Evidence Based.pdf

Evidence Based Clinical Reasoning Ariette Acevedo, O.D. PPO1 What is Evidence Based Clinical Reasoning? • Evidence Based Medicine: “a conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.” • Clinical Reasoning: “the physic...

Evidence Based Clinical Reasoning Ariette Acevedo, O.D. PPO1 What is Evidence Based Clinical Reasoning? • Evidence Based Medicine: “a conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients.” • Clinical Reasoning: “the physician’s integration of their own (biomedical and clinical) knowledge with initial patient information to form a case representation of the problem. The physician uses this problem representation to guide the acquisition of additional information (testing) and then, on the basis of this information, revises the problem representation. They repeat the information gathering-representation revision cycle until she reaches a threshold of confidence in that representation to support a final diagnosis and/or management actions. ” Clinical Reasoning • When examining a patient, we need to learn how to use critical thinking and not just the mechanics of the exam – Technicians' vs doctors • You always need to think several steps ahead of your patient… – Chief complaint will give you the diagnosis – Which test should we be performing vs which test provide us with irrelevant information at the moment Clinical Reasoning • The goal of clinical reasoning is to: – Evaluate the symptoms and signs – Reach a diagnosis – Develop an appropriate management plan • But how does a student learn how to this? – – – – Integration of knowledge and preclinical skills Developing and refining clinical decision skills Practice, practice, practice Keeping yourself updated – Evidence Based Models of Clinical Decision Making • There are 3 models: – Algorithmic Reasoning – Flow chart – Pattern Recognition – Template Matching – Hypothetico-Deductive Method – Process of differential diagnosis Algorithmic Reasoning • “Flow Chart” : Sequence of questions with a number of paths • Characteristics of the condition and associated factors are considered for diagnosis – Logical method • Not every patient fits into the algorithm leading to a change in the sequence of questions Algorithmic Reasoning CC: Blurred Vision Refractive Error Anterior Segment Condition Posterior Segment Condition Pattern Recognition • Case presentation conforms a learned picture or pattern of a disease – “Ah-Ha” moment – Usually involves visual cues and sometimes tactile or auditory cues • Not the most efficient method in conditions with less distinctive features • Generally, the clinical diagnosis has a very recognizable pattern Pattern Recognition Hypothetico-Deductive Method • This is the process of differential diagnosis • Generate several possible DDx (working hypotheses) from the beginning of the examination, corresponding with the patient’s symptoms • With the data, hypotheses are reinforced, rejected or new ones are generated – This cycle continues until the final diagnosis is reached • Tables help by displaying significant features of diagnostic categories that have some similar characteristics – Ex: Red eyes table Differential Diagnosis • • Refers to the doctor’s list of likely hypotheses according to the presenting signs and symptoms Sign (Red Eye) Diagnosis Also refers to the process of gathering clinical information to test the hypotheses that were identified and finally determining the actual diagnosis DDX – This is cyclic process: Data (Signs/Symptoms) Hypothesis (Conjunctiviti s) Clinical Diagnostic Reasoning • Clinical reasoning is the process where a clinician applies reasoning in combination with the clinician's knowledge and skills The Process of Diagnostic Reasoning • This process involves 5 stages: – – – – – • Problem identification and clarification Hypothesis generation Hypothesis testing Hypothesis review Developing a management plan This process is constant and does not necessarily end when a diagnosis has been made – Treatment must be effective Diagnostic Reasoning • Problem Identification and Clarification – Case history is the first opportunity to identify the problem – From case history the clinician starts to develop hypothesis – It is important that you have a good understanding of the chief complaint Diagnostic Reasoning • Hypothesis Generation: – Based on the patient’s complaints, patient profile (age, gender, ethnicity or racial background, occupation, and environmental factors), doctor's knowledge and epidemiology • Hypothesis Testing: – Further inquiry in case history and tests during the examination sequence will provide the doctor with the information to test various hypothesis considered Diagnostic Reasoning • Hypothesis Review – After obtaining clinical information and having an adequate level of certainty, a diagnosis is made – With this some hypothesis are rejected, added or reinforced – Many times, further testing is used to gather a more extensive database of the patient's ocular status (refractive error, binocular vision, ocular health) or monitoring the patient’s progress over time Diagnostic Reasoning • Developing a Management Plan – Depending on diagnosis, condition level or severity (ex: early vs advanced ARMD diagnosis), possible treatment options available – Other factors such as age, PMH, POH, FOH, FMH, Social history, occupation, requirement, etc., all of these have to be considered Factors Contributing to a Doctor’s Clinical Decision-Making Skills • Knowledge base, analytic and diagnostic reasoning skills, clinical experience and professional style • Attitudes and beliefs – Demeanor and manners with patients will affect the ability to obtain proper information, therefore, it affects the ability to make correct clinical diagnosis Chief Complaint • Chief Complaint is one of the most important parts of an examination – Listen, listen, listen • If your patient is complaining of chest pain, you are not thinking about a sprained ankle… – Think of a primary diagnosis, according to what your patient is complaining of what is the most likely cause of this • After you think of a primary diagnosis, then we move on to differential diagnosis – In addition to what I think it most likely is, what else could explain this… Primary Diagnosis vs Differential Diagnosis • After you've identified a primary working diagnosis and a list of differentials your job now is to 1. 2. • Validate or rule out your primary diagnosis Eliminate or validate your differential diagnosis How do we do this? Asking the right questions, performing the necessary tests and evaluating all the information in front of us – Critical analysis vs mechanical testing Intuitive vs Analytical Approach Intuitive Approach • Subconjunctival Hemorrhage – Very typical presentation – Recall memory of previous patients Analytical Approach • Red Eye – Varying presentation – Varying diagnosis – Need more information Intuitive Approach • You cultivate your intuitive approach by learning and committing to memory certain patterns and behaviors and creating mental shortcuts • But we must be very careful, because “…occasionally it fails, sometimes • Since we are working with mental shortcuts, we are also subject to biases catastrophically. Predictably, it misses the patient who presents atypically, or when the pattern is mistaken for something else.“ – “In forming their early diagnostic impressions, physicians may be consciously or subconsciously influenced by a variety of factors, including patient characteristics (appearance, demeanor, degree of discomfort, communication issues, past experience with the patient), characteristics of the illness (acuity, severity, past experience with the presenting complaints), immediate issues in the medical environment (other patients’ needs, workload, priority setting, interruptions, distractions), resource issues (availability of specific tests, procedures, consultants, hospital beds), overarching issues (professional, ethical, medicolegal), and others.” Intuitive Approach • This is a Subconjunctival Hemorrhage but due to my preconceived bias I may have dismissed that: – This is my patient's 3rd SCH in 3 months – Meaning that I should be further testing for blood dyscrasias (coagulations factors, ect…) Analytical Approach • This kicks in when the presentation we are seeing are not easily recognized or do not fit in a specific illness category – i.e. a red eye • “The degree of pathognomicity is low, and uncertainty is correspondingly high; the various possibilities must now be teased out from each other in a systematic search.” • This is slow, time and resource consuming… – Educational bases Analytical Approach • Red Eye – Differential diagnosis list: – Conjunctivitis (bacterial, viral or allergic) – – – – Acute angle closure attack Corneal insult (abrasion, laceration) Scleritis Episcleritis – Dry Eye Syndrome • “The development of genuine expertise requires struggle, sacrifice, and honest, often painful self assessment. There are no shortcuts…and you will need to invest that time wisely, by engaging in ‘deliberate practice’—practice that focuses on tasks beyond your current level of competence and comfort.