Why patients visit their doctors: assessing the most prevalent conditions in a defined American population

Abstract

Objective: To describe the prevalence of nonacute conditions among patients seeking health care in a defined US population, emphasizing age, sex, and ethnic differences.

Patients and methods: The Rochester Epidemiology Project (REP) medical records linkage system was used to identify all residents of Olmsted County, Minnesota, on April 1, 2009, who had consented to review of their medical records for research (142,377 patients). We then electronically extracted all International Classification of Diseases, Ninth Revision codes noted in the records of these patients by any health care institution between January 1, 2005, and December 31, 2009. We grouped International Classification of Diseases, Ninth Revision codes into clinical classification codes and then into 47 broader disease groups associated with health-related quality of life. Age- and sex-specific prevalence was estimated by dividing the number of individuals within each group by the corresponding age- and sex-specific population. Patients within a group who had multiple codes were counted only once.

Results: We included a total of 142,377 patients, 75,512 (53%) of whom were female. Skin disorders (42.7%), osteoarthritis and joint disorders (33.6%), back problems (23.9%), disorders of lipid metabolism (22.4%), and upper respiratory tract disease (22.1%, excluding asthma) were the most prevalent disease groups in this population. Ten of the 15 most prevalent disease groups were more common in women in almost all age groups, whereas disorders of lipid metabolism, hypertension, and diabetes were more common in men. Additionally, the prevalence of 7 of the 10 most common groups increased with advancing age. Prevalence also varied across ethnic groups (whites, blacks, and Asians).

Conclusion: Our findings suggest areas for focused research that may lead to better health care delivery and improved population health.

Figure 1

Prevalence (per 100 population) of the 10 most prevalent disease groups in five broad age categories and for all ages combined (lower right panel). Prevalence figures were age and sex standardized (when applicable). Prevalence in both sexes is shown with white bars, prevalence in men is shown with blue bars, and prevalence in women is shown with red bars.

Figure 2

Age-specific prevalence (per 100 population) of the 15 most prevalent disease groups in men (blue line) compared to women (red line). The 15 panels are presented in decreasing order of overall age- and sex-adjusted prevalence (see Table 1).

Figure 3

Prevalence (per 100 population) of the 10 most prevalent disease groups by ethnic category. Prevalence figures were standardized by age and sex (when applicable). Prevalence in whites is shown with white bars, prevalence in blacks is shown with black bars, and prevalence in Asians is shown with green bars.