Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

PH

No description
by

Caleb Yeung

on 17 April 2017

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of PH

Perceptions shaped by:
volunteerism
lack of understanding
lack of benefit
blame (nature vs. industry)
media attention
1. Income and social status
2. Social support networks
3. Education and literacy
4. Employment & working conditions
5. Social environments
6. Physical environments
7. Personal health practices and coping skills
8. Healthy child development
9. Biology and genetic endowment
10. Health services
11. Gender
12. Culture
Prevalence = incidence x average duration
(incidence does not depend on duration)
Impairment
Disability
Handicap
social disadvantage
inability
only use Odds Ratio
use for rare diseases and those with long interval between exposure and disease

Follow a group of people with common characteristics (exposure) over time.
Risk Ratio
Odds Ratio
Rate Ratio
(risk in EXPOSED group) / (risk in UNEXPOSED group)
(odds of smoking among cases)/(odds of smoking among controls)
(rate in EXPOSED group) / (rate in UNEXPOSED group)
POPULATION HEALTH METHODS
DETERMINANTS OF HEALTH
EVIDENCE-BASED MED + STUDY DESIGNS
HEALTH CARE ORGANIZATIONS & PUBLIC POLICIES
HEALTH PSYCHOLOGY
PREVENTION OF DISEASE & HEALTH PROMOTION
Measuring Statistical Association
1 = no association
biology
[(a/(a+b)]/[c/(c+d)]
(a/b)/(c/d)
Bradford Hill Postulates
1. Strength of association
2. Consistency
3. Dose-response/biological gradient
4. Temporality
5. Plausibility of the association
6. Coherence
7. Specificity
8. Experimental evidence
9. Analogy
SE = SD

n
variation among means,
95% of the time includes true population mean
variation among individuals
1 SD = 68%,
2 SD = 95%
N
ominal
O
rdinal
I
nterval
R
atio
Power
(arbitrary zero, celsius)
(true zero, Kelvin)
probability of detecting a difference if it truly exists
"flip side" of Type II error
to increase power:
increase n, decrease variability, use one-tailed testing
T-Test (t)
ANOVA (F)
What it does
Dependent (outcome) variable
continuous
unpaired:

means
of
2
groups
paired:

means
of a
repeated
measure by 1 person
Correlation (r)
Chi-square (x )
Multiple Regression
Logistic Regression
2
compares
means
of
>2
groups
linear relationship
b/w
2
measures?
r = amount
variation
explained by
linear relationship
2
proportions
comparison
Is there an
association

b/w categories?
odds ratio & relative risk
unique contribution of
several
experimental
variations
on outcome
continuous
continuous
categorical
continuous
categorical
Independent (explanatory) variable
continuous
categorical
continuous &
categorical
Non-normal equivalent
Kruskal Wallis
-
-
if non-normal
unpaired:
Mann-Whitney
paired:
Wilcoxon
yes/no
continuous &
categorical
(and many of them!)
non-normal:
Spearman's
normal:
Pearson's
It's not-normal
If E<5 in any cell,
Fisher's Exact Test

P
atient/problem / population
I
ntervention / prognositic factor / exposure
C
omparison
O
utcomes



People with a disease randomized into two or more groups: One group gets placebo, other gets best treatment.
Case Control
Cohort
RCT

People with the disease (cases) are compared to those without it (controls) for presumed risk factors, using medical records and interviews
recall bias
not randomized or prospective
retrospective or prospective
estimate incidence rate
relative risk
takes years
costs a lot
reduce confounder effects
good for looking at risk reduction
costs a lot
volunteer bias
potential ethical issues
Cause
Prognosis
Treatment
Use to study:
Epidemiology
Efficacy
Effectiveness
Efficiency
Ethics
real life application
Cost-minimization

Cost-effectiveness

Cost-utility

Cost-benefit
identical outcomes
dollars per life saved
e.g.
drug trials:
two drugs - one is better, but much more expenive, so find out if cost is worth it
quality of life
how to spend excess money
everything in terms of money
controversial
which one costs less
Follow-up to RCT
Contamination
the control group adopts the intervention intended only for the experimental group
Crossover
switching of patients between groups
i.e. if patients worsen and need the more aggressive treatment
Compliance
not following the intervention
Count
patients who drop out differ from those who remain
Co-interventions
if they are applied differently to the two groups
Control Event Rate
Experimental Event Rate
CER
EER
-
CER
ARR=
RRR=
Absolute Risk Reduction
1
NNT =
Number Needed to Treat
Relative Risk Reduction
Screening
does NOT diagnose.
It identifies those with increased RISK among those who are apparently well.
Length-time bias vs. Lead-time bias
death occurs at same time regardless of screening
patient lives longer with knowledge of the diagnosis but does not live longer overall
e.g. lung cancer
slow-progressing disease = more likely detected
longer perceived survival regardless of early detection
e.g. types of breast cancer and prostate cancer
the likelihood a
given test result
is expected in a patient
with
the target disorder,
compared with
the likelihood the
same result
is expected in a patient
without
the target disorder
likelihood a
positive test
result is a patients WITH disease.

SnOUT
– a highly sensitive test with a negative result helps to rule-out disease. A very sensitive test (100%) will not miss anyone with disease (no false negatives)
SENSITIVITY =
SPECIFICITY =
likelihood a
negative test
result is a patient WITHOUT disease.

SpIN
– a highly specific test with a positive result helps to rule-in disease. A very specific test (100%) will not mislabel healthy people as having the disease (no false positives)
True Positives
x 100
Total with disease
True Negatives
x 100
Total without disease
the likelihood that an individual with a
positive test
has disease.
Positive predictive value (PPV) =
TRUE
positives
TOTAL

testing

positive
the likelihood that an individual with a
negative test
has no disease.
Negative predictive value (NPV) =
TRUE
negatives
TOTAL testing

negative
Likelihood Ratios
SENSITIVITY
1 -
SPECIFICITY

LR+ =
LR- =
1 -
SENSITIVITY

SPECIFICITY
As prevalence of a disease increases, the PPV increase and the NPV decreases
1867
1984
1966
Canada Health Act
Replaced HIDS (1957) and Medical Care Act (1966)
Prevented regional variation in services
Discouraged any form of direct patient charges (no extra-billing by physicians)
Provided citizens of all provinces and territories access to health care regardless of their ability to pay
Attempts to influence delivery of health care
Allows Ottawa to withhold funds from provinces that don’t comply with the Act’s 5 Principles (4 Principles of the Medical Care Act of 1966,
plus accessibility
)
British North America Act
(renamed Constitution Act)
Proclaimed Canada’s confederation
Set the legal ground rules for Canada, and divided responsibilities between the provinces and the federal government
Provinces were given jurisdiction
over most health services; federal government’s role in health care system minimal
Citizens had to
rely on their own resources
for medical care
1977
1957
Established Program Financing Act
Change to
5 year block funding
(instead of 50:50 cost sharing in 1966 Medical Care Act)
Federal contributions no longer directly related to provincial expenditures on health care and education
Federal government provided some tax revenue to provinces as compensation
Medical Care Act (Medicare)
National Medicare program
Extended cost sharing with provinces for all “medically necessary” physician services;
federal government pays 50% of costs
, provinces pay the rest
To be eligible, the provincial medical services plan was required to meet the
“Four Points”
:
comprehensiveness, universality, portability, and public administration
(Accessibility was later added by the Canada Health Act)
Hospital Insurance & Diagnostic Services (HIDS) Act
A national hospital insurance program which
reimbursed provinces for half the cost of hospital insurances
The policy of
provincial autonomy
allowed each province to decide on its own administrative methods
while ensuring a basic uniformity of coverage throughout the country
Replaced by the Canada Health Act in 1984
1962
Tommy Douglas
Saskatchewan premier
introduced Medicare, the 1st of its kind in North America
ACCESSIBILITY
COMPREHENSIVENESS
PUBLIC ADMINISTRATION
UNIVERSALITY
PORTABILITY
not necessarily quantity, but quality

1.
Renewing and reorienting the health sector requires
collaborative efforts.
Strategy:
Increase the accountability of health services through improved reporting on the quality of health services in both the acute and community settings.

2.
Investing in the health and well-being of key population groups reflects recent trends that have shown decreased opportunities for optimal well-being among three groups:
children, youth and Aboriginal people.
Strategy:
Invest in early childhood health and education.


3.
Improving health by reducing inequities in literacy, education and the distribution of incomes in Canada

speaks to the findings in this report that show direct links between poor health and early death, and low levels of education, literacy and income.
Strategy:
Achieve a more equitable distribution of incomes in Canada via taxation.
meaning, values, beliefs, ideas, metaphors
the array of socially constructed roles and relationships, personality traits, attitudes, behaviours, values, relative power and influence that society ascribes to the two sexes on a differential basis.
- a) antibiotics, antisepsis, life-saving surgical procedures, as well as advances in pharmaceuticals
- b) public health interventions (sanitation, communicable disease control measures, etc.) and disease prevention (immunization, tobacco control measures, and screening)
functioning of body systems and genetic endowment
personal competence, control/mastery over one's life
natural and built environment
emotional support, social participation
daily tasks, employment, community involvement
“Second Report on the Health of Canadians”
Environmental Health
“where there are threats of serious or irreversible environmental damage,
lack of full scientific certainty should
not
be used as a reason for postponing measures
to prevent environmental degradation.”
Occupational Health
Precautionary Principle
Health Risk Assessment
Risk Perception
Step 1: Hazard identification
Step 2: Dose-response modelling
Step 3: Exposure assessment
Step 4: Risk characterization
hazard = risk + outrage
Drinking Water
Air Quality
Food
outdoor:
CVD, asthma, ozone
indoor:
CO, 2nd-hand tobacco smoke, zambonis, radon
surface:
majority of population at risk (recreation - swimmer's itch)
ground (wells):
higher risk for chemical contamination
biologic:
key is incubation period
chemical
Chemicals
Radiation
Unemployment
Poor Health
Selection of sick workers out of work force
Companies less willing/able to accommodate restrictions under certain economic conditions
Mental health issues make it difficult to find and hold employment
Association is weaker in times of high unemployment
Increased use of health services
Physical illness – Injuries
Mental illness
Increased mortality
chemical - check MSDS
biological - airborne, bloodborne, oral
ergonomic
physical
psychosocial
Potential Hazards
Consider the average amount of exposure, NOT the intensity/peak of exposure
Occupational History
1) What is the worker working with?
2) How is the worker exposed?
3) What protective measures are in place – PPE ventilation?
4) How long has the worker been exposed?
5) Are other workers sick?
6) Are there any air measurements / inspections?
Biologic monitoring vs. Medical Surveillance
measure level of agent
measure effect of exposure, not the agent itself
e.g. lung function testing, liver enzymes
Psitticosis - birds
Bruccellosis - pigs, sheep, cattle
Q fever - sheep
Speech discrimination in the
500-3000 Hz
range
Negative Pressure
Positive Pressure
inhale through, breathe in cartridge
only protect to a certain degree
fitted properly and fit tested
lowered risk by 10-fold with ½ face mask vs. 1000-fold for PAPR
powered air purifying respirator - filter
air line - air from different source
Self-Contained Breathing Apparatus - heavy
N95
filters out 95% particles greater than 3 microns
Placebos more effective...
with more and larger pills
in clinical setting (vs. lab)
for severe pain (vs. mild)
short-term (i.e. reduced effect with repeated administrations)
Gate Control Model of Pain
active role for CNS
‘pain gate’ in
dorsal horns
brain can excite or inhibit pain signals (descending pathways influence transmission)
psychological factors integral (thoughts, feelings)
reverberating circuits
in dorsal horn contribute to chronic pain
ALLODYNIA
- what is not normally painful is experienced as painful
TREATMENT
ACUTE PAIN
CHRONIC PAIN
ice
Anti-inflammatories
ice or heat
short-acting analgesics
long-acting analgesics
rest
daily activity
categorical
categorical
Rose's Theorem
helping everyone get a little healthier, and you can help the most and have a more dramatic change than focussing just on the least healthy/highest risk
shift
and
squish
increase health for all:
universal programs
targeted programs
Full transcript