Ethics And Stats

Question 1

What are the 4 tenets of medical ethics

Answer 1

Autonomy (requires that pt has mental capacity to evaluate options)

Non-maleficence (avoid deliberate/unintentional harm)

Beneficence (it is our duty to act in the best interest of the pt)

Justice (fairness to individuals)

Question 2

Pediatric trauma. Needs transfusion but parents jehovah’s witness. What is the right thing to do?

Based on which tenet?

Answer 2

Tell family you are obligated to transfuse even against their will.

Not based on autonomy.
Based on beneficence

Question 3

Which tenet is the informed consent based on?

Answer 3

Autonomy

Question 4

What is the mode of the following series:

4, 5, 8, 9, 11, 11

Answer 4

11. Mode is the number that appears most often

Question 5

Which depends on the sample size?

a) standard deviation
b) variance
c) standard error

Answer 5

Standard error

Question 6

What’s the difference between continuous, ordinal, and nominal

Answer 6

Continuous: real numbers, not integers

Ordinal: categories mean something. Young/middle aged/old or pain scale

Nominal: categories that don’t have order significance

Question 7

What study design starts with the outcome and examine the exposure?

Answer 7

Case control study

Reason to do: if the outcome is rare

Find 10 ppl who have medulloblastoma and ppl who don’t have it then compare

Question 8

You use odds ratio in what type of study?

Answer 8

Case control study. Think: you’re studying an odd disease that not very many ppl have. Odds ratio

Question 9

How to calculate specificity/sensitivity

Answer 9

For sn/sp you start with everyone who has disease

And see how good the test is.

Positive PID (positive in disease) is a sensitive issue

What % will be positive among those who have the disease?

Specificity: negative in health (NIH) NIH is specific

Question 10

How to calculate positive/negative predictive value

Answer 10

You start with the test and ask how good is the test

Question 11

Sensitivity/specificity/PPV/NPV

which is affected by the prevalence of the disease?

Answer 11

PPV and NPV

Question 12

What statistic test do you use for nominal variables?

Answer 12

Chi square

Question 13

What do you use for ordinal variables?

Answer 13

Wilcox on rank sum. Mann whitney.

Question 14

Odds ratio vs relative risk

Answer 14

Relative risk is probability 1/probability 2

Odds ratio is p1/(1-p1) divided by p2/(1-p2)

Question 15

For kaplan meier curves what is log rank test and cox?

Answer 15

Log rank compare survival between groups

Cox adjusts for confounders

Question 16

What is the most common indication for surgical intervention in older adults >65

Answer 16

Biliary tract disease

Question 17

What type of surgical procedure is at the highest risk of postop delirium?

Answer 17

Ortho according to passmachine

Cardiac according to truelearn

Question 18

Difference between adverse events, sentinel events, and close calls

Answer 18

Adverse events: shit happens

Close calls: better to be lucky than good

Sentinel events: should never happen. Wrong site surgery, foreign body, etc

Question 19

What is the most commong cause of wrong site surgery?

Answer 19

Poor communication

Question 20

What % needles under 10mm are seen on x-rays?

<25mm?

Answer 20

29%

84% of needles are seen if <25mm

Question 21

Does sleep deprivation affect the speed or accuracy of a given surgical task?

Answer 21

Slows down.

Accuracy is fine

Question 22

Technical errors are more likely to happen during routine or complex operations?

Answer 22

Routine operations in complex pt

Question 23

What is the most common reason for lawsuits in nursing home?

Answer 23

Falls and pressure ulcers

Question 24

What are formal/informal advance directives?

What is a durable power of attorney?

Answer 24

Formal: written document
Informal: not a written document. Verbal statement given to friend or family by the pt regarding medical wishes

Durable power of attorney: it’s a formal advance directive that designates a surrogate decision maker for the oatient

Question 25

What happens to systemic vascular resistance with increasing age?

Answer 25

It increases with age

Question 26

What happens to oxygen consumption with increasing age?

Answer 26

O2 consumption decreases with age

Question 27

What’s the order of priority for a incapacitated pt?

Siblings, parents, adult children, divorced wife, non-divorced wife

Answer 27

Non-divorced wife > adult children > parent > adult sibling

Question 28

What is the relationship between type II error and power?

Answer 28

Power = 1 - beta (type II error)

Question 29

Blinding vs randomization

Which one is used to minimize treatment bias introduced by the pts and clinicians

Answer 29

Blinding

Question 30

Blinding vs randomization

Which one is used minimize unrecognized variables that may affect outcomes?

Answer 30

Randomization

Question 31

1,000 total pts. 200 with diabetes 800 without

SSI: 120 (40 with diabetes, 80 without)

What is the odds ratio of SSI occurring in diabetes

Answer 31

Odds of diabetics having SSI / odds of non-diabetics having SSI

40/160 = 0.25
80/720 = 0.111

0.25/0.111 = 2.25

Question 32

How is power of a study related to null hypothesis?

Answer 32

Power = rejecting null hypothesis when in fact null hypothesis is false.

Accepting null hypothesis when in fact null hypothesis is false = beta. Type II error

Question 33

Chi square vs Mann whitney U. What variables are used for each test?

Answer 33

Chi square: nominal variables

Mann whitney: ordinal variable