This document discusses the concepts of association and causation in epidemiology. It defines association as the occurrence of two variables more often than expected by chance. Association can be spurious, indirect, or direct (causal). Additional criteria for judging causality include temporal relationship, strength of association, dose-response relationship, replication of findings, biological plausibility, and consideration of alternative explanations. Establishing causality requires evaluating these criteria to determine if changes in the suspected cause are consistently linked to changes in the effect.
A principal aim of epidemiology is to assess the cause of disease. However, since most epidemiological studies are by nature observational rather than experimental, a number of possible explanations for an observed association need to be considered before we can infer a cause-effect relationship exists.
A principal aim of epidemiology is to assess the cause of disease. However, since most epidemiological studies are by nature observational rather than experimental, a number of possible explanations for an observed association need to be considered before we can infer a cause-effect relationship exists.
Concept of Association, Causation and Correlation
Association - Spurious, Indirect & Direct
Multi-factorial causation
Guidelines for Judging causality
Additional Criteria for Judging causality
At the end of this session, the students shall be able to, Define Cause
Define Association
Define Correlation
Types of association
Additional criteria for judging causality
Differentiate between association and causation
this presentation takes you through the concept of association observed between variables in a study and how could it become a causative association in step-wise manner.Exemplify using Bradford hill criteria. slides after references are extra slides not covered in the presentation.
The ppt is a short description about how to ascertain the validity, ie; sensitivity and specificity of a screening test as well as their predictive powers. you can also find the technique to ascertain the best possible screening test through the help of an ROC curve...
Diagnostic, screening tests, differences and applications and their characteristics, four pillars of screening tests, sensitivity, specificity, predictive values and accuracy
Concept of Association, Causation and Correlation
Association - Spurious, Indirect & Direct
Multi-factorial causation
Guidelines for Judging causality
Additional Criteria for Judging causality
At the end of this session, the students shall be able to, Define Cause
Define Association
Define Correlation
Types of association
Additional criteria for judging causality
Differentiate between association and causation
this presentation takes you through the concept of association observed between variables in a study and how could it become a causative association in step-wise manner.Exemplify using Bradford hill criteria. slides after references are extra slides not covered in the presentation.
The ppt is a short description about how to ascertain the validity, ie; sensitivity and specificity of a screening test as well as their predictive powers. you can also find the technique to ascertain the best possible screening test through the help of an ROC curve...
Diagnostic, screening tests, differences and applications and their characteristics, four pillars of screening tests, sensitivity, specificity, predictive values and accuracy
Association.pptxis method we have an x -ray machine, an intraoral sensor and ...RabeaDia
is method we have an x -ray machine, an intraoral sensor and computer monitor
A sensor is placed into the mouth of the patient and exposed to x –ray, the sensor captures the
radiographic image and then transmits the image into a computer monitor. Within seconds of
exposing the sensor to x
Epidemiology is the study and analysis of the patterns, causes, and effects of health, disease & production conditions in defined populations, in terms of space and temporality.
Introductory lecture on some epidemiological models in causal inference, including the sufficient component cause model and the potential outcomes model.
Hepatitis refers to an inflammatory condition of the liver. It’s commonly caused by a viral infection, but there are other possible causes of hepatitis. These include autoimmune hepatitis and hepatitis that occurs as a secondary result of medications, drugs, toxins, and alcohol. Autoimmune hepatitis is a disease that occurs when your body makes antibodies against your liver tissue.
Evidence Based Practice is the integration of clinical expertise, patient values, and the best research evidence into the decision making process for patient care.
Clinical expertise refers to the clinician’s cumulated experience, education and clinical skills. The patient brings to the encounter his or her own personal preferences and unique concerns, expectations, and values.
The best research evidence is usually found in clinically relevant research that has been conducted using sound methodology.
Access to oral health care services around the world is limited by a lack of universal coverage. The internet and social media can be an important source for patients to access supplementary oral health related information
Statistical significance vs Clinical significanceVini Mehta
esults are said to be "statistically significant" if the probability that the result is compatible with the null hypothesis is very small. Clinical significance, or clinical importance: Is the difference between new and old therapy found in the study large enough for you to alter your practice?
A non-cavitated caries lesion ( an early lesion, an incipient lesion, a white spot lesion or a surface softened defect) is a demineralized lesion without evidence of cavitation.
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Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
2. Contents
• Introduction
• Defining Association
• Types of Association
• Additional Criteria for Judging Causality
• Establishing a Casual Inference
• Problems in Establishing Causality
• Conclusion
• References
2
3. Introduction
Epidemiological principles stand on two basic assumptions
Human disease does not occur at random
The disease and its causal as well as preventive factors
can be identified by a thorough investigation of
population
• Identification of causal relationship between a disease
and suspected risk factors forms part of epidemiological
research.
3
4. Association
(Correlation, Covariation, Statistical dependence, Relationship)
• Defined as occurrence of two variables more often than
would be expected by chance
• If two attributes say A and B are found to co-exit more often
than an ordinary chance
• Correlation indicates the degree of association between two
variables
• Causal association: when cause and effect relation is seen
4
5. • Association does not necessarily imply a causal
relationship.
• Association can be broadly grouped under three
headings:
• a. Spurious association
• b. Indirect association
• c. Direct (causal) association
• one to one causal association
• multifactorial causation
5
6. a. Spurious Association
• (Spurious= not real, artificial, false, non-causal
associations due to chance, bias or confounding)
• Observed association between a disease and suspected
factor may not be real
• This is due to selection bias
Ex: Neonatal mortality was observed to be more in the
newborns born in a hospital than those born at home.
This is likely to lead to a conclusion that home delivery is
better for the health of newborn.
However, this conclusion was not drawn in the study
because the proportion of “high risk” deliveries was
found to be higher in the hospital than in home 6
7. a. Indirect association:
• It is a statistical association between a characteristic
of interest and a disease due to the presence of
another factor i.e. common factor (confounding
variable).
• So the association is due to the presence of another
factor which is common to both, known as
CONFOUNDING factor.
7
8. Example of an indirect association is
1) Altitude and endemic goiter
• Endemic goiter is generally found in high
altitudes, showing thereby an association
between altitude and endemic goiter.
• Current knowledge- endemic goiter is not due
to altitude but due to environmental
deficiency of iodine.
8
9. a. Direct (causal) association:
One to one causal relationship:
• The association between the two attributes is not
through the third attributes.
• When the disease is present, the factor must also
be present.
9
10. • Direct (Causal) association:
1.One –to- one causal association
2.Multifactorial causation
Sufficient & necessary cause
Web of causation (Interaction)
10
11. Koch’s postulates-
The germ theory of disease insisted that the
cause must be
a. necessary and
b. sufficient for the occurrence of the
disease.
.
11
12. One –to- one causal association
• The variables are stated to be causal related if a change
in A is followed by a change in B.
• When the disease is present, the factor must also be
present.
• A single factor (cause) may lead to more than one
outcome.
• Hemolytic Streptococci
Streptococcal
tonsillitis
Scarlet fever
Erysipelas
12
13. Multifactorial causation:
• Multiple factor leads to the disease.
• Common in non-communicable diseases
• Alternative causal factors each acting
independently.
Ex: In lung cancer more than one factor (e.g. air
pollution, smoking, heredity) can produce the
disease independently.
13
14. Model of multifactorial causation
• Factor 1
• Factor 2
• Factor 3
14
REACTION AT
CELLULAR
LEVEL
Disease
15. • Model of multifactorial causation showing
synergism
• In this model , the causal factors act cumulatively to
produce disease. This is probably the correct model
for many diseases. It is possible that each of the
several factors act independently , but when an
individual is exposed to 2 or more factors, there
may be a synergistic effect.
15
Factor 1
Factor 2
Factor 3
REACTION AT
CELLULAR
LEVEL
Disease
+
+
16. ADDITIONAL CRITERIA FOR JUDGING CAUSALITY
16
1. Temporal relationship
2. Strength of the association
3. Dose-response relationship
4. Replication of the findings
5. Biologic plausibility
6. Consideration of alternate explanations
7. Cessation of exposure
8. Consistency with other knowledge
9. Specificity of the association
17. Temporal association
• The causal attribute must precede the disease or
unfavorable outcome.
• Exposure to the factor must have occurred before
the disease developed.
• Length of interval between exposure and disease
very important
18. Strength Of The Association
• Relationship between cause and outcome could be strong or
weak.
• With increasing level of exposure to the risk factor an
increase in incidence of the disease is found.
• There are statistical methods to quantify the strength of
association ( calculation of relative risk, attributable risk )
19. Dose-Response Relationship
• As the dose of exposure increases, the risk of disease also
increases
• If a dose-response relationship is present, it is strong
evidence for a causal relationship.
• However, the absence of a dose-response relationship does
not necessarily rule out a causal relationship.
• In some cases in which a threshold may exist, no disease may
develop up to a certain level of exposure (a threshold); above
this level, disease may develop
20. Replication of the Findings
• If the relationship is causal, we would expect to find it
consistently in different studies and in different populations
• Replication of findings is particularly important in
epidemiology.
• If an association is observed, we would also expect it to be
seen consistently within subgroups of the population and in
different populations, unless there is a clear reason to expect
different results.
21. Biologic Plausibility Of The Association
• The association must be consistent with the other knowledge
( mechanism of action, evidence from animal experiments
etc).
• Sometimes the lack of plausibility may simply be due to the
lack of sufficient knowledge about the pathogenesis of a
disease
22. Consideration of Alternate Explanations
• We have discussed the problem in interpreting an observed
association in regard to whether a relationship is causal or is
the result of confounding
• In judging whether a reported association is causal, the extent
to which the investigators have taken other possible
explanations into account and the extent to which they have
ruled out such explanations are important considerations.
23. Cessation of Exposure
• If a factor is a cause of a disease, we would expect the risk of
the disease to decline when exposure to the factor is reduced
or eliminated
24. Consistency Of The Association
• Consistency is the occurrence of the association at some
other time and place repeatedly.
• If a relationship is causal, the findings should be consistent
with other data.
• If lung cancer incidence increased as cigarette use was on the
decline, we would have to be able to explain how this was
consistent with a causal relationship.
• If there is no consistency it will weaken a causal
interpretation.
• The causal association between smoking and lung cancer due
to its consistency.
25. Specificity Of The Association
• The weakest of the criteria
• Specific exposure is associated with only one disease.
• This is used by tobacco companies to argue that smoking is
not causal in lung cancer.
Smoking is associated with many diseases.
• Specificity implies a one to one relationship between the
cause and effect.
27. Problems in Establishing Causality
• The existence of correlation/ association does not
necessarily imply causation.
• Concept of single cause concept of multiple
causation
• Koch’s postulates cannot be used for non-infectious
diseases.
• The period between exposure to a factor and
appearance of clinical diseases is long in non-
infectious diseases.
27
28. Conclusion
• Results from epidemiological studies are often used
as inputs for policy and judicial decisions.
• It is thus important for public health and policy
makers to understand the fundamentals of causal
inference.
28
29. References
1. Health Research Methodology- A guide for training in
Research methods – Second edition-World Health
Organization, Pg 125-140
2. Park’s Textbook of Preventive and Social Medicine-20th
edition,Pg 83-87
3. Epidemiology-Leon Gordis, W.B.Saunders Company1996,
Pg 167-182
29