Validation of predictive factors for infection in adults with chronic leg ulcers: A prospective longitudinal study.

AIMS AND OBJECTIVES: To validate the ability of factors to predict infection in adults with chronic leg ulcers over a 12-week period. BACKGROUND: Leg ulcers affect ~3% of older adults and are often hard to heal. Infection is a leading contributor for delayed healing, causing delayed wound healing, increased hospitalisation, increased healthcare costs and reduced patient quality of life. The importance of early identification of infection has been highlighted for decades, yet little is known about factors that are associated with increased risk of infection in this specific population. DESIGN: A longitudinal, prospective observational study in a single centre. METHODS: Between August 2017 and May 2018, a total of 65 adults with chronic leg ulcers were prospectively observed for a 12-week period. Patients were recruited from an outpatient wound clinic at a tertiary hospital in Australia. Data were collected from recruitment (baseline) and each visit (weekly or fortnightly) up until 12 weeks. Descriptive statistics were calculated for all variables. A Cox proportional hazards regression model was used to identify predictive factors for infection. The TRIPOD guidelines for reporting were followed (See Data S1). RESULTS: The sample consisted of 65 adults with chronic leg ulcers, and 9.2% of these had their ulcer infected at baseline. Two predictive factors, using walking aids and gout, were found to be significantly related to increased likelihood of developing infection within 12 weeks. CONCLUSION: The present study showed that patients who either used walking aids or were diagnosed with gout were at greater risk of infection compared to those without these factors. RELEVANCE TO CLINICAL PRACTICE: These findings provide new information for clinicians in early identification of patients at risk of infection, and for patients in enhancing their awareness of their own risk.

The diagnosis of infection in chronic leg ulcers: A narrative review on clinical practice.

This literature review aimed to provide a narrative review of evidence on validity of clinical and microbial indicators of infection and to gain insights into the diagnosis of infection in chronic leg ulcers (CLUs). A search was conducted in Cinahl, Medline, the Cochrane Library databases, Embase, Web of Science, ScienceDirect, Pubmed, PsycINFO, ProQuest dissertations, and Google Scholar from January 1990 to July 2017. The inclusion criteria were original studies, systematic reviews, and consensus documents focused on "infection" in CLUs, English language, clinical and community settings, and human. The reviewed studies were inconsistent in criteria for infection between investigated wound types and lack of specificity regarding wound types. There were few studies investigating the criteria for diagnosis of infection in leg ulcers. The identification of leg ulcer infection still remains problematic and relies on out-of-date and not uniform evidence. Literature in this area was mostly limited to level III and IV evidence based on The Australian National Health and Medical Research Council Levels of Evidence, or expert opinion. This literature review showed seven clinical signs and symptoms that could be diagnostic for infection in CLUs, including: new, increased, or altered ulcer pain; malodour; increased ulcer area; wound breakdown, delayed or non-healing; and erythema and increased local temperature, whilst the microbial indicators used to diagnose infected leg ulcers were varied and regarded as less important.

Risk factors for infection in patients with chronic leg ulcers: A survival analysis.

AIM: This study aimed to validate the relationships between possible predictive factors and clinically diagnosed infection in adult patients with chronic leg ulcers. METHODS: This study used a sample of 636 adult participants whose ulcers were diagnosed as either venous, arterial or mixed aetiology leg ulcers and had no clinical signs of infection at recruitment. Data were extracted from recruitment to 12 weeks from six longitudinal prospective studies from 2004 to 2015. Survival analysis was used to investigate mean time-to-infection, including the Kaplan-Meier method and the Cox proportional-hazards regression model. RESULTS: The sample included 74.7% venous, 19.6% mixed and 5.7% arterial leg ulcers. There were 101 (15.9%) participants diagnosed with infection at least once within 12 weeks of follow-up. Mean time-to-infection was 10.89 weeks (95% CI = 10.66-11.12). After adjustment for potential confounders, a Cox proportional hazards regression model found that depression, using walking aids, calf ankle ratio <1.3, wound area ≥10 cm2 and ulcers with slough tissue at recruitment were significant risk factors for wound infection. CONCLUSION: This study has validated the predictive ability of factors which have been found in a cross-sectional study to be significantly associated with infection in patients with leg ulcers, including venous leg ulcers, arterial leg ulcers and mixed aetiology leg ulcers. Results showed that patients with chronic leg ulcers, who either presented with depression, used walking aids, had a calf ankle ratio <1.3, a wound area ≥10 cm2 or an ulcer with slough tissue, had greater likelihood of developing infection compared to those without these factors.

Identifying risk factors associated with infection in patients with chronic leg ulcers.

Leg ulcers are hard to heal. Infection causes delayed healing, negatively impacting patients' quality of life, the healthcare system, and society. Early recognition of patients at high risk of infection is essential to prevent complications and reduce negative impacts. However, at present, factors associated with infection in this population are not yet clearly understood. The study aimed to identify factors that were significantly associated with infection in chronic leg ulcers. A sample of 561 patients with chronic leg ulcers, who were previously recruited at outpatient clinics and community settings within Australia between 2008 and 2015, were selected for the current analysis. The prevalence of infection in the sample at study recruitment was 7.8%. A multivariate logistic regression model was used to identify factors associated with infection. The study identified 7 factors that were significantly independently associated with infection, including depression, chronic pulmonary disease, anti-coagulant use, calf ankle circumference ratio < 1.3, ulcer area ≥ 10 cm2 , slough in the wound bed tissue, and ulcers with heavy exudate. These findings could assist clinicians in the early recognition of patients at risk of infection and individualise treatment for these patients, thereby promoting wound healing.