Aarti A Patel

Use of warfarin in long-term care: a systematic review

BackgroundThe use of warfarin in older patients requires special consideration because of concerns with comorbidities, interacting medications, and the risk of bleeding. Several studies have suggested that warfarin may be underused or inconsistently prescribed in long-term care (LTC); no published systematic review has evaluated warfarin use for stroke prevention in this setting. This review was conducted to summarize the body of published original research regarding the use of warfarin in the LTC population.MethodsA systematic literature search of the PubMed, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library was conducted from January 1985 to August 2010 to identify studies that reported warfarin use in LTC. Studies were grouped by (1) rates of warfarin use and prescribing patterns, (2) association of resident and institutional characteristics with warfarin prescribing, (3) prescriber attitudes and concerns about warfarin use, (4) warfarin management and monitoring, and (5) warfarin-related adverse events. Summaries of study findings and quality assessments of each study were developed.ResultsTwenty-two studies met the inclusion criteria for this review. Atrial fibrillation (AF) was the most common indication for warfarin use in LTC and use of warfarin for stroke survivors was common. Rates of warfarin use in AF were low in 5 studies, ranging from 17% to 57%. These usage rates were low even among residents with high stroke risk and low bleeding risk. Scored bleeding risk had no apparent association with warfarin use in AF. In physician surveys, factors associated with not prescribing warfarin included risk of falls, dementia, short life expectancy, and history of bleeding. International normalized ratio was in the target range approximately half of the time. The combined overall rate of warfarin-related adverse events and potential events was 25.5 per 100 resident months on warfarin therapy.ConclusionsAmong residents with AF, use of warfarin and maintenance of INR levels to prevent stroke appear to be suboptimal. Among prescribers, perceived challenges associated with warfarin therapy often outweigh its benefits. Further research is needed to explicitly consider the appropriate balancing of risks and benefits in this frail patient population.

Burden of comorbidities among patients with atrial fibrillation.

Objective: This study examined comorbidity prevalence and general medication use among individuals with atrial fibrillation in the United States to convey a more comprehensive picture of their total disease burden. Methods: This was a retrospective, observational evaluation of responses to the 2009 wave of the annual Internet-based National Health and Wellness survey, which collects health data including epidemiologic data and information on medical treatment from a representative nationwide sample of adults in the United States. Responses were assessed to determine three measures of comorbidity: mean number of comorbidities, CHADS2 score reflecting stroke risk (0–6 points; low risk: 0; moderate risk: 1; high risk: ≥2), and scores on the Charlson Comorbidity Index, which is a measure of general comorbidity reflecting presence of a wide range of comorbidities. Results: Of the overall sample, 1297 participants reported having been diagnosed with atrial fibrillation. Almost all (98%) of the predominantly male (65.1%) and older (≥65 years of age, 65.7%) population with atrial fibrillation had at least one additional comorbidity, and 90% had cardiovascular comorbidities. On the Charlson Comorbidity Index, 44.9% of the respondents had scores of 1–2 and 20.5% had scores of 3 or higher. High risk for stroke, demonstrated by a CHADS2 score of at least 2, was present in 45% and moderate risk (CHADS2 score 1) in 36%. Of the respondents with atrial fibrillation, 71% reported current use of medication to manage the condition, but only 48% of individuals at high risk for stroke reported use of anticoagulation therapy. Of those who reported having common risk factors for stroke, the majority reported receiving prescription therapy for these conditions. Conclusions: The health burden carried by patients often extends far beyond atrial fibrillation. Physicians should carefully consider comorbidities and concomitant medications when managing patients with atrial fibrillation.

Dyspepsia and disease burden among patients with atrial fibrillation.

This retrospective, observational study was conducted to determine overlap of prevalence between atrial fibrillation (AF), an increasingly common condition that primarily affects the elderly population, and dyspepsia, which is also common. Because the overlap of these conditions could interfere with health care including medication selection, the effect on patient outcomes was also evaluated. A demographically representative population of adults in the United States self-administered an Internet-based questionnaire, and responses were evaluated to determine the presence of AF and measures of comorbidity, including CHADS2 score of stroke risk. Health-related quality of life, work productivity and activity impairment, and health care resource utilization were also assessed. The impact of dyspepsia on these patient outcomes was then examined with multiple regressions and generalized linear models. From the sample population, 1297 participants reported being diagnosed with AF, of whom 34% (449/1297) reported diagnosis of dyspepsia. Those with dyspepsia had a higher mean CHADS2 score than those without dyspepsia. Despite this higher risk, significantly fewer AF patients with dyspepsia than those without dyspepsia were taking either prescription medication to treat AF or anticoagulants for stroke prevention. Dyspepsia was associated with significantly lower levels of both mental and physical health-related quality of life. Work and activity impairment and health care resource utilization were also significantly higher among AF patients with dyspepsia than among those without. The burden of dyspepsia in AF patients should be considered during medication selection. Selection of agents associated with lower rates of dyspepsia may lead to greater patient acceptance of and adherence to therapy.

Persistence of Warfarin Therapy for Residents in Long-term Care Who Have Atrial Fibrillation

BACKGROUND Among long-term care (LTC) residents with atrial fibrillation (AF), the use of warfarin to prevent stroke has been shown to be suboptimal. For those who begin warfarin prophylaxis in LTC, persistence on this therapy has not been reported. OBJECTIVE This study was conducted to estimate persistence on warfarin among LTC residents with AF. METHODS A retrospective analysis was conducted by using data from an LTC database. Pharmacy dispensing data were used to track warfarin use in residents with a diagnosis of AF who were newly started on warfarin therapy. The main outcome measure was persistence of warfarin over the first year of therapy. Survival analysis included Kaplan-Meier plots and a multivariate Cox proportional hazards model to test the association of resident characteristics and conditions with warfarin discontinuation. RESULTS A total of 148 residents new to warfarin therapy met all study inclusion criteria. Median age was 84 years; 69% were female. Median time to therapy discontinuation was 197 days (95% CI, 137-249) across all study residents. By 90 days after the initiation of therapy, 37% (95% CI, 28-47) of study residents had discontinued warfarin; by 1 year, 65% (54%-76%) had discontinued warfarin therapy. The multivariate Cox regression analysis found that the following factors were independently associated with discontinuation of warfarin therapy: age 65 to 74 years (hazard ratio [HR] = 3.01 [95% CI, 1.04-8.73]), female sex (HR = 0.45 [95% CI, 0.24-0.87]), Hispanic race/ethnicity (HR = 2.86 [95% CI, 1.30-6.26]), Midwest region (HR = 2.13 [95% CI, 1.02-4.48]), and Alzheimer disease or dementia (HR = 1.97 [95% CI, 1.05-3.68]). CONCLUSIONS Although clinical practice guidelines exist for the prevention of stroke in AF patients, persistence on warfarin therapy seems suboptimal in many LTC residents with AF.

Prevalence of Atrial Fibrillation in US Nursing Homes: Results from the National Nursing Home Survey, 1985–2004

OBJECTIVES To evaluate the prevalence of atrial fibrillation (AFib) in US nursing homes from 1985 to 2004 and to project the prevalence of AFib to 2030. DESIGN This study is an analysis of cross-sectional data from the US National Nursing Home Survey, years 1985, 1995, 1997, 1999, and 2004. SETTING Randomly selected long term care facilities in the United States licensed by the state or certified for Medicaid/Medicare reimbursement. PARTICIPANTS Randomly selected residents within study facilities. MEASUREMENTS National Nursing Home Survey demographics and current medical conditions data were analyzed. Population estimates were calculated using National Nursing Home Survey sample weights. Absolute observed annual linear growth of the AFib prevalence rate was calculated using linear regression. Predictive margins were estimated using logistic regression models to evaluate effect of changes in resident case-mix over the survey years. Three estimation methods predicted the number residents having AFib in 2030. RESULTS The sample sizes of surveyed resident groups were as follows: n = 5238 (1985); n = 8056 (1995); n = 8138 (1997); n = 8215 (1999); and n = 13,507 (2004). Prevalence rates of AFib by year were 2.8% (95% confidence interval [CI]: 2.3-3.4%; 1985), 5.1% (95% CI: 4.6-5.6%; 1995), 5.8% (95% CI: 5.3-6.3%; 1997), 6.9% (95% CI: 6.3-7.4%; 1999), and 10.9% (95% CI: 10.2-11.5%; 2004). Population estimates of nursing home residents with AFib (in thousands) were 42.2 (95% CI: 34.1-50.3; 1985), 78.7 (95% CI: 70.8-86.7; 1995), 93.6 (95% CI: 84.9-102.3; 1997), 111.8 (95% CI: 102.1-121.5; 1999), and 162.1 (95% CI: 152.4-171.7; 2004). Absolute annual linear growth in the prevalence rate of AFib was +0.38% observed (P = .022), +0.39% using unadjusted predictive margins (P = .007), and +0.37% using adjusted predictive margins (P = .007). Projected estimates showed that 272,000 (95% CI: 197,000-347,000), 300,000, or 325,000 residents would have AFib in the year 2030. CONCLUSION The prevalence of AFib in US nursing home residents increased from 1985 to 2004 and is projected to grow substantially over the next 20 years, potentially resulting in an increased nursing home staff burden owing to increased stroke risk evaluations.

The economic implications of switching to rivaroxaban from enoxaparin plus vitamin K antagonist in the treatment of venous thromboembolism

Abstract Objective: Venous thromboembolism (VTE) impacts ∼900,000 individuals annually in the US, causing up to 100,000 deaths. Patients experiencing VTE have heightened risk of recurrence. Initial parenteral anti-coagulation is standard therapy for acute VTE followed by ≥3 months of warfarin, which introduces the risk of major bleeding. Balancing increased risks of bleeding and recurrent VTE remains challenging. Recent clinical trials suggest that rivaroxaban, an oral direct inhibitor of factor Xa, provides an effective, safe, simplified approach to treatment. This study considers the economic implications of these data. Methods: This study modeled inpatient, acute, and 1-year VTE costs for a hypothetical commercial plan with 1 million members. At baseline, all VTE patients receive standard therapy. Alternatively, 25% are instead treated with rivaroxaban. Model inputs are trial- and literature-based. Results: Standard therapy for VTE consumes 9474 inpatient days (

Impact of CHA2DS2VASc Score on Candidacy for Anticoagulation in Patients With Atrial Fibrillation: A Multi-payer Analysis

31.6 million). Added to that is treatment for 74 recurrences (

Usage of medications with high potential to interact with warfarin among atrial fibrillation residents in long-term care facilities

1.4 million); major and non-major bleed events (

Stroke risk reduction outweighed bleeding risk increase from vitamin K antagonist treatment among nonvalvular atrial fibrillation patients with high stroke risk and low bleeding risk

1 million); and direct costs of anti-coagulation (

Anticoagulant use for the prevention of stroke in patients with atrial fibrillation: findings from a multi-payer analysis

5.3 million). Alternatively, a 25% shift to oral anti-coagulation with rivaroxaban reduces inpatient days (by 5%); associated acute-care costs (by 2%); recurrences and costs (by 6%). Four major bleeding events are prevented, at the cost of one additional non-major bleeding event, which, taken together, reduce net utilization by 9%. Direct costs of anti-coagulation increase by 5%. Conclusion: The reduction in inpatient utilization, recurrences, and major bleeding resulting from a 25% shift from standard therapy to rivaroxaban following acute VTE would conserve ∼