First Aid - Behavioral Science

Front 1

Case-control study

Back 1

Compares a group of people with disease to a group without.
Looks for prior exposure or risk factor.
Odds ratio (OR).

Front 2

Cohort Study

Back 2

Compares a group with a given exposure or risk factor to a group without. Can be prospective or retrospective. Relative risk (RR).

Front 3

Cross-sectional study

Back 3

Collects data from a group of people to assess frequency of disease (and related risk factors) at a particular point in time. Measures disease prevalence. Does not establish causality.

Front 4

Twin Concordance Study

Back 4

Compares the frequency with which both monozygotic twins or both dizygotic twins develop a disease. Measures heritability.

Front 5

Adoption study.

Back 5

Compares siblings raised by biologic vs. adoptive parents. Measures heritability and influence of environmental factors.

Front 6

Phase 1 Clinical Trial

Back 6

Small number of healthy volunteers.
Measures safety, toxicity, and pharmacokinetics.

Front 7

Phase 2 Clinical Trial

Back 7

Small number of patients with disease of interest.
Assesses treatment efficacy, optimal dosing, and adverse effects.

Front 8

Phase 3 Clinical Trial

Back 8

Large number of patients randomly assigned to either treatment or placebo.
Compares the new treatment to the current standard of care.

Front 9

Phase 4 Clinical Trial

Back 9

Postmarketing surveillance trial of patients after approval. Detects rare or long-term adverse effects.

Front 10

Sensitivity

Back 10

TP / (TP + FN)
Value approaching 1 is desirable for ruling out disease and indicates a low false-negative rate.

Front 11

Specificity

Back 11

TN / (TN + FP)
Proportion of all people without disease who test negative. Value approaching 1 is desirable for ruling in disease and indicates a low false-positive rate. Used as a confirmatory test after a positive screening test.

Front 12

Positive Predictive Value (PPV)

Back 12

TP / (TP + FP)
Probability that person actually has the disease given a positive test result.

Front 13

Negative Predictive Value

Back 13

TN / (TN + FN)
Probability that a person actually is disease free given a negative test result.

Front 14

Odds ratio for case-control studies

Back 14

Odds of having disease in exposed group divided by odds of having disease in unexposed group.

(a / b)
----------
(c / d)

Front 15

Relative risk for cohort studies

Back 15

Probability of getting a disease in the exposed group divided by the probability of getting a disease in the unexposed group.

a / (a + b)
------------
c / (c + d)

Front 16

Attributable Risk

Back 16

The difference in risk between exposed and unexposed groups, or the proportion of disease occurrences that are attributable to the exposure.

a c
------- - ---------
a + b c + d

Front 17

Absolute risk reduction

Back 17

The reduction in risk associated with a treatment as compared to a placebo.

Front 18

Number needed to treat

Back 18

1 / absolute risk reduction

Front 19

Number needed to harm

Back 19

1 / attributable risk

Front 20

Precision vs. accuracy

Back 20

Precision: the consistency and reproducibility of a test (reliability), random error reduces precision

Accuracy: the trueness of test measurements (validity), systemic error reduces accuracy in a test

Front 21

Selection bias

Back 21

nonrandom assignment to study group (e.g. loss to follow up)

Front 22

Recall bias

Back 22

Knowledge of the presence of a disorder alters recall by subjects

Front 23

Sampling bias

Back 23

subjects are not representative relative to general population; therefore, results are not generalizable

Front 24

Late-look bias

Back 24

information gathered at an inappropriate time - e.g. using a survey to study a fatal disease (only those still alive can answer)

Front 25

Procedure bias

Back 25

Subjects in different groups are not treated the same - e.g. more attention is paid to treatment group, stimulating greater compliance

Front 26

Confounding bias

Back 26

Occurs with 2 closely associated factors; the effect of 1 factor distorts or confuses the effect of the other

Front 27

Lead-time bias

Back 27

early detection is confused with increased surivval; seen with improved screening (natural history of disease is not changed, but early detection makes it seem as though survival is increased)

Front 28

Pygmalion effect

Back 28

Occurs when a researcher's belief in the efficacy of a treatment changes the outcome of that treatment

Front 29

Hawthorne effect

Back 29

occurs when the group being studied changes its behavior owing to knowledge of being studied

Front 30

SEM

Back 30

Standard error of the mean = σ / sqrt (n)
SEM decreases as n increases.

Front 31

Positive skew

Back 31

mean > median > mode
Asymmetry with tail on the right.

Front 32

Negative skew

Back 32

mean < median < mode
Asymmetry with tail on the left.

Front 33

Null (Ho) Hypothesis

Back 33

Hypothesis of no difference (no association between disease and risk factor)

Front 34

Alternate (H1) Hypothesis

Back 34

Hypothesis that there is some difference. (There is an association between disease and risk factor)

Front 35

Type I error (alpha)

Back 35

"False-positive Error"
Stating there is an effect or difference when none exists.

Front 36

Type II error (beta)

Back 36

"False-negative Error"
Stating there is not an effect or difference when one exists.

Front 37

Power (1 - Beta)

Back 37

Probability of rejecting the null hypothesis when it is in fact false; or the likelihood of finding a difference if one in fact exists. It depends on:
1. Total number of end points experienced by population
2. Difference in compliance between treatment groups (differences in the mean values between groups)
3. Size of expected effect

Front 38

Meta-analysis

Back 38

Pools data and integrates results from several similar studies to reach an overall conclusion. Increases statistical power.

Front 39

Confidence Interval

Back 39

Range of values in which a specified probability of the means of repeated samples would be expected to fall.
CI = range from [mean - Z(SEM)] to [mean + z(SEM)]
For the 95% CI, Z = 1.96.

Front 40

T-test

Back 40

Checks difference between the means of 2 groups.

Front 41

ANOVA

Back 41

"Analysis of Variance"
Checks the difference between the means of 3 or more groups.

Front 42

Chi-Square Test

Back 42

Checks difference between 2 or more percentages or proportions of categorical outcomes (not mean values)

Front 43

Correlation coefficient (r)

Back 43

- 1 < r < 1
The closer the absolute value of r is to 1, the stronger the correlation between two values.
r ^2 = Coefficient of determination (values usually reported)

Front 44

Disease Prevention (Primary, Secondary, Tertiary)

Back 44

Primary - prevent disease occurrence (e.g. HPV vaccine)
Secondary - Early detection of disease (e.g., PAP smear)
Tertiary - Reduce disability from disease (e.g. chemotherapy)

Front 45

Medicare vs. Medicaid

Back 45

Medicare - pts >65, <65 with certain disabilities, and ESRD
Medicaid - federal and state health assistance for people with very low income

Front 46

Autonomy

Back 46

Obligation to respect patients as individuals and to honor their preferences in medical care.

Front 47

Beneficence

Back 47

Physicians have a special ethical (fiduciary) duty to act in the patient's best interest. May conflict with autonomy. If the patient can make an informed decision, ultimately the patient has the right to decide.

Front 48

Nonmaleficence

Back 48

"Do no harm." However, if the benefits of an intervention outweigh the risks, a patient may make an informed decision to proceed (most surgeries and medications fall into this category).

Front 49

Justice

Back 49

To treat persons fairly.

Front 50

Informed Consent, (3) requirements

Back 50

1. Discussion of pertinent information
2. Patient's voluntary agreement with the plan of care
3. Freedom from coercion
Patient must express intelligent understanding.

Front 51

Exceptions to informed consent (4)

Back 51

1. Patient lacks decision-making capacity or is legally incompetent.
2. Implied consent in an emergency.
3. Therapeutic privilege - withholding information when disclosure would severely harm the patient or undermine informed decision-making capacity
4. Waiver - patient waives the right of informed consent

Front 52

Consent for minors

Back 52

A minor is anyone <18 yo. Parental consent must be obtained unless minor is emancipated (e.g. is married, is self-supporting, has children, or is in military). However, parental consent is not required in emergency situations; when prescribing contraceptives; or in treatment involving STDs, medical care during pregnancy, or the management of drug addiction.

Front 53

Decision-making Capacity requirements (5)

Back 53

1. Patient makes and communicates a choice
2. Patient is informed (knows and understands)
3. Decision remains stable over time
4. Decision is consistent with patient's values and goals
5. Decision is not a result of delusions or hallucinations

Front 54

Oral Advanced Directive

Back 54

incapacidated patient's prior oral statements commonly used as guide. If patient was ifnormed, directive was specific, patient made a choice, and decision was repeated to multiple people, the oral directive is more valid.

Front 55

Living Will (Written advanced directive)

Back 55

Treatments the patient wishes to receive or not receive if he/she becomes incapacitated and cannot communicate about treatment decisions.

Front 56

Durable Power of Attorney

Back 56

Patient designates a surrogate to make medical decisions in the event that he/she loses decision-making capacity. Patient may also specify decisions in clinical situations. Surrogate retains power unless revoked by patient. more flexible than a living will.

Front 57

Surrogates

Back 57

If an incompetent patient has not prepared an advanced directive, individuals (surrogates) who know the patient must determine what the patient would have done if he/she were competent. Priority of surrogates: spouse, adult children, parents, siblings, other relatives.

Front 58

Confidentiality

Back 58

Respect patient's privacy and autonomy. Disclosing information to family and friends should be guided by what the patient would want. The patient may waive the right to confidentiality.

Front 59

Exceptions to Confidentiality (4)

Back 59

1. Potential harm to others is serious
2. Likelihood of harm to self is great
3. No alternatie means exist to warn or protect those at risk
4. Physicians can take steps to prevent harm

Front 60

Examples of Exceptions to Confidentiality Agreement

Back 60

1. Reportable diseases (STDs, TB, hepatitis, food poisoning)
2. The Tarasoff decision - law requiring physician to directly inform and protect potential victim from harm; may involve breach of confidentiality
3. Child and/or elder abuse
4. Impaired automobile drivers
5. Suicidal/homicidal patients

Front 61

Ethical Situation - Patient is noncompliant.

Back 61

- attempt to identify pt's reason for noncompliance/willingness to change
- DO NOT attempt to coerce the patient into complying or refer to another physician

Front 62

Ethical Situation - Patient desires an unnecessary procedure.

Back 62

- attempt to understand why pt wants procedure/address underlying concerns
- Avoid performing unnecessary procedures

Front 63

Ethical Situation - Patient has difficulty taking medications.

Back 63

Provide written instructions; attempt to simplify treatment regimens.

Front 64

Ethical Situation - Family members ask for information about patient's prognosis.

Back 64

Avoid discussing issues with relatives without the permission of the patient.

Front 65

Ethical Situation - A child wishes to know more about his illness.

Back 65

Ask what the parents have told the child about his/her illness. Parents of a child decide what information can be relayed about the illness.

Front 66

Ethical Situation - A 17yo girl is pregnant and requests an abortion.

Back 66

Many states require parental notification or consent for minors for an abortion. unless she is at medical risk, do not advise a patient to have an abortion regardless of her age or the condition of the fetus.

Front 67

Ethical Situation - A 15yo girl is pregnant and wants to keep the child. Her parents want you to tell her to give the child up for adoption.

Back 67

The patient retains the right to make decisions regarding her child, even if her parents disagree. Provide information to the teenager about the practical issues of caring for a baby. Discuss the options, if requested. Encourage discussion between the teenager and her parents to reach the best decision.

Front 68

Ethical Situation - A terminally ill patient requests physician assistance in ending his life.

Back 68

In the majority of states, refuse involvement in any form of physician-assisted suicide. Physicians may, however, prescribe medically appropriate analgesics that coincidentally shorten the patient's life.

Front 69

Ethical Situation - Patient is suicidal.

Back 69

Assess the seriousness of the threat; if it is serious, suggest that the patient remain in the hospital voluntarily; patient can be hospitalized involuntarily if he/she refuses.

Front 70

Ethical Situation - Patient states that he finds you attractive.

Back 70

Ask direct, closed-ended questions and use a chaperone if necessary. Romantic relationships with patients are never appropriate. Never say, "There can be no relationship while you are a patient," because it implies that a relationship may be possible if the individual is no longer a patient.

Front 71

Ethical Situation - A middle-aged married woman who had a mastectomy says she feels "ugly" when she undresses at night.

Back 71

Find out why the patient feels this way. Do not offer falsely reassuring statements (e.g., "You still look good.")

Front 72

Ethical Situation - Patient is angry about the amount of time he spent int he waiting room.

Back 72

Acknowledge the patient's anger, but do not take a patient's anger personally. Apologize for any inconvenience. Stay away from efforts to explain the delay.

Front 73

Ethical Situation - Patient is upset witht he way he was treated by another doctor.

Back 73

Suggest that the patient speak directly to that physician regarding his concerns. If the problem is with a member of the office staff, tell the patient you will speak to that individual.

Front 74

Ethical Situation - A drug company offers a "referral fee" for every patient a physician enrolls in a study.

Back 74

Eligible patients who may benefit from the study may be enrolled, but it is never acceptable for a physician to receive compensation from a drug company.
Patients must be told about the existence of a referral fee.

Front 75

Ethical Situation - A physician orders an invasive test for the wrong patient.

Back 75

No matter how serious or trivial a medical error, a physician is ethically obligated to inform a patient that a mistake has been made.

Front 76

Ethical Situation - A patient requires a treatment not covered by his insurance.

Back 76

Never limit or deny care because of the expense in time or money. Discuss all treatment options with patients, even if some are not covered by their insurance companies.

Front 77

APGAR score

Back 77

10-point scale evaluted at 1- and 5- minutes. Score is based on Appearance, Pulse, Grimace, Activity and Respiration (>/=7 good, 4-6 = assist and stimulate, <4 = resuscitate)

Front 78

Early Developmental Milestones - Birth - 3 months

Back 78

Rooting reflex, holds head up, Moro reflex disappears
Social Smile
Orients and responds to voice

Front 79

Early Developmental Milestones - 7-9 months

Back 79

Sits alone, crawls, transfers toys from hand to hand
Stranger anxiety
Responds to name and simple instructions, uses gestures

Front 80

Early Developmental Milestones - 12-15 months

Back 80

Walks, Babinski reflex disappears
Separation anxiety
Few words

Front 81

Early Developmental Milestones - 12-24 months

Back 81

Climbs stairs; stacks 3 blocks at 1 year, 6 blocks at 2 years
Rapprochement (moves away from and then returns to mother)
Object permanence; 200 words and 2-word sentences at age 2

Front 82

Early Developmental Milestones - 24-36 months

Back 82

Feeds self with fork and spoon, kicks ball
Core gender identity, parallel play
Toilet training ("pee at age 3")

Front 83

Early Developmental Milestones - 3 yrs

Back 83

Rides tricycle (rides 3-cycle at age 3), copies line or circle drawings
Comfortably spends part of day away from mother
900 words and complete sentences

Front 84

Early Developmental Milestones - 4 yrs

Back 84

Uses buttons and zippers, grooms self, hops on 1 foot, makes simple drawings (stick figures)
Cooperative play, imaginary friends
Can tell detailed stores and use prepositions

Front 85

Changes in the Elderly

Back 85

1. Sexual changes - Men - slower erection/ejaculation, longer refractory period; Women - vaginal shortening, thinning, and dryness
2. Sleep pattern - dec. REM, slow-wave sleep; inc. latency and awakenings
3. Inc. suicide rate
4. decreased vision, hearing, immune response, bladder control
5. decreased renal, pulmonary and GI function
6. decreased muscle mass, increased fat

Front 86

Grief

Back 86

Normal bereavement c/b shock, denial, guilt, and somatic symptoms for up to 2 months
Pathologic grief - prolonged >2 months; or grief that is delayed, inhibited, or denied. May experience depressive symptoms, delusions, and hallucinations

Front 87

Physiologic Effects of Chronic Stress

Back 87

production of FFA, cortisol (immunosuppression), lipids, cholesterol, catecholamines
Affects water absorption, muscular tonicity, gastrocolic reflex, and mucosal circulation

Front 88

Sexual Dysfunction

Back 88

Sexual Desire Disorders - hypoactive sexual desire or sexual aversion
Sexual Arousal Disorders - erectile dysfunction
Sexual Pain Disorders - dyspareunia and vaginismus

Front 89

Sleep Stages

Back 89

Awake (eyes open) - Beta waveform on EEG
Awake (eyes closed) - Alpha waveform
Stage 1 Sleep - Light sleep - Theta Waveform
Stage 2 Sleep - Deeper sleep, bruxism - Sleep spindles and K complexes
Stage 3 Sleep - Deepest, non-REM sleep (slow-wave sleep); sleepwalking; night terrors; bedwetting - Delta waveform
REM - Dreaming, loss of motor tone, erections, Inc. brain O2 use - Beta waveform (same as eyes open)

Front 90

REM Sleep - Neurotransmitters and Details

Back 90

ACh is principle neurotransmitter in REM sleep
NE reduces REM sleep
Increased and variable pulse and blood pressure
Extraocular movements during REM sleep due to activity of PPRF
Penile/clitoral tumescence
Occurs every 90 minutes, inc. duration throughout the night

Front 91

Sleep Patterns of Depressed Patients

Back 91

1. dec. slow-wave sleep
2. dec. REM latency
3. Increased REM early in sleep cycle
4. Inc. total REM
5. Repeated nighttime awakenings
6. Early-morning awakening

Front 92

Narcolepsy

Back 92

Disordered regulation of sleep-wake cycles: excessive daytime sleepiness. May have hypnagogic and hypnopompic hallucinations. Nocturnal and narcoleptic sleep episodes start off with REM sleep.
Cataplexy (loss of all muscle tone following a strong emotional stimulus) in some patients. Treat with stimulants (e.g., ampheatmines, modafinil) and sodium oxybate (GHB).

Front 93

Circadian Rhythm

Back 93

Driven by suprachiasmatic nucleus (SCN) of hypothalamus: controls ACTH, prolactin, melatonin, nocturnal NE release. SCN --> NE release --> pineal gland --> melatonin. SCN is regulated by the environment (e.g. light)

Front 94

Sleep terror disorder

Back 94

Periods of terror with screaming in the middle of the night, most common in children; occurs during slow-wave sleep; no memory of arousal; cause unknown, but triggers may include emotional stress during the previous day, fever, or lack of sleep.

Front 95

Ethical Situation - Drunk patient wants to leave the hospital.

Back 95

Intoxicated patients lack capacity. They are unable to make decisions. While a family member should make decisions, an intoxicated patient who enters the hospital alone can not make medical decisions.

Front 96

Ethical Situation - Athlete wants medical info held from the team.

Back 96

Must notify the team, legally. Most athlete sign a release form granting the team doctors, coaches and trainers the right to interact with any treating physician.

Front 97

Ethical Situation - Suspicion of child abuse.

Back 97

File report with Child Protective Services immediately, even if a case has not been confirmed. Do not involve other providers.

Front 98

Time course for psychological erectile dysfunction?

Back 98

Usually happens "one night" - vs. other causes (intermittent -> permanent)

Front 99

Ethical Situation - Difficult patient interaction

Back 99

Answer is always to seek further information using open-ended questions.

Front 100

When should discussion about advanced directives occur?

Back 100

-Ideally with the PMD
-Any inpatient admission

Front 101

Ethical Situation - Patient wants to give an expensive gift.

Back 101

Do not accept expensive gifts from any patient.

Front 102

Ethical Situation - Mother and Daughter, both Jehovah's Witnesses (according to brief contact with father), are bleeding out after a motor vehicle accident.

Back 102

For adult, transfuse if no advanced directives.
For child, life-saving treatment trumps legal guardian.

Front 103

Ethical Situation - A woman (35yo) asks for a tubal ligation.

Back 103

Decision is solely the patient's. Suggest that the patient discuss with significant other.

Front 104

Loss to follow-up is associated with what type of bias?

Back 104

Selection bias

Front 105

How do you recognize effect modification vs. confounding?

Back 105

Effect modification occurs when the effect of a main exposure on an outcome is modified by another variable.

To distinguish this from confounding - look for a comparison between people with the variable who receive the treatment and people with the variable who do not receive the treatment - if there is no increased association or risk with the variable and no treatment, but there is with both the variable and the treatment, then this is effect modification and not confounding.

Front 106

A cancer screening test has a 5% false negative rate, what is the probability that 1 of 8 tests in patients without the cancer will test positive?

Back 106

1 - 0.95^8

Front 107

What is a crossover study?

Back 107

Each group receives both treatment and control and vice versa. Allows patients to serve as their own control. Major flaw is that effects of one treatment can "carry over" to the second half of the study. To combat this, a "washout" period is sometimes added in the middle.

Front 108

which payment plan is associated with physicians providing more preventive care and health counseling services?

Back 108

Capitation

Front 109

How is Campylobacter jejuni transmitted?

Back 109

poultry, meat, unpasteruized milk, and keep in mind that farmers and pet owners get it from domesticated animals!

Front 110

Why does strep viridans stick to heart valves?

Back 110

If there has been damage and fibrin clots have formed, strep viridans is able to bind to fibrin based on its dextran-producing ability

Front 111

what is the missing activity in the RNA-dependent RNA-polymerase of HCV that leads to genetic variability in the host?

Back 111

lack of 3' --> 5' exonuclease activity

Front 112

95% confidence interval is based on what calculation?

Back 112

mean +/- 1.96[SD/sqrt(n)]
Standard Error of the Mean = SD/sqrt(n)
Z-score for 95% CI = 1.96

Front 113

what is the difference between a test's reliability and accuracy?

Back 113

reliability is a measure of test-retest numbers - good reliability means that the test is reproducible

accuracy is defined as the test's ability to measure what it is supposed to measure (vs. a gold standard measure)

Front 114

what is the coefficient of variation?

Back 114

CV is the standard deviation of the set of repeated measurements of a test divided by their mean, expressed as a percentage. Used to compare precision between tests that have different normal values and/or different units.

Front 115

black necrotic exchar on nasal turbinate = what disease?

Back 115

mucormycosis (Mucor, Rhizopus and Absidia)

Front 116

protein A for staph aureus does what?

Back 116

binds Fc region of Ig molecules and prevents opsonization by blocking production of C3b

Front 117

most common cause of viral meningitis in children?

Back 117

Enteroviruses (coxsackievirus, echovirus, poliovirus, and enterovirus)

Front 118

what is in the denominator of the equation to calculate incidence?

Back 118

total population AT RISK ( so total population minus those who already have the disease)

Front 119

when to use T-test vs. Chi-squared test?

Back 119

T-test is used to compare means of two groups, Chi-squared test is used to compare categorical values

Front 120

how to calculate the absolute risk percentage of a given exposure?

Back 120

(RR - baseline risk) / RR

Front 121

what is Berkson's bias?

Back 121

selection bias associated with making hospitalized patients the control group in a study

Front 122

how to calculate case-fatality rate?

Back 122

# of fatal cases / # of patients who had the disease

Front 123

explain the concept of a latent period

Back 123

Latent period - the time elapsed from initial exposure to clinically apparent effect

Some diseases and risk modifiers require years to develop, an important concept to remember when looking at epidemiological studies