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21
1869

Epidemiology Statistics Tutorial

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.  
HelpHippo.com
almost 4 years ago
D525512460acf883a6150fae9403ebd508e193719745937056893971
19
3597

How to Choose the Appropriate Statistical Test

A step-by-step approach for choosing an appropriate statistical test for data analysis.  
youtube.com
over 1 year ago
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11
216

Sensitivity and Specificity

Easily understand the concepts of SENSITIVITY and SPECIFICITY! These two words can be confusing when you are first learning the basics of biostatistics.  
youtu.be
over 1 year ago
2257fe0ee21c3622a3e45cdaf279d4c3
9
144

Is ADHD a difficult diagnosis?

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  
Dr Emad Sidhom
almost 4 years ago
8d8965874de4d556d69ada325e2c4d5f40885f3d32066620626360076
9
262

Risk Factors for Osteoporosis

This is a really useful infographic showing different risk factors.  
Andrea
over 2 years ago
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10
148

Adequate Vitamin C Linked to Lower Risk for Heart Disease

High vitamin C levels may be the primary reason why people who eat lots of fruits and vegetables have lower risk of heart disease and early death.  
articles.mercola.com
almost 2 years ago
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7
96

Fact, Figures and Statistics

Summary of statistics  
Philip Welsby
over 6 years ago
4
5
65

Sepsis - Part 1

<div class="postBody">Sepsis is a common cause of death in the intensive care unit.&nbsp; In this episode I present some of the statistics on septic deaths, introduce the definitions, and present the basic science.&nbsp; Part 2 will cover fluid and drug therapy for septic shock.&nbsp; </div>  
Jeffrey S. Guy, MD, FACS
about 7 years ago
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4
101

Lecture 1 - intro to epidemiology and statistics

This is an introduction to epidemiology and statistics. Discussing discriptives.  
Nicole Chalmers
almost 4 years ago
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4
185

USMLE Epidemiology and Biostatistics Flashcards - Flashcardexchange.com

USMLE Epidemiology and Biostatistics Flashcards - Flashcardexchange.com http://www.flashcardexchange.com/cards/usmle-epidemiology-and-biostatistics-729029 “ Study Flashcards On USMLE Epidemiology and...  
mynotes4usmle.tumblr.com
over 3 years ago
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9
95

Why Are American Health Care Costs So High?

In which John discusses the complicated reasons why the United States spends so much more on health care than any other country in the world, and along the way reveals some surprising information, including that Americans spend more of their tax dollars on public health care than people in Canada, the UK, or Australia. Who's at fault? Insurance companies? Drug companies? Malpractice lawyers? Hospitals? Or is it more complicated than a simple blame game? (Hint: It's that one.) For a much more thorough examination of health care expenses in America, I recommend this series at The Incidental Economist: http://theincidentaleconomist.com/wordpress/what-makes-the-us-health-care-system-so-expensive-introduction/ The Commonwealth Fund's Study of Health Care Prices in the US: http://www.commonwealthfund.org/~/media/Files/Publications/Issue%20Brief/2012/May/1595_Squires_explaining_high_hlt_care_spending_intl_brief.pdf Some of the stats in this video also come from this New York Times story: http://www.nytimes.com/2013/06/02/health/colonoscopies-explain-why-us-leads-the-world-in-health-expenditures.html?pagewanted=all This is the first part in what will be a periodic series on health care costs and reforms leading up to the introduction of the Affordable Care Act, aka Obamacare, in 2014.  
Nicole Chalmers
almost 4 years ago
Www.bmj
3
134

Anticoagulation in atrial fibrillation

Atrial fibrillation increases the risk of stroke, which is a leading cause of death and disability worldwide. The use of oral anticoagulation in patients with atrial fibrillation at moderate or high risk of stroke, estimated by established criteria, improves outcomes. However, to ensure that the benefits exceed the risks of bleeding, appropriate patient selection is essential. Vitamin K antagonism has been the mainstay of treatment; however, newer drugs with novel mechanisms are also available. These novel oral anticoagulants (direct thrombin inhibitors and factor Xa inhibitors) obviate many of warfarin’s shortcomings, and they have demonstrated safety and efficacy in large randomized trials of patients with non-valvular atrial fibrillation. However, the management of patients taking warfarin or novel agents remains a clinical challenge. There are several important considerations when selecting anticoagulant therapy for patients with atrial fibrillation. This review will discuss the rationale for anticoagulation in patients with atrial fibrillation; risk stratification for treatment; available agents; the appropriate implementation of these agents; and additional, specific clinical considerations for treatment.  
bmj.com
over 3 years ago
0397df4d753cfc0bcc5fce7a12e5d4c033008038372951974927905
3
76

Easy statistics

Statistics made easy  
mohammed Ziny
over 2 years ago
Preview
2
167

Medicowesome: Bio-statistics mnemonics, tips & tricks

How many people need to be exposed to something to harm one patient.If 52 people are exposed to awesomeness, 1 will become awesome. 52 is the number needed to be awesome.If 13 people are exposed to an omen, one will become jinxed. 13 is the number needed to jinx.Sorry if my examples are too weird .-.  
medicowesome.blogspot.com
over 3 years ago
30401
6
83

Introduction to Medical Statistics

A brief introduction to medical statistics for any student thinking of contributing to audit/research  
Aranghan Lingham
about 5 years ago
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5
113

Frequency of Progression From Acute to Chronic Pancreatitis and Risk Factors: A Meta-analysis - Gastroenterology

Acute pancreatitis (AP) and chronic pancreatitis (CP) traditionally have been thought to be distinct diseases, but there is evidence that AP can progress to CP. Little is known about the mechanisms of pancreatitis progression. We performed a meta-analysis to quantify the frequency of transition of AP to CP and identify risk factors for progression.  
gastrojournal.org
about 2 years ago
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3
49

Caesarian Section

C-section is major surgery, with real risks, and the decision to perform such an operation should not be taken lightly!   Epidemiology Incidence in increasing, mainly due to the increased diagnoses of fetal distress, as diagnosed by CTG monitoring. Also increasing used for non-longitudinal lies (e.g. breech, transverse) WHO recommends not >15% of deliveries should be via c-section  
almostadoctor.com - free medical student revision notes
over 3 years ago
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3
83

History Taking & Risk Assessment and Mental State Examination

From the Academic Unit of Psychiatry  
bristol.ac.uk
over 2 years ago
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5
41

Relative risk, relative and absolute risk reduction, number needed to treat and confidence intervals - Smart Health Choices - NCBI Bookshelf

How do you interpret the results of a randomised controlled trial? A common measure of a treatment is to look at the frequency of bad outcomes of a disease in the group being treated compared with those who were not treated. For instance, supposing that a well-designed randomised controlled trial in children with a particular disease found that 20 per cent of the control group developed bad outcomes, compared with only 12 per cent of those receiving treatment. Should you agree to give this treatment to your child? Without knowing more about the adverse effects of the therapy, it appears to reduce some of the bad outcomes of the disease. But is its effect meaningful?  
ncbi.nlm.nih.gov
over 2 years ago
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3
48

Inactivity, disability, and death are all interlinked

Physical activity has long been recognised as an important determinant of health and longevity, and many countries have explicit physical activity guidelines for promoting health.1 2 The corollary of this is that people who do not meet the guidelines, a substantial proportion of the population,3 are at risk of worse health. However, relatively little attention has been given to the question of how much activity is needed to make a difference. Although this is not explicitly their primary purpose, two new papers shed light on this question. Dunlop and colleagues (doi:10.1136/bmj.g2472) followed a cohort of people who had mild to moderate osteoarthritis or were at risk of osteoarthritis to look at the development of disability over two years.4 Cooper and colleagues (doi:10.1136/bmj.g2219) estimated the relation between physical capability in midlife—as indicated by grip strength, chair rise speed, and standing balance—and later mortality.5 Both showed that the relation between inactivity and risk of disability or death is not linear: people …  
bmj.com
over 3 years ago