public health biggg revision lecture Flashcards
(49 cards)
define
primary
secondary
tertiary
prevention
primary - prevents a disease from occuring by modifying rfs
secondary - detects early disease to alter the course of disease, eg. BrCa screening
tertiary - minimises disability and prevents complciations
eg post stroke rehab
what is the prevention paradox
an intervention / programme that brings a lot of benefit to the population may not infer much beenfit to an individual
screening criteria? wilson and jungner…
features of the…
condition - must be important . health problem
with a detectable early stage
with a well understood natural Hx
the test
must be a suitable test existing to detect the early stage (sufficiently sensitive / specific)
must be acceptabel (ie not a prostate biopsy)
should be repeated
the treatment:
there should be an accepted treatment for the disease
facilities for diagnosis and tx should be available
health service must be able to cope with the additional people that will be identified on screening
needs to be AN AGREED POLICY on who to treat
pros and cons
costs should be outweighed by the benefits…
risks (psych / physical) should be less than the benefits
when does cervical cancer screening take place?
25-64
○ 25-50 = every 3 years
○ 50-64 = every 5 years
when does BrCa screening take place?
50 - 70 years of age
● Every 3 years
○ (May be 47-73)
● Triple assessment if positive screening ○ Imaging ■ USS (<40) ■ Mammography + USS (>40) ○ Clinical assessment ○ Biopsy
what does the newborn heel prick screening test look for?
- 1) MCADD ○ 2) Sickle CelL ○ 3) CF ○ 4) Congenital Hypothyroidism ○ 5) Maple-Syrup Disease ○ 6) PKU (PhenylKetonUria) ○ 7) Glutaric Acidaemia Type 1 ○ 8) Isovaleric Acidaemia ○ 9) Homocysteine Uria
?g6pd if asked for???
what is sensitivity?
proportion of people with the disease who are correctly IDed by the screening test…
specificity?
The proportion of people without the disease who are
correctly excluded by the screening process
ppv?
Proportion of people who have a positive screening result who, following definitive tests, have the disease
npv?
Proportion of people with a negative result who do not have the disease following definitive testing
how does selection bias apply to screening?
people who come to screening may differ from the general population
may be at higher risk - fam hx
may be at a lower risk - higher SE group, better able to attend
what is bias?
a systematic deviation from a true estimate of the association between exposure and outcome
what is length time bias
screening that happens at intervals is more likely to pick up slow-growing diseases of lower severity than fast growing shorter more aggressive disease..
lead time bias?
leads to the same outcome
screening picks up people earlier in their disease, but the treatment that is provided as a result of the screening has in fact no effect on the outcome of the disease - it just looks like it has
what are the possible causes of an observed association?
chance confounding bias reverse causality true association
what is gillick competence?
Whether a child under the age of 16 is able to give consent for medical treatment without the need for parental permission and knowledge
Are they able to understand what is being asked of them?
Are they able to reason the pros and cons?
Are they able to retain the information?
Are they able to respond / relay their answer?
what are the fraser guidelines for contraception?
the girl (although under 16) will understand the advice of the health professional
the HCP cannot persuade her to inform her parents / allow the HCP to inform the parents that she is seeking contraception advice
she is very likely to continue having sexual intercourse with or without contraceptive treatment
if she did not recieve contraceptive tx her physical or mental health or both are likely to suffer
her best interests require the HCP to give her contraceptive advice / treatment / both without parental consent
what is the bradford hill criteria for causality?
temporality biological gradient strength (effect size..) biological plausibility consistency - reproducibility concordance with biological data (ie epid)
what is the p value?
the probability of the observed event occuring, given the H0 is true
type 1 and type 2 errors in statistics - what are they?
type one errors are false positives where you accidentally reject the null hypothesis (type 1 - 1st the worst - bad because you’re saying a treatment works, or an association is true when it isn’t) - a (0.05 usually) is the probablity of this
type 2 - fail to reject the h0 when it is in fact false (B - 1-0.8 usually is the probability of this)
what are the 4 pillars of medical ethics??
justice
non-malificence
benificence
autonomy
what is the 4 quadrants approach to an ethically difficult case? - AN ETHICAL FRAMEWORK…
and apply it to a DNAR order?
Medical Indications (Beneficience and non-maleficence) Patient Preferences (respect for autonomy) Quality of Life (benificence and non-malificence) Contextual Features (justice / healthcare prof / family / law)
in terms of a DNAR order:
medical indications - if there is no potential for resus to benefit the patient, and it may certainly do harm in terms of breaking their ribs and causing other physical damage, it would seem silly from that point of view.
in terms of patient preferences, you must take into account and respect their autonomy, if they refuse it when you think it might be medically indicated you must respect that, but a pt cannot demand resus
quality of life wise - will the patient gain sufficient QOL for the loss of dignity involved in resuscitation
contextual features - take into account other serious chronic diseases
what is health need?
an individual’s capacity to benefit from an intervention
what is a health demand?
what people actually ask for
