Anticoagulation therapy in patients with chronic atrial fibrillation: a retrospective claims data analysis

Oral anticoagulation use by patients with atrial fibrillation in Germany

Atrial fibrillation (AF) is the most common significant cardiac rhythm disorder. Oral anticoagulation (OAC) is recommended by guidelines in the presence of a moderate to high risk of stroke. Based on an analysis of claims-based data, the aim of this contribution is to quantify the stroke-risk dependent OAC utilisation profile of German AF patients as well as the possible causes and the associated clinical outcomes of OAC under-use. Our data set was derived from two large mandatory German medical insurance funds. Risk stratification of patients was based on the CHADS2-score and the CHA2DS2-VASc-score. Two different scenarios were constructed to deal with factors potentially disfavouring OAC use. Causes of OAC under-use and its clinical consequences were analysed using multivariate analysis. Observation year was 2008. A total of 183,448 AF patients met the inclusion criteria. This represents an AF prevalence of 2.21%. The average CHADS2-score was 2.8 (CHA2DS2-VASc-score: 4.3). On between 40.5 and 48.7% of the observed patient-days, there was no antithrombotic protection by OAC, other anticoagulants or aspirin. Older female patients with a high number of comorbidities had a higher risk of OAC under-use. Patients who had already experienced a thromboembolic event had a lower risk of OAC under-use. In the observation year, 3,367 patients experienced a stroke (incidence rate 1.8%). In our multi-level Poisson random effects estimate, OAC use decreases the stroke rate by almost 80% (IRR 0.236). In conclusion, OAC under-use is widespread in the German market. It is associated with severe clinical consequences.

Real life anticoagulation treatment of patients with atrial fibrillation in Germany: extent and causes of anticoagulant under-use

Oral anticoagulation (OAC) with either new oral anticoagulants (NOACs) or Vitamin-K antagonists (VKAs) is recommended by guidelines for patients with atrial fibrillation (AF) and a moderate to high risk of stroke. Based on a claims-based data set the aim of this study was to quantify the stroke-risk dependent OAC utilization profile of German AF patients and possible causes of OAC under-use. Our claims-based data set was derived from two German statutory health insurance funds for the years 2007-2010. All prevalent AF-patients in the period 2007-2009 were included. The OAC-need in 2010 was assumed whenever a CHADS2- or CHA2DS2-VASC-score was >1 and no factor that disfavored OAC use existed. Causes of OAC under-use were analyzed using multivariate logistic regression. 108,632 AF-prevalent patients met the inclusion criteria. Average age was 75.43 years, average CHA2DS2-VASc-score was 4.38. OAC should have been recommended for 56.1/62.9 % of the patients (regarding factors disfavouring VKA/NOAC use). For 38.88/39.20 % of the patient-days in 2010 we could not observe any coverage by anticoagulants. Dementia of patients (OR 2.656) and general prescription patterns of the treating physician (OR 1.633) were the most important factors increasing the risk of OAC under-use. Patients who had consulted a cardiologist had a lower risk of being under-treated with OAC (OR 0.459). OAC under-use still seems to be one of the major challenges in the real-life treatment of AF patients. Our study confirms that both patient/disease characteristics and treatment environment/general prescribing behaviour of physicians may explain the OAC under-use in AF patients.

A non-experimental study of oral anticoagulation therapy initiation before and after national patient safety goals

OBJECTIVES

The Joint Commission revised its National Patient Safety Goals (NPSGs) to include oral anticoagulation therapy (OAT) in 2008. We sought to examine the effect of including OAT in The Joint Commission's NPSGs on historically low rates of OAT initiation for individuals with incident atrial fibrillation (AF).

SETTING

Southeastern state in the USA.

PARTICIPANTS

North Carolina State Health Plan claims data from 944 500 individuals enrolled between 1 January 2006 and 31 December 2010, supplemented with data from the Area Resource File and Online Survey, Certification and Reporting data network. We evaluated OAT initiation before and after the 2008 NPSGs revisions in a retrospective cohort new user design with an AF intervention group and two control groups: a positive control-patients estimated to be at very high risk of thromboembolism (mechanical heart valve and pulmonary embolism); and a negative control-patients with very low perceived risk of thromboembolism (paroxysmal AF). We developed multivariable models using a difference-in-difference parameterisation. Effects were estimated with generalised estimating equations.

PRIMARY OUTCOME MEASURE

OAT initiation, a binary outcome defined as having a prescription drug claim for warfarin within 30 days of the index claim.

RESULTS

OAT initiation was low (26.8%) for eligible individuals with incident AF in 2006-2008 but increased after NPSGs implementation (31.7%, p=0.022). OAT initiation was high but decreased in the positive control group (67.5% vs 62.0%, p=0.003). Multivariate analysis resulted in a relative 11% (95% CI (4% to 18%), p<0.01) increase in OAT initiation for incident AF patients.

CONCLUSIONS

We document a substantial increase in guideline concordant OAT initiation in incident AF after the establishment of NPSGs, suggesting that regulatory healthcare agency initiatives can influence clinical practice.

Patient-centered medical homes and oral anticoagulation therapy initiation

Despite evidence-based guidelines, oral anticoagulation therapy (OAT) initiation is low among incident atrial fibrillation (AF) patients. Patient-centered medical homes (PCMHs) may increase access, quality, and value through coordinating care. As such, PCMHs hold potential for improving OAT initiation among AF patients. We estimated the effect of receiving care in accredited PCMHs on OAT initiation for incident AF patients compared with those not receiving care in accredited PCMHs. Our study, a retrospective cohort new user design, included privately insured patients in North Carolina during years 2006 to 2010. We developed propensity scores for PCMH exposure, performed inverse probability of treatment weighting, and estimated effects with generalized estimating equations. We found a positive association between PCMH exposure and OAT initiation in unadjusted (6.78%; p < .001) and adjusted (6.25%; p < .001) models. Greater implementation and optimization of PCMH model principles may enhance this association, reducing AF-related stroke morbidity and mortality.

Trends in utilization of management strategies for newly diagnosed atrial fibrillation patients in the United States: 1999 to 2008

OBJECTIVE

To describe the trend in atrial fibrillation (AF) treatment strategies in newly diagnosed AF patients between 1999 and 2008.

METHODS

The study was a retrospective cohort study of commercial health plans claims data. Newly diagnosed adult AF patients with ≥1 claim for an AF-related intervention within 12 months of diagnosis were identified. Based on initial treatment, patients were classified into pharmacotherapy or nonpharmacotherapy groups. Pharmacotherapy group was subcategorized into rate-control or rhythm-control groups. Linear regression to assess linear trend and multinomial logistic regression to evaluate factors associated with treatment choice were conducted.

RESULTS

Three thousand ninety-four newly diagnosed AF patients were identified. Eighty percent of these patients were initiated on pharmacotherapy with the majority (84%) receiving rate-control medications only. Relative distribution of the 3 treatment groups remained similar over the study period. However, within the rate-control group, the use of beta blockers increased significantly (P < .001). Treatment with nonpharmacotherapy over rate-control medications was higher in males but lower in patients aged ≥80 (relative risk ratio [RRR]: 1.67, 95% confidence interval [CI]: 1.27-2.20 and RRR: 0.48, 95% CI: 0.30-0.77, respectively). Having stroke and congestive heart failure significantly affected the treatment choice between nonpharmacotherapy and rate-control medications.

CONCLUSION

Medication therapy, especially rate-control strategies, remains the preferred initial therapy of choice.

Characteristics of patients with venous thromboembolism and atrial fibrillation in Venezuela

Background

Studies describing venous thromboembolic event (VTEE) and atrial fibrillation (AF) in South American populations are limited. The aim of this cross-sectional study was to describe the characteristics of Venezuelan patients admitted and treated for these conditions.

Methods

A retrospective medical record review of 1397 consecutive patients admitted to three private hospitals or clinics between January 2000 and December 2005 was performed. Data was collected on demographics, anthropometrics, hospital visit, comorbidities and treatment.

Results

Among 401 VTEE and 996 AF patients, men were more likely to have AF (58%) while more women experienced a VTEE (58%). Most patients were admitted via the emergency room (87%) and had only one event during the study period (83%). Common comorbidities included hypertension (46%), heart failure (17%), diabetes (12%) and congestive heart failure (11%). Characteristics of Venezuelan patients with VTEE and AF are similar to that reported in the literature for other populations.

Conclusions

These results provide background characteristics for future studies assessing risk factors for AF and VTEE in South American populations.

Incidence rates for thromboembolic, bleeding and hepatic outcomes in patients undergoing hip or knee replacement surgery

BACKGROUND

Data on clinical outcomes of patients in the general population undergoing knee replacement or hip replacement surgery are sparse.

OBJECTIVES

To conduct an observational study using insurance claims data to assess the incidence of selected clinical events following knee replacement or hip replacement surgery in the USA.

PATIENTS/METHODS

A total of 97,469 knee replacement patients and a total of 45,203 hip replacement patients were included during the period 2004-2008; the median age was 64 years, and 63% of knee replacement patients and 55% of hip replacement patients were women.

RESULTS

During a median follow-up of 70-71 days, the incidence rates in knee replacement patients and hip replacement patients were, respectively: ischemic stroke, 15 and 19 per 1000 person-years; acute coronary syndrome (ACS), 15 and 18 per 1000 person-years; bleeding events, 46 and 47 per 1000 person-years; venous thromboembolism (VTE), 64 and 45 per 1000 person-years; and hepatic events, one and one per 1000 person-years. Approximately 45% of knee replacement and hip replacement patients had no claims for outpatient anticoagulant therapy within 1 week after discharge from hospital.

CONCLUSIONS

Ischemic events such as stroke, ACS and VTE are important adverse events following knee replacement and hip replacement surgery. The results reported here can help in making challenging decisions regarding the clinical management of risks attributable to bleeding events and clotting events.

Prevalence and cost of HIV-associated weight loss in a managed care population

OBJECTIVE

To estimate the prevalence of HIV-associated weight loss among HIV patients in a US managed care population, and compare demographic and clinical characteristics of HIV patients with and without evidence of HIV-associated weight loss.

RESEARCH DESIGN AND METHODS

A retrospective observational study was conducted using a large, geographically diverse US managed care population to identify commercial enrollees with HIV/AIDS from 1/1/2005-7/31/2007, based on a combination of HIV/AIDS diagnosis codes or antiretroviral treatment. HIV-associated weight loss status was defined according to an algorithm combining evidence for weight loss-associated conditions, anorexia symptoms, and various treatments for weight loss or wasting. Among HIV patients continuously enrolled in the health plan for one year, patient demographics, treatments, and comorbidities were compared between patients with and without evidence for weight loss.

RESULTS

A total of 22,535 patients with HIV/AIDS were identified, including 2098 who met the criteria for weight loss (estimated prevalence 9.3%; 95% CI: 8.9% - 9.7%). Among 12,187 continuously enrolled patients with HIV, 1006 (8.3%) had evidence of HIV-associated weight loss. Patients with HIV-associated weight loss were older (44.1 vs. 42.6 years), and more men had HIV-associated weight loss than women (8.8% vs. 5.3%). A number of comorbidities were more common among patients with HIV-associated weight loss. On average, these patients also had more ambulatory (24.0 vs. 13.4), ER (1.4 vs. 0.8), and inpatient visits (0.5 vs. 0.1). Total annual health care costs for patients with HIV-associated weight loss were more than double (mean $45,686 vs. $19,960) the costs for HIV patients without weight loss.

CONCLUSIONS

Despite the availability of effective antiretroviral therapy, weight loss remains a problem among patients with HIV. Based on this analysis, almost 1 in 10 managed care patients with HIV have evidence of HIV-associated weight loss. These patients tend to have more comorbidities, use more health care resources, and incur greater costs compared to patients without HIV-associated weight loss. Patients with HIV-associated weight loss were generally sicker than the non-weight loss cohort; thus, the increased costs observed in this population may not be directly or wholly attributable to HIV-associated weight loss. In addition, limitations common to analyses of administrative claims data should be considered when interpreting these results.

Increased risk of acute pancreatitis and biliary disease observed in patients with type 2 diabetes: a retrospective cohort study

OBJECTIVE

The objective of this study was to assess the risk of acute pancreatitis in patients with type 2 diabetes compared with that in patients without diabetes. We also examined the risk of biliary disease (defined as occurrence of cholelithiasis, acute cholecystitis, or cholecystectomy), which is a major cause of pancreatitis.

RESEARCH DESIGN AND METHODS

We conducted a retrospective cohort study using a large, geographically diverse U.S. health care claims database. Eligible patients (>or=18 years) were enrolled for at least 12 continuous months (1999-2005), with no incident events of pancreatitis or biliary disease during that 1 year baseline period. ICD-9 codes and prescription data were used to identify patients with type 2 diabetes; ICD-9 codes were also used to identify cases of pancreatitis and biliary disease. Overall, 337,067 patients with type 2 diabetes were matched on age and sex with 337,067 patients without diabetes. Incidence rates of disease and 95% CI were calculated per 100,000 person-years of exposure.

RESULTS

The type 2 diabetic cohort had a 2.83-fold (95% CI 2.61-3.06) greater risk of pancreatitis and 1.91-fold (1.84-1.99) greater risk of biliary disease compared with the nondiabetic cohort. Relative to patients of corresponding age without diabetes, younger type 2 diabetic patients had the highest risk of pancreatitis (<45 years: incidence rate ratio [IRR] 5.26 [95% CI 4.31-6.42]; >or=45 years: 2.44 [2.23-2.66]).

CONCLUSIONS

These data suggest that patients with type 2 diabetes may have an increased risk of acute pancreatitis and biliary disease.