Telephone follow-up after the emergency department visit: experience with acute asthma. On behalf of the MARC Investigators.

STUDY
OBJECTIVE: This study explored how a variety of demographic and illness-related factors were associated with telephone follow-up among patients visiting the emergency department for acute asthma.
METHODS: We performed a prospective cohort study as part of the Multicenter Airway Research Collaboration (MARC). The study was performed at 77 EDs in 22 US states and 4 Canadian provinces. ED patients, ages 2 to 54 years, who presented with acute asthma underwent a structured interview during their visit. Two weeks later, research personnel attempted to contact participants by telephone, using numbers obtained during the ED interview.
RESULTS: A total of 1,847 adult and 1,184 pediatric patients were interviewed in the ED. Of these, 1,308 (71%) adult patients and 1,026 (87%) pediatric patients were successfully reached for 2-week telephone follow-up. Multivariate analyses revealed the factor most strongly related to contact was age, with pediatric patients being 2.5 times more likely to be reached than adults (95% confidence interval 2.0 to 3.2). Also, participants who were black, low in socioeconomic status, lacking a primary care provider, and exposed to tobacco smoke were significantly less likely to have been reached (all P <.001).
CONCLUSION: In contrast to some reports in the literature, telephone contact rates were high. However, successful contact was not equally likely among all patient groups. Although the high contact rates support the feasibility of telephone follow-up of asthmatic patients visiting the ED, the results also act as a reminder of the potential biases that may arise when using telephone contact for clinical, quality assurance, and research reasons.