Table 1:

Demographics of the 16 radiologists at the time of each test

Parameter	Case set	First Quartile	Mean	Third Quartile	Interquartile Range
Age (years)	Set 1	36.0	45.5	57.75	21.75
	Set 2	38.25	47.5	54.75	16.5
	Set 3	36.75	47.0	57.75	21.0
No of years since qualification as radiologist	Set 1	6.25	11.5	20	13.75
	Set 2	3.25	11.5	20	16.75
	Set 3	6.25	13.5	20	13.75
No of years reading mammograms	Set 1	3.25	7.0	17.5	14.25
	Set 2	1.75	5.0	10.75	9.0
	Set 3	3.25	8.0	17.5	14.25
Annual Volume	Set 1	1620	3600	6300	4680
	Set 2	1260	1980	2700	1440
	Set 3	1620	3600	6300	4680
No of hours per week	Set 1	7.5	10.25	16.75	9.25
	Set 2	4.0	13.0	18.0	14.0
	Set 3	7.5	13.0	18.37	10.88