Evidence-based medicine (EBM) is a systemic approach that integrates the best available scientific evidence into clinical decision-making. The best available scientific evidence refers primarily to patient-centered research that covers accuracy, efficacy, and safety of diagnostic tools or treatments. Evidence-based medicine (EBM) represents the highest standard of clinical practice via an integration of scientific evidence, clinical expertise and consideration of patient values. Neither of these three alone would be sufficient for optimal patient outcome.In today’s practice, medical evidence can be synthesised into clinical guidelines which provide healthcare professionals with evidence-based recommendations on diagnosis, treatment, and management of various medical conditions, helping them make the most informed decisions and improve medical service quality. These guidelines not only drive clinical excellence but also serve as public education tools to facilitate citizens’ understanding of the healthcare services they may need in the event of different illnesses, fostering informed engagement in their own health management.​ Reference:Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS. Evidence based medicine: what it is and what it isn't. BMJ. 1996;312(7023):71-72. doi: 10.1136/bmj.312.7023.71

With the increasing popularity of social media, the public have vast access to others’ patient pathway.  However, in clinical practice, disease diagnosis and treatment require consideration of multiple factors, such as gender, age, imaging reports, blood reports, clinical symptoms, family history etc.  Relying solely on social media descriptions as the main source of medical information, or drawing conclusions based only on others’ circumstances, can often lead to misconceptions or result in misjudgment regarding one’s own medical needs.By understanding Evidence-based Medicine (EBM) and clinical guidelines, not only can the public gain more insight into the reasoning behind and process involved in diseases diagnosis and treatment, but also learn how to identify scientific and reliable medical information, thus shielding individuals from being misinformed by partial or even misleading information. What’s more, the public will also be reassured that the clinical decisions made by healthcare professionals are based on conclusions from a vast number of clinical studies, rather than being arbitrary or relying solely on textbooks and personal experience.

As the name suggests, clinical research may give answers to problems commonly encountered in clinical practice.  Clinical problems often surround the cause, diagnosis, treatment, and prognosis of illnesses.  Clinical research may be further divided into primary and secondary research based on study methods: Primary ResearchIt is a research method where studies are conducted directly on patients relating to the cause, diagnosis, treatment and prognosis of illnesses.  Conclusions are drawn by statistical analysis of the original research data obtained.Secondary ResearchIt is a method of gathering information from existing data from primary research on a clinical problem.  Conclusions are drawn based on rigorous evaluation, integration, and analysis of these primary data.  It is the higher-level evidence obtained after processing multiple primary research evidence.

A core principle of Evidence-based Medicine (EBM) is the systematic ranking of different study types into the “Hierarchy of Evidence” based on their strengths. Stronger evidence is one that derived from higher-ranked studies which employed more rigorous research methods, indicating a stronger level of confidence.At the top of this hierarchy is secondary research mentioned earlier, including Systematic Reviews and Meta-analyses, as well as Randomised Controlled Trials (RCTs) which offer the strongest evidence among primary research. The other study types at the lower ranks include Expert Opinions and Case Reports etc. While healthcare professionals and scholars gravitate more towards stronger evidence, often, some clinical topics may lack sufficient higher-ranked studies. In such cases, lower-ranked studies are also considered as reference for developing clinical guidelines. Understanding the “Hierarchy of Evidence” can help with the evaluation of reliability and quality of different studies, thus making the best clinical judgement to optimise patient care based on the best evidence available.​Reference:Murad MH, Asi N, Alsawas M, Alahdab F. New evidence pyramid. Evid Based Med. 2016;21(4):125-127. doi:10.1136/ebmed-2016-110401

Randomised Controlled Trial (RCT) is a rigorous and reliable study design.  It refers to the random assignment of samples into different treatment groups during a clinical trial. As the name suggests, RCT can be dissected into three key components:Randomisation:It refers to randomly assigning participants to different treatment groups using a computer program or other scientific methods. It ensures that participant characteristics among different groups (such as age, gender, disease severity etc.) are generally comparable, such that the difference in treatment outcomes among groups are primarily due to the intervention concerned.Control:It refers to setting a “Control Group” as a benchmark to compare and evaluate the relative efficacy or safety of the “Experimental Group”, as well as to identify unexpected results or side effects. “Control Group” typically receives a placebo, standard treatment or without intervention.Trial:It refers to an experimental study conducted on real human subjects to determine the safety, efficacy, and feasibility of a new drug or treatment.  This type of clinical trial is characterised by a detailed clinical trial protocol and adherence to data quality monitoring and ethical review, ensuring scientific validity while protecting the rights and interests of participants.Through randomisation, control setup, and strict regulations, RCTs can provide the most reliable evidence on treatment effectiveness.  Therefore, they are considered the gold standard of medical research and are widely used in clinical medicine, public health and other scientific research areas. ​Reference:Bonnie S, Martin R. Understanding controlled trials: Why are randomised controlled trials important? BMJ. 1998;316:201. doi:10.1136/bmj.316.7126.201

In clinical research, “Blinding” refers to the approach of keeping participants, researchers, or both unaware of the treatments assigned to the participants. “Blinding” is closely related to Randomised Controlled Trial (RCT) described earlier and is a key method to improve the quality of RCT.  The two most common blinding methods are “Single Blinding” and “Double Blinding”: Single BlindingIt refers to the trial course in which only the participants are unaware of their assignments to the “Experimental Group” or “Control Group”, while the researchers know.  It aims to prevent psychological factors of the participants from influencing treatment outcomes. In the absence of blinding, participants’ knowledge of their assigned treatments may influence their behaviours and responses to outcome measurements, particularly for subjective endpoints (e.g. self-reported pain relief).  However, blinding is less important for objective endpoints (e.g. tumor size reduction assessed by imaging). Double BlindingIt refers to the trial course in which neither the participants nor the researchers are aware of the treatment assignments. It aims to minimise bias on both parties and ensure objective data collection, especially to reduce researchers’ subconscious influence on disease assessment, patient care, and data analysis etc. due to a desire for positive results. This type of blinding is commonly used in drug trials. Adoption of blinding usually depends on the study design, resources available and ethical considerations.  Generally speaking, blinding helps minimise bias and maximise validity of results.  While inadequate blinding may compromise objectivity and reliability of a study.​Reference:Helene M, Gemma L C, Hayley E J, et al. Impact of blinding on estimated treatment effects in randomised clinical trials: meta-epidemiological study. BMJ. 2020;368:l6802. doi:10.1136/bmj.l6802