Reference	Objective	Design	Evidence
Singh et al. [501]	Randomized controlled trials of any inhaled corticosteroid vs. a control treatment for COPD, with at least 24 weeks of follow‐up and reporting of pneumonia as an adverse event were included	MA	1A+
Almirall et al. [502]	1336 patients with confirmed CAP were matched to control subjects by age, sex and primary centre over 1 year. Multivariable analysis confirmed inhalation therapy (particularly containing steroids and using plastic pear‐spacers) as independent risk factors	CCS	4B+
Ernst et al. [503]	To study the effect of inhaled corticosteroids on pneumonia hospitalization	CCS	4B+
Drummond et al. [504]	To study the effect of inhaled corticosteroids on pneumonia mortality	MA	1A+
Sin et al. [505]	Pooled patient data from seven clinical trials of inhaled budesonide for the risk of pneumonia	MA	1A−