Behavioral Science Flashcards
Sensitivity (give formula and description)
If person has disease, what is probability test will be positive?
a/a+c
SN-N-OUT - highly SeNsitive test, when Negative, rules OUT disease (low false negative rate)
Specificity (give formula and description)
If person does not have disease, what is probability test will be negative?
d/b+d
SP-P-IN - highly SPecific test, when Positive, rules IN disease (low false positive rate)
Positive predictive value (give formula and description)
If test is positive, what is probability person actually has disease?
a/a+b
Negative predictive value (give formula and description)
If test is negative, what is probability person does not have disease?
d/c+d
Odds ratio (give formula and description)
Odds that group with disease was exposed to risk factor (a/c) divided by odds that group without disease was exposed to risk factor (b/d)
(a/c)/(b/d)
Relative risk (give formula and description)
Risk of developing disease in exposed group divided by risk of developing disease in unexposed group
(a/[a+b])/(c/[c+d])
Attributable risk (give formula and description)
Difference in risk between exposed and unexposed
Proportion of disease occurrences attributable to exposure
(a/a+b) - (c/c+d)
Relative risk reduction (give formula and description)
Proportion of risk reduction attributable to intervention compared to control
1 - RR
or 1 - (a/[a+b])/(c/[c+d])
In this case, assume RR is ratio of risk of disease in treated group:risk of disease in control group.
Absolute risk reduction (give formula and description)
Difference in risk (not proportion!) attributable to intervention as compared to control
(c/c+d) - (a/a+b)
Number needed to treat (give formula and description)
Number of patients who need to be treated for 1 patient to benefit
1/ARR
Number needed to harm (give formula and description)
Number of patients who need to be exposed for 1 patient to be harmed
1/AR
Precision v. accuracy
Precision - consistency and reproducibility of a test (reliability)
Accuracy - trueness of test measurements (validity)
Type I error (alpha) in hypothesis testing
Stating that there is an effect or difference when none exists (null hypothesis incorrectly rejected in favor of alternative hypothesis) - a false positive error
Type II error (beta) in hypothesis testing
Stating that there is not an effect or difference when one exists (null hypothesis not rejected when it is actually false) - false negative error
Define Presbycusis
Sensorineural hearing loss (often higher frequencies) due to destruction of hair cells at cochlear base (preserved low-frequency hearing at apex)
Define cataplexy
Loss of all muscle tone following strong emotional stimulus, like laughter
How long can the survival prognosis be in a patient to recommend hospice care?
Less than 6 months
What are situations in which parental consent is not required?
Sex - contraception, STIs, pregnancy (no parental consent required for prenatal care, but is required for termination)
Drugs - addiction
Rock and roll - emergency/trauma
If a physician does not personally believe in a procedure but they have the ability to perform it (i.e. abortion), are they required to perform it?
No, physician is not required to perform a procedure that go against their personal beliefs, but they must refer the patient to another provider
If you suspect domestic abuse, what strategies can be used in the interview?
Ask others to leave room Ask open ended questions Do not pressure patient for more information Ask patient if they feel safe Ask if they have emergency plan
When can physicians challenge the medical decision made by parents about their child?
When the decision puts the child’s life in danger (i.e. stopping treatment for bacterial meningitis) - physician can get court injunction
What is the order of surrogates if the patient did not prepare an advance directive?
Spouse > adult children > parents > adult siblings > other relatives
Can physicians date former patients?
Yes as long as the physician is non-psychiatric and the physician-patient relationship has been terminated
What are instances in which a physician is able to share patient information (with family members, other non-physicians) without explicit permission?
- When patient is present and does not object to the sharing (i.e. ask if it’s okay to talk about with family members in room, patient says yes)
- When patient is not present and provider determines with best judgment that it is in patient’s best interest (i.e. patient in emergency surgery, share condition with wife)
Define lead-time bias
Lead time bias is an artificial increase in survival time among tested patients who actually have unchanged prognosis
Define case fatality rate
Number of fatal cases of disease/total number of people who had disease
What is the single most important way to decrease mortality, especially in diabetics?
Smoking cessation
How does PPV and NPV vary with prevalence of a disease in the population?
PPV - varies directly i.e. the higher the prevalence, the higher the PPV
NPV - varies inversely i.e. the lower the prevalence, the higher the NPV
What type of bias is ‘matching’ (patients with similar characteristics in treatment and control groups) used to prevent?
Confounding bias
What type of study evaluates whole population characteristics/risks instead of individuals?
Ecological study
What is effect modification?
When effect of an exposure on an outcome is modified by another variable (i.e. smoking status can modify effect of some drugs)
Once stratified, this reveals a significant difference between the stratified groups that was not present previously
Define standard error of mean (with formula)
SEM = SD/root(n)
Estimate of variability exists between sample mean and true population mean
Hence, as number of people in sample increases, SEM decreases
How is the Confidence Interval calculated?
CI = mean +/- (Z-score * SEM)
Use SEM when research is done on samples rather than entire population - accounts for variability due to sampling
Compare a T-test, ANOVA, and Chi-square test
T-test - compare means of 2 groups
ANOVA - compare means of 3 or more groups
Chi-square - check differences between 2 or more percentages/proportions of categorical oucomes
What are the different payment methods used by health insurance companies to pay physicians?
Capitation - paid fixed amount per enrollee, gives incentive to contain costs since have a fixed budget to work with, focus on preventative care more
Fee for service - paid for amount of services ordered (leads to many costly and unnecessary tests)
Discounted fee for service - less payment for services (physician may think twice before ordering some tests)
Salary - receive same payment no matter what, no incentive to change practices
In a screening test, is it more important to have high sensitivity or specificity?
Sensitivity
Want the test to have a high probability to detect the disease when the disease is present - low false negative rate
Double blinding is used to primarily prevent what type of bias?
Observer bias
Attributable risk percentage (formula an definition)
100 x ( [RR - 1] / RR)
Excess risk in exposed population that can be attributed to the risk factor (i.e. what percentage of small cell lung caricnoma in smokers can be attributed to smoking)
Also can be 100 x (AR/RR)
What is Berkson’s bias?
Study population selected from hospital is less healthy than general population
What are the 3 most common cancers affecting women in the US, listed in order of incidence?
Breast
Lung
Colon
Who should obtain informed consent?
Always the physician performing the procedure (i.e. don’t ask intern to do it)
Describe facilitation as an interviewing technique
Encouraging the patient to talk more about experience (i.e. and then what happened?)
Describe empathy as an interviewing technique
Express understanding of patient’s experience and difficulties (i.e. walk in patient’s shoes)
Describe reflection as an interviewing technique
Repeat what patient said, as a summary
Describe support as an interviewing technique
Express concern for patient and their experiences independent of understanding (vs. empathy where understanding is expressed)
Describe confrontation as an interviewing technique
Point out discrepancies in patient’s responses
What are developmental milestones for Infants (0-12 mo)?
Mnemonic: Parents Start Observing
Motor
- Primitive reflexes disappear (Moro, rooting, palmar, Babinski)
- Posture
- Picks up toys, Pincer grasp
- Points to objects
Social
- Social smile
- Stranger anxiety
- Separation anxiety
Verbal/Cognitive
- Orients - first to voice, then name and gestures
- Object permanence
- Oratory - says mama and dada
What are developmental milestones for Toddlers (1-3 years)?
Mnemonic: Child Rearing Working
Motor
- Cruises
- Climbs stairs
- Cubes stacked
- Cultured
Social
- Recreation - parallel play
- Rapprochement - moves away from another and returns to mother
- Realization - core gender identity formed
Verbal/Cognitive
- Words - 200 words by age 2 (two zeroes)
What are developmental milestones for Preschool age (3-5 years)?
Mnemonic: Don’t Forget Learning
Motor
- Drive
- Drawings - copies line or circle, stick figure
- Dexterity - hops on one foot, grooms self
Social
- Freedom
- Friends
Verbal/Cognitive
- Language - 1000 words by age 3 (three zeroes)
- Legends - tell detailed stories
What measurement is often associated with a case-control study?
Odds ratio
Case control study compares group of people with disease to group without disease and looks for prior exposure or risk factor
OR - odds that cases were exposed to risk factor/odds that controls were exposed to risk factor
What measurement is often associated with a cohort study?
Relative risk
Cohort study compared group with an exposure to group without and exposure and looks to see if exposure increases likelihood of disease
RR - risk of developing disease in exposed group/risk of developing disease in unexposed group
What are the 3 most common cancers affecting women in the US, listed in order of mortality?
Lung
Breast
Colon
