Similar In-Hospital, Long-Term Survival Rates Found Among Male, Female Patients With AECOPD

Despite some differences in clinical characteristics and treatments, female and male patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) had similar in-hospital and long-term survival, according to a study published in BMC Pulmonary Medicine.

The researchers explained that between 22% and 40% of patients with COPD experience at least 1 moderate or severe exacerbation per year. They noted that AECOPD accelerates lung function decline, hurts quality of life, and can result in an increased risk of subsequent cardiovascular or thromboembolic events; it is also associated with significant hospitalization and mortality, as well as health and socioeconomic burden.

Consequently, they emphasized the importance of identifying the characteristics and clinical outcomes of AECOPD to optimize clinical management and improve prognosis. Although several studies have explored these topics, there are limited related data available in China, as well as limited data on gender-related differences during the treatment of AECOPD.

Because of this, the researchers conducted a study that provides an overview of the characteristics, treatments, and clinical outcomes among inpatients with AECOPD. They also aimed to clarify the sex differences in patients hospitalized for AECOPD, as well as to establish and validate early warning models of adverse AECOPD outcomes.

Patient in hospital bed | Image Credit: Gorodenkoff - stock.adobe.com

To conduct their study, the researchers enrolled patients into their study population who were admitted for AECOPD at 10 medical centers in China between September 2017 and July 2021; AECOPD was diagnosed in patients with a history of COPD with an acute worsening of respiratory symptoms resulting in additional therapy.

Every enrolled patient completed a standardized case report form, which included baseline demographics, comorbidities, symptoms, treatments, and in-hospital outcomes. In terms of treatments, they evaluated the use of inhaled/nebulized bronchodilators, systemic corticosteroids, inhaled/nebulized corticosteroids, antibiotics, and theophylline drugs during hospitalization.

Additionally, the researchers recorded respiratory support usage, including noninvasive mechanical ventilation and invasive mechanical ventilation. Lastly, the researchers determined in-hospital and long-term outcomes, including all-cause in-hospital mortality, discharge against medical advice, clinical improvement at discharge, intensive care unit (ICU) admission, length of stay (LOS), total hospitalization expenses, and 3-year mortality among inpatients with AECOPD.

The study population consisted of 14,007 patients with AECOPD, with 11,020 (78.7%) patients being male. The mean (SD) age of included patients was 72.32 (10.39) years. Compared with female patients, male patients tended to be younger, have a lower body mass index (BMI), and be smokers with a high pack-year history. Despite these differences, male and female patients had similar amounts of AECOPD-related hospitalizations.

The most observed clinical manifestations of AECOPD were cough (94.3%), expectoration (91.7%), dyspnea (61.0%), and wheezing (24.6%). During hospitalization, the study population was treated with inhaled/nebulized bronchodilators (70.4%), antibiotics (64.9%), inhaled/nebulized corticosteroids (56.0%), theophylline drugs (55.1%), and systemic corticosteroids (41.0%). The researchers noted that female patients were more likely to receive antibiotics, whereas male patients were prescribed all other treatments more often.

Also, for respiratory support, 20.1% and 3.3% of patients received noninvasive and invasive mechanical ventilation during hospitalization, respectively. In particular, female patients more often received higher levels of respiratory support than male patients (including noninvasive [22.8% vs 19.3%; P < .001] and invasive [4.3% vs 3.0%; P = .001] mechanical ventilation).

In terms of the mean (SD) number of comorbidities, women (2.22 [1.64]; P < .001) showed more comorbidities per patient than men (1.73 [1.56]; P < .001). Women exhibited a higher prevalence of various comorbidities, including heart failure, asthma, and diabetes (all P < .05). However, pulmonary tuberculosis and active cancer were more prevalent in men.

Additionally, the researchers found an all-cause mortality rate of 1.4% during hospitalization. Conversely, 13,337 patients (95.2%) were discharged post improvement, 469 patients (3.3%) were discharged against medical advice, and 135 (7.4%) were admitted to the ICU; the median LOS was 9 days, with a total cost of $1911 (IQR, $1294-$2939). Overall, despite the different clinical characteristics and treatments observed between the 2 groups, the researchers did not find statistically significant differences in in-hospital mortality (1.4% vs 1.5%; P = .711) or incidences of discharge against medical advice (3.3% vs 3.4%; P = .820) between male and female patients with AECOPD.

Lastly, the study included 8652 smokers with AECOPD, the majority of whom were male (96.5%). Among this group, 112 (1.3%) died during hospitalization, with 8234 (95.2%) discharged post improvement, 586 (6.8%) admitted to the ICU, and 306 (3.5%) discharged against medical advice. Most notably, both the in-hospital mortality (3.3% vs 1.2%; P = .002) and incidence of ICU admissions (9.6% vs 6.7%; P = .002) were significantly higher in female smokers than in male smokers. However, women showed a trend toward higher long-term mortality (P = .12).

The researchers acknowledged their study’s limitations, one being that only a small proportion of patients completed follow-ups. They noted that this may prevent them from evaluating the sex differences in the long-term clinical outcomes of patients with AECOPD without bias. Despite the limitations, the researchers made conclusions and suggestions for further research based on their findings.

“Our findings provide necessary information to guide clinical management of AECOPD based on sex differences, and further research is required to understand why potential sex-associated differences exist,” the authors concluded.

Reference

Zhang J, Yi Q, Zhou C, et al. Characteristics, treatments, in-hospital and long-term outcomes among inpatients with acute exacerbation of chronic obstructive pulmonary disease in China: sex differences in a large cohort study. BMC Pulm Med. 2024;24:125. doi:10.1186/s12890-024-02948-4