Asthma and treatment with inhaled corticosteroids: associations with hospitalisations with pneumonia

BACKGROUND: Pneumonia is an important cause of morbidity and mortality. COPD patients using inhaled corticosteroids (ICS) have an increased risk of pneumonia, but less is known about whether ICS treatment in asthma also increases the risk of pneumonia. The aim of this analysis was to examine risk factors for hospitalisations with pneumonia in a general population sample with special emphasis on asthma and the use of ICS in asthmatics. METHODS: In 1999 to 2000, 7340 subjects aged 28 to 54 years from three Swedish centres completed a brief health questionnaire. This was linked to information on hospitalisations with pneumonia from 2000 to 2010 and treatment with ICS from 2005 to 2010 held within the Swedish National Patient Register and the Swedish Prescribed Drug Register. RESULTS: Participants with asthma (n = 587) were more likely to be hospitalised with pneumonia than participants without asthma (Hazard Ratio (HR 3.35 (1.97–5.02)). Other risk factors for pneumonia were smoking (HR 1.93 (1.22–3.06)), BMI < 20 kg/m2 (HR 2.74 (1.41–5.36)) or BMI > 30 kg/m2 (HR 2.54 (1.39–4.67)). Asthmatics (n = 586) taking continuous treatment with fluticasone propionate were at an increased risk of being hospitalized with pneumonia (incidence risk ratio (IRR) 7.92 (2.32–27.0) compared to asthmatics that had not used fluticasone propionate, whereas no significant association was found with the use of budesonide (IRR 1.23 (0.36–4.20)). CONCLUSION: Having asthma is associated with a three times higher risk of being hospitalised for pneumonia. This analysis also indicates that there are intraclass differences between ICS compounds with respect to pneumonia risk, with an increased risk of pneumonia related to fluticasone propionate.