Location and Timing of Inhaler Use, Exacerbations and Physical Activity in Chronic Obstructive Pulmonary Disease

Objectives: This study tested the usefulness of a GPS-enabled inhaler to study the associations between air pollution, chronic obstructive pulmonary disease (COPD) exacerbations, and physical activity. Specific aims are 1) test the feasibility of using the inhaler sensor to measure worsening symptoms and exacerbations, 2) characterize physical activity in patients with COPD, and 3) examine whether environmental factors can be linked to mild exacerbations measured by the inhaler sensor.

Research Design: A 12-week observational, longitudinal pilot study of patients with COPD.

Methodology: Participants recruited at VA Puget Sound performed spirometry and completed baseline questionnaires. An inhaler sensor was placed on their albuterol inhaler to record the time and location of inhaler actuation throughout the three month follow-up. Each month participants answered questions regarding their breathing symptoms and physical activity. Physical activity was measured by self-report using a weeklong Physical Activity Checklist. A pedometer was worn at three 7 day periods. Public use air pollution and meteorological data will be linked to the inhaler data. We will compute descriptive statistics for all measures, including sociodemographics, exacerbation rates, inhaler use, air pollution exposures and physical activity levels. In addition, a time series analysis will be used to test if the frequency of inhaler use is associated with higher levels of daily air pollution.

Inclusion criteria

• FEV1/FVC<0.70
• FEV1 >30% and <FEV1<65% predicted
• Participants must be able to walk without assistance
• No plans to leave the study area during the 12-week study period
• Non-smoker and not live with someone who smokes
• No history of asthma
• Use a short-acting bronchodilator