Read the newspaper article and identify (a) the research question the study addresses, (b) the population, (c) the sample, $(d)$ the descriptive statistics, and (e) the inferences of the study.
By Jeff Donn Associated Press February 20,2005
BOSTON-Levels of a stress-related protein in the blood could give doctors a powerful new tool for deciding which patients with clogged heart arteries are most in danger and need aggressive treatment, a study found.
This protein is yet another predictor of heart trouble, in addition to such substances as cholesterol and C-reactive protein.
The Danish study, published in Thursday's New England Journal of Medicine, focused on a substance called B-natriuretic peptide, or BNP, released into the blood when the heart is stressed. Some doctors already test for this protein to help evaluate patients with shortness of breath who may be suffering from congestive heart disease.
The researchers measured the protein levels in 1,034 patients and followed their health for nine years. People with the highest protein levels were $2 \frac{1}{2}$ times more likely to die from any cause than those with the lowest.
This protein could help doctors decide which patients need angioplasty or heart-bypass surgery. "It sort of tells you that no matter what condition you have, higher levels of these peptides are associated with worse outcomes," said cardiologist Dr. James de Lemos, at the University of Texas Southwestern Medical Center.