The burden of undertreatment and non-treatment among patients with non-valvular atrial fibrillation and elevated stroke risk: a systematic review

OBJECTIVE

Global treatment guidelines recommend treatment with oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and an elevated stroke risk. However, not all patients with NVAF and an elevated stroke risk receive guideline-recommended therapy. A literature review and synthesis of observational studies were undertaken to identify the body of evidence on untreated and undertreated NVAF and the association with clinical and economic outcomes.

METHODS

An extensive search (1/2010-4/2020) of MEDLINE, the Cochrane Library, conference proceedings, and health technology assessments (HTAs) was conducted. Studies must have evaluated rates of nontreatment or undertreatment in NVAF. Nontreatment was defined as absence of OACs (but with possible antiplatelet treatment), while undertreatment was defined as treatment with only antiplatelet agents.

RESULTS

Sixteen studies met our inclusion criteria. Rates of nontreatment for patients with elevated stroke risk ranged from 2.0-51.1%, while rates of undertreatment ranged from 10.0-45.1%. The clinical benefits of anticoagulation were reported in the evaluated studies with reductions in stroke and mortality outcomes observed among patients treated with anticoagulants compared to untreated or undertreated patients. Adverse events associated with all bleeding types (i.e. hemorrhagic stroke, major bleeding or gastrointestinal hemorrhaging) were found to be higher for warfarin patients compared to untreated patients in real-world practice. Healthcare resource utilization was found to be lower among patients highly-adherent to warfarin compared to untreated patients.

CONCLUSIONS

Rates of nontreatment and undertreatment among NVAF patients remain high and are associated with preventable cardiovascular events and death. Strategies to increase rates of treatment may improve clinical outcomes.

The IMPact of untReated nOn-Valvular atrial fibrillation on short-tErm clinical and economic outcomes in the US Medicare population: the IMPROVE-AF model

BACKGROUND

Despite treatment guidelines recommending the use of oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and moderate to high risk of stroke (CHA₂DS₂-VASc score ≥1), many patients remain untreated. A study conducted among Medicare beneficiaries with AF and a CHA₂DS₂-VASc score of ≥2 found that 51% of patients were not prescribed an OAC despite being eligible for treatment. When left untreated, NVAF poses an enormous burden to society, as stroke events are estimated to cost the US healthcare system about $34 billion each year in both direct medical costs and indirect productivity losses. This research explored the short-term clinical implications and budget impact (BI) of increasing OAC use among Medicare beneficiaries with NVAF.

METHODS

A decision-analytic model was developed from the payer and societal perspectives to estimate the impact of increasing treatment rates among Medicare-eligible NVAF patients with a moderate-to-high risk of stroke over 1 year. Results of the model compared (1) a base case scenario using literature-derived rates of OAC use, and (2) a hypothetical scenario assuming an absolute 5% increase in overall OAC use. Clinical outcomes included the incremental annual number of ischemic stroke, hemorrhagic stroke, and gastrointestinal bleeding events, and stroke-related deaths. Economic outcomes included incremental annual and per-member per-month (PMPM) direct medical costs for the payer perspective and the incremental sum of annual direct medical and indirect costs from productivity loss and caregiver burden for the societal perspective.

RESULTS

In total, 1.95 million Medicare patients with NVAF were estimated to be treated with OACs in the base case (3.8% of beneficiaries). In the hypothetical scenario analysis, nearly 200,000 more patients were treated resulting in 3,705 fewer ischemic strokes, 14 fewer gastrointestinal bleeds, 141 more hemorrhagic strokes, and 175 fewer deaths. The total incremental BI was $399.16 million ($0.65 PMPM) from the payer perspective and $377.10 million from the societal perspective due to indirect cost savings ($22.06 million).

CONCLUSION

Our findings suggest that increased overall OAC use has a positive clinical benefit on the annual number of ischemic stroke events and deaths avoided in the Medicare population, while maintaining a modest increase in the overall BI to the Medicare system.

Correlates of accelerometry non-adherence in an economically disadvantaged minority urban adult population

OBJECTIVES

The purpose of this study was to examine socio-demographic and psychosocial correlates of non-adherence to an accelerometry protocol in an economically disadvantaged urban population.

DESIGN

Cross-sectional study.

METHODS

We analyzed 985 New York City adult participants aged 18-81 years from the Physical Activity and Redesigned Community Spaces (PARCS) study. Participants were asked to wear a hip-worn ActiGraph GT3X-BT accelerometer for one week. Adherent accelerometer wear was defined as ≥3 days of ≥8 h/day of wear over a 7-day period and non-adherent accelerometry wear was defined as any wear less than adherent wear from returned accelerometers. Examined correlates of adherence included sociodemographic and psychosocial characteristics (e.g., general physical/mental health-related quality of life, self-efficacy for exercise, stress, sense of community/neighborhood well-being, and social cohesion).

RESULTS

From the total sample, 636 (64.6%) participants provided adherent wear and 349 (35.4%) provided non-adherent wear. In multivariable analysis, younger age (odds ratio [OR] = 0.63, 95% confidence interval [CI]: 0.53-0.75), poorer health-related quality of life (OR = 0.80, 95% CI: 0.65-0.98 for physical health and OR = 0.77, 95% CI: 0.62-0.94 for mental health), lower sense of community (OR = 0.79, 95% CI: 0.62-1.00) and current smoking status (OR = 1.97, 95% CI: 1.35-2.86) were associated with non-adherent wear.

CONCLUSIONS

Non-adherent wear was associated with younger age, smoking, and lower self-reported physical/mental functioning and sense of community. This information can inform targeted adherence strategies to improve physical activity and sedentary behavior estimates from accelerometry data in future studies involving an urban minority population.

The Physical Activity and Redesigned Community Spaces (PARCS) Study: Protocol of a natural experiment to investigate the impact of citywide park redesign and renovation

BACKGROUND

The built environment plays a critical role in promoting physical activity and health. The association between parks, as a key attribute of the built environment, and physical activity, however, remains inconclusive. This project leverages a natural experiment opportunity to assess the impact of the Community Parks Initiative (CPI), a citywide park redesign and renovation effort in New York City, on physical activity, park usage, psychosocial and mental health, and community wellbeing.

METHODS

The project will use a longitudinal design with matched controls. Thirty intervention park neighborhoods are socio-demographically matched to 20 control park neighborhoods. The study will investigate whether improvements in physical activity, park usage, psychosocial and mental health, and community wellbeing are observed from baseline to 3 years post-renovation among residents in intervention vs. control neighborhoods.

DISCUSSION

This study represents a rare opportunity to provide robust evidence to further our understanding of the complex relationship between parks and health. Findings will inform future investments in health-oriented urban design policies and offer evidence for addressing health disparities through built environment strategies.