Introduction to Epidemiology Flashcards
COMPLETE SAMPLEX
A 37-year-old woman with low back pain for the past four weeks want to know if you recommend surgery. You prefer to base your treatment recommendations on research evidence whenever possible. In the strongest study you can find, investigators reviewed the medical records of 40 consecutive men with low back pain under care at their clinic. Twenty-two had been referred for surgery and the other 18 patients had remained under medical care without surgery. The study compares rates of disabling pain after 2 mos. All of the surgically treated patients and 10 of the medically treated patients were still being seen in the clinic throughout this time. Rates of pain relief were slightly higher in the surgically-treated patients.
Because there are relatively few patients in this study, it may give a misleading impression of the actual effectiveness of surgery.
A. Selection bias B. Measurement bias C. Confounding bias D. Chance E. External validity (generalizability)
D
Samples can give a misleading impression of the situation in the parent population, especially if the sample is small.
COMPLETE SAMPLEX
A 37-year-old woman with low back pain for the past four weeks want to know if you recommend surgery. You prefer to base your treatment recommendations on research evidence whenever possible. In the strongest study you can find, investigators reviewed the medical records of 40 consecutive men with low back pain under care at their clinic. Twenty-two had been referred for surgery and the other 18 patients had remained under medical care without surgery. The study compares rates of disabling pain after 2 mos. All of the surgically treated patients and 10 of the medically treated patients were still being seen in the clinic throughout this time. Rates of pain relief were slightly higher in the surgically-treated patients.
The results of this study may not apply to your patient, a woman, because all the patients in the study were men.
A. Selection bias B. Measurement bias C. Confounding bias D. Chance E. External validity (generalizability)
E
Generalizing the results of a study of men to the care of a woman assumes that the effectiveness of surgery for low back pain is the same for men and women.
COMPLETE SAMPLEX
A 37-year-old woman with low back pain for the past four weeks want to know if you recommend surgery. You prefer to base your treatment recommendations on research evidence whenever possible. In the strongest study you can find, investigators reviewed the medical records of 40 consecutive men with low back pain under care at their clinic. Twenty-two had been referred for surgery and the other 18 patients had remained under medical care without surgery. The study compares rates of disabling pain after 2 mos. All of the surgically treated patients and 10 of the medically treated patients were still being seen in the clinic throughout this time. Rates of pain relief were slightly higher in the surgically-treated patients.
The patients who were referred for surgery were younger and fitter than those who remained under medical care.
A. Selection bias B. Measurement bias C. Confounding bias D. Chance E. External validity (generalizability)
A
The difference in recovery between patients who received surgery versus medical care may be the result of some other factor, such as age, that is different between the two treated groups and not the result of surgery itself.
COMPLETE SAMPLEX
A 37-year-old woman with low back pain for the past four weeks want to know if you recommend surgery. You prefer to base your treatment recommendations on research evidence whenever possible. In the strongest study you can find, investigators reviewed the medical records of 40 consecutive men with low back pain under care at their clinic. Twenty-two had been referred for surgery and the other 18 patients had remained under medical care without surgery. The study compares rates of disabling pain after 2 mos. All of the surgically treated patients and 10 of the medically treated patients were still being seen in the clinic throughout this time. Rates of pain relief were slightly higher in the surgically-treated patients.
Fewer patients who did not have surgery remained under care at the clinic two months after surgery.
A. Selection bias B. Measurement bias C. Confounding bias D. Chance E. External validity (generalizability)
B
The two treatment groups did not have an equal chance of having pain measured.
COMPLETE SAMPLEX
A 37-year-old woman with low back pain for the past four weeks want to know if you recommend surgery. You prefer to base your treatment recommendations on research evidence whenever possible. In the strongest study you can find, investigators reviewed the medical records of 40 consecutive men with low back pain under care at their clinic. Twenty-two had been referred for surgery and the other 18 patients had remained under medical care without surgery. The study compares rates of disabling pain after 2 mos. All of the surgically treated patients and 10 of the medically treated patients were still being seen in the clinic throughout this time. Rates of pain relief were slightly higher in the surgically-treated patients.
Compared with patients who had medical care alone, patients who had surgery might have been less likely to report whatever pain they had and the treating physicians less inclined to record pain in the medical record.
A. Selection bias B. Measurement bias C. Confounding bias D. Chance E. External validity (generalizability)
B
There are biases related to the measurement of the outcome (recovering from pain)
COMPLETE SAMPLEX
A 37-year-old woman with low back pain for the past four weeks want to know if you recommend surgery. You prefer to base your treatment recommendations on research evidence whenever possible. In the strongest study you can find, investigators reviewed the medical records of 40 consecutive men with low back pain under care at their clinic. Twenty-two had been referred for surgery and the other 18 patients had remained under medical care without surgery. The study compares rates of disabling pain after 2 mos. All of the surgically treated patients and 10 of the medically treated patients were still being seen in the clinic throughout this time. Rates of pain relief were slightly higher in the surgically-treated patients.
Patients without other medical conditions were both more likely to recover and more likely to be referred for surgery.
A. Selection bias B. Measurement bias C. Confounding bias D. Chance E. External validity (generalizability)
C
The other medical conditions confound the relationship between treatment and outcome; that is, they are related to both treatment and recovery and might be the reason for the observed differences.
COMPLETE SAMPLEX
Histamine is a mediator of inflammation in patients with allergic rhinitis (“hay fever”). Based on this fact, which of the following is true?
A. Drugs that block the effects of histamines will relieve symptoms.
B. A fall in histamine levels in the nose is a reliable marker of clinical success.
C. Antihistamines may be effective and their effects on symptoms (such as itching nose, sneezing and congestion) should be studied in patients with allergic rhinitis.
D. Other mediators are not important.
E. If laboratory studies of disease are convincing, clinical research is unnecessary.
C
The observation that histamines mediate inflammation in hay fever leads to a promising hypothesis that blocking histamines will relieve symptoms, but the hypothesis needs to be tested in people with hay fever. The other answers all assume more about the causes of symptoms than is actually stated. For example, histamine is only one of many mediators of inflammation in hay fever.
COMPLETE SAMPLEX
Samples of populations may have characteristics that differ from the population because of random variation. T/F
T
Samples may misrepresent populations by chance, especially when the samples are small.
COMPLETE SAMPLEX
Samples of populations are the only feasible way of studying the population. T/F
T
In nearly all situations, populations are too large to study without sampling
COMPLETE SAMPLEX
Samples of populations should be selected in a way that every member of the population has an equal chance of being chosen. T/F
T
When they are possible, random samples are best because they remove bias, although chance differences between samples and population may remain.
COMPLETE SAMPLEX
You are making a treatment decision with a 72-year-old man with colon cancer. You are aware of several good studies that have shown that a certain drug combination prolongs the life of patients with colon cancer. However, all the patients in these studies were much younger. Relying on those studies for your particular patient…
is a matter of personal judgement. T/F
T
Generalizing from younger to older patients is a matter of personal judgement based on whatever facts there are that bear on how the two might respond to the same treatment, until a study of older patients becomes available.
COMPLETE SAMPLEX
You are making a treatment decision with a 72-year-old man with colon cancer. You are aware of several good studies that have shown that a certain drug combination prolongs the life of patients with colon cancer. However, all the patients in these studies were much younger. Relying on those studies for your particular patient…
is called internal validity. T/F
F
Internal validity is about whether the results are correct for the patients in the study, not about whether they are correct for other kinds of patients.
COMPLETE SAMPLEX
You are making a treatment decision with a 72-year-old man with colon cancer. You are aware of several good studies that have shown that a certain drug combination prolongs the life of patients with colon cancer. However, all the patients in these studies were much younger. Relying on those studies for your particular patient…
is affected by chance but not bias. T/F
F
Both bias and chance affect internal validity, which in turn affect whether the results are true for anyone, young or old.
COMPLETE SAMPLEX
A group of fitness first clients was compared to the community as to their knowledge of antioxidants in preventing viral infections.
A. Selection bias B. Confounding bias C. Measurement bias D. Chance E. Random Variation
A
COMPLETE SAMPLEX
MRI was busted so they used a CT scan to diagnose the disease
a. selection bias b. chance c. measurement bias d. random variation
C
COMPLETE SAMPLEX
Divergence of the observation of the sample from the true population due to chance alone…
a. bias b. confounding c. random variation d. sampling error e. external validity
C
COMPLETE SAMPLEX
The main goal of randomization in clinical trials is
A. To make sure that the participant will have equal chances of getting into either treatment arm
B. To make the 2 groups equal
C. To make sure that the outcome is due to the interventions and not from any extraneous variable
D. AOTA
E. Only A and C
D
COMPLETE SAMPLEX
When 2 factors are associated and the effect of one is distorted by the effect of the other
A. Bias B. Selection bias C. Confounding bias D. Random variation E. Sampling error
C
COMPLETE SAMPLEX
Group of Y clients are compared to the community as to their knowledge on effectiveness of antibiotics in preventing syndrome X.
A. Selection bias B. Confounding bias C. Measurement bias D. Chance E. NOTA
A
COMPLETE SAMPLEX
External validity is also called generalizability, meaning the results only apply to the sample in the study. T/F
F
COMPLETE SAMPLEX
Convenience sampling is less likely to misrepresent their parent population to mislead the conclusion made. T/F
F
COMPLETE SAMPLEX
Enumerate the outcomes of disease
Disease Death Disability Discomfort Dissatisfaction
COMPLETE SAMPLEX
The investigator, comparing the risk of developing cancer among males in a certain community failed to explore the possibility that the lifestyle and occupation of the individuals can affect if he will develop cancer.
a. Selection Bias
b. Confounding
c. Changes
d. Sampling Error
e. External validity
B
COMPLETE SAMPLEX
A process at any stage of interference tending to produce result that departs systematically from true value.
a. Bias
b. Confounding
c. Random variation
d. Sampling error
e. External validity
A
COMPLETE SAMPLEX
Divergence of an observation on a sample from the true population value, due to chance alone.
a. Bias
b. Confounding
c. Random variation
d. Sampling Error
e. External Validity
C
COMPLETE SAMPLEX
Main reason for distinguishing bias from chance, two sources of error, is that they are
a. Mutually exclusive
b. They can be handled by same strategies
c. They are handled differently
d. All of the above
e. None of the above
C
COMPLETE SAMPLEX
Clinical Epidemiology is
a. The science of making prediction about individual patients by counting clinical events in similar patients
b. It uses scientific methods for studies of group of patients
c. It generates information needed by clinicians to make good decision in the care of patients
d. It also studies things that can be mislead us with the validity and accuracy of results like systematic error and chance
e. All of the above
E
COMPLETE SAMPLEX
Biologic outcomes cannot properly be substituted for clinical outcomes unless there is direct evidence that the two are related. T/F
T
As an example, ventricular premature depolarizations (biologic outcome) are associated with increased risk of sudden death (clinical outcome). However, studies have shown that treatment with arrhythmia-suppressing drugs often does not prevent sudden death. In this case, biologic outcome is an unreliable marker of the clinical outcome.
COMPLETE SAMPLEX
External validity is the degree to which the results or observation hold true in other setting
T
COMPLETE SAMPLEX
All observation, including clinical ones, are also influenced by the play of chance
T
COMPLETE SAMPLEX
In the Philippines, the poor pay for health care by selling property, incurring loans or depending on relatives. This burden of suffering is best described as: A. Death B. Disease C. Disability D. Dissatisfaction E. Destitution
E
COMPLETE SAMPLEX
The Philippines has among the highest maternal mortality rates in the Asean region. This burden of suffering is best described as:
A. Death B. Disease C. Disability D. Dissatisfaction E. Discomfort
A
COMPLETE SAMPLEX
Patient enrolled in the early part of the study had an hourly BP and ECG monitoring instead of using the Holster 24-hour monitoring device.
A. Selection Bias B. Measurement Bias C. Confounding D. Chance E. None of the above
B
COMPLETE SAMPLEX
Comparative evaluation of COME activities by YL 4 (Swabe) and YL 6 (Benign) students.
A. Selection Bias B. Measurement Bias C. Confounding D. Chance E. None of the above
C
COMPLETE SAMPLEX
All interviewers were trained on the data collection tool and a field manual containing possible questions in the field was developed by the principal investigators.
A. Selection Bias B. Measurement Bias C. Confounding D. Chance E. None of the above
E
COMPLETE SAMPLEX
Evidence-based medicine is the application of clinical epidemiology to the care of patients. T/F
T
COMPLETE SAMPLEX
EBM includes formulating specific clinical questions, finding the best available evidence, judging the strength of evidence and actual use of this information in the care of patients. T/F
T
COMPLETE SAMPLEX
External validity is also called at times, generalizability, meaning results of the study are true only for the sample population. T/F
F
COMPLETE SAMPLEX
Shared Decision making means all the members of the health team decide on the management of a particular patient. T/F
T
COMPLETE SAMPLEX
There is still room for expert opinion in clinical epidemiology and evidence-based medicine. T/F
T
COMPLETE SAMPLEX
Occurs when comparisons are made between groups of patients that differ in determinants of outcome other than the one under study.
A. Bias B. Selection bias C. Confounding D. Chance E. Random variation F, Sampling error
B
COMPLETE SAMPLEX
Occurs when two factors are associated and the effect of one is distorted by the effect of the other.
A. Bias B. Selection bias C. Confounding D. Chance E. Random variation F, Sampling error
C
COMPLETE SAMPLEX
A process at any stage of inference tending to produce result that departs systematically from the true value.
A. Bias B. Selection bias C. Confounding D. Chance E. Random variation F, Sampling error
A
COMPLETE SAMPLEX
Divergence of an observation on a sample form the true population value, due to chance alone.
A. Bias B. Selection bias C. Confounding D. Chance E. Random variation F, Sampling error
E
