Table 4.

Crude rate of moderate to severe COPD exacerbations during the study follow-up according to treatment regimens

	All patients					≥3 moderate to severe exacerbations in the year prior to cohort entry
Treatment	Patient-years	Rate* of OCS prescriptions	Rate* of ED visits for COPD	Rate* of hospitalizations for COPD	Rate * of exacerbations†	Patient-years	Rate* of OCS prescriptions	Rate* of ED visits for COPD	Rate* of hospitalizations for COPD	Rate* of exacerbations†
Theophyllines	6 156	72	39	32	84	350	271	126	102	273
ICS	30 413	75	30	21	77	1568	237	85	57	213
LABA	1 426	89	30	24	91	73	261	68	52	230
LABA + ICS	5 414	126	33	26	112	415	292	68	49	233
Theophyllines + ICS	10 283	118	46	33	114	974	305	106	75	268

^*Rate per 100 patient-years.

^†An exacerbation was defined either as a prescription of oral corticosteroids filled, a visit to an ED for COPD or hospitalization for COPD. Only one single exacerbation was considered if more than one marker of exacerbation (prescription of oral corticosteroids, ED visits for COPD or hospitalizations for COPD) occurred within a period of 15 days. COPD, Chronic obstructive pulmonary disease; ED, emergency department; ICS, inhaled corticosteroids; LABA, long-acting β₂ -agonists; OCS, oral corticosteroids.