Clinical study types and guidance for their correct post-pandemic interpretation.

Area of Science:

• Medical research methodology
• Clinical microbiology research

Background:

• Randomized clinical trials (RCTs) are essential for medical and microbiology advancements.
• Observational studies offer advantages in cost, speed, and studying rare events but are susceptible to confounding factors.
• Prospective pilot studies share RCT characteristics but lack external oversight and mandatory registration.

Purpose of the Study:

• To evaluate the role and limitations of various clinical study designs beyond RCTs.
• To highlight the potential for publication bias and misleading results due to multitesting.
• To advocate for the systematic registration of all clinical research.

Main Methods:

• Comparative analysis of different clinical study designs (RCTs, observational, pilot).
• Discussion of statistical principles (e.g., Bonferroni's reasoning) regarding multitesting.
• Examination of publication bias scenarios in research settings.

Main Results:

• Observational studies provide valuable long-term efficacy and safety data.
• Multitesting can inflate the probability of finding statistically significant results (P <0.05) even for ineffective treatments.
• Without registration, numerous studies on an ineffective drug could create false evidence of efficacy.

Conclusions:

• RCTs are a primary source of clinical data, but not the sole reliable method.
• Systematic registration of all clinical studies is crucial for scientific integrity.
• Implementing mandatory registration for all study types can mitigate publication bias and ensure accurate scientific conclusions.