Research Design, Biostatistics, and Literature Evaluation

Answer: C

This study seeks to compare two viable treatments of

hypovolemic shock in trauma patients. Because subject

identification would be trauma patients from the com-

munity and treatment would be initiated in the field,

potential harm is associated with each treatment, and

it is expected that many potential patients would lack

decisional capacity at the time of informed consent.

Although treatment blinding is an essential component

to trial design to limit investigator and clinician bias, it

is not an ethical consideration (Answer A is incorrect).

Given the incidence of trauma in the general population

and its burden on society, treatments to improve the out-

comes of trauma patients are necessary and informative

(Answer B is incorrect). Acknowledging the limited sup-

ply of blood products, a superiority trial is essential to

help steward the use of a finite resource (Answer D is

incorrect). The issue of informed consent in this study

is challenging, but the issue needs to be addressed for

the ethical conduct of this study (Answer C is correct).

There is precedent for this trial to receive an exception

for informed consent requirements under the FDA code

of regulations.

The study seeks to establish the effectiveness of a novel

drug compound for septic shock. This is challenging

because of the dramatic improvements in 28-day mor-

tality during the past decade. To show the effectiveness

of a novel drug compound, the drug should be tested in

a representative population of patients with the disease.

Excluding patients because of baseline comorbidity would

limit external validity (Answer A is incorrect). Including

patients with sepsis, which has a lower 28-day mortality

rate than septic shock, would not address the issue of an

appropriate end point (Answer B is incorrect). Limiting

study inclusion to patients with a pneumonia etiology

would be inappropriate unless the pharmacology of the

novel drug specifically targeted pneumonia pathophysiol-

ogy (Answer D is incorrect). Answer C is correct as the

anticipated incidence of mortality has changed overtime as

well as the likely anticipated minimum detectable effect.

With all other assumptions remaining equal, the authors

will have to increase enrollment to find the effect relative to

previous trials.

Answer: B

A QI study would likely show the effectiveness using a

pre/postintervention cohort design. In this type of study,

informed consent is generally not required because the

treatment is provided to all patients as a standard of care

(Answer A is incorrect). A community advertising cam-

paign might improve the delivery of care and improve

patient adherence, but it is unnecessary to measure the

effectiveness of the QI initiative (Answer C is incorrect).

The QI initiative is believed necessary and has therefore

been deemed to have intrinsic social value (Answer D is

incorrect). To show the effectiveness of the intervention,

the syndrome must be recognized before initiating treat-

ment (Answer B is correct).

Answer: C

To effectively determine the incidence and clinical

impact of adverse drug events on clinical outcomes in

the ICU, it would be unethical to randomize patients

to experience the event (Answer A is incorrect). A ret-

rospective design would not be ideal because of the

limitations in data extraction, assignment of events, and

interpretation of causality (Answers B and D are incor-

rect). A prospective observational design would allow

the investigator team to identify the incidence of adverse

events, sequential outcomes, and determine causality

(Answer C is correct).

Answer: D

A correct interpretation of the results is recognizing that

even though the OR suggests an associated increase of

30% in the risk of being exposed to CDI, the 95% CI

crosses 1, meaning that the odds of exposure to CDI

are as likely to increase the risk as to decrease that risk

(Answer D is correct; Answers A–C are incorrect).

Answer: B

Use of albumin reduced the odds of mortality (and

conversely, increased the odds of survival) with an OR

of 0.45, and the 95% CIs were all less than 1 in treat-

ing hypovolemic shock in trauma. In addition, the OR

was 1.1 for septic shock, whereas the 95% CI crossed

1, showing that the odds were as likely that albumin

increased mortality as that it reduced it (Answer B is

correct). Because the OR and the 95% CI for treating