Improving the Readability of Patient Education Materials in Physical Therapy.

Introduction Printed patient educational materials (PEM) are often written above the recommended sixth- to eighth-grade reading levels, resulting in decreased client understanding and subsequent poor health literacy. Researchers have demonstrated that it is possible to improve readability to enhance clients' understanding and health literacy. The purpose of this study was to evaluate the readability of physical therapy (PT) PEM with and without modifications for improvement. Methods A convenience sample of 38 PT PEM of at least 10 sentences was obtained from a large suburban hospital system in the Midwestern region of the United States. Original and three modified versions (exclusion, revision, and combined exclusion/revision of words with >3 syllables) of the documents were assessed with the Simple Measure of "Gobbledygook" (SMOG). All document means were compared to the recommended reading levels, and the original document means were compared with modified conditions. Results A majority of the documents were above an eighth-grade reading level. All modified conditions resulted in statistically significant reading level decreases, but only the combined modified condition decreased to the eighth-grade level. Conclusion Even with modifications, most PEM were above the recommended reading levels. Additional methods for improving readability and increased education about health literacy for healthcare professionals may be necessary to improve client comprehension.

Human disturbance in riparian areas disrupts predator-prey interactions between grizzly bears and salmon.

Wildlife must increasingly balance trade-offs between the need to access important foods and the mortality risks associated with human-dominated landscapes. Human disturbance can profoundly influence wildlife behavior, but managers know little about the relationship between disturbance-behavior dynamics and associated consequences for foraging. We address this gap by empirically investigating the consequences of human activity on a keystone predator-prey interaction in a region with limited but varied industrial disturbance. Using stable isotope data from 226 hair samples of grizzly bears (Ursus arctos horribilis) collected from 1995 to 2014 across 22 salmon-bearing watersheds (88,000 km2) in British Columbia, Canada, we examined how human activity influenced their consumption of spawning salmon (Oncorhynchus spp.), a fitness-related food. Accounting for the abundance of salmon and other foods, salmon consumption strongly decreased (up to 59% for females) with increasing human disturbance (as measured by the human footprint index) in riparian zones of salmon-bearing rivers. Declines in salmon consumption occurred with disturbance even in watersheds with low footprints. In a region currently among the least influenced by industrial activity, intensification of disturbance in river valleys is predicted to increasingly decouple bears from salmon, possibly driving associated reductions in population productivity and provisioning of salmon nutrients to terrestrial ecosystems. Accordingly, we draw on our results to make landscape-scale and access-related management recommendations beyond current streamside protection buffers. This work illustrates the interaction between habitat modification and food security for wildlife, highlighting the potential for unacknowledged interactions and cumulative effects in increasingly modified landscapes.

Telehealth and delivery of alcohol use disorder treatment in the Veterans Health Administration.

BACKGROUND: The use of telehealth treatment of alcohol use disorder (AUD) has increased since the start of the COVID-19 pandemic. However, it is unclear which patients are using telehealth and how telehealth visits are associated with treatment duration. This study examined characteristics associated with telehealth use among Veterans Health Administration patients receiving AUD treatment. METHODS: Using a national retrospective cohort study, we examined data from March 01, 2020 to February 28, 2021 to: First, identify patient characteristics associated with (a) any telehealth versus only in-person care for AUD treatment, and (b) video (≥1 video visit) versus only telephone visits for AUD treatment (≥1 telephone visit, no video) among any telehealth users. This analysis used mixed-effects logistic regression models to adjust for potential correlation across patients treated at the same facility. Second, we assessed whether visit modality was associated with the amount of AUD treatment received (number of AUD psychotherapy visits or medication coverage days). This analysis used mixed-effects negative binomial regression models. RESULTS: Among 138,619 patients who received AUD treatment, 52.8% had ≥1 video visit, 38.1% had ≥1 telephone but no video visits, and 9.1% had only in-person visits. In the regression analyses, patients who were male or had an opioid or stimulant use disorder (compared to having no non-AUD substance use disorder) were less likely to receive any telehealth-delivered AUD treatment compared to only in-person AUD treatment. Among patients who received any telehealth-delivered AUD treatment, those who were ≥45 years old (compared to 18-29 years old), Black (compared to White), diagnosed with a cannabis or stimulant use disorder, or diagnosed with a serious mental illness were less likely to receive a video visit than only telephone visits. Receiving any AUD telehealth was associated with receiving more psychotherapy visits and medication coverage days than only in-person care. CONCLUSIONS: Telehealth, a common modality for AUD treatment, supported a greater number of psychotherapy visits and a longer duration of medication treatment for AUD. However, some groups were less likely to receive any video telehealth than telephone visits, suggesting that multiple treatment modalities should remain available to ensure treatment access.

Inflammatory Bowel Disease Hospitalizations Are Similar for Patients Receiving Televisit-Delivered Outpatient Care and Those Receiving Traditional In-Person Care.

INTRODUCTION: The coronavirus disease 2019 pandemic resulted in widespread expansion of telehealth. However, there are concerns that telehealth-delivered outpatient care may limit opportunities for managing complications and preventing hospitalizations for patients with inflammatory bowel disease (IBD). We aimed to assess the association between outpatient IBD care delivered through televisit (video or phone) and IBD-related hospitalizations. METHODS: We conducted a case-control study of patients with IBD who had an IBD-related index hospitalization between April 2021 and July 2022 and received their care in the Veterans Health Administration. We matched these hospitalized patients to controls who were not hospitalized based on age, sex, race, Charlson comorbidity index, IBD type, IBD-related emergency department use, IBD-related hospitalizations, and outpatient gastroenterology visits in the preceding year. The variable of interest was the percentage of total clinic visits delivered through televisit in the year before the index hospitalization. We compared the risk of IBD-related hospitalization by exposure to televisit-delivered care using conditional logistic regression. RESULTS: We identified 534 patients with an IBD-related hospitalization and 534 matched controls without an IBD-related hospitalization during the study period. Patients with IBD with a higher percentage of televisit-delivered (vs in-person) outpatient care were less likely to be hospitalized during the study period (for every 10% increase in televisit use, odds ratio 0.97, 95% confidence interval 0.94-1.00; P = 0.03). DISCUSSION: Televisit-delivered outpatient IBD care is not associated with higher risk of IBD-related hospitalization. These findings may reassure clinicians that televisit-delivered outpatient care is appropriate for patients with complex chronic diseases such as IBD.

The effect of donor graft type on survival after liver transplantation for hepatoblastoma in children.

BACKGROUND: Liver transplantation (LT) is the only potentially curative option for children with unresectable hepatoblastoma (HBL). Although post-transplant outcomes have improved in the contemporary era, the impact of donor graft type on survival remains unclear. METHODS: Using the United Network for Organ Sharing database (02/2002-06/2021), demographics, clinical characteristics, and patient and graft survival were analyzed in children (<18 years) who underwent LT for HBL according to donor graft type. The Kaplan-Meier method, log-rank tests, and Cox regression modeling were used to evaluate the effect of whole, partial, and split deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT) on patient and graft survival. RESULTS: A total of 590 pediatric HBL LT recipients (344 whole graft DDLT; 62 partial graft DDLT; 139 split graft DDLT; 45 LDLT) were included. During 2012-2021 the proportion of LDLTs for HBL decreased to about 5% compared with about 11% during 2002-2011. No significant differences were identified by donor graft type in either patient survival (log-rank test, p = .45) or graft survival (log-rank test, p = .69). The results remained similar during the 2002-2011 era, while during the 2012-2021 era, split graft DDLT was associated with decreased graft loss risk versus whole graft DDLT (hazard ratio: 0.48, 95% confidence interval: 0.23-0.99, p = .046) without any other significant between-group differences. CONCLUSIONS: Utilizing non-whole liver grafts can increase access to LT in children with unresectable HBL while ensuring favorable outcomes. LDLT is underutilized in children with HBL in the United States, and efforts to explore LDLT options should be undertaken.

Modern-era successful liver transplantation outcomes in children with hepatic undifferentiated embryonal sarcoma.

BACKGROUND: Hepatic undifferentiated embryonal sarcoma (HUES) is the third most common primary hepatic malignancy in children. If unresectable, liver transplantation (LT) is the only curative option. Historically, HUES LT outcomes were not favorable; however, modern-era data are lacking. We aimed to describe LT outcomes in children with HUES and compared with LT outcomes in children transplanted for hepatoblastoma (HBL) and non-malignancy indications. METHODS: Children 18 years or younger with HUES who underwent LT from 1987 to 2021 were identified from the Scientific Registry of Transplant Recipients database. Graft and patient survival were studied in HUES and LT recipients with HBL and non-malignancy indications using Kaplan-Meier analysis. Cox regression was used to compare patient and graft survival among groups, controlling for confounders. RESULTS: Twenty-one children with HUES underwent LT during the study period with a median age at LT of 10 years (IQR: 8-12 years). One and five-year patient survival for HUES recipients was not significantly different from that of recipients with HBL (p = .3) or non-malignancy diagnoses (p = .6). There were no deaths due to HUES recurrence. In multivariable Cox regression, HUES did not increase risk of either patient or graft loss as compared to HBL (HR 2.36, p = .2) or non-malignancy indications (HR 0.74, p = .7). CONCLUSION: LT outcomes are more favorable in patients with HUES than historically described, and similar to LT outcomes of patients with HBL and non-malignancy indications. Transplant should be considered for HUES patients with unresectable localized tumors.

The outcomes of the most severe polytrauma patients: a systematic review of the use of high ISS cutoffs for performance measurement.

BACKGROUND: This systematic review aimed to describe the outcomes of the most severely injured polytrauma patients and identify the consistent Injury Severity Score based definition of utilised for their definition. This could provide a global standard for trauma system benchmarking. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was applied to this review. We searched Medline, Embase, Cochrane Reviews, CINAHL, CENTRAL from inception until July 2022. Case reports were excluded. Studies in all languages that reported the outcomes of adult and paediatric patients with an ISS 40 and above were included. Abstracts were screened by two authors and ties adjudicated by the senior author. RESULTS: 7500 abstracts were screened after excluding 13 duplicates. 56 Full texts were reviewed and 37 were excluded. Reported ISS groups varied widely between the years 1986 and 2022. ISS groups reported ranged from 40-75 up to 51-75. Mortality varied between 27 and 100%. The numbers of patients in the highest ISS group ranged between 15 and 1451. CONCLUSIONS: There are very few critically injured patients reported during the last 48 years. The most critically injured polytrauma patients still have at least a 50% risk of death. There is no consistent inclusion and exclusion criteria for this high-risk cohort. The current approach to reporting is not suitable for monitoring the epidemiology and outcomes of the critically injured polytrauma patients. LEVEL OF EVIDENCE: Level 4-systematic review of level 4 studies.

Early predictors of prolonged intensive care utilization following liver transplantation.

INTRODUCTION: Creatinine, bilirubin, and fibrinolysis resistance are associated with multi-organ dysfunction and likely risk factors for prolonged intensive care unit (pICU) stay following liver transplantation (LT). We hypothesize postoperative day-1 (POD-1) labs will predict pICU. METHODS: LT recipients had clinical laboratories and viscoelastic testing with tissue plasminogen activator thrombelastography (tPA TEG) to quantify fibrinolysis resistance (LY30) on POD-1. pICU was defined as one week or longer in the ICU. Logistic regression was used to identify the relationship between POD-1 labs and pICU. RESULTS: Of 304 patients, 50% went to the ICU, with 15% experiencing pICU. Elevated creatinine (OR 6.6, P â€‹< â€‹0.001) and low tPA TEG LY30 (OR 3.7, P â€‹= â€‹0.004) were independent predictors of pICU after controlling for other risk factors. A 9-fold increase in the rate of 90-day graft loss (19% vs 2% p â€‹< â€‹0.001) was observed patients who had these risk factors for pICU. CONCLUSION: Elevated creatine and fibrinolysis resistance are associated with pICU and poor outcomes following LT.

Engaging Operational Partners Is Critical for Successful Implementation of Research Products: a Coincidence Analysis of Access-Related Projects in the Veterans Affairs Healthcare System.

BACKGROUND/OBJECTIVE: The Veterans Health Administration (VHA) has prioritized timely access to care and has invested substantially in research aimed at optimizing veteran access. However, implementing research into practice remains challenging. Here, we assessed the implementation status of recent VHA access-related research projects and explored factors associated with successful implementation. DESIGN: We conducted a portfolio review of recent VHA-funded or supported projects (1/2015-7/2020) focused on healthcare access ("Access Portfolio"). We then identified projects with implementable research deliverables by excluding those that (1) were non-research/operational projects; (2) were only recently completed (i.e., completed on or after 1/1/2020, meaning that they were unlikely to have had time to be implemented); and (3) did not propose an implementable deliverable. An electronic survey assessed each project's implementation status and elicited barriers/facilitators to implementing deliverables. Results were analyzed using novel Coincidence Analysis (CNA) methods. PARTICIPANTS/KEY RESULTS: Among 286 Access Portfolio projects, 36 projects led by 32 investigators across 20 VHA facilities were included. Twenty-nine respondents completed the survey for 32 projects (response rate = 88.9%). Twenty-eight percent of projects reported fully implementing project deliverables, 34% reported partially implementing deliverables, and 37% reported not implementing any deliverables (i.e., resulting tool/intervention not implemented into practice). Of 14 possible barriers/facilitators assessed in the survey, two were identified through CNA as "difference-makers" to partial or full implementation of project deliverables: (1) engagement with national VHA operational leadership; (2) support and commitment from local site operational leadership. CONCLUSIONS: These findings empirically highlight the importance of operational leadership engagement for successful implementation of research deliverables. Efforts to strengthen communication and engagement between the research community and VHA local/national operational leaders should be expanded to ensure VHA's investment in research leads to meaningful improvements in veterans' care. The Veterans Health Administration (VHA) has prioritized timely access to care and has invested substantially in research aimed at optimizing veteran access. However, implementing research findings into clinical practice remains challenging, both within and outside VHA. Here, we assessed the implementation status of recent VHA access-related research projects and explored factors associated with successful implementation. Only two factors were identified as "difference-makers" to adoption of project findings into practice: (1) engagement with national VHA leadership or (2) support and commitment from local site leadership. These findings highlight the importance of leadership engagement for successful implementation of research findings. Efforts to strengthen communication and engagement between the research community and VHA local/national leaders should be expanded to ensure VHA's investment in research leads to meaningful improvements in veterans' care.

Impacts of COVID-19 on Appropriate Use of Screening Colonoscopy in a Large Integrated Healthcare Delivery System.

BACKGROUND: Decreasing low-value colonoscopy is critical to optimizing access for high-need patients, particularly in resource-constrained environments such as those created by the COVID-19 pandemic. We hypothesized that rates of screening colonoscopy overuse would decline during COVID compared to pre-COVID due to enhanced procedural scrutiny and prioritization in the setting of constrained access. OBJECTIVE: To characterize impacts of COVID-19 on screening colonoscopy overuse DESIGN: Retrospective national cohort study using Veterans Health Administration administrative data PARTICIPANTS: Veterans undergoing screening colonoscopy in Q4 2019 (pre-COVID) and Q4 2020 (COVID) at 109 endoscopy facilities MAIN MEASURES: Rates of screening colonoscopy overuse KEY RESULTS: 18,376 screening colonoscopies were performed pre-COVID, 19% (3,641) of which met overuse criteria. While only 9,360 screening colonoscopies were performed in Q4 2020, 25% met overuse criteria. Overall change in median facility-level overuse during COVID compared to pre-COVID was 6% (95%CI 5%-7%), with significant variability across facilities (IQR: 2%-11%). Of colonoscopies meeting overuse criteria, the top reason for overuse in both periods was screening colonoscopy performed <9 years after previous screening procedure (55% pre-COVID, 49% during COVID). The largest shifts in overuse category were in screening procedures performed <9 years after prior screening colonoscopy (-6% decline COVID vs. pre-COVID) and screening procedures performed in patients below average-risk screening age (i.e., age <40 (5% increase COVID compared to pre-COVID), age 40-44 (4% increase COVID vs. pre-COVID)). Within facility performance was stable over time; 83/109 facilities changed their performance by <=1 quartile during COVID compared to pre-COVID. CONCLUSIONS: Despite pandemic-related resource constraints and enhanced procedural scrutiny and prioritization in the setting of COVID-related backlogs, screening colonoscopy overuse rates remained roughly stable during COVID compared to pre-COVID, with continued variability across facilities. These data highlight the need for systematic and concerted efforts to address overuse, even in the face of strong external motivating factors.

Organizational Factors Driving Selection of Gastrointestinal Endoscopic Sedation in Veterans Health Administration and Community Settings.

INTRODUCTION: Previous studies suggest that unmeasured organizational factors drive variability in anesthesia-assisted sedation (AA) use. METHODS: A mixed-methods study of 11 Veterans Health Administration and community gastrointestinal endoscopy sites; qualitative interviews of key sedation decision-makers. RESULTS: Three key interview themes were identified: (i) Increased AA demand and changes in endoscopist sedation training in fellowship drove site-level AA capacity expansion; (ii) this expansion further influenced sedation decisions in favor of AA use; and (iii) additional organizational factors influencing AA use included site-level decision-making processes and differences between Veterans Health Administration and community practice economics/mission. DISCUSSION: Key organizational factors drive variability in AA use across settings.

Postoperative fibrinolytic resistance is associated with early allograft dysfunction in liver transplantation: A prospective observational study.

Perioperative dysfunction of the fibrinolytic system may play a role in adverse outcomes for liver transplant recipients. There is a paucity of data describing the potential impact of the postoperative fibrinolytic system on these outcomes. Our objective was to determine whether fibrinolysis resistance (FR), on postoperative day one (POD-1), was associated with early allograft dysfunction (EAD). We hypothesized that FR, quantified by tissue plasminogen activator thrombelastography, is associated with EAD. Tissue plasminogen activator thrombelastography was performed on POD-1 for 184 liver transplant recipients at a single institution. A tissue plasminogen activator thrombelastography clot lysis at 30 minutes of 0.0% was identified as the cutoff for FR on POD-1. EAD occurred in 32% of the total population. Fifty-nine percent (n=108) of patients were categorized with FR. The rate of EAD was 42% versus 17%, p <0.001 in patients with FR compared with those without, respectively. The association between FR and EAD risk was assessed using multivariable logistic regression after controlling for known risk factors. The odds of having EAD were 2.43 times (95% CI, 1.07-5.50, p =0.03) higher in recipients with FR [model C statistic: 0.76 (95% CI, 0.64-0.83, p <0.001]. An additive effect of receiving a donation after circulatory determination of death graft and having FR in the rate of EAD was observed. Finally, compared with those without FR, recipients with FR had significantly shorter graft survival time ( p =0.03). In conclusion, FR on POD-1 is associated with EAD and decreased graft survival time. Postoperative viscoelastic testing may provide clinical utility in identifying patients at risk for developing EAD, especially for recipients receiving donation after circulatory determination of death grafts.

The impact of COVID-19 on trends in alcohol use disorder treatment in Veterans Health Administration.

BACKGROUND AND AIMS: The COVID-19 pandemic disrupted health-care provision in the United States and prompted increases in telehealth-delivery of care. This study measured alcohol use disorder (AUD) treatment trends across visit modalities before and during COVID-19. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: We conducted a national, retrospective cohort study with interrupted time-series models to estimate the impact of COVID-19 on AUD treatment in the Veterans Health Administration (VHA) in the United States during pre-COVID-19 (March 2019 to February 2020) and COVID-19 (March 2020 to February 2021) periods. We analyzed monthly trends in telephone, video and in-person visits for AUD treatment and compared patient and treatment characteristics of patients receiving AUD treatment between the pre-COVID-19 and COVID-19 periods. AUD was defined using International Classification of Diseases, 10th revision (ICD-10) codes for alcohol abuse (F10.1) and alcohol dependence (F10.2), which have previously been used to study AUD in VHA. FINDINGS: The predicted percentage of VHA patients with an AUD diagnosis receiving any AUD treatment at the beginning of the pre-COVID period was 13.8% (n = 49 494). The predicted percentage decreased by 4.3% (P = 0.001) immediately at the start of the COVID-19 period due to a decline in AUD psychotherapy. Despite an increase of 0.3% per month (P = 0.026) following the start of COVID-19, the predicted percentage of VHA patients with an AUD diagnosis receiving any AUD treatment at the end of the study period remained below the pre-COVID-19 period. In February 2021, AUD psychotherapy visits were primarily delivered by video (50%, 58 748), followed by in-person (36.6%, 43 251) and telephone (13.8%, 16 299), while AUD pharmacotherapy visits were delivered by telephone (38.9%, 3623) followed by in-person (34.3%, 3193) and video (26.8%, 2498) modalities. Characteristics of VHA patients receiving AUD treatment were largely similar between pre-COVID-19 and COVID-19 periods. CONCLUSIONS: Despite increased telehealth use, the percentage of United States Veterans Health Administration patients with an alcohol use disorder (AUD) diagnosis receiving AUD treatment declined during COVID-19 (March 2020 to February 2021) mainly due to a decrease in psychotherapy.

Acute Liver Failure in a Child With Adenovirus Detected by PCR in the Explanted Liver.

As of June 15, 2022, the Centers for Disease Control and Prevention has reported 296 pediatric patients under investigation for hepatitis of unknown etiology in the United States; the World Health Organization has reported 650 probable cases worldwide. One of the leading hypotheses for this cluster of cases is adenovirus, a virus that commonly causes respiratory or gastrointestinal symptoms in healthy children but rarely causes severe hepatitis or acute liver failure in immunocompetent children. The other leading hypothesis is that prior infection with SARS-CoV-2 may predispose children to developing liver injury from a normally innocuous agent. We describe a case of a previously healthy child presenting with acute liver failure who had detectable adenovirus DNA in his stool, whole blood, and in liver explant tissue, suggesting adenovirus as the likely etiology for the liver failure. He had no evidence of prior or current SARS-CoV-2 infection, nor had he received COVID vaccination, suggesting that SARS-CoV-2 did not play a role. Additionally, we report on the ability to provide rapid evaluation of a living donor within 72 hours and successfully perform a lifesaving, left-lobe, living donor liver transplant.

Can non-directed living liver donation help improve access to grafts and correct socioeconomic disparities in pediatric liver transplantation?

BACKGROUND: Each year, children die awaiting LT as the demand for grafts exceeds the available supply. Candidates with public health insurance are significantly less likely to undergo both deceased donor LT and D-LLD LT. ND-LLD is another option to gain access to a graft. The aim of this study was to evaluate if recipient insurance type is associated with likelihood of D-LLD versus ND-LLD LT. METHODS: The SRTR/OPTN database was reviewed for pediatric LDLT performed between January 1, 2014 (Medicaid expansion era) and December 31, 2019 at centers that performed ≥1 ND-LLD LDLT during the study period. A multivariable logistic regression was performed to assess relationship between type of living donor (directed vs. non-directed) and recipient insurance. RESULTS: Of 299 pediatric LDLT, 46 (15%) were from ND-LLD performed at 18 transplant centers. Fifty-nine percent of ND-LLD recipients had public insurance in comparison to 40% of D-LLD recipients (p = .02). Public insurance was associated with greater odds of ND-LLD in comparison to D-LLD upon multivariable logistic regression (OR 2.37, 95% CI 1.23-4.58, p = .01). CONCLUSIONS: ND-LLD allows additional children to receive LTs and may help address some of the socioeconomic disparity in pediatric LDLT, but currently account for only a minority of LDLT and are only performed at a few institutions. Initiatives to improve access to both D-LLD and ND-LLD transplants are needed.

Acute Portal and Superior Mesenteric Vein Thrombosis with Topical Testosterone Therapy: An Adverse Drug Event Case Report.

This is a case report of a 55-year-old Caucasian male prescribed topical testosterone therapy for 12 months prior to admission, when he was diagnosed with acute thrombosis in the portal vein (PVT) and superior mesenteric vein (SMV). The patient had a negative thrombophilia workup, including Factor V Leiden, Prothrombin G20210A, and JAK2 V617F mutations. There were no other pertinent laboratory markers that raised concern for the cause of thrombus. No strong familial history of venous thromboembolism (VTE) was reported during the patient's initial workup. With this in mind, the patient's use of topical testosterone therapy was considered the most likely risk factor for the PVT and SMV thrombus. During hospitalization, the patient was initiated on therapeutic anticoagulation with a heparin drip and discharged to home on apixaban for 3 months with extended therapy to be determined by outpatient hematologist. With no other identified VTE risk factors, probability that this patient's VTE was attributed to testosterone was evaluated using the Naranjo scale with a calculated score of 6, which classifies the adverse reaction as "likely." Clinicians should be aware of the possibility that topical testosterone therapy may be a risk factor for venous thrombosis in unusual sites.