Statistics - MplusX QBank

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Which one of the following can be used for data analysis in Cross sectional?
1. Odds ratio
2. Relative risk
3. Chi square test ***
4. Attributable risk and Chi square test
5. odds ratio and attributable risk

cross sectional: use CHI SQUARE
Cohort: use RR or AR
Case control: use ODD’s RATIO

Which is the best study to find out the state of Vitamin D deficiency in Australia?

a. cohort study
b..case control
c..case study
d..Cross-‐sectional study.***

For Prevalance Cross Sectional Study ….. to check incidence Cohort …. So D here

In a village of 3000 people, 500 get Congo Hemorrhagic fever. 450 eventually recover from the disease in the next 4 weeks while 50 died. What is the case fatility rate for this disease?
1. 10 ***
2. 20
3.35
4.50
5. 200

Case fatality rate = # of deaths from a specific cause / total number of cases with same disease…

50 / 500 = 10 (A)

You are a doctor in a town ,where 6people out of 100 are non smoker.What are the
chances of stroke.the chances of stroke in smoker is 50%more than non smoker .Now
the pharmaceutical company is introducing a medicine which reduces the chances of
stroke upto 1/3rd in smoker population .What is the percentage of the stroke population
will get stroke
a)3%
b)6% ***
c)9%
d)12%
e)20%

6/100 = 6%, 6*1.5 = 9 , 1/3rd reduced so 9/3 = 3, => 9-3 = 6%

9/3 is to calculate reduction which is 1/3 so 9/3. Final level is if you
substract the 1/3 reduction from the 50% increased incidence that will give you final incidence or
prevalence whatever is asked in the stem.

Just take it as in general population this risk is 6/100 … for smokers it turns to be 9/100 as gnrl population has 50% less thn smokers… so in smokers risk is reduced to one third … so we ll take 1/3rd of 9 which ll be 3 ndsubtarct it from orignal risk of 9 in smokers nd v ll be left wid 6

In a small village of North QLD with a community of 3000 people, 18%females get URTI while 22% males get it as well who are exposed to factory smoke. 10% of females also get URTI who live away from the factory and are not exposed to factory smoke. The data for males is not available. Calculate the attributable risk for females to get URTI due to factory smoke?
1. 28%
2. 30%
3. 6%
4. 1.8%
5. 8% ***

ARR =risk in exposed Group – risk in Unexposed group So 18 – 10 = 8%

A study wish to make a relation btw the fatigue in track car driver in high ways & the incidence of MVA that will happen. wt is the most suitable method to carry out study?
a, cohort
b, case control
c, RCT
D,cross sectional
E,case study

Least imp study to look for effectiveness of ccf Rx?
a,case control
b, case series ***
c, cohort
d,RCT
e, Systemic Review

What is the best method of study for studying the relation between fatigue and accident in truck driver?
a. RCT
b. Cohort
c. A retrospective case-control study ***
d. Case report
e. systemic review

You find there are more and more diabetics in your practice and you want to do a research about
how many people are diabetic. What is the best study design?
a. Cohort study
b. Case-control study
c. Randomized-control trial
d. Cross-section study ***

If you need to study whether smoking causes myocardial infarction, what kind of study / group do you intend to conduct/study?
A) Cohort ***
B) Randomized Controlled
C) Case Control
D) Case series
E) Observational

least imp study to look for effectiveness of ccf Rx?
a,case control
b, case series ***
c, cohort
d,RCT
e, Systemic Review

A study wish to make a relation btw the fatigue in track car driver in high ways & the incidence of MVA happen. wt is the most suitable method to carry out study?
a, cohort
b, case control
c, RCT
D,cross sectional
E,case study

A young scientist has decided to study the causes of neonatal jaundice. He selects 150 babys with jaundice and 150 without, and examines there previous historiies looking for factors that could have determined there jaundice. This kind of study is called?
a.) cohort study
b.)case study
c.) case control study ***
d.) prospective study

in case control you choose a group with the disease, and then you choose a control group without the disease and then you follow them retrospectively

A scientist study a case which is 30% fpv, 10% fnv.study of 1100.now the test shows 100 people are +ve for the test.what is the actual number of people getting the disease for the people who did testing?
a, 10
b, 20
c, 30
d, 70 ***
e,90

here we say that 100 are positve for the test (TP+FP). of these 100 30% are FPV which means that TP (70) and FP (30). Then we have remaining 1000 of which 10% are FN, this comes out as 100. Then lastly we have T- (900). So the 2×2 table is TP (70) FP (30) F- (100) T- (900). Now we want to know the positive predictive value (likelihood that a positive result in test indicates disease). Formula is (TP/(TP+FP)). so (70)/(70+30)=70%

You want to make a study about asthmatic patients and if there have been any
exposure to smoke or
its severity to exposure to smoke. What study is the most appropriate?
a. Case control ***
b. Cross sectional
c. Cohort
d. Observational study

A study is being planned to investigate the effect of environmental exposure to pesticides on the incidence of cancer.

Which of the following study designs is most appropriate?

1.Case-control study
2.Case series
3.Cohort study ***
4.Cross-sectional survey
5.Randomised controlled trial

The cut off point of screening test is increased.
A. both sen and sp will increased
B Sen increased, Sp decreased
C.Sen decreased, SP increased***

Australian government appointed you to go through a community based service and help a local doctor there.
Hepatits B data given in a community of total population of 200.

                            2009               2010
Antibody +ve cases 10                  15
Antigen +ve cases     40                   55

Need to calculate the prevalence per 1000 population in the year 2010
A- 350 ***
B- 250
C- 70
D- 50
E- 125

for 2010 its 15 + 55 = 70 / 200* 1000 = 350

for 2009 its 40 + 10 = 50 / 200 * 1000 = 250

A new screening test is to be launched in community. Which is the most important factor to consider?
A. High sensitivity *** not confirmed yet
B. High specificity
C. High positive predictive value
D. No adverse outcomes

for screening test high sensitivity and for confirmatory high specificity

Good screening tests have high sensitivity,

pecificty-confirmatory.

Which report provides the least information ?
A) Case control
B) Cohort study
C) RCT
D) Case report ***

What study would you do if you want to find out the efficacy of a vaccine
on a group of people?
a) Randomised controlled trials ***
b) Cohort study
c) Case control study
d) Cross sectional study

In a trial of a new treatment for fulminant sepsis the mortality in the treatment group is 20%, whereas the mortality in the placebo group is 40%. What is the relative risk of death with the new treatment?
A. 0.1
B. 0.2
C. 0.4
D. 0.5 ***
E. 2.0

incidence exposed/incidence non exposed = 20/40 = 0.5…D

A new screening test was developed for a disease. According to the survey, there is an increase in percentage of people who are taking the screening test. However, there is no increase in number of people diagnosed with the disease. What’s the underlying cause?
A. Because of the cultural limitation, the number of Indigenous women who take the test are few.
B. There is not enough access to the test for the community
C. The test has low sensitivity value***

A new drug was launched in the market after getting over with the non-inferiority trials. The drug,s P value at the end of the trial was <0.03. What does this P value show!
1. Drug is superior to other drugs
2. Drug is inferior to other drugs
3. The drug is inferior to other drugs
4. The drug has better adverse event profile
5. The new drug has better efficacy.

A new drug is discovered, which affects the progression of the disease, but not the
mortality. Which is the most appropriate statement?.
a. increase incidence
b. decrease incidence
c. Increase prevalence ***
d. decrease prevalence

1. New drug is safer as compared to other drugs.

2. New drug is as useful as other drugs with fewer side effects

3. new drug is superior to other drugs

4. New drugs is not to superior to other drugs

5. New drug is inferior to other drugs

if a p value is less than 0.05 then diffe is significant , But here they changed the standard and set it at 0.02 instead of 0.05… Here you just forget about this 0.05. Now compare 0.02 and 0.04 and conclude your result from this!!… if i had not given you 0.02 as the acceptable P value for this trial then it was 0.05 but now i have given you a standard P value so why you bather about 0.05 then anymore… 0.04> 0.02 so it means drug is not superior to other drugs.. For superiority of the drug, it should have been trial final P value < Standard P value. Which is not the case here…. Here only two things should confuse you, Drug is inferior to other drugs and drug is superior to other drugs. Here they can ask you that drug is
inferior, so your justification for rejecting this is that as the trial was for superiority, so we can only comment on its superiority status here, not inferiority status

P value less thn 0.01 means something is highly specific, i.e there’s only 1% chance of occurrence of an observed difference. The standard p value is 0.05 which means that theres 5% chance of difference to occur. If p value exceeds 0.05 in a research, the test hypothesis is nullified.

In pt. with pancreatitis for purpose of statistical studies ,AOF are useful EXCEPT-
a. Case control
b. Cohort
c. Case report/case study – (one study) ***
d. double blinded study
e. systemic review

WOF the following least describe primary prevention?
A. reduce incidence
B. improve lifestyle
C. giving vaccination
D. reduce prevalence
E.identify the predisposing factor early ***

hierarchy of evidence , least explained in what
A.case control
B.case report ***
C.systemic review
D.cohort
E. randomised control

as a gp in rural area, you notice that recently more cases of hepatitis c has been
diagnosed and want to do a research to find out the incidence of hep c in the community
with a population of around 3000. how will you get the information you need for the
research?
a. find the number of all patients with current hepatitis c antibody +
b. all patients with current hepatitis c antigen positive
c. all patients with current hepatitis c pcr positive ***
c. all cases diagnosed as hepatitis c positive for the past 5 years

You are a doctor in a hospital and want to do research about the outcome of babies
born to diabetic mothers and want to compare the result with the babies born to non
diabetic mothers.Which study will be the best study?
a) Cross sectional study
b) Cohort study
c) Case control study ***
d) Randomized control trial
e) Case study

Which of the following is necessary in obtaining informed consent?
a. A description of the statistical analyses that will be carried out
b. A description of the purpose of the research ***
c.A description of the reliability and validity of test instruments
d. A list of publications that the researcher has had in the last ten years

You are supposed to submit a paper or protocol of what will be done in the research study and how it will be done to an ethical committee and on the basis of that, Ethical committee either approves it or rejects it.

How to choose sample for a research of obesity in the community?
A. Snowballing
B. From shopping center.
C. Random in general population.***
D. From news advertisement.
E. From website

You are planning on conducting a research to look at the association between hypertension and myocardial infacrtion. What is the most appropriate study design for this
research?
a. Randomised controlled trial
b. Case study
c. Cohort ***
d. Cross sectionalTop of Form

if there is experimental study then we will choose RCT.. but if there is observational study look that is there any comparison grp..if yes it means we go for analytic study… Cohort study(exposure to outcome) outcome to exposure(case control) and exposue and outcome at same time then cross sectional….there is hypertension is exposure and MI is outcome..so we will go for cohort study

15 year old boy wants to participate in a research study. He told his parents who did
not agree. He lives with his parents. Can this boy participate in the research study?

Minor living with parents..Ethics would need parents consent

What is the advantage of a randomised controlled trial?

A)will remove observer bias ***

b)will remove the chance of self selection of patients to particular group

c)will be better for comparable results

The most important advantage of proper randomization is that it minimizes allocation bias, balancing both known and unknown prognostic factors, in the assignment of treatments

When evaluating a report of clinical trial, which one of the following is correct?
A. Control and treatment groups must be equivalent in size.
B. if randomization is conducted properly, chance differences are inevitable.***
C. Inadequate sample size has been shown to produce true positives and true negatives.
D. results are invalid if the trial is of not double blind construction.
E. Withdrawal of patients from a trial by the investigator does not lead to bias

Which of the folowing statement about double blind pacebo control clinical trial is correct!
A: All patients receive a placebo.
B: Everybody receives both treatments
C. Some of the patients are not treated
D. Half of the patients don,t know which treatment they receive
E. The clinician assessing the effects of the treatment does not know which treatment the patient has been given***

Incidence rate of lung cancer among smokers is 10/1000 and among non smokers is 1 per 1000.The extent to which lung cancer can be attributed to smoking is-
a. 10%
b. 90% ***
c.1%
d. 100%

ic exposed-inc non exposed / inc exposed

What would be the best reason to make a screening program more available to the
public?
a) Possibility of early diagnosis
b) It is required for research purposes
c) It improves the treatment’s prognosis
d) Specialised treatment is available
e) It can lower the death rate from the disease**

the disease should be common, treatable and easy screend with cheap avaliable non-invasive screeing procedure

Average BP is 130 +/- 25. about 95% people will lie between :
a. 115-155
b. 80-180***
c. 95-100

or 100% its +/-D, for 95% its +/-2D

for 50% it is +/- 3SD

130 IS MEAN AND 25 IS 2 SD, 95 WILL FALL WITH 2 SD so 25=2 SD=50,……… 50 +130=180 130-50=80 then its 80 –180

one population , mean systolic BP is 115 and SD is 15 so what will be range of 95% population’s BP?
a) 100 to 130

b) 85 to 145***

95% SD(range) given then it means its plus and minus 2SD.so here they have given 15 SD,SO As i said its 2SD for 95% and 2*15=30 so plus and minus 30

if they give 99% then its plus and minus 3SD

if 66% then plus and minus 1SDBottom of Form

onlv u have given a lecture . u gave education, now we need to find out that is it benefitting the people or not.
a go for randomized group in general population.***
B case study
C case control
D cohart

A pharmaceutical company contacts you and suggests you to start prescribing the new antidepressant. What the criteria for doing that?
A. Approval of committee ethics commission ***
B. Base recent scientific research
C, Not to do so

You are planning on conducting a research to look at the association between hypertension and myocardial infacrtion. What is the most appropriate study design for this research?
a. Randomised controlled trial
b. Case study
c. Cohort
d. Cross sectional

Well not sure, whether they are asking here about all participants being hypertensive or one group is Hypertensive and another not hyptertensive, if that is the case then its C But if all participants are hypertensive, then A is the better one.

wt is the least reliable method of study for studying the pts who hvcolangitis?
a, RCT
b, cohort
c, case-controle
d, case study ***
e, systemic review

A study wish to make a relation btw the fatigue in traccar driver in high ways & the incidence of MVA happen. wt is the most suitable method to carry out study?
a. cohort
b. case control
c. RCT
d. cross sectional
e. case study

here we say that 100 are positve for the test (TP+FP). of these 100 30% are False Positive which means that True Positive (70) and False Positive (30). Then we have remaining 1000 of which 10% are False Negative,this comes out as 100. Then lastly we have T- (900). So the 2×2 table is TP (70) FP (30) F- (100) T- (900). Now we want to know the positive predictive value (likelihood that a positive result in test indicates disease). Formula is (TP/(TP+FP)). so (70)/(70+30)=70%

One population, mean systolic BP is 115 & SD is 15 so wt will be range of 95% population’s BP?
a,100-130
b,85-145***
A post marketing drug surveillance study of a new heart failure therapy to the market was carried out on 10,000 subjects who had completed clinical trials. which one of the following most accurately reflects the information genereated from such a study?
1. Adverse events profile***
2. comparative therapeutics efficacy
3. cost benefits trial
4. cost effectiveness
5. Drug potency

because always we look for drug which has less averse effects, Post marketing studies are basically placed in Phase 4 studies and in these kind of studies, people from extreme ages are taken to see even the rarest possible adv. event which can happen.These are mostly done after approval of the drug for the market which is phase 3 study mostly

An experienced group of surgeons report on a randomised placebo controlloed trial comparing a particular surgical technique for carotid artery to a sham procedure. Their study concludes that using this advanced method reduces the risk of stroke from 5% to 4% ( p<0.05). what does this study proved about the new surgical method?
1. Acceptability
2. Effectiveness
3. Efficacy***
4. Safety
5. Usefullness

which one of the following can be used for data analysis in Cross sectional?
1. Odds ratio
2. Relative risk
3. Chi square test
4. Attributable risk and Chi square test
5. odds ratio and attributable risk

Ans: ‎A,50/500 =0.1=10% , case fatality rate the ratio of the number of deaths caused by a specified disease to the number of diagnosed cases of that disease.

In a small village of North QLD with a community of 3000 people, 18%females get URTI while 22% males get it as well who are exposed to factory smoke. 10% of females also get URTI who live away from the factory and are not exposed to factory smoke. The data for males is not available. Calculate the attributable risk for females to get URTI due to factory smoke?
1. 28%
2. 30%
3. 6%
4. 1.8%
5. 8%

A pharmaceutical company before the start of the trial got approval from ethical committee to use a new anti-cancer drug for ca.Pancreas. The ethical committee gave approval and set the target P value< or = 0.02, for the drug to be superior to other drugs. At the end of the trial, the company claimed about the efficacy of the new drug to be superior to all other available drugs in the market and P value at the end of the trial was = 0.04. What does this P value show here.
1. New drug is safer as compared to other drugs.
2. New drug is as useful as other drugs with fewer side effects
3. new drug is superior to other drugs
4. New drugs is not to superior to other drugs
5. New drug is inferior to other drugs

Explanation: if a p value is less than 0.05 then diffe is significant , But here they changed the standard and set it at 0.02 instead of 0.05… Here you just forget about this 0.05. Now compare 0.02 and 0.04 and conclude your result from this!!… if i had not given you 0.02 as the acceptable P value for this trial then it was 0.05 but now i have given you a standard P value so why you bather about 0.05 then anymore… 0.04> 0.02 so it means drug is not superior to other drugs.. For superiority of the drug, it should have been trial final P value < Standard P value. Which is not the case here…. Here only two things should confuse you, Drug is inferior to other drugs and drug is superior to other drugs. Here they can ask you that drug is inferior, so your justification for rejecting this is that as the trial was for superiority, so we can only comment on its superiority status here, not inferiority statu

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