Trends in common rhinologic illnesses: analysis of U.S. healthcare surveys 1995-2007

Background: Up to date information on the epidemiology of, and recent changes in, allergic rhinitis (AR), acute sinusitis (AS), and chronic sinusitis (CS) office and emergency department (ED) visits and prevalence is sparse. Current studies may quote data that is outdated or based solely on patient self-report. The purpose of this work was to describe basic epidemiologic measures of office and ED visits for AR, AS, and CS between 1995 and 2007, and to analyze trends over time for each of these diseases.

Methods: Survey data from the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) were examined from 1995 to 2007 for AR, AS, and CS by International Classification of Diseases, 9th edition (ICD-9) code, using the STATA statistical package survey-specific commands to obtain appropriate estimates. Subgroup analyses were performed for age, sex (male and female), race (white and black), and region. Logistic regression was used in order to investigate the predictors mentioned above in a multivariate model, and to analyze trends over time.

Results: For AR, there has been an increase in visits in both the office and ED settings between 1995 and 2007. For CS, there has been a decrease in the proportion of both office and ED visits over this time period, as well as in the visit rate. For CS office visits, there has been an increase in the total number of visits. For AS, descriptive data show an increase in both the total number and proportion of office visits, but logistic regression did not validate these findings. There has been a decrease in ED visits for AS. Age, sex, race, and region have differing effects on each these diseases, and these factors appear to be setting-dependent as well.

Conclusion: While regression did not show statistically significant changes for AS, the odds ratio along with the number and proportion of visits suggests that an increase for AS at a similar rate of AR is possible, lending support to a relationship between these disease processes. The relatively small increase in the prevalence of AR in the United States when compared with the worldwide increase in developing countries suggests that the hygiene theory and environmental factors play a leading role in the development of AR. The relative decrease in the prevalence of CS may be the result of successful medical therapy with the increased use of nasal steroids and nasal saline irrigation.