Clinical trial: Phase 1 - who are the subjects? - what are you testing?

- Small number of healthy volunteers. - “Is it safe?” Assesses safety, toxicity, and pharmacokinetics.

Clinical trial: Phase 2 - who are the subjects? - what are you testing?

- Small number of patients with disease of interest. - “Does it work?” Assesses treatment efficacy, optimal dosing, and adverse effects.

Clinical trial: Phase 3 - who are the subjects? - what are you testing?

- Large number of patients randomly assigned either to the treatment under investigation or to the best available treatment (or placebo). - “Is it as good or better?” Compares the new treatment to the current standard of care.

Precision - aka? - define - relationship to standard deviation?

- Reliability - The consistency and reproducibility of a test. - More precise a test, the smaller the standard deviation.

Berkson bias - what type of bias? - what is it?

- Selection & sampling bias. - A study looking only at inpatients.

Power of a study - equation: - what is it? - aka?

- (1 – β) - ability to detect a difference btwn groups when a difference truly exists. - like "true positive".

Chi-square (χ²) - what is it? - mnemonic?

- Checks difference between 2 or more percentages or proportions of categorical outcomes (not mean values). - "Pronounce Chi-tegorical" -Example: comparing the percentage of members of 3 different ethnic groups who have essential hypertension.

3/21 BS Flashcards by Mike Mah

Case control study

prospective or retrospective?
odds ratio or relative risk?

retrospective

- odds ratio

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Clinical trial: Phase 1

who are the subjects?
what are you testing?

Small number of healthy volunteers.

- “Is it safe?” Assesses safety, toxicity, and pharmacokinetics.

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Clinical trial: Phase 2

who are the subjects?
what are you testing?

Small number of patients with disease of interest.

- “Does it work?” Assesses treatment efficacy, optimal dosing, and adverse effects.

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Clinical trial: Phase 3

who are the subjects?
what are you testing?

Large number of patients randomly assigned either to the treatment under investigation or to the best available treatment (or placebo).
“Is it as good or better?” Compares the new treatment to the current standard of care.

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Clinical trial: Phase 4

who are the subjects?
what are you testing?

-Postmarketing surveillance trial of patients after
approval.
-“Can it stay?” Detects rare or long-term adverse effects. Can result in a drug being withdrawn from market.

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Vaccine

-whats reduced, incidence or prevalence?

Both

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Precision

aka?
define
relationship to standard deviation?

Reliability
The consistency and reproducibility of a test.
More precise a test, the smaller the standard deviation.

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Accuracy

aka?
define

Validity

- The trueness of test measurements. The absence of systematic error or bias in a test.

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Internal validity:

How well the conclusion corresponds to the real situation in the sample population.

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Berkson bias

what type of bias?
what is it?

Selection & sampling bias.

- A study looking only at inpatients.

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Hawthorne effect

what type of bias?
what is it?

Measurement bias

- Groups who know they’re being studied behave differently than they would otherwise.

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Pygmalion effect

-aka?

-Observer-expectancy bias

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Lead-time bias

-what is it?

Early detection confused w/inc. survival.

-seen w/improved screening techniques.

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Lead-time bias

-how do you reduce this bias?

Measure “back-end” survival (adjust survival according to

the severity of disease at the time of diagnosis).

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Crossover studies

-what is it?

-subjects act as their own controls.

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Matching

-what is it?

patients with similar characteristics in both treatment and control groups.
the matching variables should be the confounders of that study.
a way to reduce confounding bias.

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standard error of mean (SEM)

-relationship w/sample size

As (n) increases, SEM decreases.

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Skew:

-define it

Think of normal bell curve but you grab one side and pull
it a little. If you pull it to the right, its positive skew. And
in ABC order, you drag the Mean, Median, and Mode along with it.

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Power of a study

equation:
what is it?
aka?

(1 – β)
ability to detect a difference btwn groups when a difference truly exists.
like “true positive”.

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Chi-square (χ²)

what is it?
mnemonic?

Checks difference between 2 or more percentages or proportions of categorical outcomes (not mean values).
“Pronounce Chi-tegorical”

-Example: comparing the percentage of members of 3 different ethnic groups who have essential hypertension.

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Coefficient of determination =

r^2 (value that is usually reported).

- r = Pearson correlation coefficient

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Disease prevention

-mnemonic?

PST:

Prevent
Screen
Treat

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Disease prevention: primary

-Prevent disease occurrence (e.g., HPV vaccination).

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Disease prevention: tertiary

-Treatment to reduce disability from disease (e.g., chemotherapy).

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Disease prevention: Quaternary

-Identifying patients at risk of unnecessary treatment, protecting from the harm of new interventions.

Informed consent requires what 4 things?

- Disclosure - Understanding - Mental capacity - Voluntariness

Therapeutic privilege | -what is it?

-withholding information when disclosure would severely | harm the patient or undermine informed decision-making capacity.

Situations in which parental consent is usually not required for minors:

- Sex (contraception, STDs, pregnancy) - Drugs (addiction) - Rock and roll (emergency/trauma) *they can get prenatal care BUT 2/3 of the states require parental consent for abortions.

Medical power of attorney | -Can a pt revoke it even if hes not competent?

-Yes. Can be revoked anytime patient wishes (regardless of competence).

Surrogate decision maker | -order:

Spouse, adult children, parents, adult siblings, other relatives.

Reportable diseases | -examples:

-STDs, TB, hepatitis, food poisoning.

The Tarasoff decision | -what is it?

- Scenario when Dr can break pt. confidentiality. | - California Supreme Court decision requiring physician to directly inform and protect potential victim from harm.

Can a Dr. break confidentiality to report impaired automobile drivers (e.g., epileptics)?

Yes

Apgar score - whats apgar stand for? - what do scores mean? - at which time intervals?

- Appearance, Pulse, Grimace, Activity, and Respiration. - (≥ 7 = good; 4–6 = assist and stimulate; < 4 = resuscitate). - 1 & 5 min.

Low birth weight - definition: - associated w/inc risk of what?

- Defined as < 2500 g. | - inc. risk of SIDS

Low birth weight | -potential complications:

-Infections, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage, and persistent fetal circulation.

#1 killer of 65+ in USA

Heart disease | -cancer = #2

#1-#3 killers of 35-44 in USA

Unintentional injury = #1 - Cancer = #2 - Heart disease = #3

Deltoid | -innervation?

axillary n

What % of the coronary lumen do atheromas need to obstruct to produce angina?

75%

Langerhans cell histiocytosis | -presentation?

-child w/lytic bone lesions & skin ras or -recurrent otitis media w/mass involving the mastoid bone.

Bleomycin | -S/E:

pulm fibrosis, skin discoloration, mucositis. | *minimal myelosuppression.

Echinocandins - mech: - examples: - use:

- inhibits cell wall synth by inhibiting synth of beta-glucan. - "-fungin" - invasive aspergillosis, candida

How does capsaicin reduce pain?

reduces substance P in PNS

Most commonly injured rotator cuff tendon?

supraspinatus | -can be impinged btwn humeral head and acromion.

Name an important flexor of humerus

ant. deltoid.

main adductor of humerus

latissimus dorsi

Rb two hit mutation leads to what cancer?

retinoblastoma & osteosarcoma

Rb protein - active form: phosphorylated or not phosphorylated? - which form allows cell division?

not phosphorylated. | -phosphorylation inactivated Rb => allowing cell division.

Unilat. dmg to recurrent laryngeal => | Bilat damage =>

- Unliateral = hoarsness | - Bilateral = resp difficulty due to airway obstruction by immobile vocal cords

Succinylcholine - phase 1: antidote? - phase 2: antidote?

- phase 1: no antidote | - phase 2: cholinesterase inhibitors

actin-containing fibroblasts | -aka?

myofibroblasts

Berylliosis | -what type of inflammation?

granulomatous

etoposide | -which topoisomerase does it block?

topoisomerase 2

Relative Risk Reduction (RRR) | -equation:

RRR = 1 - RR

ARPexposed =

ARPexposed = 100 * [(RR-1)/RR]

Number needed to treat | -equation:

1/ARR

Number needed to harm | -equation:

1/AR

Type I error (α)

- false positive error - saying there is a difference when there isn't one. - null hypothesis incorrectly rejected in favor of alternative hypothesis.

False positive error - type 1 or type 2 error? - alpha or beta?

type 1 | -alpha

Type II error (b)

- false-negative error. - saying there is no difference when one really does exist. - null hypothesis is not rejected when it is in fact false.

How to increase power? (aka decrease beta)

- inc sample size - inc. expected effect size - inc. precision of measurement

true positive rate - equation: - is this sensitivity or specificity?

= 1 - FN | -sensitivity

true negative rate - equation: - is this sensitivity or specificity?

= 1 - FP | -positivity

For the 95% CI, Z =

Z = 1.96.

For the 99% CI, Z =

Z = 2.58.

somatosensation from ant. 2/3 of tongue | -which nerve?

trigeminal n. => mandibular n. => lingual n.

somatosensation from post. 1/3 of tongue | -which nerve?

CN 9

somatosensation & taste from post. 1/3 of tongue | -which nerve?

CN 9

taste from pharynx and epiglottus

CN 10

humeral midshaft injury | -which nerve?

radial n.

how do tumor cells die? | -apop or necrosis?

apoptosis

What % of normal adults have patent foramen ovales?

20-30%

Li-Fraumeni syndrome - what is it? - inheritance pattern?

- germline p53 mutation. | - auto dom.

BRCA-1 | -associated w/which cancers?

breast & ovary

CD34 | -stain for what?

endothelial cells

light stools and dark urine | -whats it mean?

direct hyperbili via bile obstruction. | -no bile getting into intestines so no bilirubin in stool BUT bilirubin getting into blood so urine will be dark.

Most common type of childhood neoplasm? | -2nd most common?

leukemia = #1 | brain tumor = #2