Ethics/Research SAQ Flashcards
- You attend the birth of a known term anencephalic baby. The mother asks you about the possibility of organ donation. Is this a possibility? Give the reason for your yes or no answer (1 line).
No. The use of anencephalic newborns as organ donors is not supported because:
- infants don’t usually meet criteria for brain death b/c of adequate brainstem function that maintains spontaneous respiration + HR after birth
- if they meet criteria for somatic death, they have often sustained ischemic injury to their organs/multisystem organ failure and the organs are no longer suitable
- the maintenance of anencephalic infants on life-sustaining intensive care therapies for the purpose of organ donation is deemed unethical
- You are speaking with a 16 year old girl and her mother in your office. You have recommended that she have some bloodwork done as a part of the work up you are performing. Her mother wants her to have the bloodwork done, but the girl refuses. You respect the girl’s decision not to have the bloodwork performed.
What ethical principle is demonstrated by this clinical scenario?
Autonomy
- Name 3 necessary parts of informed consent.
- Capacity
- Adequately informed
- Free of coercion
- 9 year old girl diagnosed with ALL. Parents do not tell child of this diagnosis. Name and describe the ethical principles as they apply to the following:
a) You agree with the parents and do not tell the child.
b) You disagree with the parents and opt to tell the child.
a) Agree with the parents and do not tell the child
- Beneficience: act in pt’s best interests
- Non-maleficience: act to not harm pt, either by commission or omission
b) You disagree with the parents and opt to tell the child
* Autonomy: pt has the right to make decisions and act on them without interference
- 4 “medical reasons” why brain dead patient may not be able to be an organ donor.
- Severe untreated systemic sepsis
- AIDS
- Active disseminated TB
- Active viral hepatitis B or C
- Metastatic malignancy
- Prematurity (<32wk GA, <500g)
- Age of consent to sexual activity (non-coercive); oldest individual a 13 year-old child can have consenting sex with?
Similar Questions:
What does the “age of consent” or “age of protection” mean?
To what kind of sexual activity does this apply?
What is Canada’s age of consent?
Are there any exceptions to this?
A. Age of consent = 16yo
B. Does not apply to exploitive sexual situations or if there is a relationship of trust, authority or dependency
C. 12+13yo have close in age exception of <=2yo. 13yo -> 15yo
- 15 yr old boy with CF & really bad chest comes in with exacerbation. He refuses to go on a ventilator. After discussions with his parents & the health care team, it’s decided not to put him on the vent.
a) What ethical principle does this scenario demonstrate?
b) Name 3 components of informed consent?
a) Autonomy
b)
- Capacity
- Adequately informed
- Voluntary, free of coercion
- 10 yo brother of boy with AML, decision for palliative care at home. Brother going out to play with his friends rather than spending time with family. Counsel the parents. (1 – one line given!)
- 10yo brother may not have full understanding of what is happening. Parents should have age + developmentally appropriate conversations about death + dying wtih him. He may be feeling overwhelmed + is trying to cope by being with his friends.
Given 2x2 table, calculate sensitivity and specificity (careful because they switch the (axis label). Define sensitivity and specificity.
SN = TP/(TP+FN) = 76/(76+12) = 86%
= Of those who have the disease, the proportion that test positive
SP = TN/(TN+FP) = 36/(36+24) = 60%
= Of those who do not have the disease, the proportion that test negative
Define ARR. How do you calculate NNT and define it.
ARR = CER - EER (experimental event rate - control event rate)
The difference between the absolute risks of an outcome in the individuals exposed to the intervention and the absolute risks of an outcome in the individuals not exposed to the intervention
NNT = 1/ARR
The number of individuals who need to be receive an intervention in order for one individual to achieve the desired outcome
What is intention to treat
- Study participants are analyzed according to the groups in which they were randomized, even if they did not receive or comply with treatment
- Benefits
- Preserves the benefits of randomization
- Better accounts for factors that can influence the outcomes of a prescribed Tx, not just the effects of those who adhered to it
- Challenges
- Uncertain what to do with subjects who were lost to F/U
- Contrast to “as treated” or “per protocol” analysis, in which subjects are analyzed according to the actual Tx they received
- Four ways to avoid systematic bias in a trial
- Randomize test subjects to test intervention or placebo (prevents confounding)
- Double blind studies (subjects and clinicians do not know what the subject is receiving)
- Use control groups
- Clearly define exposure prioir to study (avoid exposure misclassifcation)
- Use objective data sources (e.g. corroborate subjective data soruces with medical record) (prevent recall bias)
- In a new study looking at the effect of steroid treatment in preventing meningitis-related hearing loss, it was shown that those treated with steroid developed hearing loss in only 10% of cases whereas those not treated with steroid developed hearing loss in 30% of cases.
A. Define ‘number needed to treat’ [1 point].
B. What is the number needed to treat in this study (show your calculations) [1 point].
A. The number of individuals who need to receive the intervention in order for one individual to have the desired outcome
B. NTT = 1/ARR = 1/(CER - EER) = 1/(0.30-0.10) = 5 (remember to change % to proportions!)
A study reports that 25% of people who receive opiates have delayed surgery and 23% who receive opiates have immediate surgery. The odds ratio is 1.11, with 95% confidence interval of 0.53-3.45.
A. Explain what the odds ratio is and interpret this odds ratio.
B. Explain what the 95% confidence interval is and interpret the 95% confidence interval.
A. Odds ratio: the ratio of the odds of an event occurring in one group to the odds of it occurring in another group
In this example, odds radio is the odds of delayed surgery with opioid exposure compared to the odds of delayed surgery with no opioid exposure
It is 1.11 times more likely to have delayed surgery with opioid exposure than it is without opioid exposure
B. There is a 95% probability that the true odds ratio lies between 0.53 and 3.45. If the study was repeated, you would expect the true value to fall within this range 95% of the time.
As this confidence value contains the odds ratio of 1, which means the exposure does not affect odds of outcome, the odds are NOT significantly different.
- A new diagnostic test has been developed for cystic fibrosis. It is being compared to the sweat chloride test. 100 patients were given the test. 80 patients had negative tests and 20 patients had positive tests. Of the patients with negative tests, 70 of them also had a negative sweat chloride. Of the 20 patients with a positive test, 10 of them also had a positive sweat chloride.
A. What is the positive predictive value?
B. Explain the meaning of the positive predictive value?
C. What is the sensitivity?
D. Explain the meaning of the sensitivity?
B. PPV is the probability of the person having a disease if the test is positive
A. PPV = TP/(TP + FP) = 10/(10+10)= 50%
C. SN = TP/(TP+FN) = 10/(10+10) = 50%
D. SN is the probabiliy of having a postiive test if the person has the disease
- Mother of daughter with recurrent complex febrile seizures, comes to see you with an article about the use of a magnetic bracelet for the prevention of febrile seizures. In the study: of 50 children not wearing the bracelet, 20 had no further seizures; of the 50 wearing the bracelet, 40 had no further seizures.
a) Name 3 features that would improve your confidence in the study
b) Calculate the relative risk reduction
A.
- Randomization to control + experimental groups
- Use of control group
- Matching of participatns between groups
B. RRR = (CER-EER)/CER = [c/(c+d) - (a/(a+b)]/(c/(c+d))
(30/50 - 10/50)/(30/50) = 0.67.
CER = c/ (c+d) = ratio of having the outcome desired to having the exposure
- White counts and blood cultures are obtained for 20 children with fever. The WBC for those with and without bacteremia are listed below:
Negative blood C&S
7, 7.2, 7.2, 8.6, 9, 9.1, 10.1, 10.2, 11, 11.1, 12.1, 12.2, 14.7, 15.1, 17
Positive blood C&S
11, 14.6, 15.5, 18.3, 26.7
a) What is the prevalence of bacteremia in this population?
b) What is the sensitivity and specificity of a WBC>10 for detecting bacteremia?
c) What is the negative predictive value of a WBC <12 for ruling out bacteremia?
A. 5/20 = 25%
B. SN = TP/(TP+FN) = 5/(5+0)= 1. SP = TN/(TN+FP) = 6/(6+9) = 0.4
C. NPV = TN/(TN+FN) = 10/(10+1) = 0.91
What is the EBM Levels Of Evidence?
Cohort studies
- Pros
- Cons
- Based on EXPOSURES
- Exposure to causal agent NOT under investigators’ control
- Subjects divided into exposed (or treated) vs. unexposed (untreated)
- Can be retrospective or prospective
- Prospective: none of the subjects have developed any of the outcome of interest at the start of the study
- Retrospective: go back in time and symptoms have developed already
- Pros
- Treatment not withheld
- Cheaper than RCT
- Can estimate relative risk/incidence (new initiation of disease process)
- Cons
- Controls may be difficult to obtain
- Confounders
- Challenging for rare diseases/outcomes
- Loss to follow up
- Expensive
- Example: matched infants to were and were not exposed to cigarette smoke and compared rates of bronchiolitis
Case Control
- Pros
- Cons
- Based on OUTCOMES
- Groups identified by outcome
- Compares rates of exposure retrospectively
- Can match cases and controls based on potential confounders
- Example: matched infants who had bronchiolitis with infants who did not have bronchiolitis and compared rates of cigarette smoke
- Pros
- Quick and cheap
- May be the only feasible method to study rare diseases or long lag from exposure to outcome
- Cons
- Recall/record bias (relying on records)
- Choice of controls can be problematic
- Does not deal with unanticipated confounders
