Randomized, controlled trials, observational studies, and the hierarchy of research designs

Article Abstract:

A well-designed observational study may produce results similar to that of a randomized, controlled trial. Both types of research are used to evaluate treatments, but randomized controlled trials are considered more valuable. Researchers analyzed 99 reports that evaluated five different treatments. For each treatment, there were several observational studies and several randomized controlled trials. The results of the observational studies were similar to the results of the randomized controlled trials. Observational studies are of interest because they are cheaper than randomized controlled trials and easier to do.

---

A comparison of observational studies and randomized, controlled trials

Article Abstract:

Observational studies may produce results similar to a randomized, controlled clinical trial and may be cheaper and easier to do. This was the conclusion of researchers who compared the outcomes of 136 reports evaluating 19 different treatments, all of which were published between 1985 and 1998. Of the 136 reports, 53 were observational studies and 83 were randomized controlled trials. For each treatment, there was at least one observational study and one randomized controlled trial. For 17 of the treatments, both types of study produced similar estimates of effectiveness.

---

Randomized trials or observational tribulations?

Article Abstract:

It may be imprudent to abandon randomized controlled trials in favor of observational studies just because the latter are cheaper and easier to do. Two studies published in 2000 found that observational studies sometimes produce the same result as randomized controlled trials. However, this is not always the case. Randomized controlled trials have achieved such prominence precisely because they are the research method that is most likely to produce an unbiased result.

Editorial

Similar abstracts:

• Abstracts: A multicenter controlled trial of fetal pulse oximetry in the intrapartum management of nonreassuring fetal heart rate patterns
• Abstracts: A randomized, controlled trial of a behavioral intervention to prevent sexually transmitted disease among minority women
• Abstracts: A prospective, randomized, controlled trial of high and low maintenance doses of magnesium sulfate for acute tocolysis
• Abstracts: Scientists irked by ethicists' alternatives for embryo research. RAC tries to regain foothold
• Abstracts: Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.