23/03/2022
💊💊randomized controlled trial (RCT)💊💊
● Definition:
Randomized studies are studies in which the participants are divided "randomly" into two or more groups, and are considered the gold standard in the search for preventive and treatment interventions, and this is because they have a high degree of reliability, and they are a type of experimental studies more than they are descriptive.
Experimental studies have more control than descriptive studies, and this is good because it is possible to isolate the factor we want to study and make everything else similar between the two groups.
For example; Things like randomization and blinding are not possible for most types of descriptive studies, however: In RCTs, you can use these methods, which increases their reliability.
The biggest difference between descriptive studies and experimental studies such as RCTs is how participants are divided into groups. In randomized experimental studies, researchers divide the participants according to several structured techniques. In descriptive studies, the natural conditions are what determine which group the participant will be, such as genetics, the environment, lifestyle..etc, and the result of all these things either expose the person to some risk factors or lead to some treatments.
In addition to that; When you prepare a descriptive study, you only see things that happen naturally and take some observations, and you can see that there is a great chance of bias in the descriptive studies. Because you cannot control a lot of things.
● Advantage:
•"Control over risk assignment"
Unlike the observational study designs, clinical trials enable the investigators to determine which participants are allocated to each treatment. This allows investigators to employ random allocation procedures in order to obtain nearly equal study groups.
•"Strong evidence"; RCTs are the gold standard studies; owing to their high internal validity, RCTs are regarded as gold-standard clinical research studies.
● Disadvantages:
• Expensive evaluation of risk factors
• Experimentation sometimes may be difficult, inappropriate or unethical.
● Placebo:
Inert material that is administrated by the control group in blinded studies to overcome and eliminate the psychological effect. In surgeries, blinding is not possible in all studies; most surgery interventions cannot be blinded.
example : https://www.annfammed.org/content/10/4/337.long
و في هذه الدراسات يقوم الباحثون بعمل تدخل معين (إعطاء دواء ما، تجريب طريقة علاجية جديدة، التقليل من مؤثر معين) ثم يقومون بمتابعة الحالات لمعرفة تأثير هذا التدخل على سير المرض أو حالة المرضى. و قد تكون هذه الدراسات مضبوطة Controlled (تحتوي على مجموعة ضابطة للمقارنة بها) او غير مضبوطة Non-controlled (لا تحتوي على مجموعة ضابطة للمقارنة بها). و عند استعمال مجموعة ضابطة في الدراسة التجريبية يمكن أن يتم توزيع الحالات بشكل عشوائي بين مجموعة التجربة و المجموعة الضابطة للحصول على تجربة عشوائية مضبوطة Randomised Controlled Trial أو قد لا يتم استعمال التوزيع العشوائي للحالات بين مجموعة التجربة و المجموعة الضابطة و تكون النتيجة تجربة غير عشوائية مضبوطة non-randomized controlled trial.
