[Epidemiological features of comorbidity and its influence on the use of health services from Health Survey Madrid 2007, Spain].

Background: The accumulation of chronic conditions in a same patient is increasingly more frequent for which is becoming a problem of public health. The objectives of this study are to describe the prevalence of comorbidity in the population, its epidemiological characteristics and its influence in the utilization of health services from the Regional Health Survey of Madrid (ERSM2007) and to compare two indicators of comorbidity.

Methods: Cross-sectional study. The ERSM2007 was analyzed (n=12.190 over 15 years old). Two indicators were developed: the presence of 2 or more chronic conditions (PC) and the existence of 2 or more affected clinical categories according to a definition of comorbidited patient (PP). Other variables analyzed were: sex, age, social class, education, body mass index, physical activity, alcohol and tobacco consumption, and the utilization of health services. A descriptive analysis was carried out, bivariate and multivariate by means of logistic regression with odds ratios (OR) and confidence intervals of 95%.

Outcomes: The prevalence of comorbidity measured with PC was 23.7% in men and 37.3% in women and with PP was 5.4% and 8.2% respectively. Comorbidity increased with age, with low educational level (OR=2.0; 1.4-2.8, in women without or with primary studies regarding university degree), with obesity (OR=2.6; 1.9-3.3, in obese women with regard to normal weighted women), and with the previous alcohol and tobacco consumption. The highest association was observed between PP and hospitalization (OR=4.1; 3.0-5.5 in men and OR=3.3; 2.6-4.3 in women).

Conclusions: The prevalence of comorbidity was higher in women, in older people, with smaller level of studies or in more disadvantaged social classes. Comorbidity was associated with the obesity and with consumption of tobacco or alcohol. The utilization of the healthcare services enlarged with the comorbidity. These indicators can be complementary, because of their differential association with each healthcare level.