Table 6A.

Characteristics of the first antidepressant treatment episode among persons with a diagnosis of depression

Characteristics	Canada						USA		UK		Taiwan
	Ontario		Montreal sample		Quebec city and Mtl		Boston		CPRD		NHIRDB
	n	%	n	%	n	%	n	%	n	%	n	%
All patients	4407	100	1221	100	324	100	1259	100	2152	100	835	100
No treatment change	2383	54	680	56	220	68	757	60	1317	61	566	68
Treatment change	2024	46	541	44	104	32	502	40	835	39	269	32

	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
All patients
Dose*	1.3	1.0	0.9	0.6	0.9	0.5	1.3	0.8	1.0	0.5	0.7	0.4
Duration (days)	519.5	285.1	462.5	298.9	467.7	255.0	395.6	266.2	356.2	278.7	217.0	248.0
No treatment change†
Dose	0.9	0.7	0.7	0.4	0.8	0.4	1.0	0.9	0.8	0.4	0.6	0.4
Duration (days)	289.1	309.6	246.3	290.4	340.9	243.2	225.7	212.3	192.8	239.9	104.7	179.7
Treatment change†
Dose	1.5	1.0	1.0	0.6	1.1	0.6	1.4	0.8	1.2	0.6	0.8	0.4
Duration (days)	616.9	209.8	569.0	240.8	574.7	213.9	507.7	239.4	469.5	247.6	312.6	260.2

	n	%	n	%	n	%	n	%	n	%	n	%
Type of changes‡
Added molecule (different class)	796	18	139	11	31	10	125	10	125	6	72	9
Added molecule (same class)	174	4	22	2	6	2	42	3	54	3	26	3
Dose decrease	921	21	246	20	38	12	151	12	407	19	105	13
Dose increase	1464	33	387	32	64	20	348	28	611	28	171	20
Removed molecule (different class)	710	16	132	11	26	8	34	3	19	1	75	9
Removed molecule (same class)	178	4	23	2	5	2	6	0	6	0	28	3
Switch class	10	0	48	4	–	–	56	4	70	3	1	0
Switch molecule (same class)	5	0	11	1	–	–	19	2	24	1	–	–

*Dose is the proportion of the WHO recommended daily dose (dose prescribed/recommended daily dose).

†Treatment change in the first antidepressant episode, defined as continuous therapy with gaps of no greater than 90 days.

‡Patients can have more than one type of change in the episode of antidepressant use.

CPRD, Clinical Practice Research Datalink; NHIRDB, National Health Insurance Research Database.