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Journal of Thoracic Disease logoLink to Journal of Thoracic Disease
. 2017 Mar;9(3):636–645. doi: 10.21037/jtd.2017.03.34

One-year and long-term mortality in patients hospitalized for chronic obstructive pulmonary disease

María-Teresa García-Sanz 1,, Juan-Carlos Cánive-Gómez 2, Laura Senín-Rial 3, Jorge Aboal-Viñas 4, Alejandra Barreiro-García 3, Eva López-Val 3, Francisco-Javier González-Barcala 5,6,7,8
PMCID: PMC5394058  PMID: 28449471

Abstract

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. Identifying potentially-modifiable predictors of mortality could help optimize COPD patient management. The aim of this study is to determine long-term mortality following hospitalization due to acute exacerbations of COPD (AECOPD), as well as AECOPD mortality predictors.

Methods

We conducted a retrospective study by reviewing the medical records of all patients admitted with AECOPD in the University Hospital Complex of Santiago de Compostela in 2007 and 2008. In order to identify variables independently associated with mortality, we conducted a multivariate Cox proportional hazard regression analysis including those variables which proved to be significant in the univariate analysis.

Results

Seven hundred and fifty seven patients were assessed. Patient mean age was 74.8 years and males accounted for 77% of all patients. Mean stay was 12.2 days. Three point six percent of all patients required intensive care. As for mortality rates, 1-year mortality was 26.2%, and 5-year mortality was 64.3%. In both scenarios, the most frequent causes of death were respiratory and cardiovascular disorders. Factors independently associated with mortality were older age, hospitalization by internal medicine (IMU), length of stay, the need for mechanical ventilation (MV) or noninvasive mechanical ventilation (NIV), early readmission, and history of atrial fibrillation (AF) and dementia.

Conclusions

In patients with COPD, age, exacerbation severity and comorbidity have long-term prognostic significance.

Keywords: Chronic obstructive pulmonary disease (COPD), exacerbation, hospitalization, long-term mortality

Introduction

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide (1). Recurrent in the course of the disease, acute exacerbations of COPD (AECOPD) worsen baseline symptoms, impair pulmonary function over time and increase the likelihood of new exacerbations (2,3). Initially, increased mortality had been attributed to baseline disease severity. However, recent studies have shown that AECOPD increase short-term and long-term mortality risk, especially those exacerbations requiring hospitalization (4). Other prognostic factors include age, several comorbidities, the need for oxygen therapy at home, previous hospitalization due to AECOPD, exacerbation severity and a number of physiological and laboratory parameters, such as anemia and hypercapnia (5-8). Nevertheless, these factors vary across studies, probably due to differences in analyzed populations, collected variables and statistical methods. Thus, identifying potentially-modifiable predictors of mortality could help optimize both therapeutic strategies and COPD patient management upon discharge.

The aim of this study is to determine long-term mortality following hospitalization due to AECOPD, as well as AECOPD mortality predictors.

Methods

We conducted a retrospective study by reviewing the medical records of all patients admitted with AECOPD in the University Hospital Complex of Santiago de Compostela in 2007 and 2008. Data were retrieved from the hospital database, and included the first admission of all patients admitted to the Internal Medicine (IMU) and Pneumology Units in the study period. The study sample includes 757 patients, whose baseline characteristics, comorbidities and AECOPD characteristics during hospitalization were recorded.

COPD diagnosis and baseline severity were defined following GOLD criteria (9). In those cases with no spirometry available, COPD diagnosis was accepted by consensus of the research team for patients with a smoking history and clinical and radiological characteristics consistent with such diagnostic hypothesis (10-12). Patients who had quitted smoking at least 1 year before the moment of admission were considered former smokers (13). Alcohol users were sorted into four different categories: those consuming over one gram alcohol per day (regular drinkers) (14), those consuming less than one gram alcohol per day (occasional drinkers); those who quitted at least 1 year before (former drinkers) (15) and never drinkers. Comorbidities registered include atrial fibrillation (AF), arterial hypertension (HTN), ischemic heart disease (IHD), cancer, cerebrovascular accident (CVA), dementia, chronic kidney disease (CKD) and liver disease. Comorbidity was assessed with the Charlson Index (16), and categorized into three groups: patients scoring “zero”, “1 or 2”, and “over 2” points, respectively. COPD baseline therapy was noted: short-acting and long-acting beta2-agonist inhalers, oral or inhaled corticosteroids, anticholinergics, theophylline, oxygen therapy and noninvasive mechanical ventilation (NIV) at home. The use of at least 5 mg prednisone per day for at least 3 months in a row was considered chronic steroid therapy (17).

Weekends were defined as the period between Friday midnight and Sunday midnight (18). Early readmission was defined as that occurring within 15 days upon discharge (19).

Vital signs and arterial blood gas values were obtained upon patient arrival to the Emergency Department (ED). In those cases where no blood gas was determined, a record of O2 saturation by pulse oximetry was obtained. Data from the CBC and serum biochemistry tests conducted on the first sample obtained upon arrival to the hospital were recorded. Anemia was defined as per WHO criteria: hemoglobin (Hb) <13 g/dL in males and Hb <12 g/dL in females (20).

Causes of death were retrieved from patient clinical records, both for deaths during the admissions studied and in subsequent admissions. We reviewed the death certificates of patients in doubtful cases, as well as the death certificates of those who died at home. Cause of death was sorted as follows: (I) respiratory causes: AECOPD (ICD-10 DJ440/DJ441), respiratory failure (DJ96) and lower respiratory tract infection (DJ12-DJ18); (II) cardiovascular causes: acute coronary syndrome (ACS) (DI21), heart failure (DI50), CVA (DI61-DI63), and pulmonary embolism (DI26); (III) cancer; (IV) other causes, including septic shock (DR57) and aspiration (DJ69) (21); (V) unknown origin (DR98, DR99).

Ethical approval

All procedures performed in this study were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

As a retrospective study, formal consent is not required.

Statistical analysis

Data obtained were expressed as mean values ± standard deviation (SD) for continuous variables, and as frequencies and percentages for categorical variables. Continuous variables were compared with either Student’s t-test or with Wilcoxon’s test; as for categorical variables, they were compared with the chi-squared and Fisher’s exact tests. In order to identify variables independently associated with 1-year mortality, we conducted a Cox regression including those variables with P≤0.05 in the univariate analysis. We considered statistically significant those variables associated with P<0.05. Data were analyzed with SPSS 15.

Results

Seven hundred and fifty seven patients were assessed; 77% were males and mean age was 74.8 years (SD 11.2). Mean stay was 12.2 days (SD 9.1), and 3.6% of all patients required intensive care. Patient baseline characteristics are shown in Table 1. Acute exacerbation characteristics and complementary test results are shown in Table 2.

Table 1. Patient baseline characteristics.

Characteristics 1-year survival 5-year survival
No [198] Yes [559] P No [485] Yes [269] P
Age (mean ±SD) 78.9 (8.8) 73.3 (11.6) 0.001 77.4 (9.9) 69.9 (11.8) <0.0001
Gender (male), n (%) 154 (77.8) 431 (77.1) 0.800 377 (77.7) 206 (76.6) 0.70
Tobacco use, n (%) 0.600 0.10
   Never smokers 47 (32.4) 127 (29.1) 110 (29.6) 63 (30.1)
   Active smokers 33 (22.8) 111 (25.4) 81 (21.8) 62 (29.7)
   Former smokers 65 (44.8) 199 (45.5) 180 (48.5) 84 (40.2)
OH use, n (%) 0.400 0.70
   Regular drinkers 54 (40.6) 157 (41.6) 127 (39.7) 83 (43.9)
   Occasional drinkers 6 (4.5) 18 (4.8) 14 (4.4) 10 (5.3)
   Never drinkers 22 (16.5) 42 (11.1) 42 (13.1) 22 (11.6)
   Former drinkers 51 (38.3) 160 (42.4) 137 (42.8) 74 (39.2)
GOLD, n (%) 0.001 <0.0001
   I 16 (11.6) 65 (17.9) 39 (12.0) 42 (24.4)
   II 47 (34.1) 159 (43.8) 130 (39.9) 75 (43.6)
   III 4 (2.9) 8 (2.2) 9 (2.8) 3 (1.7)
   IV 71 (51.4) 131 (36.1) 148 (45.4) 52 (30.2)
FEV1 (mean ±SD) 1.3 (1.29) 1.39 (0.94) 0.500 1.34 (1.14) 1.41 (0.84) 0.60
Comorbidities, n (%)
   AF/flutter 64 (32.3) 126 (22.5) 0.006 140 (28.9) 50 (18.6) 0.002
   HTN 114 (57.6) 265 (47.5) 0.010 243 (50.2) 133 (49.4) 0.80
   DM 44 (22.3) 265 (47.5) 0.400 111 (23.0) 73 (27.1) 0.20
   IHD 55 (27.8) 102 (18.3) 0.005 113 (23.3) 44 (16.5) 0.02
   Cancer 32 (16.2) 69 (12.3) 0.100 69 (14.2) 32 (11.9) 0.30
   CVA 27 (13.7) 46 (8.2) 0.020 53 (11.0) 20 (7.4) 0.10
   Dementia 14 (7.1) 19 (3.8) 0.030 29 (6.0) 4 (1.5) 0.004
   CKD 25 (12.7) 40 (7.2) 0.010 55 (11.4) 10 (3.7) <0.0001
   Liver disease 14 (1.8) 38 (5.0) 0.800 35 (7.2) 17 (6.3) 0.60
Charlson, n (%) 0.030 0.003
   0 2 (1.0) 5 (0.9) 4 (0.8) 3 (1.1)
   1–2 57 (28.8) 212 (37.9) 154 (31.8) 114 (42.4)
   >2 139 (70.2) 342 (61.2) 327 (67.4) 152 (56.5)
Baseline therapy, n (%)
   Inhaled Ach 117 (64.6) 305 (60.9) 0.300 284 (63.5) 138 (59.5) 0.30
   SABA 55 (30.6) 175 (35.0) 0.200 144 (32.3) 84 (36.4) 0.20
   LABA 109 (60.6) 284 (56.8) 0.300 260 (58.3) 131 (56.7) 0.60
   Inhaled corticosteroids 114 (63.3) 296 (59.2) 0.300 273 (61.2) 135 (58.4) 0.40
   Theophylline 11 (6.1) 25 (5.0) 0.500 26 (5.8) 10 (4.3) 0.40
   Oral corticosteroids 8 (4.4) 26 (5.2) 0.600 22 (4.9) 12 (5.2) 0.80
   O2 therapy at home 69 (35.0) 127 (22.8) 0.001 144 (29.8) 50 (18.6) 0.001
   NIV at home 16 (8.2) 42 (7.6) 0.700 43 (9.0) 15 (5.6) 0.10
Hospitalization due to AECOPD-previous year, n (%) 66 (33.3) 143 (25.6) 0.030 148 (30.5) 61 (22.7) 0.02
Emergency due to AECOPD-previous year, n (%) 67 (33.8) 217 (38.8% 0.200 192 (39.6) 92 (34.2) 0.10

OH, alcohol; AF, atrial fibrillation; HTN, hypertension; DM, diabetes mellitus; IHD, ischemic heart disease; CVA, cerebrovascular accident; CKD, chronic kidney disease; Ach, anticholinergics; SABA, short-acting beta2 agonists; LABA, long-acting beta2 agonists; NIV, noninvasive ventilation.

Table 2. Characteristics of acute exacerbation (univariate analysis).

Characteristics 1-year survival 5-year survival
NO [198] YES [559] P NO [488] YES [269] P
Weekend admission, n (%) 47 (23.7) 112 (20.0) 0.200 107 (22.1) 51 (19.0) 0.30
Mean stay, n (SD) 16 (1.8) 11 (6.2) <0.0001 13.6 (10.5) 9.8 (5.1) <0.0001
Admission unit, n (%) <0.0001 <0.0001
   Pneumology 118 (22.2) 414 (77.8) 308 (58.1) 222 (41.9)
   Internal medicine 80 (35.6) 145 (64.4) 177 (79.0) 47 (21.0)
Laboratory data
   Hb <12 mg/dL, n (%) 68 (34.3) 89 (16.1) <0.0001 122 (25.4) 35 (13.1) <0.0001
   Platelets 247,755 [105,168] 25,0452 [103,966] 0.700 250,624 [106,384] 247,691 [99,385] 0.70
   Leukocytes 11,695 [5,231] 11,600 [5,622] 0.800 11,569 [5,328] 11,662 [5,834] 0.80
   Glucose 148 [77] 141 [63] 0.200 146 [73] 137 [55] 0.80
   Urea 67.7 (39.2) 66 (36.1) 0.500 66 (38.0) 65 (35.0) 0.70
   Creatinine 1.2 (0.6) 1.1 (0.7) 0.700 1.14 (0.6) 1.15 (0.8) 0.90
   Total protein count 6.4 (0.6) 6.3 (0.7) 0.200 6.4 (0.6) 6.3 (0.7) 0.05
   Albumin 3.8 (2.5) 3.9 (3.7) 0.700 3.9 (4.0) 3.6 (1.8) 0.20
   Fibrinogen 482 (162.8) 243.8 (62.3) 0.300 459 (156.0) 446 (146.0) 0.40
Initial blood gas
   pH 7.4 (0.8) 7.4 (0.8) 0.200 7.4 (0.08) 7.4 (0.07) 0.10
   PCO2 48 (15.5) 46.3 (15.8) 0.200 47.4 (16.1) 45.8 (15.0) 0.10
   PO2 56.3 (14.3) 59 (20.4) 0.100 57 (16.3) 59 (15.0) 0.40
   Bicarbonate 28.7 (5.8) 28.2 (5.6) 0.200 28.4 (5.8) 28.1 (5.4) 0.40
   O2/FiO2 239 (57.2) 244 (62.3) 0.300 244 (61) 238 (59) 0.30
Chest radiograph, n (%)
   pleural effusion 20 (10.1) 83 (14.9) 0.090 66 (13.6) 37 (13.8) 0.90
   Cardiomegaly 51 (25.8) 153 (27.4) 0.600 125 (25.8) 79 (29.4) 0.20
   Atelectasis 14 (7.1) 26 (4.7) 0.200 33 (6.8) 7 (2.6) 0.01
   Bronchiectasis 5 (2.5) 26 (4.7) 0.200 15 (3.1) 16 (5.9) 0.05
   CHF/APE 0 (0) 7 (1.3) 0.100 4 (0.8) 4 (0.8) 0.60
   Pneumonia 14 (7.1) 40 (7.2) 0.900 34 (7.0) 18 (6.7) 0.80
ICU, n (%) 17 (8.6) 10 (1.8) 0.090 22 (4.5) 5 (1.9) 0.05
ICU mean stay 14.7 (12.9) 8 (4.7) 0.0600 13.2 (11.8) 7.8 (5.4) 0.30
NIV, n (%) 39 (19.7) 75 (13.4) 0.0300 82 (16.9) 31 (11.5) 0.04
MV, n (%) 18 (9.1) 9 (1.6) <0.0001 22 (4.5) 5 (1.9) 0.05
Antibiotic therapy, n (%) 178 (89.5) 489 (87.5) 0.300 431 (88.9) 234 (87.0) 0.40
Early readmission, n (%) 19 (10.1) 25 (4.5) 0.005 34 (7.2) 10 (3.7) 0.05
Late readmission, n (%) 87 (43.9) 287 (51.3) 0.070 250 (51.1) 123 (45.7) 0.12

CHF, congestive heart failure; APE, acute pulmonary edema; ICU, intensive care unit; NIV, noninvasive ventilation, MV, mechanical ventilation; Hb, hemoglobin.

Hospital mortality rate was 4.8%, and the most frequent cause of death were respiratory disorders. One-year mortality rate was 26.2%, due to respiratory causes (52%), cardiovascular causes (19.6%), cancer (7.2%), other (18%) and unknown causes (3%). Five-year mortality rate was 64.3%, with the following causes: respiratory (49.1%), cardiovascular (20.1%), cancer (9.7%), other (19.2%) and unknown causes (1.6%). Factors significantly associated with increased mortality within the year following hospitalization for AECOPD included older age (P=0.001), COPD baseline severity (P=0.001), comorbidities such as AF (P=0.006), HTN (P=0.01), IHD (P=0.005), CVA (P=0.02), dementia (P=0.03) and KCD (P=0.01), comorbidity index (P=0.03), and the need for oxygen therapy at home (P=0.001) and hospitalization due to AECOPD the year before the first admission in the study period (P=0.03). Other mortality-related factors were prolonged mean stay (P<0.0001), hospitalization by IMU (P<0.0001), anemia (P<0.0001), and the need for MV (NIV: P=0.03; MV: P<0.0001). Factors associated with 5-year mortality were age (P<0.0001), baseline COPD severity (P<0.0001), AF (P=0.002), IHD (P=0.02), dementia (P=0.004), CKD (P=0.0001), comorbidity index (P=0.003), the need for oxygen therapy at home (P=0.001), hospitalization due to AECOPD the year before (P=0.02), prolonged mean stay (P<0.0001), hospitalization by IMU (P<0.0001), anemia (P<0.0001) or atelectasis (P=0.01), as well as the need for NIV (P=0.04).

Factors independently associated with 1-year mortality in multivariate analysis were older age (HRR 1.05), length of stay (HRR 1.04), the need for MV (HRR 2.68), early readmission (HRR 2.32), and history of AF (HRR 1.54) and dementia (HRR 2.44) (Table 3); those associated with 5-year mortality were older age (HRR 1.04), hospitalization by IMU (HRR 1.41), prolonged mean stay (HRR 1.03), the need for NIV (HRR 1.38), and history of AF (HRR 1.37) and dementia (HRR 2.79) (Table 4).

Table 3. Factors related to 1-year mortality following hospitalization due to AECOPD.

Variables Hazard ratio 95% CI P value
Age 1.05 1.03–1.07 <0.0001
AF 1.54 1.01–2.35 0.0400
Dementia 2.44 1.08–5.49 0.0300
MV 2.68 1.16–6.15 0.0200
Mean stay 1.04 1.02–1.06 <0.0001
Early readmission 2.32 1.30–4.17 0.0050

AECOPD, acute exacerbations of COPD; AF, atrial fibrillation; MV, mechanical ventilation.

Table 4. Factors related to 5-year mortality following hospitalization due to AECOPD.

Variables Hazard ratio 95% CI P value
Age 1.04 1.02–1.05 <0.0001
AF 1.37 1.05–1.78 0.0200
Dementia 2.79 1.55–5.02 0.0010
NIV 1.38 1.03–1.86 0.0300
Mean stay 1.03 1.02–1.04 <0.0001
Admission to IMU 1.41 1.09–1.84 0.0090

AECOPD, acute exacerbations of COPD; AF, atrial fibrillation; NIV, non-invasive ventilation; IMU, Internal Medicine Unit.

Discussion

Mid-term and long-term mortality of patients admitted for AECOPD to our hospital are mainly due to respiratory and cardiovascular causes. Mortality risk factors include older age, length of stay, the need for MV, hospitalization by the IMU, early readmission, AF and dementia.

In our sample, both hospital mortality and one-year mortality rates are similar to those in previous studies (5,7). However, our 5-year mortality rate is lower to that referred by other authors. Chung et al. report a 74% mortality rate following hospitalization due to AECOPD requiring NIV (22), and the rate reported is 76% for patients with AECOPD requiring admission to the ICU (23); 5-year mortality is 73% in the study by Steinmetz (24) and 79% in that by Gudmundsson (21). The difference could be explained by the fact that some of these studies only include patients admitted to the ICU or treated with NIV, probably due to the more severe nature of AECOPD. Thus, they could result in increased mortality in spite of more intensive patient management. However, Gudmundsson’s patients, admitted to Pneumology Units, show higher mortality rates even if younger, and the study by Steinmetz includes both hospitalized patients and outpatients, a priori with apparently less severe exacerbations.

Indications for NIV include respiratory acidosis and severe dyspnea with clinical signs of muscle fatigue or increased work of breathing (10). NIV has been shown to effectively treat respiratory failure from various causes, including AECOPD (25,26). In fact, previous studies and international guidelines on COPD clearly suggest the use of noninvasive ventilation (NIV) as the first-line choice for hospitalized patients with severe AECOPD (10,27-31). However, patients treated with NIV in our study show higher long-term mortality, leaving the impression that these results support the concept that the use of NIV for AECOPD may be a dangerous approach instead of a beneficial one.

Other authors also refer this finding, which could be related to inadequate indication of NIV or to greater exacerbation severity. Greater baseline severity of patients may also influence, as it is the case of those patients not considered subsidiary of MV due to comorbidities and treated with NIV.

Factors such as old age and underlying diseases may influence the decision to intubate or not to intubate some patients, thus assuming a worse prognosis in these cases (32). Besides, patients requiring NIV are known to have poor prognosis (33-35).

Possible reasons to explain our seemingly contradictory results could include: PCO2 high levels, suggesting AECOPD severity; the history of NIV therapy, suggesting higher COPD baseline severity; and a number of indicators of the overall health condition could explain the worse prognosis and the high long-term mortality risk in those patients treated with NIV and admitted for AECOPD (36-40). In our study, over half of all patients with ventilatory support were classified as stage IV in the GOLD classification and ranked high on the Charlson scale. Severe AECOPD may require admission to the ICU and the use of MV, especially with ineffective NIV (41), and subsequent complications due to AECOPD severity or decompensation. So, patient characteristics and the decision to put them or not into particular care seem to influence prognosis, and not NIV per se.

Patients hospitalized for AECOPD with prolonged stay show higher hospital and long-term mortality rates (5,42), possibly due to the contribution by other factors justifying worse prognosis, such as nosocomial infections, thromboembolic disease and decompensation of underlying diseases (43-45). Prolonged stays may help identify frailer patients potentially requiring more careful attention, either due to COPD baseline severity or due to AECOPD severity (46,47). These factors may also contribute to a higher mortality risk (4). In our sample, both anemia and underlying diseases, as well as older age and indicators of higher AECOPD severity, such as admission to the ICU or the need for MV, were predictors of higher long-term mortality, although not all of them were confirmed by multivariate analysis.

According to a recent study, mortality risk increases over time in a 3-year follow-up period for those patients readmitted within the first month after discharge (2). The number of comorbidities, advanced age, respiratory acidosis and the need for NIV are factors directly associated with the probability of early readmission following AECOPD discharge (48,49). These factors were also associated with long-term mortality in our sample.

Admission for AECOPD to the IMU is a long-term mortality risk factor compared to patient admission to the Pneumology Unit. These results seem real in our population, as they are adjusted for multiple factors. However, we cannot exclude potential impacts from other variables not analyzed in our study.

AF and IHD rates were higher in those patients admitted to the IMU. Both diseases are subject to decompensation with the beta2-agonists and the anticholinergics used to treat AECOPD, and complications therefrom could influence mortality (50). The contribution by these factors seems relevant in our patients, as both older age and AF were independently associated with mortality in our multivariate analysis.

Nevertheless, other authors report differences in respiratory disease management outcomes depending on the specialist staff providing the medical care (51,52), which could contribute to greater survival. In a recent study by Wijayaratne et al. (52), 1-year mortality was 10.7% in the General Medicine group, and 6% in that of respiratory specialists. The difference seems relevant, being almost twice as much. However, it was not statistically significant, probably due to the reduced sample size. Other study with asthma patients objectively reports significant differences between specialists and general practitioners (53).

Patients with COPD have a significant prevalence of cognitive impairment (54), and patients with dementia have worse prognosis and shorter life expectancy (55). In spite of these data, little is known regarding how dementia is an additional risk for the worse prognosis of patients with COPD. A recent study has shown that dementia increases the risk of respiratory failure and hospital mortality in patients with COPD (56). Factors accounting for the higher long-term mortality risk could include weight loss and lower BMI as a result of poor diet and various catabolic problems in patients with dementia (57), as well as physical inactivity, deficiency in self-care and bronchial aspiration, which are frequent in these patients and are possible causes of mortality (58).

AF is the most common arrhythmia in the general population (59) and in patients with COPD, and the incidence of AF increases with decreasing FEV1 (60). AF has an adverse impact on COPD prognosis and mortality (61); also, a recent study in patients with AF reported COPD to be independently associated with increased mortality from both cardiovascular and non-cardiovascular causes (62). The mechanism responsible for increased mortality in patients with AF and COPD seems not only related to the shared risk factors, such as tobacco use or age, but rather to thromboembolic events associated with FA and resulting from hypercoagulable states, and increased platelet aggregation, frequent in COPD (63,64), regardless of pulmonary HTN and prescribed treatment for underlying cardiovascular diseases (62). On the other hand, bleeding complications resulting from the use of anticoagulants, frequent in patients with AF and favored by age, comorbidities and polypharmacy, could influence the increased mortality of these patients (65). We have no reason to think the possible causes of higher mortality attributed to AF to differ therefrom in our patients.

Our study shows the prognostic significance of age, those factors related to AECOPD severity and a number of comorbidities for mortality risk. Nevertheless, the results should be interpreted with caution due to limitations, such as the lack of recorded information, inherent to retrospective studies, and the assumption that the information in the files reflects clinical practice. The seemingly high number of never-smokers seems attributable to the fact that tobacco use is underreported in medical records, a rather common problem in our country, as we know from the data in other studies. Thus, patients are not considered smokers if no information on tobacco use has been recorded. Furthermore, as our data come from a single hospital, they might not be generalized to other populations.

In conclusion, long-term mortality rate of COPD patients is high, and patient age, AECOPD severity and a number of comorbidities influence prognosis.

Acknowledgements

The authors thank S. García Sanz for the translation of the manuscript.

Ethical Statement: All procedures performed in this study were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. As a retrospective study, formal consent is not required.

Footnotes

Conflicts of Interest: The authors have no conflicts of interest to declare.

References

  • 1.Liu Y, Croft JB, Anderson LA, Wheaton AG, et al. The association of chronic obstructive pulmonary disease, disability, engagement in social activities, and mortality among US adults aged 70 years or older, 1994-2006. Int J Chron Obstruct Pulmon Dis 2014;9:75-83. 10.2147/COPD.S53676 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Guerrero M, Crisafulli E, Liapikou A, et al. Readmission for Acute Exacerbation within 30 Days of Discharge Is Associated with a Subsequent Progressive Increase in Mortality Risk in COPD Patients: A Long-Term Observational Study. PLoS One 2016;11:e0150737. 10.1371/journal.pone.0150737 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Wedzicha JA, Brill SE, Allinson JP, et al. Mechanisms and impact of the frequent exacerbator phenotype in chronic obstructive pulmonary disease. BMC Med 2013;11:181. 10.1186/1741-7015-11-181 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Suissa S, Dell'Aniello S, Ernst P. Long-term natural history of chronic obstructive pulmonary disease: severe exacerbations and mortality. Thorax 2012;67:957-63. 10.1136/thoraxjnl-2011-201518 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Ho TW, Tsai YJ, Ruan SY, et al. HINT Study Group In-hospital and one-year mortality and their predictors in patients hospitalized for first-ever chronic obstructive pulmonary disease exacerbations: a nationwide population-based study. PLoS One 2014;9:e114866. 10.1371/journal.pone.0114866 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.Singanayagam A, Schembri S, Chalmers J. Predictors of mortality in hospitalized adults with acute exacerbation of chronic obstructive pulmonary disease. Ann Am Thorac Soc 2013;10:81-9. 10.1513/AnnalsATS.201208-043OC [DOI] [PubMed] [Google Scholar]
  • 7.Slenter RH, Sprooten RT, Kotz D, et al. Predictors of 1-year mortality at hospital admission for acute exacerbations of chronic obstructive pulmonary disease. Respiration 2013;85:15-26. 10.1159/000342036 [DOI] [PubMed] [Google Scholar]
  • 8.Martinez-Rivera C, Portillo K, Muñoz-Ferrer A, et al. Anemia is a mortality predictor in hospitalized patients for COPD exacerbation. COPD 2012;9:243-50. 10.3109/15412555.2011.647131 [DOI] [PubMed] [Google Scholar]
  • 9.Global Initiative for Chronic Obstructive Lung Disease (GOLD). Global strategy for the diagnosis, management and prevention of chronic obstructive pulmonary disease. NHLBI/WHO workshop report 2006. Updated: November 2006. Accessed October 2013. Available online: http://www.who.int/respiratory/copd/GOLD_WR_06.pdf
  • 10.Global Initiative for Chronic Obstructive Lung Disease (GOLD). Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. Updated 2015. Accessed February 2016. Available online: http://www.msc.es/organizacion/sns/planCalidadSNS/pdf/GOLD_Report_2015_Apr2.pdf
  • 11.Kadhim-Saleh A, Green M, Williamson T, et al. Validation of the diagnostic algorithms for 5 chronic conditions in the Canadian Primary Care Sentinel Surveillance Network (CPCSSN): a Kingston Practice-based Research Network (PBRN) report. J Am Board Fam Med 2013;26:159-67. 10.3122/jabfm.2013.02.120183 [DOI] [PubMed] [Google Scholar]
  • 12.Quint JK, Müllerova H, DiSantostefano RL, et al. Validation of chronic obstructive pulmonary disease recording in the Clinical Practice Research Datalink (CPRD-GOLD). BMJ Open 2014;4:e005540. 10.1136/bmjopen-2014-005540 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Pace E, Ferraro M, Minervini MI, et al. Beta defensin-2 is reduced in central but not in distal airwais of smoker COPD patients. PLoS One 2012;7:e33601. 10.1371/journal.pone.0033601 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14.Im HJ, Park SM, Choi JH, et al. Binge drinking and its relation to metabolic syndrome in korean adult men. Korean J Fam Med 2014;35:173-81. 10.4082/kjfm.2014.35.4.173 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Costa GR, Berjón MF, Mochales JA, et al. Epidemiological features of comorbidity and its influence on the use of health services from Health Survey Madrid 2007, Spain. Rev Esp Salud Publica 2009;83:835-46. [PubMed] [Google Scholar]
  • 16.Charlson ME, Pompei P, Ales KL, et al. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation J Chronic Dis 1987;40:373-83. 10.1016/0021-9681(87)90171-8 [DOI] [PubMed] [Google Scholar]
  • 17.Dewan NA, Rafique S, Kanwar B, et al. Acute exacerbation of COPD: factors associated with poor treatment outcome. Chest 2000;117:662-71. 10.1378/chest.117.3.662 [DOI] [PubMed] [Google Scholar]
  • 18.Barba R, Zapatero A, Losa JE, et al. The impact of weekends on outcome for acute exacerbations of COPD. Eur Respir J 2012;39:46-50. 10.1183/09031936.00013211 [DOI] [PubMed] [Google Scholar]
  • 19.Ashton CM, Kuykendall DH, Johnson ML, et al. The association between the quality of inpatient care and early readmission. Ann Intern Med 1995;122:415-21. 10.7326/0003-4819-122-6-199503150-00003 [DOI] [PubMed] [Google Scholar]
  • 20.Nutritional anaemias. Report of a WHO scientific group. World Health Organ Tech Rep Ser 1968;405:5-37. [PubMed] [Google Scholar]
  • 21.Gudmundsson G, Ulrik CS, Gislason T, et al. Long-term survival in patients hospitalized for chronic obstructive pulmonary disease: a prospective observational study in the Nordic countries. Int J Chron Obstruct Pulmon Dis 2012;7:571-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 22.Chung LP, Winship P, Phung S, et al. Five-year outcome in COPD patients after their first episode of acute exacerbation treated with non-invasive ventilation. Respirology 2010;15:1084-91. 10.1111/j.1440-1843.2010.01795.x [DOI] [PubMed] [Google Scholar]
  • 23.Ai-Ping C, Lee KH, Lim T. In-hospital and 5-year mortality of patients treated in the ICU for acute exacerbation of COPD: a retrospective study. Chest 2005;128:518-24. 10.1378/chest.128.2.518 [DOI] [PubMed] [Google Scholar]
  • 24.Steinmetz J, Rasmussen LS, Nielsen S. Long-term prognosis for patients with COPD treated in the prehospital setting: Is it influenced by hospital admission? Chest 2006;130:676-80. 10.1378/chest.130.3.676 [DOI] [PubMed] [Google Scholar]
  • 25.Garpestad E, Brennan J, Hill N. Noninvasive ventilation for critical care. Chest 2007;132:711-20. 10.1378/chest.06-2643 [DOI] [PubMed] [Google Scholar]
  • 26.2Nava S, Hill N. Non-invasive ventilation in acute respiratory failure. Lancet 2009;374:250-9. 10.1016/S0140-6736(09)60496-7 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.Plant PK, Owen JL, Elliott M. Non-invasive ventilation in acute exacerbations of chronic obstructive pulmonary disease: long term survival and predictors of in-hospital outcome. Thorax 2001;56:708-12. 10.1136/thorax.56.9.708 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Confalonieri M, Parigi P, Scartabellati A, et al. Noninvasive mechanical ventilation improves the immediate and long-term outcome of COPD patients with acute respiratory failure. Eur Respir J 1996;9:422-30. 10.1183/09031936.96.09030422 [DOI] [PubMed] [Google Scholar]
  • 29.Bardi G, Pierotelo R, Desideri M, et al. Nasal ventilation in COPD exacerbations: early and late results of a prospective, controlled study. Eur Respir J 2000;15:98-104. 10.1183/09031936.00.15109800 [DOI] [PubMed] [Google Scholar]
  • 30.Vitacca M, Rubini F, Foglio K, et al. Non-invasive modalities of positive pressure ventilation improve the outcome of acute exacerbations in COLD patients. Intensive Care Med 1993;19:450-5. 10.1007/BF01711086 [DOI] [PubMed] [Google Scholar]
  • 31.Davidson AC, Banham S, Elliott M, et al. BTS/ICS guideline for the ventilatory management of acute hypercapnic respiratory failure in adults. Thorax 2016;71 Suppl 2:ii1-35. 10.1136/thoraxjnl-2015-208209 [DOI] [PubMed] [Google Scholar]
  • 32.Titlestad IL, Lassen AT, Vestbo J. Long-term survival for COPD patients receiving noninvasive ventilation for acute respiratory failure. Int J Chron Obstruct Pulmon Dis 2013;8:215-9. 10.2147/COPD.S42632 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 33.Hartl S, Lopez-Campos JL, Pozo-Rodriguez F, et al. Risk of death and readmission of hospital-admitted COPD exacerbations: European COPD Audit. Eur Respir J 2016;47:113-21. 10.1183/13993003.01391-2014 [DOI] [PubMed] [Google Scholar]
  • 34.Ankjærgaard KL, Rasmussen DB, Schwaner SH, et al. COPD: Mortality and Readmissions in Relation to Number of Admissions with Noninvasive Ventilation. COPD 2017;14:30-6. 10.1080/15412555.2016.1181160 [DOI] [PubMed] [Google Scholar]
  • 35.Tokgoz Akyil F, Gunen H, Agca M, et al. Patient Outcome after Chronic Obstructive Pulmonary Disease Exacerbations Requiring Non-invasive Ventilation during Hospitalization. Arch Bronconeumol 2016;52:470-6. 10.1016/j.arbres.2016.01.021 [DOI] [PubMed] [Google Scholar]
  • 36.Piquet J, Chavaillon JM, David P, et al. French College of General Hospital Respiratory Physicians (CPHG). High-risk patients following hospitalisation for an acute exacerbation of COPD. Eur Respir J 2013;42:946-55. 10.1183/09031936.00180312 [DOI] [PubMed] [Google Scholar]
  • 37.Lun CT, Tsui MS, Cheng SL, et al. Differences in baseline factors and survival between normocapnia, compensated respiratory acidosis and decompensated respiratory acidosis in COPD exacerbation: A pilot study. Respirology 2016;21:128-36. 10.1111/resp.12652 [DOI] [PubMed] [Google Scholar]
  • 38.Oga T, Taniguchi H, Kita H, et al. Analysis of the relationship between health status and mortality in hypercapnic patients with noninvasive ventilation. Clin Respir J 2015. [Epub ahead of print]. 10.1111/crj.12415 [DOI] [PubMed] [Google Scholar]
  • 39.Zacho-Priess-Leere M, Møller-Weinreich U. Mortality and readmissions in patients with acute exacerbation of chronic obstructive pulmonary disease treated at a specialised pulmonary ward and general wards. Dan Med J 2014;61:A4938. [PubMed] [Google Scholar]
  • 40.Steer J, Gibson GJ, Bourke S. Predicting outcomes following hospitalization for acute exacerbations of COPD. QJM. 2010;103:817-29. 10.1093/qjmed/hcq126 [DOI] [PubMed] [Google Scholar]
  • 41.Quon BS, Gan WQ, Sin D. Contemporary management of acute exacerbations of COPD: A systematic review and metaanlysis. Chest 2008;133:756-66. 10.1378/chest.07-1207 [DOI] [PubMed] [Google Scholar]
  • 42.Cheng Y, Borrego ME, Frost FJ, et al. Predictors for mortality in hospitalized patients with chronic obstructive pulmonary disease. Springerplus 2014;3:359. 10.1186/2193-1801-3-359 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 43.Yao Z, Peng Y, Chen X, et al. Healthcare Associated Infections of Methicillin-Resistant Staphylococcus aureus: A Case-Control-Control Study. PLoS One 2015;10:e0140604. 10.1371/journal.pone.0140604 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 44.Shapira-Rootman M, Beckerman M, Soimu U, et al. The prevalence of pulmonary embolism among patients suffering from acute exacerbations of chronic obstructive pulmonary disease. Emerg Radiol 2015;22:257-60. 10.1007/s10140-014-1280-7 [DOI] [PubMed] [Google Scholar]
  • 45.Agboado G, Peters J, Donkin L. Factors influencing the length of hospital stay among patients resident in Blackpool admitted with COPD: a cross-sectional study. BMJ Open 2012;2. doi: . 10.1136/bmjopen-2012-000869 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 46.Roche N, Rabbat A, Zureik M, et al. Chronic obstructive pulmonary disease exacerbations in emergency departments: predictors of outcome. Curr Opin Pulm Med 2010;16:112-7. 10.1097/MCP.0b013e328335f039 [DOI] [PubMed] [Google Scholar]
  • 47.Quintana JM, Unzurrunzaga A, Garcia-Gutierrez S, et al. IRYSS-COPD Group .Predictors of Hospital Length of Stay in Patients with Exacerbations of COPD: A Cohort Study. J Gen Intern Med 2015;30:824-31. 10.1007/s11606-014-3129-x [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 48.Sharif R, Parekh TM, Pierson KS, et al. Predictors of early readmission among patients 40 to 64 years of age hospitalized for chronic obstructive pulmonary disease. Ann Am Thorac Soc 2014;11:685-94. 10.1513/AnnalsATS.201310-358OC [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 49.deMiguel-Díez J, Jiménez-García R, Hernández-Barrera V, et al. Readmissions following an initial hospitalization by COPD exacerbation in Spain from 2006 to 2012. Respirology 2016;21:489-96. 10.1111/resp.12705 [DOI] [PubMed] [Google Scholar]
  • 50.Lee CH, Choi S, Jang EJ, et al. Inhaled bronchodilators and the risk of tachyarrhythmias. Int J Cardiol 2015;190:133-9. 10.1016/j.ijcard.2015.04.129 [DOI] [PubMed] [Google Scholar]
  • 51.Pothirat C, Liwsrisakun C, Bumroongkit C, et al. Comparative study on health care utilization and hospital outcomes of severe acute exacerbation of chronic obstructive pulmonary disease managed by pulmonologists vs internists. Int J Chron Obstruct Pulmon Dis 2015;10:759-66. 10.2147/COPD.S81267 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 52.Wijayaratne K, Wilson J, Sivakumaran P, et al. Differences in care between general medicine and respiratory specialists in the management of patients hospitalized for acute exacerbations of chronic obstructive pulmonary disease. Ann Thorac Med 2013;8:197-203. 10.4103/1817-1737.118499 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 53.Laforest L, VanGanse E, Devouassoux G, et al. Management of asthma in patients supervised by primary care physicians or by specialists. Eur Respir J 2006;27:42-50. 10.1183/09031936.06.00035805 [DOI] [PubMed] [Google Scholar]
  • 54.Singh B, Parsaik AK, Mielke MM, et al. Chronic obstructive pulmonary disease and association with mild cognitive impairment: the Mayo Clinic Study of Aging. Mayo Clin Proc 2013;88:1222-30 10.1016/j.mayocp.2013.08.012 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 55.Sampson EL, Leurent B, Blanchard MR, et al. Survival of people with dementia after unplanned acute hospital admission: a prospective cohort study. Int J Geriatr Psychiatry 2013;28:1015-22. 10.1002/gps.3919 [DOI] [PubMed] [Google Scholar]
  • 56.Liao KM, Lin TC, Li CY, et al. Dementia Increases Severe Sepsis and Mortality in Hospitalized Patients With Chronic Obstructive Pulmonary Disease. Medicine (Baltimore) 2015;94:e967. 10.1097/MD.0000000000000967 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 57.Luchsinger JA, Patel B, Tang MX, et al. Body mass index, dementia, and mortality in the elderly. J Nutr Health Aging 2008;12:127-31. 10.1007/BF02982565 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 58.Nägga K, Wattmo C, Zhang Y, et al. Cerebral inflammation is an underlying mechanism of early death in Alzheimer's disease: a 13-year cause-specific multivariate mortality study. Alzheimers Res Ther 2014;6:41. 10.1186/alzrt271 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 59.Chinitz JS, Castellano JM, Kovacic JC, et al. Atrial fibrillation, stroke, and quality of life. Ann N Y Acad Sci 2012;1254:140-50. 10.1111/j.1749-6632.2012.06494.x [DOI] [PubMed] [Google Scholar]
  • 60.Li J, Agarwal SK, Alonso A, et al. Airflow obstruction, lung function, and incidence of atrial fibrillation: the Atherosclerosis Risk in Communities (ARIC) study. Circulation 2014;129:971-80. 10.1161/CIRCULATIONAHA.113.004050 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 61.Steer J, Gibson J, Bourke S. The DECAF Score: predicting hospital mortality in exacerbations of chronic obstructive pulmonary disease. Thorax 2012;67:970-6. 10.1136/thoraxjnl-2012-202103 [DOI] [PubMed] [Google Scholar]
  • 62.Durheim MT, Cyr DD, Lopes RD, et al. Chronic obstructive pulmonary disease in patients with atrial fibrillation: Insights from the ARISTOTLE trial. Int J Cardiol 2016;202:589-94. 10.1016/j.ijcard.2015.09.062 [DOI] [PubMed] [Google Scholar]
  • 63.Undas A, Kaczmarek P, Sladek K, et al. Fibrin clot properties are altered in patients with chronic obstructive pulmonary disease. Beneficial effects of simvastatin treatment. Thromb Haemost 2009;102:1176-82. [DOI] [PubMed] [Google Scholar]
  • 64.Maclay JD, McAllister DA, Johnston S, et al. Increased platelet activation in patients with stable and acute exacerbation of COPD. Thorax 2011;66:769-74. 10.1136/thx.2010.157529 [DOI] [PubMed] [Google Scholar]
  • 65.DiMarco JP, Flaker G, Waldo AL, et al. AFFIRM Investigators Factors affecting bleeding risk during anticoagulant therapy in patients with atrial fibrillation: observations from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study. Am Heart J 2005;149:650-6. 10.1016/j.ahj.2004.11.015 [DOI] [PubMed] [Google Scholar]

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