Datafile Name: Calcium 
Datafile Subjects: Health , Medical 
Story Names: Calcium and Blood Pressure 
Reference: Moore, David S., and George P. McCabe (1989). Introduction to the 
Practice of Statistics. Original source: Lyle, Roseann M., et al., "Blood 
pressure and metabolic effects of calcium supplementation in normotensive white 
and black men," JAMA, 257(1987), pp. 1772-1776, 
Authorization: contact authors 
Description: Results of a randomized comparative experiment to investigate the 
effect of calcium on blood pressure in African-American men. A treatment group 
of 10 men received a calcium supplement for 12 weeks, and a control group of 11 
men received a placebo during the same period. All subjects had their blood 
pressure tested before and after the 12-week period. 
Number of cases: 21 
Variable Names: 
  Treatment: Whether subject received calcium or placebo 
  Begin: seated systolic blood pressure before treatment 
  End: seated systolic blood pressure after treatement 
  Decrease: Decrease in blood pressure (Begin - End) 
The Data: 
Treatment Begin	End	Decrease
Calcium	107	100	7
Calcium	110	114	-4
Calcium	123	105	18
Calcium	129	112	17
Calcium	112	115	-3
Calcium	111	116	-5
Calcium	107	106	1
Calcium	112	102	10
Calcium	136	125	11
Calcium	102	104	-2
Placebo	123	124	-1
Placebo	109	97	12
Placebo	112	113	-1
Placebo	102	105	-3
Placebo	98	95	3
Placebo	114	119	-5
Placebo	119	114	5
Placebo	112	114	2
Placebo	110	121	-11
Placebo	117	118	-1
Placebo	130	133	-3