Predicting the Diagnosis of Asthma
Condition: Asthma
MeSH terms: Asthma
Study type: Observational

Summary: 
      Despite the development of effective medications for treatment, asthma remains a significant
      contributor of morbidity, mortality, and financial hardship to patients with the disease. An
      estimated 300 million people worldwide have asthma, making it one of the most common chronic
      diseases in the world. Asthma accounts for 250,000 deaths per year worldwide, and 1.7 million
      emergency room visits per year in the United States. Cost of asthma in the United States was
      an estimated $12.7 billion dollars per year in 1998, and the prevalence is increasing. In
      2002, there were 13.9 million outpatient asthma visits to private physician offices and
      hospital outpatient departments, and 484,000 asthma hospitalizations. Children 5-17 years of
      age missed 14.7 million school days, and adults missed 11.8 million work days due to asthma
      in 2002.

      There is no single diagnostic test or symptom that defines asthma. Asthma is a syndrome
      consisting of a constellation of symptoms that include wheeze, cough, shortness of breath,
      and chest tightness. The diagnosis of asthma takes into account history, physical examination
      findings, and objective measures of pulmonary function and markers of inflammation. In many
      cases the diagnosis is not in question, allowing for early recognition and appropriate
      treatment. In other cases, confounding factors makes the diagnosis both challenging and time
      consuming for the physician and the patient. According to the National Asthma Education and
      Prevention Program Expert Panel Report 2, asthma is defined as:

      "a chronic inflammatory disorder of the airways in which many cells and cellular elements
      play a role, in particular, mast cells, eosinophils, T lymphocytes, macrophages, neutrophils,
      and epithelial cells. In susceptible individuals, this inflammation causes recurrent episodes
      of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the
      early morning. These episodes are usually associated with widespread but variable airflow
      obstruction that is often reversible either spontaneously or with treatment. The inflammation
      also causes an associated increase in the existing bronchial hyperresponsiveness to a variety
      of stimuli."

      Airway obstruction and reversibility is measured by pulmonary function testing before and
      after inhalation of a short acting beta agonist. Airway hyperresponsiveness is measured by
      methacholine challenge.

      Estimates of asthma prevalence are generated by the use of written questionnaires in
      epidemiologic studies. , One of the difficulties with reliance on questionnaires is that
      patients often misinterpret the questions or fail to answer the question altogether. In this
      study, a physician will review the questionnaire with the patient in order to clarify each
      question.

      The goal in this study is to evaluate a simplified set of questions that can be easily
      implemented into clinical practice that will predict the presence or absence of asthma.

      Hypothesis

      A simplified questionnaire will predict asthma in adults.

      Study Objectives

      § Primary Objective

      o To evaluate the predictive value of a questionnaire designed to diagnose asthma in adults
    


Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Male or female Females are eligible to participate only if they are currently non-pregnant
        and non-lactating. All premenopausal women will undergo a urine pregnancy test at the
        beginning of the study. Female subjects should not be enrolled if they plan to become
        pregnant during the time of the study.
      
Keywords: ASTHMA