NBME Answers : Questions tagged with biostats

Retired NBME Answer Explanations

Questions tagged with biostats

nbme24 : A new screening test... {reveal}

Question#14 (reveal difficulty score)
A new screening test for colon cancer is done ...
118/124 = 95% 🔍 / 📺 / 🌳 / 📖

nbme24 : A clinical study is... {reveal}

Question#28 (reveal difficulty score)
A clinical study is designed to evaluate the ...
10% 🔍 / 📺 / 🌳 / 📖

nbme20 : A study is conducted... {reveal}

Question#33 (reveal difficulty score)
A study is conducted to assess the effect of ...
Lead-time 🔍 / 📺 / 🌳 / 📖

nbme20 : A new antiplatelet... {reveal}

Question#45 (reveal difficulty score)
A new antiplatelet agent is developed for the ...
8% 🔍 / 📺 / 🌳 / 📖

nbme16 : A case-control study... {reveal}

Question#41 (reveal difficulty score)
A case-control study is conducted to explore ...
Biased measurement of the exposure 🔍 / 📺 / 🌳 / 📖

nbme27 : A 65-year-old man... {reveal}

Question#17 (reveal difficulty score)
A 65-year-old man comes to the physician ...
65% 🔍 / 📺 / 🌳 / 📖

step2ck_form8 : A biotechnology... {reveal}

Question#33 (reveal difficulty score)
A biotechnology company sponsors a ...
Selection bias 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : A cohort study is... {reveal}

Question#19 (reveal difficulty score)
A cohort study is conducted to compare the ...
Selection bias 🔍 / 📺 / 🌳 / 📖

nbme13 : A study is conducted... {reveal}

Question#19 (reveal difficulty score)
A study is conducted to evaluate the onset ...
Population-based 🔍 / 📺 / 🌳 / 📖

nbme19 : Case-control study; 95... {reveal}

Question#27 (reveal difficulty score)
Case-control study; 95 percent confidence ...
The likelihood is 95% that the true value for the odds ratio is between [the reported range] 🔍 / 📺 / 🌳 / 📖

nbme17 : An investigator wishes... {reveal}

Question#41 (reveal difficulty score)
An investigator wishes to conduct a study of ...
Cohort 🔍 / 📺 / 🌳 / 📖

nbme15 : A study was begun in... {reveal}

Question#49 (reveal difficulty score)
A study was begun in the 1950s to determine ...
Cohort study 🔍 / 📺 / 🌳 / 📖

nbme13 : In order to determine... {reveal}

Question#9 (reveal difficulty score)
In order to determine risk factors for death ...
Observational cohort study 🔍 / 📺 / 🌳 / 📖

nbme24 : A cohort study is done... {reveal}

Question#14 (reveal difficulty score)
A cohort study is done to evaluate the ...
0.05 < p < 1.0 🔍 / 📺 / 🌳 / 📖

nbme23 : A cohort study is... {reveal}

Question#28 (reveal difficulty score)
A cohort study is conducted to examine the ...
200 🔍 / 📺 / 🌳 / 📖

step2ck_form8 : A randomized,... {reveal}

Question#46 (reveal difficulty score)
A randomized, double-blind, controlled study ...
Variability among observers 🔍 / 📺 / 🌳 / 📖

nbme17 : A randomized... {reveal}

Question#36 (reveal difficulty score)
A randomized controlled study of 2000 ...
Failure to distinguish between statistical significance and clinical significance 🔍 / 📺 / 🌳 / 📖

free120 : A randomized... {reveal}

Question#19 (reveal difficulty score)
A randomized controlled trial is conducted to ...
0.2 🔍 / 📺 / 🌳 / 📖

nbme22 : A randomized... {reveal}

Question#26 (reveal difficulty score)
A randomized controlled trial is conducted to ...
(194/2371) – (123/2365) 🔍 / 📺 / 🌳 / 📖

free120 : A placebo-controlled... {reveal}

Question#22 (reveal difficulty score)
A placebo-controlled clinical trial is ...
Significant findings can be reported with greater confidence 🔍 / 📺 / 🌳 / 📖

nbme22 : A case-control study... {reveal}

Question#32 (reveal difficulty score)
A case-control study is conducted to assess ...
Cannot be determined from the data given 🔍 / 📺 / 🌳 / 📖

step2ck_form7 : A 67-year-old man... {reveal}

Question#6 (reveal difficulty score)
A 67-year-old man comes to the physician ...
Randomized, controlled clinical trial 🔍 / 📺 / 🌳 / 📖

nbme19 : What advantage does... {reveal}

Question#42 (reveal difficulty score)
What advantage does randomized controlled ...
Better control for confounding variables 🔍 / 📺 / 🌳 / 📖

nbme22 : The risk for... {reveal}

Question#34 (reveal difficulty score)
The risk for hemorrhagic stroke from drug X ...
Case-control study 🔍 / 📺 / 🌳 / 📖

nbme24 : A researcher... {reveal}

Question#1 (reveal difficulty score)
A researcher hypothesizes that exposure to ...
Case-control study 🔍 / 📺 / 🌳 / 📖

nbme24 : A 21-year-old woman... {reveal}

Question#7 (reveal difficulty score)
A 21-year-old woman with asthma comes to the ...
Phase 3 🔍 / 📺 / 🌳 / 📖

nbme23 : A study is conducted... {reveal}

Question#5 (reveal difficulty score)
A study is conducted to examine the ...
Phase 2 🔍 / 📺 / 🌳 / 📖

nbme18 : To decrease his risk... {reveal}

Question#50 (reveal difficulty score)
To decrease his risk for cardiovascular ...
630 🔍 / 📺 / 🌳 / 📖

free120 : In a cohort study of... {reveal}

Question#23 (reveal difficulty score)
In a cohort study of elderly women, the ...
Statistically significant overall increase in risk 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : A clinical trial is... {reveal}

Question#99 (reveal difficulty score)
A clinical trial is performed to assess the ...
Absolute risk reduction is 1% 🔍 / 📺 / 🌳 / 📖

step2ck_form8 : The physician reads a... {reveal}

Question#31 (reveal difficulty score)
The physician reads a news report about a 50% ...
Relative risk reduction 🔍 / 📺 / 🌳 / 📖

nbme21 : A study was performed... {reveal}

Question#3 (reveal difficulty score)
A study was performed that evaluated the ...
Odds ratio 🔍 / 📺 / 🌳 / 📖

nbme21 : A screening program is... {reveal}

Question#21 (reveal difficulty score)
A screening program is instituted for ...
10% 🔍 / 📺 / 🌳 / 📖

nbme20 : The frequency of an... {reveal}

Question#1 (reveal difficulty score)
The frequency of an autosomal recessive ...
1/25 🔍 / 📺 / 🌳 / 📖

nbme21 : A 46-year-old man... {reveal}

Question#39 (reveal difficulty score)
A 46-year-old man comes to the physician ...
1/15 🔍 / 📺 / 🌳 / 📖

nbme20 : A 35-year-old man... {reveal}

Question#47 (reveal difficulty score)
A 35-year-old man comes to the physician to ...
1:4 🔍 / 📺 / 🌳 / 📖

nbme24 : An 80-year-old man is... {reveal}

Question#12 (reveal difficulty score)
An 80-year-old man is admitted to the ...
20 🔍 / 📺 / 🌳 / 📖

nbme22 : A 45-year-old woman... {reveal}

Question#23 (reveal difficulty score)
A 45-year-old woman comes to the physician ...
25% 🔍 / 📺 / 🌳 / 📖

nbme17 : In an epidemiologic... {reveal}

Question#50 (reveal difficulty score)
In an epidemiologic study of workers in the ...
3 🔍 / 📺 / 🌳 / 📖

nbme16 : A study is conducted... {reveal}

Question#46 (reveal difficulty score)
A study is conducted to assess 32 patients in ...
31 🔍 / 📺 / 🌳 / 📖

step2ck_form8 : A randomized trial is... {reveal}

Question#22 (reveal difficulty score)
A randomized trial is conducted to assess the ...
There is a 95% probability that the difference between the two cure rates is between 8% and 26% 🔍 / 📺 / 🌳 / 📖

nbme23 : A researcher is asked... {reveal}

Question#13 (reveal difficulty score)
A researcher is asked to prospectively ...
Prevalence: above the standard; Incidence: above the standard 🔍 / 📺 / 🌳 / 📖

step2ck_form6 : a program for the... {reveal}

Question#36 (reveal difficulty score)
a program for the primary prevention of ...
Incidence 🔍 / 📺 / 🌳 / 📖

nbme21 : A study is conducted... {reveal}

Question#11 (reveal difficulty score)
A study is conducted on patients with asthma ...
If the treatment really changes the mean asthma score by 0.4, there is an 80% chance that a study of this size will find a p-value < 0.05 🔍 / 📺 / 🌳 / 📖

nbme15 : A study is conducted... {reveal}

Question#48 (reveal difficulty score)
A study is conducted to evaluate the ...
Lack of blinding between groups 🔍 / 📺 / 🌳 / 📖

nbme20 : Serum cholesterol... {reveal}

Question#26 (reveal difficulty score)
Serum cholesterol concentrations are measured ...
16% 🔍 / 📺 / 🌳 / 📖

nbme29 : The table shows... {reveal}

Question#6 (reveal difficulty score)
The table shows survival information for ...
0.901 🔍 / 📺 / 🌳 / 📖

nbme18 : MI study, 500 in... {reveal}

Question#10 (reveal difficulty score)
MI study, 500 in operation, 250 each to 2 ...
Randomized clinical trial 🔍 / 📺 / 🌳 / 📖

nbme17 : A randomized clinical... {reveal}

Question#9 (reveal difficulty score)
A randomized clinical trial is conducted to ...
Neither procedure is superior 🔍 / 📺 / 🌳 / 📖

nbme20 : A randomized clinical... {reveal}

Question#43 (reveal difficulty score)
A randomized clinical trial is conducted to ...
Neither procedure is superior 🔍 / 📺 / 🌳 / 📖

nbme21 : A clinical trial is... {reveal}

Question#4 (reveal difficulty score)
A clinical trial is conducted to compare the ...
Surgical procedure group: 400; Medical management group: 400 🔍 / 📺 / 🌳 / 📖

free120 : Over 1 year, a study... {reveal}

Question#11 (reveal difficulty score)
Over 1 year, a study is conducted to assess ...
Open-labeled clinical trial 🔍 / 📺 / 🌳 / 📖

nbme22 : During a study of... {reveal}

Question#20 (reveal difficulty score)
During a study of symptomatic proximal deep ...
Open-label clinical trial 🔍 / 📺 / 🌳 / 📖

nbme17 : A study is designed to... {reveal}

Question#33 (reveal difficulty score)
A study is designed to evaluate the efficacy ...
Randomized clinical trial 🔍 / 📺 / 🌳 / 📖

nbme22 : A population of... {reveal}

Question#6 (reveal difficulty score)
A population of vegetarians is surveyed to ...
t-Test 🔍 / 📺 / 🌳 / 📖

nbme15 : A paper says, "We... {reveal}

Question#48 (reveal difficulty score)
A paper says, "We chose the sample size to ...
5%, Type I error 🔍 / 📺 / 🌳 / 📖

nbme22 : A study is conducted... {reveal}

Question#26 (reveal difficulty score)
A study is conducted to assess the extent of ...
Type I error: No change;
Type II error: decreased 🔍 / 📺 / 🌳 / 📖

nbme29 : The table summarizes... {reveal}

Question#2 (reveal difficulty score)
The table summarizes the result of a study of ...
2.27 - 0.07 (Attribuatble risk) 🔍 / 📺 / 🌳 / 📖

nbme29 : In a series of 1000... {reveal}

Question#6 (reveal difficulty score)
In a series of 1000 patients with colonic ...
The follow-up period is too short 🔍 / 📺 / 🌳 / 📖

nbme30 : Optimal diagnostic cut... {reveal}

Question#31 (reveal difficulty score)
Optimal diagnostic cut point for the results ...
B on the curve. 🔍 / 📺 / 🌳 / 📖

step2ck_form8 : A study is conducted... {reveal}

Question#35 (reveal difficulty score)
A study is conducted to assess the accuracy ...
95% 🔍 / 📺 / 🌳 / 📖

step2ck_form8 : A study is conducted... {reveal}

Question#16 (reveal difficulty score)
A study is conducted to determine if a ...
Positive predictive value is 88% 🔍 / 📺 / 🌳 / 📖

step2ck_form7 : Four CAGE questions... {reveal}

Question#22 (reveal difficulty score)
Four CAGE questions are used to screen for ...
Sensitivity: increased; Specificity: decreased 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : A 5-year-old boy is... {reveal}

Question#55 (reveal difficulty score)
A 5-year-old boy is brought to the physician ...
The findings are clinically insignificant but statistically significant 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : A study is conducted... {reveal}

Question#120 (reveal difficulty score)
A study is conducted to assess the ...
Chance of a type II error 🔍 / 📺 / 🌳 / 📖

step2ck_form7 : A health status survey... {reveal}

Question#46 (reveal difficulty score)
A health status survey compares the clinical ...
The results are not adjusted for comorbidities 🔍 / 📺 / 🌳 / 📖

step2ck_form8 : A study is done to... {reveal}

Question#46 (reveal difficulty score)
A study is done to determine the effect of ...
Low statistical power 🔍 / 📺 / 🌳 / 📖

step2ck_form6 : The genetic disease... {reveal}

Question#43 (reveal difficulty score)
The genetic disease institute at a university ...
Positive Predictive Value Decreases 🔍 / 📺 / 🌳 / 📖

step2ck_form6 : A study is conducted... {reveal}

Question#20 (reveal difficulty score)
A study is conducted to compare the ...
Confounding variables 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : An investigator would... {reveal}

Question#8 (reveal difficulty score)
An investigator would like to decrease the ...
Withdraw from the study now 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : A 52-year-old man with... {reveal}

Question#11 (reveal difficulty score)
A 52-year-old man with hepatic cirrhosis ...
5 (five) 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : Which of the following... {reveal}

Question#12 (reveal difficulty score)
Which of the following most strongly limits ...
EPCS is available only at specialty centers 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : Which of the following... {reveal}

Question#13 (reveal difficulty score)
Which of the following conclusions is most ...
EPCS is more effective than EST in decreasing hospital readmissions for variceal bleeding requiring transfusion 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : Three days after an... {reveal}

Question#98 (reveal difficulty score)
Three days after an operation for uterine ...
Develop an institutional policy with standardized orders for DVT prophylaxis 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : A 32-year-old man... {reveal}

Question#111 (reveal difficulty score)
A 32-year-old man comes to the office because ...
Ketorolac 0.5% solution, 1 drop in right eye, four times daily 🔍 / 📺 / 🌳 / 📖

step2ck_free120 : A 68-year-old woman... {reveal}

Question#57 (reveal difficulty score)
A 68-year-old woman comes to the office ...
No additional diagnostic studies are indicated 🔍 / 📺 / 🌳 / 📖