Identifying phenotypes and factors impacting outcomes in older adults with asthma: A research protocol and recruitment results

Success in testing research outcomes requires identification of effective recruitment strategies in the targeted population. In this paper, we present the protocol for our NIH-funded study as well as success rates for the various recruitment strategies employed. This longitudinal observational study is: developing a phenotyping algorithm for asthma in older adults, exploring the effects of the asthma phenotype and of volatile organic compounds on asthma control, and developing a predictive model of asthma quality of life. A sub-aim is to characterize barriers to successful medication management in older adults with asthma. Individuals are eligible if they are ≥60 years, have a positive response to at least 1 of 6 asthma screening questions, are non-smokers, and demonstrate bronchodilator reversibility or a positive bronchial challenge test with methacholine. Exclusion criteria are smokers who quit <5 years ago or with a >20 pack year smoking history, and those having other chronic pulmonary diseases. Participants (N = 190) complete baseline pulmonary function testing, questionnaires, sputum induction, skin prick testing, and have blood drawn for Vitamin D and Immunoglobulin E. Home environmental assessments are completed including 24-hr particulate and volatile organic compound measurements. At 9-months post-baseline, home spirometry, medication assessment, and assessment of asthma quality of life and asthma control are assessed. At 18-months post-baseline, home spirometry, completion of baseline questionnaires, and a home environmental assessment are completed. We have employed multiple recruitment efforts including referrals from clinical offices, no-cost media events, flyers, and ads. The most successful efforts have been referrals from clinical offices and media events.