[Factors associated with the use of Emergency Services by the Spanish population in 2017.].

Objective: In modern health systems, emergency services (ES) constitute one of the cornerstones of health care, and they have an essential role in the conception of current health services. The objective of this work was to analyze the effect of sociodemographic characteristics and clinical factors in the use of ES.

Methods: A cross-sectional study was carried out with data from the National Health Survey of Spain (2017) in which 23,089 adults (15 years or more) participated. Three population profiles were defined to analyze visits to ES (young people between 15 and 24 years of age; people aged 75 or over and with multiple pathologies; the general population). Descriptive analyses were performed by population profile, and logistic regression models by population profile and type of service (public hospital, public non-hospital emergency center, and private health center) were applied to evaluate the association between the use of ES and the independent variables.

Results: The percentage of use of ES was higher in the elderly population with multiple pathologies (41.1%) compared to young people (35.7%) and the general population (28.4%). Young people between 15 and 24 years of age used ES more in private centers, and the associated factors were female sex (OR=2.862; 95% CI=1.139-7.191), the use of diagnostic tests (OR=9.401; 95% CI=3.183-27.760), belonging to the lowest social classes (OR=0.207; 95% CI=0.073-0.585) and residing in municipalities with more than 50,000 inhabitants and capitals (OR=5.985; 95% CI=1.143-31.330). The elderly population with multiple pathologies presented a worse state of health than the other two population groups and with a higher demand for ES in public hospitals. In addition, in the elderly population group, the factors associated with the use of ES in public hospitals were having been hospitalized (OR=2.229; 95% CI=1.333-3.730), belonging to the lowest social classes (social class III: OR=2.794; 95% CI=1.154-6.768/social class IV-V- VI: OR=3.767; 95% CI=2.236-6.344), residing in municipalities with more than 50,000 inhabitants and capitals (OR=1.679; 95% CI=1.042-2.704) and having had at least one visit to the PC doctor (OR=0.603; 95% CI=0.396-0.918). Finally, in the general population the variables associated with increased use of ES in public hospitals were age (OR=1.009; 95% CI=1.001-1.016), the highest number of visits to the PC doctor (OR=1.550; 95% CI=1.180-2.170), the use of diagnostic tests (OR=1.480; 95% CI=1.236-1.773) and belonging to the lowest social classes (social class IV-V-VI: OR=1.581; 95% CI=1.229-2.033).

Conclusions: The characteristics associated with the use of ES, both public and private, as well as hospital and extra-hospital, differ according to socioeconomic characteristics and clinical factors. The results of this study suggest redirecting interventions to improve care outcomes, as well as achieving a more rational use of ES.