Table 4. Age-standardised incidence ratios (SIRs) of interstitial pneumonitis among 35 823 Danish breast cancer patients diagnosed between 1994 and 2004.

	Observed number of IP cases	Expected number of IP cases	SIR (O/E) (95% CI)
All interstitial pneumonitis	28	3.34	8.4 (5.7–11.9)
Radiation-induced interstitial pneumonitis	26	0.90	28.9 (19.3–41.7)
Drug-induced interstitial pneumonitis	2	1.34	1.5 (0.3–4.8)