Table 2.

Incidence rate ratio (IRR) with 95% confidence interval (CI) of pneumonia comparing proton pump inhibitor (PPI) treatment periods with unexposed periods

Exposure	Pneumonias (number)	Crude IRR (95% CI)	Adjusted IRR (95% CI) *
No PPI	479,103	1.00 (reference)	1.00 (reference)
PPI	197,983	2.44 (2.42–2.47)	1.73 (1.71–1.75)
No PPI
Baseline	437,599	1.00 (reference)	1.00 (reference)
60 days prior to PPI	41,504	4.25 (4.20–4.31)	3.64 (3.59–3.68)
PPI
First month (1–30 days)	18,809	3.01 (2.96–3.06)	2.59 (2.55–2.63)
Second and third month (31–90 days)	27,570	2.69 (2.65–2.73)	2.25 (2.22–2.28)
After the third month (> 90 days)	151,604	3.50 (3.46–3.54)	2.20 (2.17–2.23)

^*Adjusted for age and calendar year