Epidemiology

Slideshow covering the some of the key conditions in gastroenterology.  

A brief presentation of basic epidemiology.  

A simple brief introduction to Health ecconomics by Dr. Sanjay Sharma, a Professor of Ophthalmology and Epidemiology at Queen's University. US Health system centric.  

Great flow chart to help you understand how study types are classified. Each type is then discussed individually so you can learn more about its purpose.  

Odds ratio can mislead if a "Common Event" is studied, since it can exaggerate effects. Relative risk is appropriate for randomized control studies and cohort studies.  

Excellent slideshow including epidemiology, evidence for management, pathophysiology and prevention.  

A step-by-step approach for choosing an appropriate statistical test for data analysis.  

Some easy methods to remember: - the definition of 'Epidemiology' and 'Public Health'. - what are Primary, Secondary, and Tertiary disease prevention. - the Bradford-Hill criteria for disease causation.  

A informative document about psoriasis including the histology, epidemiology, triggers, types and treatment of the condition.  

Easily understand the concepts of SENSITIVITY and SPECIFICITY! These two words can be confusing when you are first learning the basics of biostatistics.  

A basic outline of pathophysiology, symptoms, diagnosis, treatment and epidemiology.  

A presentation on ‘Anxiety Disorders’ that systematically goes through the Clinical features, Epidemiology, Aetiology, Management and Prognosis of the follow...  

In this first video on ischemic stroke, we'll look at some of the epidemiology of stroke - it's a pretty devastating disease on our population.  

British Medical Podcasts’ second podcast in the series.  Created by Doctors for Doctors.  We aim to give a comprehensive overview of each topic including need to know information.  Content includes Definition, Aetiology, Epidemiology, Anatomy if relevant, Pathology, Clinical Presentation and Features, Treatment and Prognosis.  

Note summaries of the basics of epidemiology  

SImple, to-the-point 10 minute powerpoint overview of gout. Discusses the epidemiology, pathophysiology, investigations, diagnosis, differentials and management.  

In a recent article in the BMJ the author wonders about the reasons beyond the rising trend diagnosing Attention Deficit Hyperactivity Disorder (ADHD). The article attempts to infer reasons for this. One possible reason was that the diagnostic criteria especially DSM may seem for some to be more inclusive than ICD-10. The speculation may explain the rise of the diagnosis where DSM is used officially or have an influence. In a rather constructive way, an alternative to rushing to diagnosis is offered and discussed in some details. The tentative deduction that the Diagnostic Statistical Manual (DSM) may be one of the causes of rising diagnosis, due to raising the cut-off of age, and widening the inclusion criteria, as opposed to International Classification of Diseases, 10th revision (ICD-10), captured my attention. On reading the ICD-10 diagnostic criteria for research (DCR) and DSM-5 diagnostic criteria, I found them quite similar in most aspects, even the phraseology that starts with 'Often' in many diagnostic criteria, they seem to differ a bit in age. In a way both classification, are attempting to describe the disorder, however, it sounds as if someone is trying to explain a person's behaviour to you, however, this is not a substitute to direct clinical learning, and observing the behaviour, as if the missing sentence is 'when you see the person, it will be clearer'. El-Islam agrees with the notion that DSM-5 seems to be a bit more inclusive than ICD-10. A colleague of mine who is a child psychiatrist and she is doing her MSc. thesis in ADHD told me, that DSM-5 seems to be a substantial improvement as compared to its predecessor. The criteria - to her - though apparently are more inclusive, they are more descriptive with many examples, and she infers that this will payback in the reliability of the diagnosis. She hopes gene research can yield in biological tests for implicated genes and neurotransmitters in ADHD e.g. DRD4, DAT, gene 5,6,11 etc. One child psychiatrist, regretted the fact that misdiagnosis and under-diagnoses, deprive the patient from one of the most effective treatments in psychiatry. It is hoped the nearest forthcoming diagnostic classification (ICD-11), will address the issue of the diagnosis from a different perspective, or else converge with DSM-5 to provide coherence and a generalised newer standard of practice. The grading of ADHD into mild, moderate, and severe seem to blur the border between disorder and non-disorder, however, this quasi-dimensional approach seems realistic, it does not translate yet directly in differences in treatment approaches as with the case of mild, moderate, severe, and severe depression with psychotic symptoms, or intellectual disability. The author states that one counter argument could be that child psychiatrists are better at diagnosing the disorder. I wonder if this is a reflection of a rising trend of a disorder. If ADHD is compared to catatonia, it is generally agreed that catatonia is less diagnosed now, may be the epidemiology of ADHD is not artefact, and that we may need to look beyond the diagnosis to learn for example from environmental factors. Another issue is that there seems to be significant epidemiological differences in the rates of diagnosis across cultures. This may give rise to whether ADHD can be classified as a culture-bound syndrome, or whether it is influenced by culture like anorexia nervosa, or it may be just because of the raising awareness to such disorders. Historically, it is difficult to attempt to pinpoint what would be the closest predecessor to ADHD. For schizophrenia and mania, older terms may have included insanity, for depression it was probably melancholia, there are other terms that still reside in contemporary culture e.g. hypochondriasis, hysteria, paranoia etc. Though, it would be too simplistic to believe that what is meant by these terms was exactly what ancient cultures meant by them, but, they are not too far. ADHD seems to lack such historical underpinning. Crichton described a disorder he refers to as 'mental restlessness'. Still who is most often credited with the first description of ADHD, in his 1902 address to the Royal College of Physicians. Still describes a number of patients with problems in self-regulation or, as he then termed it, 'moral control' (De Zeeuw et al, 2011). The costs and the risks related to over-diagnosis, ring a warning bell, to enhance scrutiny in the diagnosis, due to subsequent stigma, costs, and lowered societal expectations. They all seem to stem from the consequences of the methodology of diagnosis. The article touches in an important part in the psychiatric diagnosis, and classifications, which is the subjective nature of disorders. The enormous effort done in DSM-5 & ICD-10 reflect the best available evidence, but in order to eliminate the subjective nature of illness, a biological test seems to be the only definitive answer, to ADHD in particular and psychiatry in general. Given that ADHD is an illness and that it is a homogeneous thing; developments in gene studies would seem to hold the key to understanding our current status of diagnosis. The suggested approach for using psychosocial interventions and then administering treatment after making sure that it is a must, seems quite reasonable. El-Islam, agrees that in ADHD caution prior to giving treatment is a recommended course of action. Another consultant child psychiatrist mentioned that one hour might not be enough to reach a comfortable diagnosis of ADHD. It may take up to 90 minutes, to become confident in a clinical diagnosis, in addition to commonly used rating scales. Though on the other hand, families and carers may hypothetically raise the issue of time urgency due to scholastic pressure. In a discussion with Dr Hend Badawy, a colleague child psychiatrist; she stated the following with regards to her own experience, and her opinion about the article. The following is written with her consent. 'ADHD is a clinically based diagnosis that has three core symptoms, inattention, hyperactivity and impulsivity in - at least - two settings. The risk of over-diagnosis in ADHD is one of the potentially problematic, however, the risk of over-diagnosis is not confined to ADHD, it can be present in other psychiatric diagnoses, as they rely on subjective experience of the patient and doctor's interviewing skills. In ADHD in particular the risk of under-diagnosis is even more problematic. An undiagnosed child who has ADHD may suffer various complications as moral stigma of 'lack of conduct' due to impuslivity and hyperactivity, poor scholastic achievement, potential alienation, ostracization and even exclusion by peer due to perceived 'difference', consequent feelings of low self esteem and potential revengeful attitude on the side of the child. An end result, would be development of substance use disorders, or involvement in dissocial behaviours. The answer to the problem of over-diagnosis/under-diagnosis can be helped by an initial step of raising public awareness of people about ADHD, including campaigns to families, carers, teachers and general practitioners. These campaigns would help people identify children with possible ADHD. The only risk is that child psychiatrists may be met with children who their parents believe they might have the disorder while they do not. In a way, raising awareness can serve as a sensitive laboratory investigation. The next step is that the child psychiatrist should scrutinise children carefully. The risk of over-diagnosis can be limited via routine using of checklists, to make sure that the practice is standardised and that every child was diagnosed properly according to the diagnostic criteria. The use of proper scales as Strengths and Difficulties Questionnaire (SDQ) in its two forms (for parents SDQ-P and for teachers SDQ-T) which enables the assessor to learn about the behaviour of the child in two different settings. Conner's scale can help give better understanding of the magnitude of the problem. Though some people may voice criticism as they are mainly filled out by parents and teachers, they are the best tools available at hands. Training on diagnosis, regular auditing and restricting doctors to a standard practice of ensuring that the child and carer have been interviewed thoroughly can help minimise the risk of over-diagnosis. The issue does not stop by diagnosis, follow-up can give a clue whether the child is improving on the management plan or not. The effects and side effects of treatments as methylphenidate should be monitored regularly, including regular measurement height and weight, paying attention to nausea, poor appetite, and even the rare side effects which are usually missed. More restrictions and supervision on the medication may have an indirect effect on enhancing the diagnostic assessment. To summarise, the public advocacy does not increase the risk of over-diagnosis, as asking about suicidal ideas does not increase its risk. The awareness may help people learn more and empower them and will lead to more acceptance of the diagnosed child in the community. Even the potential risk of having more case loads for doctors to assess for ADHD may help give more exposure of cases, and reaching more meaningful epidemiological finding. From my experience, it is quite unlikely to have marked over-representation of children who the families suspect ADHD without sufficient evidence. ADHD remains a clinical diagnosis, and it is unlikely that it will be replaced by a biological marker or an imaging test in the near future. After all, even if there will be objective diagnostic tests, without clinical diagnostic interviewing their value will be doubtful. It is ironic that the two most effective treatments in psychiatry methylphenidate and Electroconvulsive Therapy (ECT) are the two most controversial treatments. May be because both were used prior to having a full understanding of their mechanism of action, may be because, on the outset both seem unusual, electricity through the head, and a stimulant for hyperactive children. Authored by E. Sidhom, H. Badawy DISCLAIMER The original post is on The BMJ doc2doc website at http://doc2doc.bmj.com/blogs/clinicalblog/#plckblogpage=BlogPost&plckpostid=Blog%3A15d27772-5908-4452-9411-8eef67833d66Post%3Acb6e5828-8280-4989-9128-d41789ed76ee BMJ Article: (http://www.bmj.com/content/347/bmj.f6172). Bibliography Badawy, H., personal communication, 2013 El-Islam, M.F., personal communication, 2013 Thomas R, Mitchell GK, B.L., Attention-deficit/hyperactivity disorder: are we helping or harming?, British Medical Journal, 2013, Vol. 5(347) De Zeeuw P., Mandl R.C.W., Hulshoff-Pol H.E., et al., Decreased frontostriatal microstructural organization in ADHD. Human Brain Mapping. DOI: 10.1002/hbm.21335, 2011) Diagnostic Statistical Manual 5, American Psychiatric Association, 2013 Diagnostic Statistical Manual-IV, American Psychiatric Association, 1994 International Classification of Diseases, World Health Organization, 1992  

First in a series of Medical Podcasts created by two Doctors for Doctors.  We aim to give a comprehensive overview of each topic.  Content includes Definition, Aetiology, Epidemiology, Anatomy if relevant, Pathology, Clinical Presentation and Features, Treatment and Prognosis.  

Here's a brief introduction to how to evaluate systematic reviews.  

We all hear about Ebola being a deadly disease, and indeed it is. The rather agressive virus has already claimed about 10,000 lives. But what really makes Ebola such a deadly virus? Let’s try and understand how Ebola really attacks the cells within the body which in turn leads to multiple organ failure and then exigency. This 3D Medical Animation illustrates the Mechanism of Action of the Ebola Virus.