Original ArticleImpact of COPD on outcomes in hospitalized patients with community-acquired pneumonia: Analysis of the Spanish national hospital discharge database (2004–2013)
Introduction
Community-acquired pneumonia (CAP) is one of the most common infectious cause of hospitalization in developed countries. It has been consistently associated with high morbidity and mortality, being the ninth leading cause of death [1]. Complications of this disease include the development of empyema, sepsis, acute respiratory distress syndrome and respiratory failure [2], [3].
The risk factors for the development of CAP include advanced age and comorbid illnesses [4]. Chronic obstructive pulmonary disease (COPD) is a frequent associated condition in patients hospitalized with CAP. Previous studies have reported rates between 15% and 42%, depending on the population studied [5], [6], [7], [8], [9], [10], [11], [12]. Patients with COPD may have increased susceptibility to pneumonia for several reasons. They have structural disruptions in the lung parenchyma, and frequently receive antibiotic and oral or inhaled steroids treatment. Moreover, this condition is characterized by a chronic inflammation of the respiratory tract and it may be associated with an altered local and systemic immunity [1], [13]. For these reasons, the presentation of CAP in COPD patients may differ from that of patients without this condition [14].
The true impact of COPD in patients hospitalized with CAP is not yet clear [12]. Previous studies of the interaction between both disorders have yielded conflicting results. Some studies have shown that COPD is a risk factor for higher CAP severity [15], whereas others suggest that COPD is a protective factor against the development of complications of CAP [16], [17]. Moreover, the influence of COPD on the mortality of CAP patients remains controversial [18].
In Europe, the admissions due to CAP are increasing, with COPD being a commonly encountered comorbidity [19], [20]. However, to our knowledge, no previous studies have investigated national trends in the incidence, characteristics and outcomes of CAP in people with COPD in Spain.
The analysis of large population databases could provide a “real-world” perspective of the impact of COPD in patients with CAP. In this study, we used national hospital discharge data to examine trends in incidence and outcomes of CAP among patients with or without COPD in Spain from 2004 to 2013. In particular, we analyzed patient comorbidities, diagnostic and therapeutic procedures, pneumonia pathogens and in-hospital outcomes, such as readmission, in-hospital mortality (IHM) and length of hospital stay (LOHS).
Section snippets
Methods
We performed a retrospective, observational study using the Spanish National Hospital Discharge Database (CMBD, Conjunto Mínimo Básico de Datos). This database is managed by the Spanish Ministry of Health, Social Services and Equality and compiles all public and private hospital data, covering > 98% of hospital admissions [22]. The CMBD includes patient variables (sex, date of birth), admission and discharge dates, up to 14 discharge diagnoses, and up to 20 procedures performed during the
Results
During the study period, we identified 901,136 hospital admissions for CAP as primary diagnosis in patients aged ≥ 40 years. 33.25% of them also had a diagnosis of COPD. Fig. 1 shows the incidence of hospitalizations for CAP and its distribution according to sex among patients with and without COPD. In both cases, we found a significant increase in incidence over time from 1344 cases per 100,000 inhabitants in the period 2004–2005 to 1640 in the period 2012–2013 among COPD patients. In patients
Discussion
In this study, we found a significant increase in hospitalization rates for CAP in patients with and without COPD from 2004 to 2013. These results are in agreement with those registered by other authors [27], [28]. Among the possible explanations that may justify these findings are, more low-severity cases are presenting to hospital and being admitted and ageing population [28], [29], [30]. We also demonstrated that readmissions for CAP increased over time in patients with and without COPD and
Conflict of interest statement
The authors do not have any commercial or other association that might pose a conflict of interest.
Acknowledgements
This study was funded by the FIS (Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III) co-financed by the European Union through the Fondo Europeo de Desarrollo Regional (FEDER, “Una manera de hacer Europa”)—Health Research Fund, grants no. PI13/00118 and PI16/00564, and by the Grupo de Excelencia Investigadora URJC-Banco Santander No. 30VCPIGI03: Investigación traslacional en el proceso de salud—enfermedad (ITPSE).
References (52)
- et al.
Treatment failure in community-acquired pneumonia
Chest
(2007) - et al.
Prognosis in patients with pneumonia and chronic obstructive pulmonary disease
Arch Bronconeumol
(2005) - et al.
Epidemiology of community-acquired pneumonia in adult patients at the dawn of the 21st century: a prospective study on the Mediterranean coast of Spain
Clin Microbiol Infect
(2005) - et al.
Characteristics of community-acquired pneumonia in patients with chronic obstructive pulmonary disease
Respir Med
(2007) - et al.
Community-acquired pneumonia in patients with and without chronic obstructive pulmonary disease
J Inf Secur
(2009) - et al.
Risk factors for community-acquired pneumonia diagnosed by general practitioners in the community
Respir Med
(2000) - et al.
Pulmonary complications of pneumococcal community-acquired pneumonia: incidence, predictors, and outcomes
Clin Microbiol Infect
(2012) - et al.
A new method of classifying prognostic comorbidity in longitudinal studies: development and validation
J Chronic Dis
(1987) - et al.
Nationwide trends in pneumonia hospitalization rates and mortality, Denmark 1997–2011
Respir Med
(2014) - et al.
The role of noninvasive positive pressure ventilation in community-acquired pneumonia
Crit Care
(2015)