Introduction
Chronic obstructive pulmonary disease (COPD) is a worldwide public
health problem and one of the leading causes of mortality and morbidity
[1,2]. Acute exacerbation of COPD (AECOPD), a severe status of COPD,
is characterized by worsening of respiratory manifestations and was
associated with increased mortality [3,4]. It was reported that
AECOPD accounted for about 13% of all admitted patients [5].
Mounting evidence showed that length of hospital stay (LHS) was
independently associated with the severity of AECOPD [6]. Although
the risk factors for hospitalization in AECOPD were well explored
[7-10], the predictors for prolonged LHS in AECOPD patients were
still not very clear.
In developing countries, AECOPD causes a heavy burden on the health care
system [11,12]. The direct and indirect costs of AECOPD at least
include health care resources devoted to the diagnosis, illness
management, workability loss, premature mortality, and family caregiver
costs [13,14]. Dalal AA, et al. found that the average cost was
$9,745 for standard admission, and $33,440 for an ICU stay in
hospitalized AECOPD patients [2]. Chen YH, et al. showed that length
of ICU stay, non-invasive or invasive ventilation intervention, and use
of antibiotics and systemic steroids were the major predictors of
hospitalization costs in AECOPD [15]. Therefore, LHS was noticeably
associated with the medical costs of hospitalized AECOPD patients.
LHS was essential for the prediction of AECOPD severity [8,16-18].
However, the threshold of prolonged LHS in AECOPD was still in
controversy [8,17,18]. In a cohort study, Mushlin AI et al. showed
that the mean LHS was 6 to 7 days in AECOPD patients [19]. They also
found that longer LHS was associated with increased PCO2levels, symptoms of more than 1 day, and antibiotic treatment at the
time of admission. In another prospective study, Crisafulli E et al.
divided the AECOPD patients into normal (≤7 days) and prolonged LHS
(>7 days) groups [20]. Their results showed that
prolonged LHS were independently associated with mMRC (modified Medical
Research Council) dyspnea score ≥2 and the presence of acute respiratory
acidosis. In a retrospective study, 8 days were obtained to define the
prolonged LHS in hospitalized AECOPD [17]. Meanwhile, in a
prospective cohort study, 9 days was used as the threshold of prolonged
LHS in AECOPD [18]. They revealed that baseline dyspnea, physical
activity level, and hospital variability were the independent predictors
of prolonged LHS in hospitalized AECOPD patients. Simultaneously, Wang
Y, found that LHS above the 75th percentile was 11 days in AECOPD
patients. And, they also identified that admission between Thursday and
Saturday, heart failure, diabetes, stroke, high arterial
PCO2, and low serum albumin level were independently
associated with prolonged LHS in AECOPD patients.
Collectively, in our study, 7 days and 11 days were used as the
thresholds of mild prolonged LHS and severe prolonged LHS in AECOPD
patients, respectively. The purpose of this cross-sectional study was to
identify the independent risk factors for prolonged LHS in hospitalized
AECOPD patients.