residents. There are 16 752 new individuals with a chronic wound in 2017, with 598 venous ulcers, 2206 arterial insufficiency ulcers, 6680 diabetic ulcers and 7268 pressure injuries.Primary outcome measures expressed in monetary terms are the value of all hospital bed days lost for the population; monetary value of quality-adjusted life years (QALYs) lost in the population; costs of all outpatient visits; and costs of all poly clinic, use of Community Health Assist Scheme (CHAS) and emergency departments (EDs) visits. Intermediate outcomes that inform the primary outcomes are also estimated. RESULTS: Total annual cost of illness was $350 million (range $72-$1779 million). With 168 503 acute bed days taken up annually (range 141 966-196 032) that incurred costs of $139 million (range 117-161 million). Total costs to health services were $184 million (range $120-$1179 million). Total annual costs of lost health outcomes were 2077 QALYs (range -2657 to 29 029) valued at $166 million (range -212 to 2399 million). CONCLUSIONS: The costs of chronic wounds are large to Singapore. Costs can be reduced by making positive investments for comprehensive wound prevention and treatment programmes.

A Novel Randomized Trial Protocol for Evaluating Wound Healing Interventions.

Background: Randomized controlled trials using complete healing as an endpoint suffer from poor statistical power, owing to the heterogeneity of wounds and their healing trajectories. The Food and Drug Administration (FDA) has recently consulted with expert groups to consider percentage area reduction (PAR) of the wound over a 4-week period as a valid intermediate endpoint, creating the opportunity for more powerful study designs. Methods: A within-subject controlled study design comparing the PAR of venous leg ulcers (VLU) in patients over 4 weeks receiving different interventions. Twenty-nine patients received multilayer compression over 4 weeks, followed by neuromuscular electrostimulation (NMES) of the leg muscle pump in addition to compression for a further 4 weeks. Paired comparison was then made of PAR between the two phases. A second cohort of 22 patients received only multilayer compression throughout both 4-week phases. Results: Patients randomized to NMES saw a significant increase in healing rate compared with compression alone, whereas patients receiving compression only saw no significant change in healing rate throughout the course of the study. Conclusions: Intermittent NMES of the common peroneal nerve significantly accelerates the healing of VLU. It is well tolerated by patients and deserves serious consideration as an adjuvant to compression therapy. PAR is a useful metric for comparing the performance of wound healing interventions, and the self-controlled trial design allows sensitive discrimination with a relatively small number of subjects over a reasonably short trial period. The study is reported according to the CONSORT reporting guidelines. Clinical Trial Registration: NCT03396731 (ClinicalTrials.gov).

A prospective study on the wound healing and quality of life outcomes of patients with venous leg ulcers in Singapore-Interim analysis at 6 month follow up.

Venous leg ulceration results in significant morbidity. However, the majority of studies conducted are on Western populations. This study aims to evaluate the wound healing and quality of life for patients with venous leg ulcers (VLUs) in a Southeast Asian population. This is a multi-centre prospective cohort study from Nov 2019 to Nov 2021. All patients were started on 2- or 4-layer compression bandage and were reviewed weekly or fortnightly. Our outcomes were wound healing, factors predictive of wound healing and the EuroQol 5-dimensional 5-level (EQ-5D-5L) health states. Within our cohort, there were 255 patients with VLU. Mean age was 65.2 ± 11.6 years. Incidence of diabetes mellitus was 42.0%. Median duration of ulcer at baseline was 0.30 years (interquartile range 0.136-0.834). Overall, the median time to wound healing was 4.5 months (95% confidence interval [CI]: 3.77-5.43). The incidence of complete wound healing at 3- and 6-month was 47.0% and 60.9%, respectively. The duration of the wound at baseline was independently associated with worse wound healing (Hazard ratio 0.94, 95% CI: 0.89-0.99, P = .014). Patients with healed VLU had a significantly higher incidence of perfect EQ-5D-5L health states at 6 months (57.8% vs 13.8%, P < .001). We intend to present longer term results in subsequent publications.

nWASP Inhibition Increases Wound Healing via TrKb/PLCγ Signalling.

(1) Background: Chronic wounds represent a major burden to patients and healthcare systems and identifying new therapeutic targets to encourage wound healing is a significant challenge. This study evaluated nWASP as a new therapeutic target in human wound healing and determined how this can be regulated. (2) Methods: Clinical cohorts from patients with chronic wounds were tested for the expression of nWASP and cell models were employed to evaluate the influence of nWASP on cellular functions that are key to the healing process following knockdown and/or the use of nWASP-specific inhibitors. (3) Results: nWASP was significantly elevated at transcript levels in human non-healing chronic wounds versus healing tissues. nWASP inhibitors, wiskostatin and 187-1, along with the knockdown of nWASP, modified both HaCaT and HECV cell behaviour. We then identified two signalling pathways affected by nWASP inhibition: TrkB signalling and downstream PLCγ1 phosphorylation were impaired by nWASP inhibition in HaCaT cells. The healing of wounds in a diabetic murine model was significantly improved with an nWASP inhibitor treatment. (4) Conclusions: This study showed that nWASP activity was related to the non-healing behaviour of chronic wounds and together with the findings in the in vivo models, it strongly suggested nWASP as a therapeutic target in non-healing wounds that are regulated via TrkB and PLCγ1 signalling.

The impact of a new intervention for venous leg ulcers: A within-patient controlled trial.

A major obstacle to the development of new treatments for venous leg ulcers is the difficulty in generating evidence for their effectiveness. Randomised controlled trials using complete healing as the endpoint are seldom powered to be successful, owing to the heterogeneity of cohorts. A novel approach to the evaluation of treatments is presented, using a self-controlled trial model and two metrics of short-term healing rate as alternate endpoints: rate of wound margin advance, and percentage area reduction over 4 weeks. Two different treatment regimens are compared: multi-layer compression alone, versus multi-layer compression combined with activation of the venous leg pump by neuromuscular stimulation. With 60 patients, adding neuromuscular stimulation to multilayer compression resulted in a significant two-fold increase in the rate of wound healing over a 4-week period, both in terms of wound margin advance and in terms of percentage area reduction. The use of these short-term intermediate endpoint metrics together with a self-controlled study design offers potential for distinguishing between the relative efficacies of interventions more rapidly, with greater sensitivity, and with fewer subjects than a conventional RCT cohort model.

Initial Reduction in Ulcer Size As a Prognostic Indicator for Complete Wound Healing: A Systematic Review of Diabetic Foot and Venous Leg Ulcers.

Significance: Percent area reduction (PAR) is commonly reported in trials including diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs). It is unclear how well PAR performs as a surrogate marker for complete wound closure. This review aimed to summarize all available evidence evaluating PAR as a predictor of complete DFU and VLU healing. Recent Advances: A review searching the CENTRAL, MEDLINE, EMBASE, and EMCARE databases was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Randomized-controlled trials and observational studies reporting PAR and any measure of its predictive ability were included. Outcomes included performance measures of PAR, timing of PAR, outcome measurement, and specific PAR cutoffs. Critical Issues: Meta-analysis was not possible due to high variability in wound duration at study start (2-48 weeks), PAR timing (2-8 weeks), PAR cutoff (-3% to 90%; determined post hoc in most studies), and outcome assessment (10-24 weeks). Six studies (21,430 DFU patients) report PAR as having acceptable to outstanding discriminatory ability (C-statistic 0.720-0.910). Five studies (29,775 VLU patients) report PAR as having poor to excellent discriminatory ability (C-statistic 0.680-0.830). One study (241 DFU and VLU patients) reports PAR sensitivity and specificity of 58.5% and 90.5%, respectively. All studies were determined to have high risk of bias. Future Directions: Despite promising discriminatory ability, most studies report post hoc analysis of patients in randomized trials, are highly heterogenous in study design, and have high risk of bias. There is scant evidence to support PAR in isolation as a surrogate for complete DFU or VLU healing in routine clinical practice.

A cross-sector systematic review and synthesis of knowledge on telemedicine interventions in chronic wound management-Implications from a system perspective.

Based on initially identified needs for further telemedicine (TM) and chronic wound management research, the objective of this article is twofold: to conduct a systematic review of existing knowledge on TM interventions in chronic wound management-including barriers and opportunities-across the specialist and primary care sectors, and to incorporate the review findings into a system framework that can be further developed and validated through empirical data. We conclude that there is a pressing need for broader and more comprehensive empirical explorations into quality improvement and integration of TM in chronic wound management, including using system frameworks that can capture cross-sector system perspectives and associated implications. Of practical consideration, we suggest that the design and execution of TM improvement interventions and associated research projects should be conducted in close cooperation with managers and practitioners knowledgeable about barriers and opportunities that can influence the implementation of important interventions within chronic wound management.

Retrospective matched cohort study of incidence rates and excess length of hospital stay owing to pressure injuries in an Asian setting.

Background: Little is known about stage 1 and 2 pressure injuries that are health care-acquired. We report incidence rates of health care-acquired stage 1 and stage 2 pressure injuries, and, estimate the excess length of stay using four competing analytic methods. We discuss the merits of the different approaches. Methods: We calculated monthly incidence rates for stage 1 and 2 health care-acquired pressure injuries occurring in a large Singapore acute care hospital. To estimate excess stay, we conducted unadjusted comparisons with a control cohort, performed linear regression and then generalized linear regression with a gamma distribution. Finally, we fitted a simple state-based model. The design for the cost attribution work was a retrospective matched cohort study. Results: Incidence rates in 2016 were 0.553% (95% confidence interval [CI] 0.55, 0.557) and 0.469% (95% CI 0.466, 0.472) in 2017. For data censored at 60 days' maximum stay, the unadjusted comparisons showed the highest excess stay at 17.68 (16.43-18.93) days and multi-state models showed the lowest at 1.22 (0.19, 2.23) days. Conclusions: Poor-quality methods for attribution of excess length of stay to pressure injury generate inflated estimates that could mislead decision makers. The findings from the multi-state model, which is an appropriate method, are plausible and illustrate the likely bed-days saved from lowering the risk of these events. Stage 1 and 2 pressure injuries are common and increase costs by prolonging the length of stay. There will be economic value investing in prevention. Using biased estimates of excess length of stay will overstate the potential value of prevention.