PHTY208 Lecture Notes - Lecture 1: Melanoma, Rheumatic Fever, Healthy Life Years
Concepts of health
• Health and disease
o Pathophysiology: physiology of altered health
o WHO (1948): "health is a state of complete physical, mental and social well-being
and not merely the absence of disease and infirmity"
o Healthy People 2010: Health is an interation eteen an indiidual’s iology and
behaviour, physical and social environments, government policies and
interventions, and access to quality health care
o Study of pathophysiology
• Pathology: the study of structural changes in cells, tissues, and organs
• Physiology: the study of body function
• Pathophysiology is the study of the ody’s response to dysfuntion or disease.
▪ Can provide the background for treatment
o Aspects of disease
• Aetiology: causes of disease
▪ Causes can be split into
• Congenital: defects at birth
• Acquired: caused by an event that occurs after birth
▪ Biologic agents
▪ Physical forces
▪ Chemical agents
▪ Nutritional excesses or deficits
▪ Genetic defects
• Pathogenesis
▪ Sequence of cellular and tissue events that take place from the time of
initial contact with an aetiological agent until the ultimate expression of
the disease
▪ Once the cause occurs, what happens in the body until the symptoms
occur
• Morphologic changes
▪ Fundamental structure or form of cells or tissue
• Gross anatomical
• Microscopic
▪ Lesion is discontinuity of a body organ or tissue
• Clinical manifestations
▪ Signs: manifestation noted by an observer
• what we can see and measure
▪ Symptom: is a subjective complaint that is noted by the person
• Diagnosis and Predictive Factors
▪ Diagnosis: designation of the nature or cause of a health problem
▪ Reliability: the extent to which an observation, when repeated, gives
the same result
▪ Validity: the extent to which a measurement tool measures what it is
intended to measure
▪ Sensitivity and specificity: how well the test or observation identifies
people with or without a disease
▪ Predictive value: extent to which an observation or test result is able to
predict the presence of a given disease or condition
• Clinical course
▪ Evolution of a disease
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• Acute: self-limiting
• Chronic: implies a continuous, long term process
• Subacute: between acute and chronic
• Natural history
▪ Progression and projected outcome of diseases without medical
intervention
▪ Information about the natural history of a disease and the potential of
effective treatment methods provides direction for preventive
measures.
▪ Prognosis: possible outcome and prospect of
▪ recovery from a disease
• Epidemiology
o Epidemiology: study of factors that affect the health of populations. Study of
disease occurrence in human populations
• What are the risk factors?
• How disease is spread?
• How to control disease?
• How to prevent disease?
• How to eliminate disease?
o Factors Derived Using Epidemiologic Methods
• Epidemiology looks for patterns of persons affected with a disease
▪ Age
▪ Race
▪ Dietary habits
▪ Lifestyle
▪ Geographic location
• Basis for clinical decision making, allocation of health care dollars and
development of policies
o Disease frequency
• Disease case: an existing case or the number of new episodes of a particular
illness
• Incidence: the number of new cases arising in a population at risk during a
specified time
• Prevalence: a measure of existing disease in a population at a given point in
time
• Mortality
o Measurement of disease and consequently health in the planning of public health
care
o Helps to understand how the health status of the population is changing and assists
us in the implementation of preventative measures
o Life expectancy derived from mortality data
o Mortality rates
• Mortality rates have fallen considerably over the past century in Australia.
▪ Male - 67% from 2,234 deaths (per 100,000) in 1907 to 731 deaths (per
100,000) in 2006.
▪ Females – 73% from 1,844 deaths (per 100,000) in 1907 to 494 deaths
(per 100,000) in 2006.
• A diverse range of commercial companies use mortality data
• Highlight health differences among different groups of people and how readily
one group can access a health care service
• Males/females
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o Why have death rates declined
• Improvements in health over the past 100 years.
▪ Improved understanding of environmental factors
▪ Improvements to public infrastructure
▪ Improved understanding of health risk and beneficial factors, and
improvement in general education levels within the general population.
▪ Medical and surgical advances
▪ Improvements in access to medical and other health services.
o Cancer
• In 2007, the most commonly reported cancers were:
▪ Prostate cancer (19,403 cases)
▪ Bowel cancer (14,234 cases)
▪ Breast cancer (12,670 cases)
▪ Melanoma of the skin (10,342 cases)
▪ Lung cancer (9,703 cases)
• In 2007, the most common causes of cancer death were:
▪ Lung cancer (7,626 deaths)
▪ Bowel cancer (4,047 deaths)
▪ Prostate cancer (2,938 deaths)
▪ Breast cancer (2,706 deaths)
▪ Lymphoid cancers (2,552 deaths).
• Life expectancy
o Life expectancy: expected number of years of life remaining at a given age
o A common measure of population health in general
• Important when comparing different populations
• Also used in public policy planning, especially as an indicator of future
population ageing in developed nations
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find more resources at oneclass.com
Document Summary
Fundamental structure or form of cells or tissue: gross anatomical, microscopic. Lesion is discontinuity of a body organ or tissue: clinical manifestations. Signs: manifestation noted by an observer: what we can see and measure. Subacute: between acute and chronic: natural history, progression and projected outcome of diseases without medical intervention. Lifestyle: basis for clinical decision making, allocation of health care dollars and development of policies, disease frequency, disease case: an existing case or the number of new episodes of a particular illness. Improvements in health over the past 100 years. Improved understanding of health risk and beneficial factors, and improvement in general education levels within the general population: medical and surgical advances. Improvements in access to medical and other health services: cancer. In 2007, the most commonly reported cancers were: prostate cancer (19,403 cases, bowel cancer (14,234 cases, breast cancer (12,670 cases, melanoma of the skin (10,342 cases) In 2007, the most common causes of cancer death were:
