Hospital admission decisions for older Veterans with community-onset pneumonia: An analysis of 118 U.S. Veterans Affairs Medical Centers

Abstract

Objectives: Age is important for prognosis in community-onset pneumonia, but how it influences admission decisions in the emergency department (ED) is not well characterized. Using clinical data from the electronic health record in a national cohort, we examined pneumonia hospitalization patterns, variation, and relationships with mortality among older versus younger Veterans.

Methods: In a retrospective cohort of patients ≥ 18 years presenting to EDs with a diagnosis of pneumonia at 118 VA Medical Centers January 1, 2006, to December 31, 2016, we compared observed, predicted, and residual hospitalization risk for Veterans < 70, 70-79, and ≥ 80 years of age using generalized estimating equations and machine learning models with 71 patient factors. We examined facility variation in residual hospitalization across facilities and explored whether facility differences in hospitalization risk correlated with differences in 30-day mortality.

Results: Among 297,498 encounters, 165,003 (55%) were for Veterans < 70 years, 61,076 (21%) 70-80, and 71,419 (24%) ≥ 80. Hospitalization rates were 52%, 67%, and 76%, respectively. After other patient factors were adjusting for, age 70-79 had an odds ratio (OR) of 1.39 (95% confidence interval [CI] 1.34-1.44) and ≥ 80 had an OR of 2.1 (95% CI 2.0-2.2) compared to age < 70. There was substantial variation in hospitalization across facilities among Veterans < 70 (<35% hospitalization at the lowest decile of facilities vs. > 66% at the highest decile) that was similar but with higher risk for patients 70-79 years (54% vs. 82%) and ≥ 80 years (59% vs. 85%) and remained after accounting for patient factors, with no consistently positive or negative associations with facility-level 30-day mortality.

Conclusions: Older Veterans with community-onset pneumonia experience high risk of hospitalization, with widespread facility variation that has no clear relationship to short-term mortality.

Keywords: emergency department; epidemiology; hospitalization; older adult; pneumonia.

Figure 1.

Study Population.

Figure 2.

Facility variation in hospitalization. Observed (top row) and residual (observed – predicted – bottom row) hospitalization rates for each facility are shown for Veterans <70 years(left column), Veterans ≥70 years (middle column), and Veterans ≥80 years(right column). Marker size is in proportion to the total number of encounters. Color of facility are assigned based on quantile of observed or residual hospitalization

Figure 3.

Geographic variation in hospitalization for overall cohort, Veterans ≥70 years, and Veterans ≥80 years, ranked by residual (observed – predicted from patient characteristics) hospitalization risk (green). Negative values denote a lower-than-predicted hospitalization rate. Red bars indicate observed proportion of patients hospitalized and black bars indicate residual 30-day mortality risk.

Figure 4.

Sources of variation in hospitalization. Variation attributed to provider (red dash), facility (red line), and VISN (grey dash) levels. Black line indicated sum of variation. Wider curves represent greater variation.

Figure 5.

Facility-level mortality versus hospitalization. Observed (Top row), predicted (Middle row), and residual (Bottom row) 30-day mortality versus hospitalization are shown for Veterans <70 years (left column), Veterans ≥70 years (middle column), and Veterans ≥80 years (right column). Bubble size is in proportion to number of ED encounters. Color of facility represents the degree of residual (observed –predicted) hospitalization. Pearson’s correlation coefficient and test of statistical significance describes the overall relationship between facility mortality and hospitalization.