Longitudinal Study of Children With a Chronic Cough and the Impact of Gastroesophageal Reflux

Introduction

1.1. Cough

Cough is both an important physiologic component of lung defense and a cardinal indicator of disease. It is the second most common reason for medical visits during childhood. The metamorphosis of coughing from a normal to a pathologic event occurs along a gradient that includes frequency, character and duration.1 When considered with the age of the child, each of these characteristics informs decisions about diagnosis and management. For those with chronic cough, defined as cough lasting for more than 3 weeks2, the differential diagnosis is broad, including self-limited, persistent, and chronic diseases. An isolated cough in an otherwise healthy child may be secondary to recurrent viral bronchiolitis, post-infectious etiology, pertussis, cough variant asthma, post-nasal drip, or may be psychogenic in origin. Possible significant underlying causes of cough include cystic fibrosis, primary ciliary dyskinesia, immune deficiencies, chronic bronchitis, retained foreign bodies, airway lesions, tracheomalacia, or extrinsic compression of the airway3. Gastroesophageal reflux (GER) is also included in the differential diagnosis of chronic cough in children.

Specific Aims

1. To conduct a randomized , placebo controlled trial to test the null hypothesis that treatment of children with a chronic cough of more than 3 weeks' duration is not effected by medicine designed specifically to treat gastroesophageal reflux (GER) and its extraesophageal manifestations.
2. To utilize the "gold standard population"(identified through the protocol outlined in specific aim number 1) to use logistic regression analysis to identify which tests currently employed to identify GER can be employed within a statistically sound predictive model.