Evaluating Asthma Exacerbation-induced Changes in Lung Function With a Home-based Spirometer

Asthma is a common chronic illness and significant expense to our healthcare system. Asthma
affects nearly 25 million Americans, including 10% of U.S. adolescents. Teenagers are one of
the most difficult groups to engage in self-management of chronic health problems like asthma
and are at greater risk of poorly controlled asthma compared to younger children. Up to 80%
of children with asthma are non-adherent to their controller medications, often due to lack
of parent or child-perceived need or beneficial effects of these medications. Adolescents may
have a higher threshold for initiating rescue treatment due to the perceived normalcy of
asthma symptoms and frequently under-report symptoms to parents and healthcare providers.

Poor perception of asthma symptoms leads to overestimation of asthma control. Defining well
controlled versus poorly controlled asthma is highly dependent on self-reported asthma
symptoms. Up to half of patients with severe asthma symptoms report well controlled asthma.
Many have low expectations of asthma control and have adapted to the disease so much so that
they no longer perceive their limitations. Inaccurate self-reported data can be problematic
in studies evaluating the impact of environmental factors or the efficacy of asthma
treatments. An objective measure of asthma impairment is pulmonary function testing performed
by spirometry. Ready access to a conventional spirometer is not always realistic in clinical
care or research settings. The investigators propose integrating technology-based tools that
leverage on the high rates of smartphone use among youth to identify early signs of
deteriorating asthma control.

The VitalFlo spirometer is a compact, portable, home-based spirometer approximately the size
of an inhaler that pairs with a smartphone app. The device uses an energy conserving turbine.
Exhaled air flow causes the turbine to rotate, generating a voltage analogous to the rate of
air flow across the turbine. The spirometer measures Forced expiratory volume in 1 second
(FEV1), or the volume of air that is exhaled in the first second. The device prompts the user
to perform a minimum of three expiratory maneuvers in and records the best of the three
maneuvers. The information generated is collected on a microprocessor and then transmitted by
a low power Bluetooth radio to the VitalFlo App (password protected) on the user's iPhone.
The user is alerted, by the App, if their expiratory effort is inadequate (such as early
termination of exhalation) and is provided coaching for proper technique. The data is then
transmitted to a HIPAA-compliant cloud database. Participants will receive a survey after
each time they measure lung function to gather information about any asthma symptoms they are
experiencing. Investigators will ask that they use the VitalFlo spirometer prior to using
albuterol for symptoms if possible. VitalFlo will also track, via cloud databases, outdoor
temperature, humidity, air quality, and pollen counts: all environmental factors that can
influence asthma symptoms. Routine calibration is not needed. The eventual goal of VitalFlo
use is to identify drops in lung function preceding asthma symptoms to allow persons with
asthma to intervene with rescue medications early in hopes of preventing progression to a
more serious exacerbation of asthma ("red zone") requiring healthcare utilization, such as
emergency care or hospitalization.

This is a prospective single arm intervention study of 12-21 year olds with persistent
asthma. Participants will be given the VitalFlo spirometer after receiving instruction on
proper use of the device. The participants will also receive an iPhone 5S (without SIM card)
loaded with the VitalFlo app. Participants will be asked to use the VitalFlo spirometer at
least twice daily (in the morning between 6am and 10am and in the evening between 6am and
10pm) and whenever rescue medication (albuterol) is administered or the participant feels
symptoms of asthma (such as cough, wheezing, or shortness of breath) in order to document
lung function. Pulmonary function testing is known to show diurnal variability. Investigators
will use the morning and evening measurements to calculate the mean FEV1 for the day. After
performing the spirometry maneuver, the user will be prompted to answer questions about their
asthma symptoms. The lung function measurements and responses to the questions will be
transmitted to a cloud-based HIPAA-compliant database and will be available for the
investigators to download. Changes in lung function will be matched to subject-reported
asthma symptoms and/or albuterol use.

Inclusion Criteria:

1. Ages 12 to 21 years, inclusive, of both genders

2. Physician diagnosis of persistent asthma or symptoms consistent with persistent asthma
based on NHLBI Expert Panel Review 3 guidelines for diagnosis and management of
asthma.

3. Current use of a controller therapy such as an inhaled corticosteroid (ICS), ICS in
combination with long-acting beta agonist (LABA), or leukotriene receptor antagonist
(LTRA).

4. A history of at least one asthma exacerbation requiring oral corticosteroids (OCS) in
the past 12 months.

5. Wireless internet access in the participant's home

Exclusion Criteria:

1. Systemic corticosteroid-dependent asthma (i.e. people who take oral steroids such as
prednisone daily for asthma control).

2. Pulmonary disease other than asthma that in the opinion of investigators may affect
the interpretation of spirometry data, including but not limited to vocal cord
dysfunction, restrictive lung disease, or cystic fibrosis.

3. Inability to perform spirometry.

4. History of spirometry-induced bronchoconstriction.

5. Pregnancy or nursing a baby.