Behavioral Science Flashcards
Sensitivity equation?
TP/(TP+FN)
Specificity equation?
TN/(TN+FP)
PPV equation?
TP/(TP+FP)
NPV equation?
TN/(TN+FN)
Incidence rate?
new cases/# ppl at risk
Prevalance?
of existing cases/total # in population
Odds rato
(a/c)/(b/d)=ad/bc or (a/b)/(c/d)
Relative risk
(a/(a+b)/(c/(c+d))
Attributable risk
AR=(a/a+b)-(c/c+d)
Relative risk reduction
RRR=1-RR
Absolute risk reduction
c/c+d-(a/a+b)
Number needed to treat
NNT=1/ARR
Number needed to harm
NNH=1/AR
Risk (probability of developing a disease over a certain period of time)
(a/a+b)
Standard deviation vs Standard error in terms of description
Standard deviation-how much variability exists from the mean in a set of values
Standard error-variance in mean between the sample and the true population mean
When does mean=median=mode?
only in a normal distribution
Error in assigning subjects to a study group resulting in an unrepresentative sample
Selection bias
Awareness of disorder alters recall by subjects; common in retrospective studies
Recall bias
Information is gathered in a way that distorts it
Measurement bias
Subjects in different groups are not treated the same
Procedure bias
Researcher’s belief in the efficacy of a treatment changes the outcome of that treatment
Pygmalion effect seen in observer expectancy bias
Sending survey out to patients 5 years after diagnosis is preferentially sampling those with low grade disease
Late-look bias
When a factor is related to both the exposure and outcome, but not the causal pathway–> factor distorts or confuses effect of exposure on outcome
Confounding bias
Present when the effect of the main exposure on the outcome is modified by the presence of another variable. It is a natural phenomenon that should be described, but not connected
Effect modification
Tendencey of subjects to change their behavior as a result of awareness that they are being studied
Hawthorne effect (or observer effect)
Early dectection is confused with increased survival
lead-time bias
Applied to both disease and pathogenesis and exposure to risk modifiers. Initial steps in pathogenesis and or expsoure to a risk factor sometimes occur years before clinical manifestations of disease are evident. Additionally, exposure to risk modifiers may need to be continuous over a period of time before influencing the outcome
Latent period
How can you increase power and decrease Beta
Increase sample size, increase expected effect size, increase precision of measurement
confidence interval equation
mean+/z(SEM)
What happens if CI between 2 groups overlap?
No significant difference exists
What happens if CI between 2 groups do not overlap?
Significant difference exists
If 95% CI for 2 variables includes 0 (null value), what happens?
H0 is not rejected and no significant difference exists
If 95% CI for odds ratio or relative risk includes 1 (null value), what happens?
H0 is not rejected and and no significant difference exists
A 95% CI that does not cross the null value corresponds to what?
A 99% CI that does not cross the null value corresponds to what?
Exception to medicare for >65
4 parts of informed consent
Discloure, Understanding, Capacity (ability to reason and make one’s own decisions), Voluntariness
2 situations where parental consent does not need to be obtained for minor
Emergent treatment or legally emancipated
3 situations where parenteral consent is not required
1) Sex (contraception, STIs, pregnancy)
2) Drugs (addiction)
3) Rock and roll (emergency and trauma)
Capacity vs Competency
Capacity-ability to reason and make one’s own decisions
Competency-legal determination
Can a patient who is incompetent revoke a medical power of attorney?
Yes
What 2 things do not decrease as you get older?
Sexual interest, intelligence
Common causes of death by age
Congenital malformation, Preterm birth, SIDS
Common causes of death age 1-14 year
Unintentional injury, Cancer, Congenital malformations
Common causes of death 15-34 year
Untintentional injury, Suicide, Homicide
Common causes of death 35-44 years
Unintential injury, Cancer, Heart disease
Common cause of death 45-64 year
Cancer, Heart disease, Unintentional injury
Common cause of death 65 year +
Heart disease, Cancer, Chronic respiratory disease
What is presbycusis
Sensorineural hearing loss (often of higher frequencies) due to destruction of hair cells at the base. Lower frequency sounds is preserved becuause hair cells at apex preserved
Cessation of what is the most effective preventative intervention in almost all patients
Smoking cessation
