Good working relationships: how healthcare system proximity influences trust between healthcare workers.

Trust between healthcare workers is a fundamental component of effective, interprofessional collaboration and teamwork. However, little is known about how this trust is built, particularly when healthcare workers are distributed (i.e., not co-located and lack a shared electronic health record). We interviewed 39 healthcare workers who worked with proximal and distributed colleagues to care for patients with diabetic foot ulcers and analyzed transcripts using content analysis. Generally, building trust was a process that occurred over time, starting with an introduction and proceeding through iterative cycles of communication and working together to coordinate care for shared patients. Proximal, compared to distributed, dyads had more options available for interactions which, in turn, facilitated communication and working together to build trust. Distributed healthcare workers found it more difficult to develop trusting relationships and relied heavily on individual initiative to do so. Few effective tools existed at the level of interprofessional collaborations, teams, or broader healthcare systems to support trust between distributed healthcare workers. With increasing use of distributed interprofessional collaborations and teams, future efforts should focus on fostering this critical attribute.

A systematic review of multidisciplinary teams to reduce major amputations for patients with diabetic foot ulcers.

OBJECTIVE: Multiple single-center studies have reported significant reductions in major amputations among patients with diabetic foot ulcers after initiation of multidisciplinary teams. The purpose of this study was to assess the association between multidisciplinary teams (ie, two or more types of clinicians working together) and the risk of major amputation and to compile descriptions of these diverse teams. METHODS: We searched PubMed, Scopus, Cumulative Index to Nursing and Allied Health, and Cochrane Central Register of Controlled Trials from inception through May 24, 2019 for studies reporting the association between multidisciplinary teams and major amputation rates for patients with diabetic foot ulcers. We included original studies if ≥50% of the patients seen by the multidisciplinary team had diabetes, they included a control group, and they reported the effect of a multidisciplinary team on major amputation rates. Studies were excluded if they were non-English language, abstracts only, or unpublished. We used the five-domain Systems Engineering Initiative for Patient Safety Model to describe team composition and function and summarized changes in major amputation rates associated with multidisciplinary team care. A meta-analysis was not performed because of heterogeneity across studies, their observational designs, and the potential for uncontrolled confounding (PROSPERO No. 2017: CRD42017067915). RESULTS: We included 33 studies, none of which were randomized trials. Multidisciplinary team composition and functions were highly diverse. However, four elements were common across teams: teams were composed of medical and surgical disciplines; larger teams benefitted from having a "captain" and a nuclear and ancillary team member structure; clear referral pathways and care algorithms supported timely, comprehensive care; and multidisciplinary teams addressed four key tasks: glycemic control, local wound management, vascular disease, and infection. Ninety-four percent (31/33) of studies reported a reduction in major amputations after institution of a multidisciplinary team. CONCLUSIONS: Multidisciplinary team composition was variable but reduced major amputations in 94% of studies. Teams consistently addressed glycemic control, local wound management, vascular disease, and infection in a timely and coordinated manner to reduce major amputation for patients with diabetic foot ulcerations. Care algorithms and referral pathways were key tools to their success.

Non-small cell lung cancer clinical trials requiring biopsies with biomarker-specific results for enrollment provide unique challenges.

BACKGROUND: Clinical trials in lung cancer increasingly require patients to provide fresh tumor tissue as a prerequisite to enrollment. The effects of this requirement on enrollment rates, enrollment durations, and patient selection have not been fully elucidated. METHODS: The authors retrospectively reviewed data generated by patients who consented to 1 or more interventional lung cancer clinical trials at the University of California-Los Angeles Jonsson Comprehensive Cancer Center between January 2013 and December 2014. Trials were considered to require a biopsy when enrollment was conditional on the procurement of tissue without intervening therapy between procurement and enrollment. RESULTS: In total, 311 patients underwent 368 screening incidents for 1 or more of 19 trials. Trials that required a new biopsy had a longer median screening duration (34 vs 14 days) than trials that did not require a biopsy (P < .001). Trials that required a biopsy had a greater screen failure rate (49.1% vs 26.5%; P < .001), which was largely driven by patients who did not undergo the required biopsy or lacked the required biomarker. Worsening performance status led to the majority of screen failures (56.5%) among biomarker-eligible patients. CONCLUSIONS: Although the scientific benefits of obtaining a new biopsy and requiring specific results for trial enrollment are clear, these requirements lead to a lengthening of the screening period, which, in some patients, is associated with clinical decline before enrollment. Implications for the interpretation of data from studies of this design should be explored. Cancer 2017;123:4800-7. © 2017 American Cancer Society.

Effect of Axillary Dissection vs No Axillary Dissection on 10-Year Overall Survival Among Women With Invasive Breast Cancer and Sentinel Node Metastasis: The ACOSOG Z0011 (Alliance) Randomized Clinical Trial.

Importance: The results of the American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) trial were first reported in 2005 with a median follow-up of 6.3 years. Longer follow-up was necessary because the majority of the patients had estrogen receptor-positive tumors that may recur later in the disease course (the ACOSOG is now part of the Alliance for Clinical Trials in Oncology). Objective: To determine whether the 10-year overall survival of patients with sentinel lymph node metastases treated with breast-conserving therapy and sentinel lymph node dissection (SLND) alone without axillary lymph node dissection (ALND) is noninferior to that of women treated with axillary dissection. Design, Setting, and Participants: The ACOSOG Z0011 phase 3 randomized clinical trial enrolled patients from May 1999 to December 2004 at 115 sites (both academic and community medical centers). The last date of follow-up was September 29, 2015, in the ACOSOG Z0011 (Alliance) trial. Eligible patients were women with clinical T1 or T2 invasive breast cancer, no palpable axillary adenopathy, and 1 or 2 sentinel lymph nodes containing metastases. Interventions: All patients had planned lumpectomy, planned tangential whole-breast irradiation, and adjuvant systemic therapy. Third-field radiation was prohibited. Main Outcomes and Measures: The primary outcome was overall survival with a noninferiority hazard ratio (HR) margin of 1.3. The secondary outcome was disease-free survival. Results: Among 891 women who were randomized (median age, 55 years), 856 (96%) completed the trial (446 in the SLND alone group and 445 in the ALND group). At a median follow-up of 9.3 years (interquartile range, 6.93-10.34 years), the 10-year overall survival was 86.3% in the SLND alone group and 83.6% in the ALND group (HR, 0.85 [1-sided 95% CI, 0-1.16]; noninferiority P = .02). The 10-year disease-free survival was 80.2% in the SLND alone group and 78.2% in the ALND group (HR, 0.85 [95% CI, 0.62-1.17]; P = .32). Between year 5 and year 10, 1 regional recurrence was seen in the SLND alone group vs none in the ALND group. Ten-year regional recurrence did not differ significantly between the 2 groups. Conclusions and Relevance: Among women with T1 or T2 invasive primary breast cancer, no palpable axillary adenopathy, and 1 or 2 sentinel lymph nodes containing metastases, 10-year overall survival for patients treated with sentinel lymph node dissection alone was noninferior to overall survival for those treated with axillary lymph node dissection. These findings do not support routine use of axillary lymph node dissection in this patient population based on 10-year outcomes. Trial Registration: clinicaltrials.gov Identifier: NCT00003855.

Transmission of Babesia microti Parasites by Solid Organ Transplantation.

Babesia microti, an intraerythrocytic parasite, is tickborne in nature. In contrast to transmission by blood transfusion, which has been well documented, transmission associated with solid organ transplantation has not been reported. We describe parasitologically confirmed cases of babesiosis diagnosed ≈8 weeks posttransplantation in 2 recipients of renal allografts from an organ donor who was multiply transfused on the day he died from traumatic injuries. The organ donor and recipients had no identified risk factors for tickborne infection. Antibodies against B. microti parasites were not detected by serologic testing of archived pretransplant specimens. However, 1 of the organ donor's blood donors was seropositive when tested postdonation and had risk factors for tick exposure. The organ donor probably served as a conduit of Babesia parasites from the seropositive blood donor to both kidney recipients. Babesiosis should be included in the differential diagnosis of unexplained fever and hemolytic anemia after blood transfusion or organ transplantation.

Barriers and facilitators of hepatitis C screening among people who inject drugs: a multi-city, mixed-methods study.

BACKGROUND: People who inject drugs (PWID) are at high risk of contracting and transmitting and hepatitis C virus (HCV). While accurate screening tests and effective treatment are increasingly available, prior research indicates that many PWID are unaware of their HCV status. METHODS: We examined characteristics associated with HCV screening among 553 PWID utilizing a free, multi-site syringe exchange program (SEP) in 7 cities throughout Wisconsin. All participants completed an 88-item, computerized survey assessing past experiences with HCV testing, HCV transmission risk behaviors, and drug use patterns. A subset of 362 clients responded to a series of open-ended questions eliciting their perceptions of barriers and facilitators to screening for HCV. Transcripts of these responses were analyzed qualitatively using thematic analysis. RESULTS: Most respondents (88%) reported receiving a HCV test in the past, and most of these (74%) were tested during the preceding 12 months. Despite the availability of free HCV screening at the SEP, fewer than 20% of respondents had ever received a test at a syringe exchange site. Clients were more likely to receive HCV screening in the past year if they had a primary care provider, higher educational attainment, lived in a large metropolitan area, and a prior history of opioid overdose. Themes identified through qualitative analysis suggested important roles of access to medical care and prevention services, and nonjudgmental providers. CONCLUSIONS: Our results suggest that drug-injecting individuals who reside in non-urban settings, who have poor access to primary care, or who have less education may encounter significant barriers to routine HCV screening. Expanded access to primary health care and prevention services, especially in non-urban areas, could address an unmet need for individuals at high risk for HCV.

Identifying and supporting vaccine champions in pediatric primary care: a qualitative interview study.

Implementation science research identifies clinical champions as instrumental in aligning healthcare professionals' (HCPs) behavior with practice guidelines for delivering health services, including vaccinations. However, we know relatively little about identifying or supporting champions. To characterize who vaccine champions are, what they do, and how to support their work in pediatric primary care. In 2022, we interviewed a purposive sample of peer-nominated or self-identified vaccine champions (n=20) and HCPs who worked with vaccine champions (n=4). We thematically analyzed qualitative data. Vaccine champions' defining characteristics were firsthand primary care experience, whether as providers or nursing staff, and a strong belief in vaccinations as uniquely effective tools for primary prevention. Participants noted these beliefs were "part of the DNA" of specialties like pediatrics and infectious disease, where they perceived champions as especially common. Being "insatiable in their quest for knowledge," champions primarily conceptualized their role as understanding and sharing complex information and performance metric data related to vaccine administration. Champions' role in leading other implementation strategies, such as communication training, was more peripheral. Champions reported that dedicated time and staff support helped them "go above and beyond" to improve vaccination rates. Our findings suggest that vaccine champions can be found among providers and nursing staff with deep clinical experience and commitment to primary prevention through vaccination, including through providing vaccine education to colleagues. Healthcare systems can allocate resources to support champions as educators, while exploring opportunities to extend their role in other implementation strategies to improve vaccination rates.

Clinical champions are healthcare professionals who seek to help their colleagues improve the quality of health services, including vaccinations. However, efforts to engage clinical champions are challenged by our limited understanding of these individuals. Thus, we interviewed 24 healthcare professionals from 8 healthcare systems in Wisconsin to explore who vaccine champions are, how they promote vaccination, and how healthcare systems can support them. Our interviewees described vaccine champions as healthcare professionals with direct patient care experience, whether as physicians or nurses, who demonstrated a strong dedication to vaccine promotion primarily through learning and sharing complex vaccine information and data. Having dedicated time was an important support for champions in their efforts to promote vaccination, with champions relying on their colleagues to participate in or assist with those efforts. Interviewees recommended identifying champions through nominations from their colleagues, rather than relying on vaccination rates alone. Healthcare systems may need to provide additional time and staff support to meaningfully engage champions and expand their involvement in other vaccine promotion strategies.

Barriers and facilitators of universal HIV screening among internal medicine residents.

BACKGROUND: Adoption of universal HIV screening has been low despite national recommendations. OBJECTIVE: To describe the barriers and facilitators to adoption of universal HIV screening in a low-prevalence setting. DESIGN: Qualitative, thematic analysis of focus group discussions among internal medicine residents who introduced universal HIV screening into their primary care practice in Madison, Wisconsin. APPROACH: Deductive and inductive codes constructed a hybridized thematic analysis model. Deductive codes stemmed from a knowledge-attitude-behavior framework for physician nonadherence to guidelines. Inductive codes emerged from the focus group discussions and were embedded into broader deductive codes to provide an HIV-specific model. KEY RESULTS: Residents were knowledgeable and had positive attitudes toward recommendations for universal HIV screening. Residents felt the majority of their patients were receptive to HIV screening, especially when introduced with normalizing techniques and reference to an expert authority such as the Centers for Disease Control and Prevention (CDC). They still perceived patient discussions as challenging due to stigma surrounding HIV and patients' perceptions of being at low risk. Residents employed individualized electronic medical record cues as a memory aid to discuss the issue. CONCLUSION: This qualitative study of internal medicine residents training in an area with low HIV prevalence suggests that stigma and patient perception of being at low risk are barriers that should be addressed to effectively integrate universal HIV screening into primary care.

Using the National Institute on Minority Health and Health Disparities framework to better understand disparities in major amputations.

Recently, the United States experienced its first resurgence of major amputations in more than 20 years. Compounding this rise is a longstanding history of disparities. Patients identifying as non-Hispanic Black are twice as likely to lose a limb as those identifying as non-Hispanic White. Those identifying as Latino face a 30% increase. Rural patients are also more likely to undergo major amputations, and the rural-urban disparity is widening. We used the National Institute on Minority Health and Health Disparities framework to better understand these disparities and identify common factors contributing to them. Common factors were abundant and included increased prevalence of diabetes, possible lower rates of foot self-care, transportation barriers to medical appointments, living in disadvantaged neighborhoods, and lack of insurance. Solutions within and outside the health care realm are needed. Health care-specific interventions that embed preventative and ambulatory care services within communities may be particularly high yield.

Next Steps: Studying Diabetic Foot Infections with Next-Generation Molecular Assays.

Purpose of Review: In 2019, the International Working Group on the Diabetic Foot voiced six concerns regarding the use of molecular microbiology techniques for routine diagnosis of infection complicating diabetic foot ulcers. The purpose of this review is to evaluate contemporary evidence addressing each of these concerns and describe promising avenues for continued development of molecular microbiology assays. Recent Findings: Since 2019, the feasibility of conducting metagenomic and metatranscriptomic studies on diabetic foot ulcer samples has been shown. However, these preliminary studies used small samples with concerns for selection bias. We await larger-scale, longitudinal studies, potentially using the recently formed Diabetic Foot Consortium, to identify microbiome profiles associated with infection and patient outcomes. How these results would translate into a clinical diagnostic requires further clarification. Summary: High-throughput molecular microbiology techniques are not yet ready for clinical adoption as first-line diagnostics. However, moving from amplicon sequencing to metagenomic and metatranscriptomic studies has the potential to significantly accelerate development of assays that might meaningfully impact patient care.

Association of rurality and identifying as black with receipt of specialty care among patients hospitalized with a diabetic foot ulcer: a Medicare cohort study.

INTRODUCTION: Rural patients with diabetic foot ulcers, especially those identifying as black, face increased risk of major amputation. Specialty care can reduce this risk. However, care disparities might beget outcome disparities. We aimed to determine whether a smaller proportion of rural patients, particularly those identifying as black, receive specialty care compared with the national proportion. RESEARCH DESIGN AND METHODS: This 100% national retrospective cohort examined Medicare beneficiaries hospitalized with diabetic foot ulcers (2013-2014). We report observed differences in specialty care, including: endocrinology, infectious disease, orthopedic surgery, plastic surgery, podiatry, or vascular surgery. We used logistic regression to examine possible intersectionality between rurality and race, controlling for sociodemographics, comorbidities, and ulcer severity and including an interaction term between rurality and identifying as black. RESULTS: Overall, 32.15% (n=124 487) of patients hospitalized with a diabetic foot ulcer received specialty care. Among rural patients (n=13 100), the proportion decreased to 29.57%. For patients identifying as black (n=21 649), the proportion was 33.08%. Among rural patients identifying as black (n=1239), 26.23% received specialty care. This was >5 absolute percentage points less than the overall cohort. The adjusted OR for receiving specialty care among rural versus urban patients identifying as black was 0.61 (95% CI 0.53 to 0.71), which was lower than that for rural versus urban patients identifying as white (aOR 0.85, 95% CI 0.80 to 0.89). This metric supported a role for intersectionality between rurality and identifying as black. CONCLUSIONS: A smaller proportion of rural patients, particularly those identifying as black, received specialty care when hospitalized with a diabetic foot ulcer compared with the overall cohort. This might contribute to known disparities in major amputations. Future studies are needed to determine causality.

Regional and racial disparities in major amputation rates among medicare beneficiaries with diabetes: a retrospective study in the southeastern USA.

Objective: While rates for non-traumatic lower extremity amputations (LEA) have been declining, concerns exist over disparities. Our objectives are to track major LEA (MLEA) rates over time among Medicare beneficiaries residing in a high diabetes prevalence region in the southeastern USA (the diabetes belt) and surrounding areas. Methods: We used Medicare claims files for ~900 000 fee-for-service beneficiaries aged ≥65 years in 2006-2015 to track MLEA rates per 1000 patients with diabetes. We additionally conducted a cross-sectional analysis of data for 2015 to compare regional and racial disparities in major amputation risks after adjusting for demographic, socioeconomic, access-to-care and foot complications and other health factors. The Centers for Disease Control and Prevention defined the diabetes belt as 644 counties across Appalachian and southeastern US counties with high prevalence. Results: MLEA rates were 3.9 per 1000 in the Belt compared with 2.8 in the surrounding counties in 2006 and decreased to 2.3 and 1.6 in 2015. Non-Hispanic black patients had 8.5 and 6.9 MLEAs per 1000 in 2006 and 4.8 and 3.5 in 2015 in the Belt and surrounding counties, respectively, while the rates were similar for non-Hispanic white patients in the two areas. Although amputation rates declined rapidly in both areas, non-Hispanic black patients in the Belt consistently had >3 times higher rates than non-Hispanic whites in the Belt. After adjusting for patient demographics, foot complications and healthcare access, non-Hispanic blacks in the Belt had about twice higher odds of MLEAs compared with non-Hispanic whites in the surrounding areas. Discussion: Our data show persistent disparities in major amputation rates between the diabetes belt and surrounding counties. Racial disparities were much larger in the Belt. Targeted policies to prevent MLEAs among non-Hispanic black patients are needed to reduce persistent disparities in the Belt.

Associations between specialty care and improved outcomes among patients with diabetic foot ulcers.

OBJECTIVE: Specialty care may improve diabetic foot ulcer outcomes. Medically underserved populations receive less specialty care. We aimed to determine the association between specialty care and ulcer progression, major amputation, or death. If a beneficial association is found, increasing access to specialty care might help advance health equity. RESEARCH DESIGN AND METHODS: We retrospectively analyzed a cohort of Wisconsin and Illinois Medicare patients with diabetic foot ulcers (n = 55,409), stratified by ulcer severity (i.e., early stage, osteomyelitis, or gangrene). Within each stratum, we constructed Kaplan-Meier curves for event-free survival, defining events as: ulcer progression, major amputation, or death. Patients were grouped based on whether they received specialty care from at least one of six disciplines: endocrinology, infectious disease, orthopedic surgery, plastic surgery, podiatry, and vascular surgery. Multivariate Cox proportional hazard models estimated the association between specialty care and event-free survival, adjusting for sociodemographic factors and comorbidities, and stratifying on ulcer severity. RESULTS: Patients who received specialty care had longer event-free survival compared to those who did not (log-rank p<0.001 for all ulcer severity strata). After adjusting, receipt of specialty care, compared to never, remained associated with improved outcomes for all ulcer severities (early stage adjusted hazard ratio 0.34, 95% CI 0.33-0.35, p<0.001; osteomyelitis aHR 0.22, 95% CI 0.20-0.23, p<0.001; gangrene aHR 0.22, 95% CI 0.20-0.24, p<0.001). CONCLUSIONS: Specialty care was associated with longer event-free survivals for patients with diabetic foot ulcers. Increased, equitable access to specialty care might improve diabetic foot ulcer outcomes and disparities.

Limited model antigen expression by transgenic fungi induces disparate fates during differentiation of adoptively transferred T cell receptor transgenic CD4+ T cells: robust activation and proliferation with weak effector function during recall.

CD4(+) T cells are the key players of vaccine resistance to fungi. The generation of effective T cell-based vaccines requires an understanding of how to induce and maintain CD4(+) T cells and memory. The kinetics of fungal antigen (Ag)-specific CD4(+) T cell memory development has not been studied due to the lack of any known protective epitopes and clonally restricted T cell subsets with complementary T cell receptors (TCRs). Here, we investigated the expansion and function of CD4(+) T cell memory after vaccination with transgenic (Tg) Blastomyces dermatitidis yeasts that display a model Ag, Eα-mCherry (Eα-mCh). We report that Tg yeast led to Eα display on Ag-presenting cells and induced robust activation, proliferation, and expansion of adoptively transferred TEa cells in an Ag-specific manner. Despite robust priming by Eα-mCh yeast, antifungal TEa cells recruited and produced cytokines weakly during a recall response to the lung. The addition of exogenous Eα-red fluorescent protein (RFP) to the Eα-mCh yeast boosted the number of cytokine-producing TEa cells that migrated to the lung. Thus, model epitope expression on yeast enables the interrogation of Ag presentation to CD4(+) T cells and primes Ag-specific T cell activation, proliferation, and expansion. However, the limited availability of model Ag expressed by Tg fungi during T cell priming blunts the downstream generation of effector and memory T cells.

Septic arthritis in the native joint.

Septic arthritis of the native joint is an uncommon infection but, when present, creates a significant risk for functional impairment of the affected joint or, in severe cases, mortality. Knowledge of the most common pathogens, as well as appropriate diagnostics, can facilitate earlier diagnosis and treatment, which, ideally, leads to improved long-term outcomes. In this article, we discuss recent microbiologic trends and diagnostic tests, with an update on use of molecular testing. Empiric antibiotic regimens for native joint septic arthritis are reviewed, as well as potential new therapies on the horizon.

Effect of health system on the association of rurality and level of disadvantage with receipt of diabetic eye screening.

INTRODUCTION: Rural versus urban disparities have been observed in diabetic eye screening, but whether the level of disadvantage in rural versus urban areas is related to these disparities is unclear. Our goal was to determine the role of level of disadvantage in explaining the effect of health systems on rural and urban disparities in diabetic eye screening. RESEARCH DESIGN AND METHODS: This is a retrospective cohort study using an all-payer, state-wide claims database covering over 75% of Wisconsin residents. We included adults with diabetes (18-75 years old) who had claims billed throughout the baseline (2012-2013) and measurement (2013-2014) years. We performed multivariable regressions to assess factors associated with receipt of diabetic eye screening. The primary exposure was the primary care clinic's combined level of rurality and disadvantage. We adjusted for the health system as well as patient-level variables related to demographics and comorbidities. Health system was defined as an associated group of physicians and/or clinics. RESULTS: A total of 118 707 adults with diabetes from 698 primary care clinics in 143 health systems met the inclusion criteria. Patients from urban underserved clinics were less likely to receive screening than those from rural underserved clinics before adjusting for health system in the model. After adjusting for health system fixed effects, however, the directionality of the relationship between clinic rurality and screening reversed: patients from urban underserved clinics were more likely to receive screening than those from rural underserved clinics. Similar findings were observed for both Medicare and non-Medicare subgroups. CONCLUSIONS: The effect of health system on receipt of diabetic eye screening in rural versus urban areas is most pronounced in underserved areas. Health systems, particularly those providing care to urban underserved populations, have an opportunity to increase screening rates by leveraging health system-level interventions to support patients in overcoming barriers from social determinants of health.

Ankle brachial indices and anaerobes: is peripheral arterial disease associated with anaerobic bacteria in diabetic foot ulcers?

Background: Lower extremity amputations from diabetic foot ulcers (DFUs) are rebounding, and new biomarkers that predict wound healing are urgently needed. Anaerobic bacteria have been associated with persistent ulcers and may be a promising biomarker beyond currently recommended vascular assessments. It is unknown whether anaerobic markers are simply a downstream outcome of peripheral arterial disease (PAD) and ischemia, however. Here, we evaluate associations between two measures of anaerobic bacteria-abundance and metabolic activity-and PAD. Methods: We built a prospective cohort of 37 patients with baseline ankle brachial index (ABI) results. Anaerobic bacteria were measured in two ways: DNA-based total anaerobic abundance using 16S rRNA gene amplicon sequencing and resulting summed relative abundance, and RNA-based metabolic activity based on bacterial read annotation of metatranscriptomic sequencing. PAD was defined three ways: PAD diagnosis, ABI results, and a dichotomous definition of mild ischemia (versus normal) based on ABI values. Statistical associations between anaerobes and PAD were evaluated using univariate odds ratios (ORs) or Spearman's correlations. Results: Total anaerobe abundance was not significantly associated with PAD diagnosis, ABI results, or mild ischemia (ORPAD = 0.47, 95% CI = 0.023-7.23, p = 0.60; Spearman's correlation coefficientABI = 0.24, p = 0.17; ORmild ischemia = 0.25, 95% CI = 0.005-5.86, p = 0.42). Anaerobic metabolic activity was not significantly associated with PAD diagnosis, ABI results, or mild ischemia (ORPAD = 1.99, 95% CI = 0.17-21.44, p = 0.57; Spearman's correlation coefficientABI = 0.12, p = 0.52; ORmild ischemia = 0.90, 95% CI = 0.03-15.16, p = 0.94). Conclusion: Neither anaerobic abundance nor metabolic activity was strongly associated with our three definitions of PAD. Therefore, anaerobic bacteria may offer additional prognostic value when assessing wound healing potential and should be investigated as potential molecular biomarkers for DFU outcomes.

Association of Race, Ethnicity, and Rurality With Major Leg Amputation or Death Among Medicare Beneficiaries Hospitalized With Diabetic Foot Ulcers.

Importance: Patients identifying as Black and those living in rural and disadvantaged neighborhoods are at increased risk of major (above-ankle) leg amputations owing to diabetic foot ulcers. Intersectionality emphasizes that the disparities faced by multiply marginalized people (eg, rural US individuals identifying as Black) are greater than the sum of each individual disparity. Objective: To assess whether intersecting identities of Black race, ethnicity, rural residence, or living in a disadvantaged neighborhood are associated with increased risk in major leg amputation or death among Medicare beneficiaries hospitalized with diabetic foot ulcers. Design, Setting, and Participants: This retrospective cohort study used 2013-2014 data from the US National Medicare Claims Data Database on all adult Medicare patients hospitalized with a diabetic foot ulcer. Statistical analysis was conducted from August 1 to October 27, 2021. Exposures: Race was categorized using Research Triangle Institute variables. Rurality was assigned using Rural-Urban Commuting Area codes. Residents of disadvantaged neighborhoods comprised those living in neighborhoods at or above the national 80th percentile Area Deprivation Index. Main Outcomes and Measures: Major leg amputation or death during hospitalization or within 30 days of hospital discharge. Logistic regression was used to explore interactions among race, ethnicity, rurality, and neighborhood disadvantage, controlling for sociodemographic characteristics, comorbidities, and ulcer severity. Results: The cohort included 124 487 patients, with a mean (SD) age of 71.5 (13.0) years, of whom 71 286 (57.3%) were men, 13 100 (10.5%) were rural, and 21 649 (17.4%) identified as Black. Overall, 17.6% of the cohort (n = 21 919), 18.3% of rural patients (2402 of 13 100), and 21.9% of patients identifying as Black (4732 of 21 649) underwent major leg amputation or died. Among 1239 rural patients identifying as Black, this proportion was 28.0% (n = 347). This proportion exceeded the expected excess for rural patients (18.3% - 17.6% = 0.7%) plus those identifying as Black (21.9% - 17.6% = 4.3%) by more than 2-fold (28.0% - 17.6% = 10.4% vs 0.7% + 4.3% = 5.0%). The adjusted predicted probability of major leg amputation or death remained high at 24.7% (95% CI, 22.4%-26.9%), with a significant interaction between race and rurality. Conclusions and Relevance: Rural patients identifying as Black had a more than 10% absolute increased risk of major leg amputation or death compared with the overall cohort. This study suggests that racial and rural disparities interacted, amplifying risk. Findings support using an intersectionality lens to investigate and address disparities in major leg amputation and mortality for patients with diabetic foot ulcers.