Researchers are interested in further investigating the side effects of a relatively recent hypolipidemic drug. A literature review showed several studies in which patients who took this drug reported severe acute myositis as an adverse event. In many instances, affected patients experienced life-threatening complications from myositis, including rhabdomyolysis leading to acute renal failure and profound electrolyte abnormalities. However, none of these studies documented a statistically significant difference in the occurrence of severe acute myositis between the treatment and placebo groups. Which of the following is the best method to further investigate the association between use of this hypolipidemic drug and development of severe acute myositis?
A)Conduct a new large-scale clinical trial.
B)Perform stratified analysis on multiple risk factors.
C)Pool the data from several trials.
D)Review the medical charts to re-ascertain the events.
E)There is no need to further study this statistically nonsignificant association.

Question

Researchers are interested in further investigating the side effects of a relatively recent hypolipidemic drug.  A literature review showed several studies in which patients who took this drug reported severe acute myositis as an adverse event.  In many instances, affected patients experienced life-threatening complications from myositis, including rhabdomyolysis leading to acute renal failure and profound electrolyte abnormalities.  However, none of these studies documented a statistically significant difference in the occurrence of severe acute myositis between the treatment and placebo groups.  Which of the following is the best method to further investigate the association between use of this hypolipidemic drug and development of severe acute myositis?
A)Conduct a new large-scale clinical trial.
B)Perform stratified analysis on multiple risk factors.
C)Pool the data from several trials.
D)Review the medical charts to re-ascertain the events.
E)There is no need to further study this statistically nonsignificant association.

Quizplus · Accepted Answer

Explanation: Pooling the data from several studies to perform an analysis is called meta-analysis. Meta-analysis is a valuable epidemiologic tool used to increase the power of a study (ie, its ability to detect difference in outcome of interest between groups, if such a difference exists). If an outcome is rare or if the difference in outcomes between groups is small, it is difficult for a single study-even a relatively large-scale one-to detect that difference, making it unlikely that the results will reach statistical significance. In such cases, meta-analysis can be used to increase the sample size, thereby increasing the power of the analysis. The major disadvantage of meta-analysis includes concomitant "pooling" of the biases and limitations of individual studies into one analysis. (Choice A) Conducting a new large-scale clinical trial is problematic at this point because a potentially life-threatening complication (eg, severe acute myositis) can be induced by the drug. (Choice B) Stratified analysis refers to analyzing patients based on the presence or absence of a certain variable; it can be used to control confounding factors and distinguish between confounding and effect modification. (Choice D) Reviewing the medical charts may be used if misclassification of the events is suspected. Such an error is unlikely to have occurred in different studies and patient groups. (Choice E) The side effect described is severe; therefore, drug safety should be investigated as the lack of statistical significance could be due to small sample sizes regarding a rare adverse event. Educational objective: Meta-analysis is conducted by pooling the data from several studies to increase statistical power.

Researchers Are Interested in Further Investigating the Side Effects of a Relatively