Bias: A 30-Year Review of Randomized Controlled Trials Published in Three Prosthodontic Journals

Area of Science:

• Prosthodontics
• Clinical Trials
• Research Methodology

Background:

• Bias can compromise the validity of results in randomized controlled trials (RCTs).
• Effective bias control is crucial for reliable findings in clinical research.
• Prosthodontic research relies on high-quality RCTs to inform treatment decisions.

Purpose of the Study:

• To assess the improvement in bias control in prosthodontic RCTs.
• To compare bias control in RCTs published between 2008-2017 with those from 1988-1997.
• To evaluate specific aspects of bias control including randomization, blinding, and subject accountability.

Main Methods:

• A systematic search of MEDLINE was conducted for RCTs published in key prosthodontic journals from 2008-2017.
• RCTs were included if they involved human subjects, had at least two treatment groups, and used random allocation.
• Bias control was assessed based on reported methods for randomization, blinding, and accounting for all subjects, with scores ranging from 0 (poor) to 3 (good).

Main Results:

• Ninety-six RCTs from 2008-2017 were reviewed; 32% achieved the maximum bias control score (3 points).
• Explicit reporting of randomization (68%), blinding (50%), and subject accountability (85%) were observed in the recent period.
• Compared to 1988-1997 RCTs (16% with max score), the later period showed improvements in all assessed bias control dimensions.

Conclusions:

• Overall quality and bias control in prosthodontic RCTs have significantly improved.
• Enhanced reporting of methodological details contributes to more reliable research findings.
• The findings suggest a positive trend in the rigor of prosthodontic clinical trials over the past decades.