A national survey of adult asthma prevalence by urban-rural residence U.S. 2005.

OBJECTIVES

We analyzed national data to estimate asthma prevalence among U.S. adults by urban-rural residence and to determine the relative contributions of sociodemographic and health behavior characteristics on the probability of reporting asthma.

METHODS

We linked the 2005 Behavioral Risk Factor Surveillance System (BRFSS) to Urban Influence Codes (UICs), categorizing respondents into four urban-rural groups: metropolitan, adjacent metropolitan, micropolitan, and remote. BRFSS collects health data from all 50 states. UICs classify respondent's county as urban or rural based on population size and proximity to metropolitan areas. We calculated asthma prevalence estimates and generated odds ratios (ORs) for the probability of reporting asthma.

RESULTS

Overall asthma prevalence (7.9%; 95%CI = 7.73-8.08) was not statistically different (p = 0.28) by urban-rural residence. After adjusting for selected characteristics, adjacent metropolitan (OR = 0.96; 95%CI = 0.90-1.02) and remote (OR = 0.95; 95%CI = 0.85-1.05) residents were less likely--and micropolitan (OR = 1.04; 95%CI = 0.93-1.16) residents were more likely--to report asthma compared with metropolitan residents; but confidence intervals included null.

CONCLUSIONS

Asthma prevalence is as high in rural as in urban areas. Certain demographic, behavioral, and health care characteristics unique to place of residence might affect asthma prevalence. Because these results substantially change our understanding of asthma prevalence in rural areas, further investigation is needed to determine geographic-related risk factors.