Background: Pneumonia remains the foremost cause for hospitalization. The objective of our study was to look at the predictors of longer length of stay (LOS) in patients admitted in the hospital with community acquired pneumonia (CAP) based on a recent large nationwide database.
Methods: We identified patients aged ≥18 years with a primary discharge diagnosis of CAP in the Nationwide Inpatient Sample from the year 2011. We categorized these patients into groups: one with longer LOS (≥75% percentile) and other with shorter LOS (<75% percentile).We compared the demographics (age, sex, race, insurance status), comorbidities (HTN, Diabetes, MI, chronic lung disease, vascular disease, liver disease, renal disease, cancer, CHF), hospital characteristics (size, location, teaching status) and complications (septic shock and intubation) between these two groups. We then performed multivariate regression analysis to look for the predictors of longer LOS.
Results: There were 1,185,572 patients (weighted for national estimate) with discharge diagnosis of CAP. Mean, median and 75% quartile (percentile) of LOS were 6.5, 4 and 7 days, respectively. Out of this, 811, 311 (68%) were categorized into the group with shorter LOS (<7 days) and 374,261 (32%) into the one with longer LOS (>=7 days). On multivariate regression analysis, the independent predictors of longer LOS were: older age (>=75 yrs vs. 18-45 yrs: Odds Ratio (OR) 1.26, 95% Confidence Interval [CI] 1.18-1.34, p<0.0001], Female sex (vs Male: OR 1.10, 95% CI 1.07-1.13, p<0.0001), Black race (vs White: OR 1.2, 95% CI 1.1-1.3, p<0.0001), large bed-sized hospital (vs medium: OR 1.2, 95% CI 1.1-1.3, p<0.0001), Urban location of the hospital (vs rural: OR 1.5, 95% CI 1.4-1.6, p<0.0001), septic shock (OR 3.3, 95% CI 3.1-3.5, p<0.0001), and intubation/mechanical ventilation (OR 8.2, 95% CI 7.7-8.7, p<0.0001). Majority of the comorbidities were also predictive of longer LOS.
Conclusions: Our study based on nationwide database showed that older age, female sex, Black race, large bed-sized hospital, urban location of the hospital, multiple comorbidities and severity of the disease (septic shock and intubation/mechanical ventilation) were predictors of longer LOS in patients admitted for CAP. More prospective studies are needed to further evaluate the predictors of LOS in patients with CAP and help risk-stratify, and reduce the total length of hospital stay and the economic burden associated with CAP.