Randomized controlled trials: part 17 of a series on evaluation of scientific publications.
BACKGROUND
In clinical research, randomized controlled trials (RCTs) are the best way to study the safety and efficacy of new treatments. RCTs are used to answer patient-related questions and are required by governmental regulatory bodies as the basis for approval decisions.


METHODS
To help readers understand and evaluate RCTs, we discuss the methods and qualitative requirements of RCTs with reference to the literature and an illustrative case study. The discussion here corresponds to expositions of the subject that can be found in many textbooks but also reflects the authors' personal experience in planning, conducting and analyzing RCTs.


RESULTS
The quality of an RCT depends on an appropriate study question and study design, the prevention of systematic errors, and the use of proper analytical techniques. All of these aspects must be attended to in the planning, conductance, analysis, and reporting of RCTs. RCTs must also meet ethical and legal requirements.


CONCLUSIONS
RCTs cannot yield reliable data unless they are planned, conducted, analyzed, and reported in ways that are methodologically sound and appropriate to the question being asked. The quality of any RCT must be critically evaluated before its relevance to patient care can be considered.
Interdisziplinäres Zentrum Klinische Studien-IZKS, Universitätsmedizin der Johannes-Gutenberg-Universität Mainz.
Maria
M
Kabisch
Christian
C
Ruckes
Monika
M
Seibert-Grafe
Maria
M
Blettner
D000022:Abortion, Spontaneous; D001241:Aspirin / Q000008:administration & dosage; D015415:Biomarkers; D017277:Drug Approval / Q000331:legislation & jurisprudence*; D004359:Drug Therapy, Combination; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage; D006493:Heparin / Q000008:administration & dosage; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth; D011247:Pregnancy; D011786:Quality Control; D016032:Randomized Controlled Trials as Topic / Q000592:standards*
D015415:Biomarkers; D005343:Fibrinolytic Agents; D006493:Heparin; D001241:Aspirin