Table 1.

Description of included studies

Clinical trial	Country-City	Year	Patient age	Type of examination
			(years)
UK Age Trial [17,18]	England, Wales, Scotland	1991	39-41	Mammography: 2 views, and then 1 view every 12 months
Goteborg [7,8,19,20]	Goteborg, Sweden	1982	39-59	Mammography: 2 views, and then 1 view every 18 months, 4 to 5 screening rounds
Malmo [7,8,21,22]	Malmo, Sweden	MMST 1: 1976	MMST 1: 44–68	Mammography: 2 views (first 2 rounds) and then 1 view every 18 to 24 months, 5 screening rounds
		MMST 2: 1978	MMST 2: 45-50
Stockholm [8,23]	Stockholm, Sweden	1981	40-64	Mammography: 1 view every 24 months, 2 screening rounds
Canada [24-27]	15 centers, Canada	1980	NBSS-1: 40–49	NBSS-1:
				Mammography: 2 views then 1 clinical examination every 12 months
			NBSS-2:50-59	S: Self-examination training
				C: Self-examination training + annual history taking
				NBSS-2:
				S: Mammography: 2 views then1 clinical examination every 12 months
				C: Self-examination training and 1 clinical examination every 12 months
Edinburgh [34]	Edinburgh, Scotland	1978	45-64	S: Mammography : 2 views and then 1 view every 24 months
				+ Clinical examination every 12 months
				8 screening rounds
				C: Self-examination
2 Swedish counties [28-30]	Kopparberg, Ostergotland, Sweden	1977 Kopparberg	40-74	Mammography: 1 view
		1978 Ostergoland		- every 24 months for women aged 40 to 49
				-every 33 months for women over 49
				2 screening rounds
New York [31-33]	New York, USA	1963	40-64	Mammography: 2 views and then 1 view every 12 months
				+ Clinical examination every 12 months
				+ History taking only during the 1st round
				4 screening rounds

S: study group; C: control group.