Tucson Epidemiology Study of Chronic Obstructive Lung Diseases

BACKGROUND: The Tucson Epidemiology Study of Chronic Obstructive Lung Diseases had been supported by the Specialized Center of Research (SCOR) mechanism since 1971. The SCOR mechanism was instituted to advance basic knowledge and to generate the most effective techniques and methods of clinical management and prevention. In 1970, the chronic obstructive lung diseases (COLD) of bronchitis, emphysema, and asthma were the tenth leading cause of death in the United States. At that time United States mortality from emphysema had been increasing at the rate of 20-25 percent per year. In 1969 the death rate for COLD as a whole was 15.6 per 100,000 and that rate was considered to be only about one-half of all those deaths in which COLD was either an underlying or an important contributory cause. By 1986 COLD had risen to be the fifth leading cause of death in the United States with a death rate of 31.3 per 100,000. By 1972 many prevalence surveys had been conducted in the United States and abroad on specific subgroups of populations. At that time, most longitudinal studies were limited in the scope of examinations conducted, dealt with restricted age groups, and conducted few studies of familial concordance of diseases. The Tucson study was designed to include a wide age span, family units, and a variety of features relating to reversible or irreversible obstructive lung disease. Studies have provided evidence relating acute lower respiratory tract illnesses in the first few years of life to the development of chronic lung disease in later life. Epidemiologic studies have demonstrated that geographic areas with high morbidity and mortality rates due to chronic obstructive lung disease among adults are also likely to show a high incidence of respiratory illness among children. A number of risk factors may be associated with lower respiratory tract illness in children. Some studies suggested that familial or genetic factors may predispose certain children to respiratory disorders early in life. Family size, viral and bacterial infections, allergic reaction, air pollution, gas stoves, formaldehyde, and passive smoking have all been implicated. Research was needed on the interrelationships of potential risk factors and lower respiratory tract infections in producing chronic respiratory disease. DESIGN NARRATIVE: The Tucson Study of Chronic Obstructive Lung Diseases was longitudinal in design. By 1986, nine surveys had been completed on 70 percent of the same population surveyed at baseline in 1972. Data collected in the surveys included basic standardized questionnaires and maximum expiratory flow volume (MEFV) curves using the same pneumotachograph equipment. Additional questionnaires were included on smoking, medical and occupational history, socio-economic characteristics, and height and weight measurements. Blood was sampled for studies of alpha-1-antitrypsin level. Several surveys included allergy skin testing, blood pressure, and anthropometric measurements. Studies of the 504 out-migrants continued since 1982. Twelve surveys were planned to insure a follow-up of at least 15 years on all adults. Funding represented approximately 26 percent of the dollars of the Specialized Center of Research in Chronic Diseases of the Airways (P5OHL14136) used to support the Tucson Study. Childrens' Respiratory Study of Tucson was also longitudinal in design and assessed the role of infectious, physiologic, immunologic, allergic, genetic, environmental, and familial factors in the development of acute and chronic lower respiratory tract illnesses in childhood. Enrollment of the study population and their families occurred between May 1980 and October 1984. Healthy infants were enrolled within a few days of birth, at which time baseline data were collected. Cord and 9-month bloods were evaluated for a number of immunologic tests. In the first few months of life, prior to any lower respiratory tract illnesses, a subset of the population underwent pulmonary function testing. During lower respiratory tract illness, specimens were obtained for viral, chlamydial, and mycoplasma cultures and tests. Environmental factors evaluated included passive smoking, number of siblings, overcrowding, and air pollution. Data collection was continued on the children and their family members over the years. The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.