QUESTIONS
- Which of the following terms best describes a test used to detect
disease before it presents clinically?
a) diagnostic test;
b) sensitive test;
c) screening test;
d) prognostic test;
e) specific test.
- The term used to describe the cause of a disease is:
a) manifestation;
b) etiology;
c) pathogenesis;
d) mortality;
e) epidemiology.
- A Na+ solution of 10 mmol dm–3 was measured by two methods X
and Y. The value obtained with method X was 11.8 mmol dm–3 and
for method Y it was 9.7 mmol dm–3. Which one of the following state-
ments is correct?
a) Method X is more accurate than method Y.
b) Method X is more precise than method Y.
c) Method Y is more accurate than method X.
d) Method Y is more precise than method X.
e) Method X is as accurate as method Y.
- The concentration of Mg2+ in the serum of an individual is 0.5 mmol
dm–3. The reference range is 0.7 to 1.0 mmol dm–3. Is it possible to be
100% certain that this individual has a deficiency of Mg2+? Explain
your answer.
Further Reading
Henny, J and Hyltoft Petersen, P (2004) Reference values: from philosophy to
a tool for laboratory medicine. Clin. Chem. Lab. Med.42: 686–691.
Hooper, J, McCreanor, G, Marshall, W and Myers, P (1996) Primary Care and
Laboratory Medicine. ACB Venture Publications, Cambridge.
Irjala, KM and Gronroos, PE (1998) Preanalytical and analytical factors
affecting laboratory results. Ann. Med.30: 267–272.
Khan, KS, Dinnes, J and Klijnen, J (2001) Systematic reviews to evaluate
diagnostic tests. Eur. J. Obstet. Gynecol. Reprod. Biol.95: 6–11.
Libeer, J-C (2001) Role of external quality assurance schemes in assessing
and improving quality in medical laboratories. Clin. Chim. Acta 309:
173–177.
Moyer, VA and Kennedy, KA (2003) Understanding and using diagnostic tests.
Clin. Perinatol.30: 189–204.
X]VeiZg&/ THE NATURE AND INVESTIGATION OF DISEASES
'' W^dad\nd[Y^hZVhZ