Open Access Research article

Comorbidities as a driver of the excess costs of community-acquired pneumonia in U.S. commercially-insured working age adults

Daniel Polsky14*, Machaon Bonafede2 and Jose A Suaya3

Author Affiliations

1 Perelman School of Medicine and the Wharton School, University of Pennsylvania, Philadelphia, PA, USA

2 Outcomes Research, Thomson Reuters, Andover, MA, USA

3 GlaxoSmithKline Vaccines, Philadelphia, PA, USA

4 University of Pennsylvania, Division of General Internal Medicine, Philadelphia, PA, USA

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BMC Health Services Research 2012, 12:379  doi:10.1186/1472-6963-12-379

Published: 31 October 2012

Abstract

Background

Adults with certain comorbid conditions have a higher risk of pneumonia than the overall population. If treatment of pneumonia is more costly in certain predictable situations, this would affect the value proposition of populations for pneumonia prevention. We estimate the economic impact of community-acquired pneumonia (CAP) for adults with asthma, diabetes, chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) in a large U.S. commercially-insured working age population.

Methods

Data sources consisted of 2003 through 2007 Thomson Reuters MarketScan Commercial Claims and Encounters and Thomson Reuters Health Productivity and Management (HPM) databases. Pneumonia episodes and selected comorbidities were identified by ICD-9-CM diagnosis codes. By propensity score matching, controls were identified for pneumonia patients. Excess direct medical costs and excess productivity cost were estimated by generalized linear models (GLM).

Results

We identified 402,831 patients with CAP between 2003 through 2007, with 25,560, 32,677, 16,343, and 5,062 episodes occurring in patients with asthma, diabetes, COPD and CHF, respectively. Mean excess costs (and standard error, SE) of CAP were $14,429 (SE=44) overall. Mean excess costs by comorbidity subgroup were lowest for asthma ($13,307 (SE=123)), followed by diabetes ($21,395 (SE=171)) and COPD ($23,493 (SE=197)); mean excess costs were highest for patients with CHF ($34,436 (SE=549)). On average, indirect costs comprised 21% of total excess costs, ranging from 8% for CHF patients to 27% for COPD patients.

Conclusions

Compared to patients without asthma, diabetes, COPD, or CHF, the excess cost of CAP is nearly twice as high for patients with diabetes and COPD and nearly three times as high for patients with CHF. Indirect costs made up a significant but varying portion of excess CAP costs. Returns on prevention of pneumonia would therefore be higher in adults with these comorbidities.

Keywords:
Community-acquired pneumonia (CAP); Medical cost; Productivity cost; Economic evaluation; Asthma; Diabetes; Chronic Obstructive Pulmonary Disease (COPD); Congestive Heart Failure (CHF)