Stat 250 Fall 1998 Name ________________________________
Activity #5: Relative risk and related measures Student ID __ __ __ - __ __ - __ __ __ __
Section #    1      2
 
You will be given 15 minutes to complete this activity.   Work on this activity with at least one other student. Read the following two news articles, and then answer the questions that follow on the back.
 
Article A
Plaque Breaks and Heart Attacks
 
ORLANDO, Fla., Nov. 10 (Reuters)-- Researchers say they have found out why sudden strenuous exercise can bring on a heart attack in men with blocked arteries. 
      The fatty plaque that blocks the arteries of some people with heart disease is delicate and liable to rupture, they said.  Bits of plaque then block the arteries leading to the heart, causing heart attacks, the researchers said on Sunday at the meeting here of the American Heart Association. 
    So men with high cholesterol and other evidence of heart disease who do not exercise regularly should be careful		 about strenuous activity.  Dr. Renu Virmani of the Armed Forces Institute of Pathology in Washington and her colleagues studied 146 sedentary men, most of them in their 50's, with heart disease. 
    The researchers found that those who died during exercise were more than three times as likely to have evidence of ruptured plaque than men who died during normal daily activities or while resting. 
    The plaque burst in 68 percent of the men who died while engaged in strenuous activity, compared with 21 percent of the men who died during 		 normal daily activities.  
   Dr. Virmani said the men who were doing exercise, like mowing the lawn, doing heavy lifting, playing basketball or having sex, had more vulnerable plaque. 
    Men who have coronary heart disease and high cholesterol should be careful about undertaking vigorous physical activity, and they should try to lower their cholesterol through diet or drugs before beginning any type of exercise program, Dr. Virmani said. 

(New York Times, 11/11/97)
 
Article B
 Being Thin While Pregnant is Seen as Best
 
By the Associated Press
    Women who are very thin when they become pregnant for the first time are far more likely to have healthy babies than obese women or even those of normal weight, a Swedish study has found. 
     The study, being published today in the New England Journal of Medicine, contradicts the common belief that heavier women are more likely to have healthy, full-term babies. 
     Although the thinnest women are more likely to have underweight babies, they are no more likely to give birth prematurely or to have their babies die in the first week after birth, the study found. 
    "Advising lean women to gain weight before becoming pregnant may not be justified," the researchers concluded in		 the study, led by Dr. Sven Cnattingius of the Karolinska Institute in Stockholm. 
The study looked at the medical records of 167,750 Swedish women who gave birth in 1992 and 1993.  The women were divided into four groups based on their body-mass index: lean, normal, overweight, or obese.  For a woman who is 5 feet 5 inches, for example, a weight of less than 120 pounds is lean; a weight of 120 to 149 pounds is normal; a weight of 150 to 179 pounds is overweight, and a weight greater than 180 pounds is obese. 
    The researchers then looked for problems: stillbirths after 28 weeks of pregnancy, infant deaths in the first week after birth, premature deliveries and low birth weight.  
    The mother's weight before pregnancy 		 proved most important in women having their first babies.  
   Among first-time mothers, the study found, normal women had twice the risk of stillbirths compared with lean women; overweight women had three times the risk, and obese women had four times the risk.  Among women who already had children, only the most overweight women had a greater risk of stillbirths than the thinnest. 
     The babies of normal, overweight and obese first-time mothers were twice as likely to die in the first week of life as the babies of lean women. 

(New York Times, 1/15/98)
 
 
  1. In article A, what allows the researchers to claim that "those who died during exercise were more than three times as likely to have evidence of ruptured plaque than men who died during normal activities or while resting."?
 
 
 
 

 
 
 
 
 
 

  1. Try to create a two-way table that summarizes the comparisons that were made in the study discussed in Article A.  You won't be able to fill the table in with numbers--just try to create the structure of the table.
 
 
 
 
 
 
 
 
 
 

 
 
 

  1. In article B, the journalist reported "the babies of normal, overweight and obese first-time mothers were twice as likely to die in the first week of life as babies of lean women."  Related to this statement, what isn't reported in Article B that was reported in Article A?  Does it matter whether "this" is not reported?