Temporal trends in pharmacologic prophylaxis for venous thromboembolism after hip and knee replacement in older adults.

Trends in prescription for venous thromboembolism (VTE) prophylaxis following total hip (THR) and knee replacement (TKR) since the approval of direct oral anticoagulants (DOACs) and the 2012 guideline endorsement of aspirin are unknown, as are the risks of adverse events. We examined practice patterns in the prescription of prophylaxis agents and the risk of adverse events during the in-hospital period (the 'in-hospital sample') and 90 days following discharge (the 'discharge sample') among adults aged ⩾ 65 undergoing THR and TKR in community hospitals in the Institute for Health Metrics database over a 30-month period during 2011 to 2013. Eligible medications included fondaparinux, DOACs, low molecular weight heparin (LMWH), other heparin products, warfarin, and aspirin. Outcomes were validated by physician review of source documents: VTE, major hemorrhage, cardiovascular events, and death. The in-hospital and the discharge samples included 10,503 and 5722 adults from 65 hospitals nationwide, respectively (mean age 73, 74 years; 61%, 63% women). Pharmacologic prophylaxis was near universal during the in-hospital period (93%) and at discharge (99%). DOAC use increased substantially and was the prophylaxis of choice for nearly a quarter (in-hospital) and a third (discharge) of the patients. Aspirin was the sole discharge prophylactic agent for 17% and 19% of patients undergoing THR and TKR, respectively. Warfarin remained the prophylaxis agent of choice for patients aged 80 years and older. The overall risk of adverse events was low, at less than 1% for both the in-hospital and discharge outcomes. The low number of adverse events precluded statistical comparison of prophylaxis regimens.

Incidence of severe renal dysfunction among individuals taking warfarin and implications for non-vitamin K oral anticoagulants.

BACKGROUND: The purpose of this study is to assess incidence and risk factors for severe renal dysfunction in patients requiring oral anticoagulation to help guide initial drug choice and provide a rational basis for interval monitoring of renal function for patients prescribed non-vitamin K oral anticoagulants. METHODS: Patients on warfarin for atrial fibrillation or venous thromboembolism were consecutively enrolled from January 2007 to December 2010. Baseline kidney function was assessed, and patients were followed to their first decline of kidney function to creatinine clearance<30 mL/min. Multivariate regression assessed independent risk factors for the primary outcome. Severe renal impairment based on baseline kidney function was assessed by Kaplan-Meier analyses. RESULTS: Of 787 patients identified, 34 were excluded for baseline CrCl <30 mL/min. The mean age was 71 years, and 74% and 31% had hypertension and diabetes mellitus, respectively. At baseline, 23% (n=174) had moderate chronic kidney disease (CKD) (CrCl 30-59mL/min), whereas 31% had mild CKD (CrCl 60-89mL/min). Severe renal impairment occurred in 92 patients (12%), 25% of which was seen within 5.3 months. Of those with baseline stage 3 CKD, 37% developed severe renal impairment. Stage 3 CKD conferred a 14-fold increased risk in the development of severe renal dysfunction (odds ratio 14.5, 95% CI 6.7-31.3, P<.001). Coronary artery disease was also associated with severe renal impairment (odds ratio 2.2, 95% CI 1.3-3.8, P=.004). CONCLUSIONS: Acute and chronic renal dysfunction is common among individuals requiring long-term anticoagulant therapy. Patients with moderate chronic kidney disease and coronary artery disease are at the highest short-term risk of developing severe renal impairment. More frequent monitoring of these patients is warranted.

Limited health literacy and decline in executive function in older adults.

Limited health literacy is associated with worse executive function, but the association between limited health literacy and decline in executive function has not been established because of a lack of longitudinal studies. The authors aimed to examine this association by studying a prospective cohort in the setting of a randomized controlled trial to promote walking in older adults. Participants were community-dwelling older adults (65 years of age or older) who scored 2 or more on the Mini-Cog, without depression (score of less than 15 on the 9-item Patient Health Questionnaire), and who completed baseline and 12-month evaluations (n = 226). Health literacy was measured using the Short Test of Functional Health Literacy in Adults. Executive function measured at baseline and 12 months using the Trail Making Test (TMT), Controlled Oral Word Association Test, and Category Fluency. The associations between health literacy and 12-month decline in each test of executive function were modeled using multivariate linear regression. Health literacy was found to be limited in 37% of participants. Limited health literacy was associated with reduced performance on all 3 executive function tests. In fully adjusted models, limited health literacy was associated with greater 12-month decline in performance on the TMT than higher health literacy (p = .01). In conclusion, older adults with limited health literacy are at risk for more rapid decline in scores on the TMT, a measure of executive function.

The mediating effect of health literacy on COVID-19 vaccine confidence among a diverse sample of urban adults in Boston and Chicago.

BACKGROUND: A high rate of COVID-19 vaccination is critical to reduce morbidity and mortality related to infection and to control the COVID-19 pandemic. Understanding the factors that influence vaccine confidence can inform policies and programs aimed at vaccine promotion. We examined the impact of health literacy on COVID-19 vaccine confidence among a diverse sample of adults living in two major metropolitan areas. METHODS: Questionnaire data from adults participating in an observational study conducted in Boston and Chicago from September 2018 through March 2021 were examined using path analyses to determine whether health literacy mediates the relationship between demographic variables and vaccine confidence, as measured by an adapted Vaccine Confidence Index (aVCI). RESULTS: Participants (N = 273) were on average 49 years old, 63 % female, 4 % non-Hispanic Asian, 25 % Hispanic, 30 % non-Hispanic white, and 40 % non-Hispanic Black. Using non-Hispanic white and other race as the reference category, Black race and Hispanic ethnicity were associated with lower aVCI (-0.76, 95 % CI -1.00 to -0.50; -0.52, 95 % CI -0.80 to -0.27, total effects from a model excluding other covariates). Lower education was also associated with lower aVCI (using college or more as the reference, -0.73 for 12th grade or less, 95 % CI -0.93 to -0.47; -0.73 for some college/associate's/technical degree, 95 % CI -1.05 to -0.39). Health literacy partially mediated these effects for Black and Hispanic participants and those with lower education (indirect effects -0.19 and -0.19 for Black race and Hispanic ethnicity; 0.27 for 12th grade or less; -0.15 for some college/associate's/technical degree). CONCLUSIONS: Lower levels of education, Black race, and Hispanic ethnicity were associated with lower scores on health literacy, which in turn were associated with lower vaccine confidence. Our findings suggest that efforts to improve health literacy may improve vaccine confidence, which in turn may improve vaccination rates and vaccine equity. CLINICAL TRIALS NUMBER: NCT03584490.

COVID-19 Vaccine Confidence Mediates the Relationship between Health Literacy and Vaccination in a Diverse Sample of Urban Adults.

We sought to analyze the relationship between health literacy, confidence in COVID-19 vaccines, and self-reported vaccination. We hypothesized that the relationship between health literacy and vaccination would be mediated by vaccine confidence. We recruited (N = 271) English- and Spanish-speaking adults in Boston and Chicago from September 2018 to September 2021. We performed a probit mediation analysis to determine if confidence in COVID-19 vaccines and health literacy predicted self-reported vaccination. We hypothesized that the relationship between health literacy and vaccination would be mediated by vaccine confidence. Participants were on average 50 years old, 65% female, 40% non-Hispanic Black, 25% Hispanic, and 30% non-Hispanic White; 231 (85%) reported at least one COVID-19 vaccination. A higher mean vaccine confidence score (t = -7.9, p < 0.001) and higher health literacy (t = -2.2, p = 0.03) were associated with vaccination, but only vaccine confidence predicted vaccination in a multivariate model. Vaccine confidence mediated the relationship between health literacy and COVID-19 vaccination (mediated effects: 0.04; 95% CI [0.02, 0.08]). We found that using a simple tool to measure vaccine confidence identified people who declined or delayed COVID-19 vaccination in a diverse sample of adults with varying levels of health literacy. Simple short survey tools can be useful to identify people who may benefit from vaccine promotion efforts and evidence-based communication strategies.

Using highly variable warfarin dosing to identify patients at risk for adverse events.

BACKGROUND: Patients who receive highly variable doses of warfarin may be at risk for poor anticoagulation control and adverse events. However, we lack a system to identify patients with the highest dose variability. Our objectives were to develop a scoring system to identify patients with high dose variability, and to validate this new measure by demonstrating that patients so identified have poor anticoagulation control and higher rates of adverse events (criterion validity). METHODS: We used a database of over 4, 000 patients who received oral anticoagulation in community practice between 2000-2002. We reviewed the charts of 168 patients with large warfarin dose variation and agreed on 18 risk factor definitions for high dose variability. We identified 109 patients with the highest dose variability (cases), as measured by coefficient of variation (CoV, SD/mean). We matched each case to two controls with low dose variability. Then, we examined all 327 charts, blinded to case/control status, to identify the presence or absence of the 18 risk factors for dose variability. We performed a multivariable analysis to identify independent predictors of high CoV. We also compared anticoagulation control, as measured by percent time in therapeutic range (TTR), and rates of adverse events between groups. RESULTS: CoV corresponded with other measures of anticoagulation control. TTR was 53% among cases and 79% among controls (p < 0.001). CoV also predicted adverse events. Six cases experienced a major hemorrhage versus 1 control (p < 0.001) and 3 cases had a thromboembolic event versus 0 control patients (p = 0.04). Independent predictors of high dose variability included hospitalization (OR = 21.3), decreased oral intake (OR = 12.2), use of systemic steroids (OR = 6.1), acetaminophen (OR = 4.0) and antibiotics (OR = 2.7; p < 0.05 for all). CONCLUSION: CoV can be used to identify patients at risk for poor anticoagulation control and adverse events. This new measure has the potential to identify patients at high risk before they suffer adverse events.

How to achieve informed consent for research from Spanish-speaking individuals with low literacy: a qualitative report.

Investigators have the responsibility to ensure that prospective participants are fully informed about a research protocol prior to consenting to participate, yet many researchers face challenges when obtaining consent, since the majority of the general population has limited or no familiarity with research studies. These challenges are further magnified when obtaining consent from individuals with low literacy levels and who speak languages other than English. In this article we present findings from a qualitative study conducted with Spanish-speaking individuals with low-literacy designed to refine the Agency for Healthcare Research and Quality's Informed Consent and Authorization Toolkit for Minimal Risk Research. Findings from this study indicate that familiarity with providing informed consent and authorization for research or the experience of being a research participant appear to play key roles in an individual's ability to understand the consent and authorization process. While the text of the consent and authorization documents can be simplified using plain language principles, comprehension of several fundamental ideas such as risk and privacy need to be safeguarded with a consent process that confirms comprehension. Recommendations are provided to address the informational needs of individuals with low literacy levels and limited or no experience with research participation.

Usability of conversational agents by patients with inadequate health literacy: evidence from two clinical trials.

Embodied Conversational Agents (ECA) are computer-animated characters that simulate face-to-face conversation with patients. These agents can be programmed with best practices in human-human health communication and used for automated health education and behavior change counseling interventions. Evidence is presented from two ongoing clinical trials demonstrating that patients at different levels of health literacy find these agents acceptable and easy to use for automated health communication interventions. Innovative computer interface systems can be used to ensure that inadequate health literacy not serve as a barrier to interventions using health information technology.

The "gender gap" in authorship of academic medical literature--a 35-year perspective.

BACKGROUND: Participation of women in the medical profession has increased during the past four decades, but issues of concern persist regarding disparities between the sexes in academic medicine. Advancement is largely driven by peer-reviewed original research, so we sought to determine the representation of female physician-investigators among the authors of selected publications during the past 35 years. METHODS: Original articles from six prominent medical journals--the New England Journal of Medicine (NEJM), the Journal of the American Medical Association (JAMA), the Annals of Internal Medicine (Ann Intern Med), the Annals of Surgery (Ann Surg), Obstetrics & Gynecology (Obstet Gynecol), and the Journal of Pediatrics (J Pediatr)--were categorized according to the sex of both the first and the senior (last listed) author. Sex was also determined for the authors of guest editorials in NEJM and JAMA. Data were collected for the years 1970, 1980, 1990, 2000, and 2004. The analysis was restricted to authors from U.S. institutions holding M.D. degrees. RESULTS: The sex was determined for 98.5 percent of the 7249 U.S. authors of original research with M.D. degrees. The proportion of first authors who were women increased from 5.9 percent in 1970 to 29.3 percent in 2004 (P<0.001), and the proportion of senior authors who were women increased from 3.7 percent to 19.3 percent (P<0.001) during the same period. The proportion of authors who were women increased most sharply in Obstet Gynecol (from 6.7 percent of first authors and 6.8 percent of senior authors in 1970 to 40.7 percent of first authors and 28.0 percent of senior authors in 2004) and J Pediatr (from 15.0 percent of first authors and 4.3 percent of senior authors in 1970 to 38.9 percent of first authors and 38.0 percent of senior authors in 2004) and remained low in Ann Surg (from 2.3 percent of first authors and 0.7 percent of senior authors in 1970 to 16.7 percent of first authors and 6.7 percent of senior authors in 2004). In 2004, 11.4 percent of the authors of guest editorials in NEJM and 18.8 percent of the authors of guest editorials in JAMA were women. CONCLUSIONS: Over the past four decades, the proportion of women among both first and senior physician-authors of original research in the United States has significantly increased. Nevertheless, women still compose a minority of the authors of original research and guest editorials in the journals studied.

Risk of thromboembolism with short-term interruption of warfarin therapy.

BACKGROUND: Significant uncertainty surrounds the treatment of patients who must discontinue warfarin sodium therapy before an invasive procedure. In part, the uncertainty results from the lack of published information about the risk of thromboembolism associated with short-term warfarin therapy interruption. We aimed to assess the frequency of thromboembolism and bleeding within a large cohort of patients whose warfarin therapy was temporarily withheld for an outpatient invasive procedure. METHODS: This prospective, observational cohort study was performed at 101 sites (primarily community-based physician office practices) in the United States. Enrollment was conducted from April 4, 2000, to March 6, 2002. The main outcome measures were thromboembolism or clinically significant hemorrhage within 30 days of warfarin therapy interruption. RESULTS: A total of 1293 episodes of warfarin therapy interruption in 1024 individuals were included. The mean (SD) patient age was 71.9 (10.6) years; 438 (42.8%) were female. The most common indications for anticoagulant therapy were atrial fibrillation (n=550), venous thromboembolism (n=144), and mechanical heart valve (n=132). The most common procedures were colonoscopy and oral and ophthalmic surgery. Perioperative heparin or low-molecular-weight heparin was used in only 8.3% of cases overall. Seven patients (0.7%; 95% confidence interval [CI], 0.3%-1.4%) experienced postprocedure thromboembolism within 30 days. None of the 7 patients who experienced thromboembolism received periprocedural bridging therapy. Six patients (0.6%; 95% CI, 0.2%-1.3%) experienced major bleeding, whereas an additional 17 patients (1.7%; 95% CI, 1.0%-2.6%) experienced a clinically significant, nonmajor bleeding episode. Of these 23 patients who had bleeding episodes, 14 received periprocedural heparin or low-molecular-weight heparin. The duration of warfarin therapy interruption was variable; however, more than 80% of patients had warfarin therapy withheld for 5 days or fewer. CONCLUSIONS: For many patients receiving long-term anticoagulation who need to undergo a minor outpatient intervention, a brief (< or =5 days) periprocedural interruption of warfarin therapy is associated with a low risk of thromboembolism. The risk of clinically significant bleeding, even among outpatients undergoing minor procedures, should be weighed against the thromboembolic risk of an individual patient before the administration of bridging anticoagulant therapy.

Major hemorrhage and tolerability of warfarin in the first year of therapy among elderly patients with atrial fibrillation.

BACKGROUND: Warfarin is effective in the prevention of stroke in atrial fibrillation but is under used in clinical care. Concerns exist that published rates of hemorrhage may not reflect real-world practice. Few patients > or = 80 years of age were enrolled in trials, and studies of prevalent use largely reflect a warfarin-tolerant subset. We sought to define the tolerability of warfarin among an elderly inception cohort with atrial fibrillation. METHODS AND RESULTS: Consecutive patients who started warfarin were identified from January 2001 to June 2003 and followed for 1 year. Patients had to be > or = 65 years of age, have established care at the study institution, and have their warfarin managed on-site. Outcomes included major hemorrhage, time to termination of warfarin, and reason for discontinuation. Of 472 patients, 32% were > or = 80 years of age, and 91% had > or = 1 stroke risk factor. The cumulative incidence of major hemorrhage for patients > or = 80 years of age was 13.1 per 100 person-years and 4.7 for those < 80 years of age (P=0.009). The first 90 days of warfarin, age > or = 80 years, and international normalized ratio (INR) > or = 4.0 were associated with increased risk despite trial-level anticoagulation control. Within the first year, 26% of patients > or = 80 years of age stopped taking warfarin. Perceived safety issues accounted for 81% of them. Rates of major hemorrhage and warfarin termination were highest among patients with CHADS2 scores (an acronym for congestive heart failure, hypertension, age > or = 75, diabetes mellitus, and prior stroke or transient ischemic attack) of > or = 3. CONCLUSIONS: Rates of hemorrhage derived from younger noninception cohorts underestimate the bleeding that occurs in practice. This finding coupled with the short-term tolerability of warfarin likely contributes to its underutilization. Stroke prevention among elderly patients with atrial fibrillation remains a challenging and pressing health concern.

Disparate stroke rates on warfarin among contemporaneous cohorts with atrial fibrillation: potential insights into risk from a comparative analysis of SPORTIF III versus SPORTIF V.

BACKGROUND AND PURPOSE: The rate of stroke among warfarin-treated patients in SPORTIF V was approximately half that of patients enrolled in SPORTIF III (1.16%/year versus 2.30%/year). SPORTIF III was an open-label trial comparing ximelagatran with warfarin for stroke prevention in atrial fibrillation. SPORTIF V was a double-blind trial performed in North America. The trial design was otherwise identical. We sought to determine if differences in baseline characteristics, use of potentially risk-modifying medications, or anticoagulation control help to explain the lower risk of stroke among warfarin-treated patients in SPORTIF V. METHODS: Cox regression with stepwise model selection was used to define the covariates independently associated with stroke. Secondary analyses identified covariates with the strongest influence on the study factor (V/III). These covariates were then added to the primary model. Cox regression was used to determine the degree of confounding exerted by these covariates that might help to explain the differences between the trials. RESULTS: Independent risk factors for stroke on warfarin included prior stroke/transient ischemic attack, coronary artery disease, international normalized ratio, weight, and study. Patients in SPORTIF V were at half the risk as those in SPORTIF III. We found that lower international normalized ratio variability, a higher proportion of prevalent warfarin use, lower systolic blood pressure, high-density lipoprotein, and a greater proportion of statin use among patients in SPORTIF V collectively conferred a lower risk of stroke. CONCLUSIONS: Differences in blood pressure control, international normalized ratio variability, proportion of prevalent warfarin users, statin exposure, and high-density lipoprotein collectively conferred a lower risk of stroke to patients in SPORTIF V. These findings suggest that the different event rates were not due to chance and provide potential insights into stroke risk among warfarin-treated patients with atrial fibrillation.

Effect of intensity of oral anticoagulation on stroke severity and mortality in atrial fibrillation.

BACKGROUND: The incidence of stroke in patients with atrial fibrillation is greatly reduced by oral anticoagulation, with the full effect seen at international normalized ratio (INR) values of 2.0 or greater. The effect of the intensity of oral anticoagulation on the severity of atrial fibrillation-related stroke is not known but is central to the choice of the target INR. METHODS: We studied incident ischemic strokes in a cohort of 13,559 patients with nonvalvular atrial fibrillation. Strokes were identified through hospitalization data bases and validated on the basis of medical records, which also provided information on the use of warfarin or aspirin, the INR at admission, and coexisting illnesses. The severity of stroke was graded according to a modified Rankin scale. Thirty-day mortality was ascertained from hospitalization and mortality files. RESULTS: Of 596 ischemic strokes, 32 percent occurred during warfarin therapy, 27 percent during aspirin therapy, and 42 percent during neither type of therapy. Among patients who were taking warfarin, an INR of less than 2.0 at admission, as compared with an INR of 2.0 or greater, independently increased the odds of a severe stroke in a proportional-odds logistic-regression model (odds ratio, 1.9; 95 percent confidence interval, 1.1 to 3.4) across three severity categories and the risk of death within 30 days (hazard ratio, 3.4; 95 percent confidence interval, 1.1 to 10.1). An INR of 1.5 to 1.9 at admission was associated with a mortality rate similar to that for an INR of less than 1.5 (18 percent and 15 percent, respectively). The 30-day mortality rate among patients who were taking aspirin at the time of the stroke was similar to that among patients who were taking warfarin and who had an INR of less than 2.0. CONCLUSIONS: Among patients with nonvalvular atrial fibrillation, anticoagulation that results in an INR of 2.0 or greater reduces not only the frequency of ischemic stroke but also its severity and the risk of death from stroke. Our findings provide further evidence against the use of lower INR target levels in patients with atrial fibrillation.

The new Medicare Part D prescription drug benefit: an estimation of its effect on prescription drug costs in a Medicare population with atrial fibrillation.

OBJECTIVES: To compare prescription drug cost savings under the most commonly selected Medicare Part D prescription plan in 2006 with savings under the Medicare standard benefit and with drug costs assuming no coverage in an elderly cohort of patients. DESIGN: Inception cohort study. SETTING: An academic medical center. PARTICIPANTS: Four hundred seventy-two patients aged 65 and older who were followed as part of a larger study assessing stroke prevention in patients with atrial fibrillation. MEASUREMENTS: Prescription drug expenditures were calculated for each patient in the cohort under three conditions: the 2006 AARP-endorsed prescription drug plan, the Medicare standard benefit, and no prescription drug coverage. RESULTS: Total prescriptions drug costs were lower under the AARP plan, yet patients paid a similar percentage of total costs under the AARP plan and the Medicare standard benefit. Using different cost assessments, 27% to 46% of patients entered the "doughnut hole" in the AARP plan, and 3% to 11% emerged to receive catastrophic coverage. CONCLUSION: Both the AARP-sponsored and standard Medicare Part D prescription drug benefit programs offer significant savings to enrollees. A greater savings is achieved under the private AARP drug insurance plan, largely due to greater discounts reflected in the negotiated drug prices. A substantial portion of enrollees enter but do not emerge from the coverage gap.

Effectiveness of warfarin among patients with cancer.

BACKGROUND: Among patients treated with warfarin for venous thromboembolism (VTE), cancer patients have more thrombotic and hemorrhagic events than patients without cancer. Is this also the case when cancer patients are anticoagulated for other indications? OBJECTIVE: The objective of the study is to evaluate the effectiveness of warfarin, given for any indication, among patients with cancer in a community setting. METHODS: We identified patients with cancer from a larger prospective cohort of 6,761 patients from 101 clinical sites in the United States, matched to controls without cancer. The proportion of time spent in the therapeutic range, international normalized ration (INR) variability, and the rate of thromboembolic and major hemorrhagic events were compared between the two groups. RESULTS: Ninety-five patients undergoing treatment for cancer were matched to 283 patients without cancer. The cancer group spent less time in the target INR range (54 vs 66%, P < .001) and had more variable INR values (standard deviation around the mean INR value 1.30 vs 0.71, P < .001). There were more thrombotic events in the cancer group than in the control group (5 vs 0 events, P < .001). These analyses were repeated after excluding all of the patients anticoagulated for VTE; the results were unchanged. CONCLUSIONS: Compared to matched controls, cancer patients receiving warfarin spend less time in the target INR range, have more variable INR values, and have more thrombotic events. These effects are not dependent on whether the patient is anticoagulated for VTE or another indication.

Rationale and design of the Atrial Fibrillation health Literacy Information Technology Trial: (AF-LITT).

BACKGROUND: Atrial Fibrillation (AF) is a common cardiac arrhythmia that is challenging for patients and adversely impacts health-related quality of life (HRQoL). Long-term management of AF requires that patients adhere to complex therapies, understand difficult terminology, navigate subspecialty care, and have continued symptom monitoring with the goal of preventing adverse outcomes. Continued interventions to ameliorate the patient experience of AF are essential. DESIGN: The Atrial Fibrillation health Literacy Information Technology Trial (AF-LITT; NCT03093558) is an investigator-initiated, 2-arm randomized clinical trial (RCT). This RCT is a pilot in order to implement a novel, smartphone-based intervention to address the patient experience of AF. This pilot RCT will compare a combination of the Embodied Conversational Agent (ECA) and the Alive Cor Kardia Mobile heart rhythm monitor to the current standard of care. The study will enroll 180 adults with non-valvular AF who are receiving anticoagulation for stroke prevention and randomize them to receive a 30-day intervention (smartphone-based ECA/Kardia) or standard of care, which will include a symptom and adherence journal. The primary end-points are improvement in HRQoL and self-reported adherence to anticoagulation. The secondary end-points are the acceptability of the intervention to participants, its use by participants, and acceptability to referring physicians. CONCLUSIONS: The AF-LITT pilot aims to evaluate the efficacy of the ECA/Kardia to improve HRQoL and anticoagulant adherence, and to guide its implementation in a larger, multicenter clinical trial. The intervention has potential to improve HRQoL, adherence, and health care utilization in individuals with chronic AF.

Gender differences in the risk of ischemic stroke and peripheral embolism in atrial fibrillation: the AnTicoagulation and Risk factors In Atrial fibrillation (ATRIA) study.

BACKGROUND: Previous studies provide conflicting results about whether women are at higher risk than men for thromboembolism in the setting of atrial fibrillation (AF). We examined data from a large contemporary cohort of AF patients to address this question. METHODS AND RESULTS: We prospectively studied 13,559 adults with AF and recorded data on patients' clinical characteristics and the occurrence of incident hospitalizations for ischemic stroke, peripheral embolism, and major hemorrhagic events through searching validated computerized databases and medical record review. We compared event rates by patient sex using multivariable log-linear regression, adjusting for clinical risk factors for stroke, and stratifying by warfarin use. We identified 394 ischemic stroke and peripheral embolic events during 15,494 person-years of follow-up off warfarin. After multivariable analysis, women had higher annual rates of thromboembolism off warfarin than did men (3.5% versus 1.8%; adjusted rate ratio [RR], 1.6; 95% CI, 1.3 to 1.9). There was no significant difference by sex in 30-day mortality after thromboembolism (23% for both). Warfarin use was associated with significantly lower adjusted thromboembolism rates for both women and men (RR, 0.4; 95% CI, 0.3 to 0.5; and RR, 0.6; 95% CI, 0.5 to 0.8, respectively), with similar annual rates of major hemorrhage (1.0% and 1.1%, respectively). CONCLUSIONS: Women are at higher risk than men for AF-related thromboembolism off warfarin. Warfarin therapy appears be as effective in women, if not more so, than in men, with similar rates of major hemorrhage. Female sex is an independent risk factor for thromboembolism and should influence the decision to use anticoagulant therapy in persons with AF.

Translating the results of randomized trials into clinical practice: the challenge of warfarin candidacy among hospitalized elderly patients with atrial fibrillation.

BACKGROUND AND PURPOSE: Numerous studies have documented under use of warfarin particularly among elderly patients. A better understanding of the discrepancy between trials and clinical practice will help inform stroke prevention strategies in this vulnerable age group. The study objective was to prospectively assess the use of antithrombotic therapy among a contemporary cohort of patients with atrial fibrillation at the time of hospital discharge. In addition to baseline characteristics, we sought to define the physician-cited reason for not prescribing warfarin for each patient. METHODS: Patients with atrial fibrillation were prospectively identified and followed to hospital discharge. Enrolled patients were > or =65 years of age, not taking warfarin on admission, and had their longitudinal care provided at our institution. Predictors of warfarin use were determined and physician-cited contraindications were compared across age groups. RESULTS: Fifty-one percent (n=206) of patients were discharged on warfarin: 75% of those 65 to 69 years of age, 59% 70 to 79, 45% 80 to 89, and 24% age > or =90 years. Of the remaining 199 patients, 83% had > or =2 major risk factors for stroke, and 98% were felt to have contraindications including nearly 25% who were unable to tolerate warfarin in the past. Among patients age > or =80, falling was the most often physician-cited reason for not prescribing warfarin (41%) followed by hemorrhage (28%). CONCLUSIONS: Our findings suggest that many elderly patients at high risk for stroke may not be optimal candidates for anticoagulant therapy. There is a pressing need for alternative stroke prevention strategies for this expanding patient population.

Age and the risk of warfarin-associated hemorrhage: the anticoagulation and risk factors in atrial fibrillation study.

OBJECTIVES: To assess whether older age is independently associated with hemorrhage risk in patients with atrial fibrillation, whether or not they are taking warfarin therapy. DESIGN: Cohort study. SETTING: Integrated healthcare delivery system. Thirteen thousand five hundred fifty-nine adults with nonvalvular atrial fibrillation. MEASUREMENTS: Patient data were collected from automated clinical and administrative databases using previously validated search algorithms. Medical charts were reviewed from patients hospitalized were for major hemorrhage (intracranial, fatal, requiring >or=2 units of transfused blood, or involving a critical anatomic site). Age was categorized into four categories (<60, 60-69, 70-79, and >or=80), and multivariable Poisson regression was used to assess whether major hemorrhage rates increased with age, stratified by warfarin use and adjusted for other clinical risk factors for hemorrhage. RESULTS: A total of 170 major hemorrhages were identified during 15,300 person-years of warfarin therapy and 162 major hemorrhages during 15,530 person-years off warfarin therapy. Hemorrhage rates rose with older age, with an average increase in hemorrhage rate of 1.2 (95% confidence interval (CI) 1.0-1.4) per older age category in patients taking warfarin and 1.5 (95% CI=1.3-1.8) in those not taking warfarin. Intracranial hemorrhage rates were significantly higher in those aged 80 and older (adjusted rate ratio=1.8, 95% CI=1.1-3.1 for those taking warfarin, adjusted rate ratio=4.7, 95% CI=2.4-9.2 for those not taking warfarin) than in those younger than 80. CONCLUSION: Older age increases the risk of major hemorrhage, particularly intracranial hemorrhage, in patients with atrial fibrillation, whether or not they are taking warfarin. Hemorrhage rates were generally comparable with those reported in previous randomized trials, indicating that carefully monitored warfarin therapy can be used with reasonable safety in older patients.

Challenges to the effective use of unfractionated heparin in the hospitalized management of acute thrombosis.

BACKGROUND: Unfractionated heparin therapy is care intensive because of dose-response variability, and because of the necessity of constant intravenous infusion and frequent monitoring. We sought to assess the real-world course of transition from heparin to warfarin in hospitalized patients undergoing anticoagulation therapy for acute venous or arterial thrombosis at our medical center. METHODS: Patients were retrospectively identified from July 1998 to December 1998. Data collected included initiation and maintenance doses of heparin, frequency of monitoring and dose adjustments, time to the therapeutic range, complications and interruptions of therapy, and characteristics of heparin-to-warfarin transition. RESULTS: Of the 311 patients who met the study criteria during the 6-month period, 134 had venous thromboembolism, 122 had cerebral arterial thrombosis, and 55 had peripheral arterial thrombosis. Groups differed in use and magnitude of initial heparin bolus, frequency of monitoring, and time to the therapeutic range. Dose response to intravenous heparin was highly variable. Even when the activated partial thromboplastin time reached the therapeutic range of 55 to 85 seconds, the next 2 consecutive measurements remained in this range in only 29% of the patients. Patients received an average of 4 different heparin doses over the first 3 days of treatment, and the therapeutic range was maintained on each of 4 sequential days in only 7% of them. During the course of therapy, 54% of the patients had at least 1 prolonged interruption in heparin infusion, and 4.8% sustained a major hemorrhage. Overall, 20% of the patients met the currently recommended treatment guideline of 4 days or more of heparin and warfarin overlap, until the international normalized ratio is greater than 2.0 for 2 consecutive days. CONCLUSIONS: Multiple challenges to effective anticoagulation treatment with unfractionated heparin exist in the hospital setting. Strategies are needed to improve the overall quality of anticoagulant care, including the substitution of low-molecular-weight heparin for unfractionated heparin, where appropriate.