Prematurity and Respiratory Outcomes Program (PROP)

The primary goal of the PROP studies is to identify biomarkers (biochemical, physiological
and genetic) and clinical variables that are associated with and thus potentially predictive
of pulmonary status in preterm infants up to 1 year corrected age. An objective and
validated measure of pulmonary outcome at 1 year does not currently exist. Some promising
measures are in development but not yet ready for use in a multi-center large clinical
study.

Moreover, the burden of chronic respiratory illness on the infants and their families is of
utmost importance. A composite primary outcome of morbidity that is based on serial parental
reports of respiratory symptoms, medications, hospitalizations and dependence on technology
during the first year of life has been developed.

Data collection for the outcome assessment will be based on interviews conducted with the
infant's main caregiver at 3, 6, 9 and 12 months corrected age. The time frame for data
collection is based on questions "since last contact." Numerous epidemiological studies of
asthma have used parental or self report of symptoms, physician-diagnosed asthma and
allergies, or the use of medications (which may abrogate symptoms) as critical outcomes.

Survey items selected for the determination of the primary outcome will be focused on the
following four domains, with any positive response to any element identifying morbidity:

1. Respiratory medications: inhaled bronchodilators, inhaled steroids, systemic steroids,
methylxanthines, diuretics, pulmonary vasodilators

2. Hospitalizations for cardiopulmonary causes: any hospitalization regardless of duration

3. Symptoms: any wheeze, cough without cold

4. Home technology dependence: use of home oxygen, ventilator or continuous positive
airway pressure (CPAP or BiPAP) of any duration since last contact

The primary outcome will be dichotomous, and defined as "No substantial post-prematurity
respiratory disease" or "Post-prematurity respiratory disease." To be classified as having
post-prematurity respiratory disease, infants must have a positive response in at least 1 of
4 morbidity domains during at least 2 separate parental interviews. Quarterly data
collection up to 1 year corrected age will allow us to identify phenotypes based on the
trajectory of post-prematurity respiratory disease and how these different trajectories
predict later lung function and the diagnosis of asthma, if we continue to follow this
cohort of children.

During hospitalization, all centers will obtain samples of tracheal aspirate, urine and
saliva (for DNA extraction) from enrolled infants. At 36 weeks PMA, infants will have
respiratory assessments dependent upon their respiratory status: i) respiratory inductive
plethysmography (RIP) assesses alterations in tidal breathing resulting from reduced lung
compliance and airway obstruction, ii) and a room air challenge (RAC).

Inclusion Criteria:

- Infants who are less than or equal to 7 days old

- Gestational Age (GA) between 23 weeks and 0/7 days and 28 weeks and 6/7 days

Exclusion Criteria:

- Infants who meet any of the following conditions will be excluded from the PROP
cohort:

1. The infant is not considered to be viable (decision made not to provide
life-saving therapies)

2. Congenital heart disease (not including PDA and hemodynamically insignificant
VSD or ASD)

3. Structural abnormalities of the upper airway, lungs or chest wall

4. Other congenital malformations or syndromes that adversely affect life
expectancy or cardio-pulmonary development

5. Family is unlikely to be available for long-term follow-up