# Veterans Affairs Study of a Real-World Inhaler Delivery Device Transition on Climate and Health Outcomes (VA-SWITCH)

> **NIH VA I01** · VETERANS HEALTH ADMINISTRATION · 2024 · —

## Abstract

PROJECT ABSTRACT
Background. Combination inhaled-corticosteroid/long-acting beta-agonist (ICS/LABA) inhalers are a mainstay
for controlling respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD).
These inhaled medications can be delivered to the patient with a metered-dose inhaler (MDI) or a dry-powder
inhaler (DPI). Although the active ingredients of MDI and DPI inhalers are similar, the mode of drug delivery is
different, and there are limited real-world data on their comparative effectiveness. Additionally, MDIs have a
disproportionate environmental toll because they use hydrofluorocarbon aerosol propellants with high global
warming potential. A global phase-down of hydrofluorocarbons to reduce greenhouse gas emissions will likely
result in disruptions to the inhaler aerosol market, further underscoring the importance of developing evidence-
based guidelines to inform clinical decision-making. A 2021 Veterans Health Administration (VHA) national
formulary change provides a unique opportunity to assess both the clinical outcomes and the net
environmental impacts of a switch from MDI to DPI inhalers in a national cohort of adults with a high burden of
respiratory disease. Specific Aims: (A1) Test the real-world clinical effectiveness of metered-dose vs dry-
powder ICS/LABA controller inhaler therapy. (A2) Identify patient and facility factors associated with successful
conversion from MDI to DPI controller therapy. (A3) Estimate the greenhouse gas emissions avoided under a
variety of inhaler prescribing scenarios. Impact: Our results will assess the impact of the 2021 VHA formulary
change on 181,524 Veterans impacted by the 2021 VHA formulary change and inform optimal inhaler
prescribing to maximize control of common respiratory diseases while minimizing the environmental impact of
care. Innovation: Our study is innovative because it leverages a large natural experiment (2021 VHA
formulary change) and addresses under-studied topics (real-world clinical effectiveness of MDI vs DPI therapy;
the climate impact of healthcare). Methods: In a national cohort of 181,524 patients switched from metered-
dose to dry-powder ICS/LABA under the 2021 VHA formulary change, we will use a within-person study design
to test the clinical effectiveness of metered-dose vs dry-powder ICS/LABA therapy. Clinical outcomes will
include albuterol fills, prednisone fills, and healthcare utilization. We will identify patient and facility factors
associated with successful conversion from MDI to DPI controller therapy using a sequential mixed methods
study design. We will complete life-cycle assessments to quantify the environmental impact of inhalers on the
VHA formulary; calculate the greenhouse gas emissions averted by the VHA formulary change; and estimate
the greenhouse gas emissions that could be avoided under a variety of scenarios for optimizing inhaler
therapy.

## Key facts

- **NIH application ID:** 10748063
- **Project number:** 1I01HX003774-01
- **Recipient organization:** VETERANS HEALTH ADMINISTRATION
- **Principal Investigator:** Hallie Christine Prescott
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2023-10-01 → 2027-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10748063

## Citation

> US National Institutes of Health, RePORTER application 10748063, Veterans Affairs Study of a Real-World Inhaler Delivery Device Transition on Climate and Health Outcomes (VA-SWITCH) (1I01HX003774-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10748063. Licensed CC0.

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