When a cohort study was started on a college campus, it was determined that at the outset 200 of 1200 students in the cohort already had the illness under study. Over the next year, 150 students contracted the illness for the first time. What was the incidence rate?A) 150/1000B) 350/1000C) 150/1200D) 200/1200E) 350/1200Answer
A comparison of the crude death rates in two populations is misleading because the two populations vary considerably in their age distributions. Assuming that the age distributions are known for each of the two populations, what could be done to provide a more adequate comparison of death rates in the two populations?A) Multiply the two crude death rates to arrive at a single death rate.B) Divide the larger of the two crude death rates by the smaller to obtain a measure of relative risk.C) Use a procedure called direct adjustment of rates.D) Subtract the smaller crude death rate from the larger death rate to obtain the attributable risk.E) Combine the two populations into one larger group and determine the overall crude death rate for both groups combined.answer
In the abstract of a research article, it was stated that the relative risk for the high risk group compared to the low risk group was 0.8 and that the 95 percent confidence interval for that relative risk value was from 0.3 to 1.7. What interpretation can be made from this finding?A) The increased risk for the high risk group was statistically significant.B) The increased risk for the high risk group was not statistically significant.C) The decreased risk for the high risk group was statistically significant.D) The decreased risk for the high risk group was not statistically significant.E) No interpretation can be made from the limited information provided.Answer
If it were determined from a cohort study that 90 heavy smokers out of 20,000 in the study developed a particular illness over a 10 year period while nine nonsmokers out of 10,000 in the study developed the same illness over that same time period, what was the risk ratio for heavy smokers as compared with nonsmokers?A) 54B) 45C) 36D) 10E) 5Answer
In a study, a group of similar patients were randomly assigned to two different groups. One group received Treatment A and the other received Treatment B. After two weeks of treatment, treatment effects were measured. This was followed by a two week wash-out period. Then the group which originally received Treatment A was given Treatment B and the group which received Treatment B initially was given Treatment A. After another two weeks, treatment effects were again measured. This type of study design is called a:A) cohort studyB) case-control studyC) cross-over studyD) cross-sectional studyAnswer
A relationship between the effects of two or more causal factors as observed in a set of data, such that it is not logically possible to separate the contribution that any single causal factor has made to an effect or outcome is called:A) randomizationB) causationC) confoundingD) regressionE) containmentanswer
Two studies were completed to test the same hypothesis. Both studies showed a 20 percent reduction in mortality comparing the new treatment to the standard treatment. However, that finding in Study A was statistically significant at p 0.05). What is the most likely cause of this difference in findings between the two studies?A) Study A used larger samples that Study B.B) Study A had more confounding variables that Study B.C) Study A used lower doses of the treatments that Study B.D) Study A used more chronically ill patients that Study B.E) Study A used stratified, random sampling while Study B did not.Answer
A research study was designed to have a power of 70 percent to detect a 50 percent difference in the two study group means. How can this statement be interpreted?A) The investigator had a 70 percent chance of detecting a difference of 50 percent or more if it was actually present.B) The investigator had a 70 percent chance of rejecting the null hypothesis if it is actually true.C) The investigator had a 70 percent chance of retaining the null hypothesis if it is actually false.D) The probability of rejecting a false null hypothesis is 30 percent.Answer
To establish a reference range for a particular blood test in pregnant teenagers, your laboratory has plotted measurements for a large cohort of healthy subjects. The laboratory finds that these measurements fit a Gaussian distribution, and sets its reference range to include measurements within two standard deviations above and below the mean.What is the approximate probability that a healthy person will have a test result that falls outside the laboratory reference range?A) 10%B) 5%C) 1%D) 0.1%E) 0.01%AnswerTags: MCQ, PSM, Range, Deviation
A 22-year-old woman, gravida 4, para 3, at 38 weeks' gestation comes to the labor and delivery ward with a gush of fluid. Sterile speculum examination reveals a pool of fluid that is nitrazine positive and forms ferns when viewed under the microscope. The fetal heart rate is in the 150s and reactive. An ultrasound demonstrates that the fetus is in the breech position. A cesarean delivery is performed. During the operation, the physician, who has received no recent immunizations, is stuck with a needle that had been used on the patient. Which of the following is this physician at greatest risk of contracting?A. HIVB. Hepatitis BC. Hepatitis CD. ScabiesE. SyphilisAnswerTags: MCQ, PSM, Needle Stick
Which of the following is the best method for detecting protein calorie malnutrion in the elderly hospital inpatient?Serum albumin Body mass index Triceps skin fold thickness Total lymphocyte count Calculated arm muscle areaAnswerTags: MCQ, PSM, PEM, Malnutrition
Which one of the following best describes the reason for the marked decline in the incidence of epiglottitis in the pediatric population?A) Genetic drift in strains of parainfluenza virus.B) More effective use of appropriate broad-spectrum cephalosporin antibiotics.C) Immunization with Haemophilus influenzae type b vaccine.D) Increased use of the new polyvalent pneumococcal vaccines.E) Effective education concerning hand washing.AnswerTags: MCQ, PSM, Epidemiology
EPIDEMIOLOGY OF BACKACHE IN THE UNITED KINGDOM A. More than 10 million working days are lost per year. B. The average general practitioner sees less than 30 acute backs per year. C. The majority recover within one month without treatment. D. Less than 1 in 200 undergo surgery . E. Rest has been shown to reduce the overall time away from work.AnswerTags: MCQ, PSM, Epidemiology, Back Pain
