You are of course concerned about the quality of studies included in a systematic review.In general RCTs are the 'gold standard' design, especially for interventions,
But there are many circumstances when they are infeasible, unethical or otherwise
Inappropriate.Identify for which of the following research questions an RCT would
Not be the optimal design.
A)Does beta‐carotene prevent skin cancers in Scandinavians?
B)Does smoking cigarettes cause heart attacks in women?
C)How effective are large‐scale population‐based screening programmes in lowering mortality from breast cancer?
D)Does long‐term aspirin use lower mortality after a heart attack among male doctors?
E)None of the above

Question

Quizplus · Accepted Answer

This question is not directly amenable to an experimental approach, as it is
clearly unethical to randomise anyone to being a smoker.An inverted approach -
randomising women who smoke to a quit smoking programme - could test some
aspects of the hypothesis if the anti‐smoking programme worked, numbers were large
and follow‐up was long.(The latter two factors compromised an experiment to test D in
an RCT of over 20,000 male doctors followed up for 12 years.This had to be abandoned
without the question being answered because the death rates were very low in both
arms of the trial).And while RCTs are crucial in evaluating whether under research
conditions a screening programme can save lives (C), once the programme has been
implemented as a wide‐scale service, its evaluation rests largely on simple descriptive
measures of population mortality (see Chapter 15).For A an experimental design is
critical to getting the right answer.

You Are of Course Concerned About the Quality of Studies