Dental professionals tend to be excellent critical thinkers, accustomed to incorporating only the most reliable evidence into their practice. Evidence-based dentistry (EBD) involves the integration of the best available research with the clinician’s own knowledge, skills and experience regarding the patient’s needs and preferences. Relying on substantiated, authentic and ethically-produced research is one of the cornerstones of best practice.
There are several challenges in consistently practising EBD, which can include insufficient time, and low confidence in searching for and evaluating scientific literature. The process of finding high-quality, valid evidence can be perceived as a daunting and time-consuming pursuit.[i]
However experienced a professional may be, it can still be possible to miss the signs of flawed evidence. The consequences of integrating clinical practice based on poorly researched information could be very serious, and this should be mitigated against consistently.
Valid research, trustworthy evidence
The validity of a research study is associated with removing the likelihood of bias, misconduct or error. Validity can be internal or external. Internal validity is defined as the extent to which the observed results represent the truth in the population under scrutiny, ensuring that these are not due to methodological errors. External validity references the extent to which the results of a study can be generalised to patients in daily practice, especially for the population that the sample is designed to represent.
In the hierarchy of the trustworthiness of evidence, a systematic review and meta-analysis is considered the gold standard. Randomised controlled trials (RCTs) are also considered to be level 1 evidence. Cohort studies and case–control studies are given less gravitas, and case reports, animal studies, and in vitro studies are considered to be the least reliable in terms of research evidence, though some of these methods may help to illustrate data referred to in more comprehensive research.
Methodology should be consistent throughout a trial, and ethics should abide by international conventions, such as those described in the Declaration of Helsinki.[ii] Inclusion and exclusion criteria should also be observed to ensure there are no additional characteristics that could create bias and interfere with the validity of the study. For instance, inclusion criteria might specify demographic, clinical or geographic characteristics of interest. Common exclusion criteria include personal characteristics that might affect adherence to trial frameworks, or comorbidities that could influence outcomes or result in adverse effects for the patient.iii
The problem of bias
Bias is any trend or deviation in data collection, analysis, interpretation and publication which carries a risk of leading to false conclusions.[iii] Bias can be conscious or unconscious, and the effects can be far-reaching. It can affect the validity of research that might otherwise provide useful insight.
There are many examples, but a common problem is sampling bias, which can occur when the subjects of research do not reflect the population to which the research needs to be applied. This can happen when subjects are self-selecting, or recruited without factoring in or declaring characteristics that may be over or under-represented in the outcome of the study. Sampling bias can also occur when the sample size is too small to be representative of the population under scrutiny.iv
Other common biases in research include classification and confounding bias. Classification bias, also known as measurement or information bias, arises from improper, inadequate, or unclear recording of individual factors affecting the quality of the process or outcome. Confounding bias refers to a misleading association between the outcome and a factor that is not causally related to the outcome. Unlike other biases, the latter can be corrected after the study is completed.[iv]
It is important to employ critical thinking when evaluating any clinical research, and this is certainly true of surveys. Surveys are a common research method used in medical and dental education.[v] However, a 2017 analysis of medical research published in 2013 found that only 35.6% of the 185 studies that included surveys met inclusion criteria in their methodology.[vi]
Evidence-based practice and education
All postgraduate and standalone CPD courses at the ICE Postgraduate Institute and Hospital are developed using extensive clinical research and experience in implant dentistry. ICE is supported by the exceptional dedication and skills of expert faculty, led by eminent specialist oral surgeon, Professor Cemal Ucer and post-graduate courses are accredited by the University of Salford. The mission of ICE is to provide evidence-based training to all members of the dental team. For example, the Advanced Certificate In Bone and Tissue Regeneration and Sinus Grafting employs the most current, gold-standard research to support predictable results.
Incorporating practices based on unreliable evidence can be harmful to patients, and affects the reputation of individual practitioners as well as the wider profession. With the right tools, clinicians can ensure they maintain awareness of what makes research valid, and that their clinical education is based on fully evidenced data.
Please contact Professor Ucer at ucer@icedental.institute or Mel Hay at mel@mdic.co
01612 371842
www.ucer-clinic.dental
[i] Durr-E-Sadaf. How to apply evidence-based principles in clinical dentistry. J Multidiscip Healthc. 2019 Feb 11;12:131-136. doi: 10.2147/JMDH.S189484. PMID: 30804675; PMCID: PMC6375114.
[ii] World Medical Association Declaration of Helsinki. JAMA Network. November 2013. Available at: https://jamanetwork.com/journals/jama/fullarticle/1760318 Accessed October 2024
[iii] Simundić AM. Bias in research. Biochem Med (Zagreb). 2013;23(1):12-5. doi: 10.11613/bm.2013.003. PMID: 23457761; PMCID: PMC3900086.
[iv] Lambert J. Statistics in brief: how to assess bias in clinical studies? Clin Orthop Relat Res. 2011 Jun;469(6):1794-6. doi: 10.1007/s11999-010-1538-7. PMID: 20809163; PMCID: PMC3094617.
[v] Phillips AW, Artino AR Jr. Lies, Damned Lies, and Surveys. J Grad Med Educ. 2017 Dec;9(6):677-679. doi: 10.4300/JGME-D-17-00698.1. PMID: 29270252; PMCID: PMC5734316.
[vi] Phillips AW, Friedman BT, Utrankar A, Ta AQ, Reddy ST, Durning SJ. Surveys of Health Professions Trainees: Prevalence, Response Rates, and Predictive Factors to Guide Researchers. Acad Med. 2017 Feb;92(2):222-228. doi: 10.1097/ACM.0000000000001334. PMID: 27532869.
