Seasonality, risk factors and burden of community-acquired pneumonia in COPD patients: a population database study using linked health care records

Abstract

BackgroundCommunity-acquired pneumonia (CAP) is more common in patients with COPD than in the adult general population, with studies of hospitalized CAP patients consistently reporting COPD as a frequent comorbidity. However, despite an increasing recognition of its importance, large studies evaluating the incidence patterns over time, risk factors and burden of CAP in COPD are currently lacking.MethodsA retrospective observational study using a large UK-based database of linked primary and secondary care records was conducted. Patients with a diagnosis of COPD aged ≥40 years were followed up for 5 years from January 1, 2010. CAP and exacerbation episodes were identified from hospital discharge data and primary care coding records, and rates were calculated per month, adjusting for mortality, and displayed over time. In addition, baseline factors predicting future risk of CAP and hospital admission with CAP were identified.ResultsA total of 14,513 COPD patients were identified: 13.4% (n=1,938) had ≥1 CAP episode, of whom 18.8% suffered from recurrent (≥2) CAP. Highest rates of both CAP and exacerbations were seen in winter. A greater proportion of frequent, compared to infrequent, exacerbators experienced recurrent CAP (5.1% versus 2.0%, respectively, P<0.001); 75.6% of CAP episodes were associated with hospital admission compared to 22.1% of exacerbations. Older age and increasing grade of airflow limitation were independently associated with increased odds of CAP and hospital admission with CAP. Other independent predictors of future CAP included lower body mass index, inhaled corticosteroid use, prior frequent exacerbations and comorbidities, including ischemic heart disease and diabetes.ConclusionCAP in COPD demonstrates clear seasonal patterns, with patient characteristics predictive of the odds of future CAP and hospital admission with CAP. Highlighting this burden of COPD-associated CAP during the winter period informs us of the likely triggers and the need for more effective preventive strategies.

Seasonality of postoperative pneumonia after coronary artery bypass grafting: A national inpatient sample study

“…Our results demonstrate statistically significant differences in rates of diagnosis of pneumonia as well as pneumonia or respiratory infection specifically secondary to seasonal influenza, H. influenzae , or S. pneumoniae based on surgical timing, defined as the month in which CABG was performed. While seasonal variation in the incidence of community‐acquired pneumonia secondary to infection with the aforementioned pathogens has previously been described in the general population 13 and among patients with chronic obstructive pulmonary disease, 14 we are the first to report seasonality in postoperative pulmonary complications and pneumonia following cardiac surgery. Although the absolute risk difference for pneumonia between our Fall/Winter and Spring/Summer cohorts was small, the rarity of our outcome diminishes the significance of this value.…”

A time for everything and everything in its time &ndash; exploring the mechanisms underlying seasonality of COPD exacerbations

“…The association of COPD with seasonality is notable. 9 , 10 Individuals with COPD recognize that they are more likely to experience exacerbations in winter, with 30% of COPD patients being frightened of this season. 11 Indeed, some of the more affluent patients with chronic conditions such as COPD and rheumatoid arthritis holiday in sunnier climates during winter, a fact evidenced by the presence of websites encouraging extended winter holidays for this population.…”

Pneumonic versus Nonpneumonic Exacerbations of Chronic Obstructive Pulmonary Disease

“…36 The incidence has a clear seasonal pattern, with the highest rates of CAP in the winter period, especially in December. 38 Along with liver, renal, and neurological disorders, COPD is an independent host risk factor for severe CAP (OR ¼ 1.30; 95% CI: 1.01-1.67) presenting to the emergency room with at least two organ dysfunctions. 38 These severe cases of CAP account for 11% of all cases and are associated with greater and early mortality compared with cases with one or no organ dysfunctions (12.4 vs. 3.4%).…”

“…38 Along with liver, renal, and neurological disorders, COPD is an independent host risk factor for severe CAP (OR ¼ 1.30; 95% CI: 1.01-1.67) presenting to the emergency room with at least two organ dysfunctions. 38 These severe cases of CAP account for 11% of all cases and are associated with greater and early mortality compared with cases with one or no organ dysfunctions (12.4 vs. 3.4%). 39 In general, hospitalization for CAP in patients with COPD is associated with the severity of airflow obstruction.…”