# Effect of Bypass Policies on Stroke Treatment in a National Sample of Medicare Beneficiaries

> **NIH AHRQ R01** · STANFORD UNIVERSITY · 2021 · $390,626

## Abstract

Project Summary
For a person with stroke symptoms, rapid hospital-based treatment with intravenous alteplase is critical for
superior patient outcomes. To rapidly deliver intravenous alteplase, several counties implemented a bypass
policy that requires paramedics to bypass the local emergency departments and directly route patients to
stroke centers. However, scientific evidence that the policy results in effective, higher quality and equitable
care to stroke patients is limited. Our proposed study will test policy's effect on intravenous alteplase use, 30-
day mortality and short- and long-term functional independence.. If higher benefit is observed, the policy could
be extended to non-policy counties. In our preliminary work (funded by AHRQ K08 HS17965), we used a
before-after design of two counties to test the policy's effect on treatment. Although our work showed higher
treatment in one of the counties the evaluation was limited to two urban counties and did not control for secular
trends. The proposed study will address the above limitations using the following three aims. First, we will
examine if the bypass policy leads to increase in countywide intravenous alteplase use, mortality and short-and
long term functional independence. For this analysis, we will leverage on the natural experiment that happened
in the US in which counties implemented the policy at different times during an eight-year period (2006-2013).
We will identify 896 counties with the policy and match them 1792 counties without the bypass policy (total n
=2688) and use a difference-in-differences approach to examine the effectiveness of the policy. Second, we
will examine if county factors (e.g., variation in policy components, urban/suburban/rural counties) are
associated with differential effects on outcomes. Third, we will use a multiple case study design, a qualitative
approach to perform in-depth evaluation of 24 counties (72 provider interviews) using interviews, county
surveys and document analysis of the county stroke protocols, to explain the policy effect and identify the
enablers of the policy's effect. We will use an explanatory sequential design, a mixed-methods approach, to
integrate the breath of the quantitative data in aims 1 and 2 with the qualitative data in aim 3 and use a joint
display to present the findings. This study is significant because it will provide an accurate estimate of the
policy effect on patient outcomes. The study also fits with AHRQ' mission on study of healthcare models using
comparative effectiveness methods, quantitative evaluation using large databases, special emphasis on sub-
population such as urban-rural differences and a qualitative examination with the goal of identifying best
practices for the counties.

## Key facts

- **NIH application ID:** 10140314
- **Project number:** 5R01HS026207-03
- **Recipient organization:** STANFORD UNIVERSITY
- **Principal Investigator:** Prasanthi Govindarajan
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** AHRQ
- **Fiscal year:** 2021
- **Award amount:** $390,626
- **Award type:** 5
- **Project period:** 2019-07-01 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10140314

## Citation

> US National Institutes of Health, RePORTER application 10140314, Effect of Bypass Policies on Stroke Treatment in a National Sample of Medicare Beneficiaries (5R01HS026207-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10140314. Licensed CC0.

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