Behavioral Science Flashcards
Study measuring disease prevalence and risk factor association in a snapshot of time.
Controls are patients without the risk factor.
CROSS-SECTIONAL STUDY
Prevalence odds ratio.
Study comparing prior exposure or risk factors for an outcome of interest.
Controls are patients who do not have the outcome regardless of prior exposure status.
CASE-CONTROL STUDY
Exposure odds ratio.
Susceptible to recall bias (always retrospective)
Control founding with matching
Study determining if exposure affects the likelihood of disease - can be prospective or historical.
Controls are patients without the risk factor.
COHORT STUDY
Relative risk.
Assessment of safety, toxicity, kinetics, and dynamics of a new drug.
PHASE I
Healthy volunteers.
Assessment of efficacy, dosing, and adverse effects of a new drug.
PHASE II
Patients with disease of interest.
Assessment of new drug vs standard of care.
PHASE III
Large randomized controlled trial.
Assessment of rare or long-term adverse effects.
PHASE IV
Postmarketing surveillance.
Proportion of people with disease who test positive.
SENSITIVITY
High sensitivity useful for ruling out disease (screening) - low false-negative rate.
Proportion of all people without disease who test negative.
SPECIFICITY
High specificity useful for ruling in disease (confirmatory) - low false-positive rate.
Proportion of positive test results that are true positives.
POSITIVE PREDICTIVE VALUE
Increases with increasing pretest probability (prevalence) - high pretest probability means higher PPV
Proportion of negative test results that are true negatives.
NEGATIVE PREDICTIVE VALUE
Decreases with increasing pretest probability (prevalence) - high pretest probability means lower NPV
Odds of exposure of people with the disease, compared with odds of exposure of people without the disease.
ODDS RATIO
If rows are exposed/unexposed and columns are disease/no disease then OR = ad/bc
Relative risk
RELATIVE RISK
Treatment Rate/Control Rate
If prevalence is low, OR = RR (rare disease assumption)
Absolute risk increase (Attributable Risk)
Treatment Rate - Control Rate
Relative Risk Reduction (RRR) - The proportion of risk reduction attributable to the intervention
RELATIVE RISK REDUCTION
RRR = 1 - RR = ARR/Control Rate
Note: ARP = (RR - 1)/RR
Absolute risk reduction (ARR)
Control Rate - Treatment Rate
Number needed to treat.
1/ARR
Number needed to harm.
1/ARI
The absence of random variation in a test.
PRECISION
A measure of reliability/reproducibility
The absence of systematic error or bias in a test.
ACCURACY
A measure of validity
Null hypothesis incorrectly rejected in favor of alternative hypothesis.
TYPE I ERROR (ALPHA)
Null hypothesis is not rejected when it is in fact false.
TYPE II ERROR (BETA)
Statistical power = 1 - Beta
Motor milestones.
1 mo: Lifts head 6 mo: Rolls and sits, passes toy hand to hand 8 mo: Crawls 10 mo: Stands, pincer grasp 12 mo: Walks, points 18 mo: Climbs stairs 20 mo: Feeds self 24 mo: Kicks ball 3 yr: Tricycle 4 yr: Copies line or circle, hops 5 yr: Grooms self
Social milestones.
2 mo: Social smile 6 mo: Stranger anxiety 9 mo: Separation anxiety 24 mo: Away from mother 24-36 mo: Parallel play 36 mo: Gender identity 3 yr: Time away from mother 4 yr: Cooperative play
Verbal/Cognitive milestones.
4 mo: Orients to voice 9 mo: Orients to name, object permanence 10 mo: Mama and dada 2 yr: 200 words, 2 word sentences 3 yr: 1000 words, complete sentences 4 yr: Tells stories
Sleep chances in the elderly.
Decreased REM sleep and slow-wave sleep
Increased sleep onset latency
Increased early awakenings
Sensorineural hearing loss of higher frequencies (cochlear base).
PRESBYCUSIS
Basic information that can be shared to presumed family when patient cannot give consent.
Patient is stable.
Procedure in a case of suspected child abuse.
Interview child alone then contact CPS immediately if any suspicion.
Selection bias created by selecting hospitalized patients as the control group.
Berkson’s bias
Difference between confounding variables and effect modification.
After stratification there will be a significant difference in risk in effect modification, but not with a confounding variable.
Equation for SE - Used when describing the confidence interval for a sample rather than the normal distribution of a population.
SE = SD/sqrt(n)
Observer bias leading to the tendency of subjects to change their behavior as a result of their awareness that they are being studied.
Hawthorne effect
Effect describing the fact that a researcher’s belief in the efficacy of treatment can potentially affect the outcome.
Pygmalion effect
Selection bias in which subjects lost to follow up differ in their risk of developing the outcome compared to the remaining subjects.
Attrition bias
Bias occurring when either exposure or outcome is not identified correctly.
Misclassification bias
If random (nondifferential) - will affect all groups to the same extent.
Study where the unit of analysis is populations rather than individuals.
Ecological study
Attempting to connect these results to individuals is known as ecological fallacy
Study that starts out as cohort studies and then recruits patients who develop an outcome of interest into a case-control study.
Nested case-control design
Bias referring to the fact that a risk factor itself may lead to extensive diagnostic investigation and increase the probability that a disease is detected.
Detection bias
Requirement for hospice care.
Life expectancy of < 6 months.
Response to suspected intimate partner violence.
Investigate emergency safety plans and give referrals - do not pressure the patient to disclose to act
Probably that one event will turn out differently (independent events)
1 - P(all will turn out the same)
Standard deviations
1 - 68%
2 - 95%
3 - 99.7%
Note - Includes both tails so divide in half for one tail
Positive likelihood ratio
Sensitivity/(1-Specificity)
Note - Negative LR is (1 - Sensitivity)/Specificity
Incidence
New cases/Total at risk
Note - Total at risk is total population minus those who already have the disease
Covered by Medicare (Federal)
> 65 with work history
Disabilities
ESRD
ALS
Note - Parts A (hospitalization), B (outpatient, devices), C (dental/vision), D (prescription)
Covered by Medicaid (State)
Low-income families
Pregnant women
Homeless
Undocumented immigrants
