In a study of the adverse effects of x-rays among children, a retrospective cohort study was doneusing records from several large children's hospitals for the period of 1980 to 1985. 5,000children were selected as a representative population of ill children seen at the hospitals duringthat time. Subjects were classified according to whether or not they received an x-ray duringtheir stay in the hospital and were followed from their hospital stay through 2005 for thedevelopment of cancer. During the follow-up period, 30 incident cancers occurred in 3,000children who had received an x-ray, and 5 incident cancers occurred in the 2,000 children whohad not received an x-ray during their hospitalization.1q. What are the rates of cancer incidence in each exposure group (per 1,000)?b.What is the attributable risk of cancer due to x-ray in this study population?11c..What is the risk ratio for the effect of exposure on the development of cancer in thisstudy? What is the interpretation of this estimated ratio?(Hint: Another way to think of the risk ratio calculation is to divide the incidence of theoutcome in those exposed by those not exposed.)

Given that: Number of cancer incident occurs in exposed group = 30 Number of children taken in…

Answered: In a study of the adverse effects of…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Consider the following studies. Study I: A researcher randomly divided 200 high school students into two groups. The first group was told to not exercise. The second group was told to exercise at least 5 hours each week. At the end of two months, the heart rates of each participant in each group were measured at rest. It was found that the group that exercised 5 hours a week had a significantly lower average heart rate. Study II: A researcher gathered 200 high school students randomly, asked them how long they exercised each week, and then measured their heart rates at rest. It was found that students who exercised at least 5 hours a week had a significantly lower average heart rate. Part A: Which study was experimental? Why? Study IStudy II Part B: List the explanatory and response variables in the studies. Explanatory: heart rate; Response: exercise timeExplanatory: student; Response: amount of exerciseExplanatory: exercise time; Response: heart rate Part C: State whether the…
A researcher is conducting an experimental study on the effect of aspirin on heart attack risk. In order to assign who will receive aspirin and who will receive a placebo, she first divides her study into three age groups (18-29, 30-49, and 50 or older). She then randomly assigns individuals within these age groups to either receive aspirin or the placebo. This is an example of a cluster ?
. A researcher suspects that the actual prevalence of generalized anxiety among children and adolescents is higher than the previously reported prevalence of generalized anxiety disorder among children and adolescents. The previously reported prevalence of generalized anxiety disorder among children and adolescents is 4.1%, and the researcher conducts a study to test the accuracy of the previously reported prevalence of generalized anxiety disorder by recruiting 98 children and adolescents from various pediatricians’ offices and tests them for generalized anxiety disorder using the DSM-5. The researcher determines that the prevalence of generalized anxiety disorder among the participants of the study is 6.8%. The researcher’s hypothesis, for a level of significance of 5%, should resemble which of the following sets of hypothesis? A) H0: p > .041; H1: p = .041; alpha= .05 B) H0: p > .041; H1: p = .041; alpha= .95 C) H0: p = .041; H1: p > .041; alpha= .05 D) H0: p = .041; H1: p…
In a population-based cohort study, an entire community was interviewed regarding smoking habits and then followed for one year. Upon ascertainment of all lung cancer deaths, the investigator obtained the following data: Number of Individuals Lung Cancer Deaths Smokers 24,500 15 Nonsmokers 10,500 2 Calculate the risk difference per 100,000 per year. Round to the tenth decima
An investigation is performed to evaluate two new experimental treatments for allergies. 18 subjects who suffer from allergies are enrolled in the study and randomly assigned to one of three treatments: Control Group, Experimental Treatment 1, or Experimental Treatment 2. Each subject is instructed to take the assigned treatment, and symptoms of allergies are recorded on a scale of 1 to 20, with higher scores indicating worse symptoms. The data is summarized in the table below: SBP Std. Deviation Group Mean Control Treatment 6. 16.17 2.483 Experimental Treatment 1 6. 11.33 1.966 Experimental Treatment 6. 3.83 1.472 Total 18 10.44 5.554 Use this data to complete an ANOVA table to test for a significant difference in the means of each of the groups. Round all answers to the third decimal point.
A study is performed to assess the prevalence of use of anti-hypertensive medication (MEDS) in the non-institutionalized U.S. population. The following data are reported for MEDS status of the U.S. population by age-sex group: Table 1 Estimated MEDS Status of the U.S. Population by age and sex group, NHANES study 1999-2018 Males Females Age Group MEDS = yes Na Age Group MEDS = yes Na 18-29 160,617 23,069,867 18-29 168,940 22,132,949 30-39 899,152 18,690,754 30-39 759,532 18,937,878 40-49 2,264,304 18,316,125 40-49 2,257,203 18,816,304 50-59 3,215,688 15,022,905 50-59 4,059,363 15,997,653 60-69 2,936,183 8,400,156 60-69 4,260,975 10,993,805 70-79 1,677,664 4,012,930 70-79 2,953,646 6,012,728 aN = total sample size in specific age-sex groups. a. What is the prevalence of use of MEDS in 40-49 year-old females? b. Suppose a married couple consists…
A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in a cohort of 600 adults participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table. Mild Severe 100 Death No Death Total None 40 100 140 40 100 140 Moderate 20 100 120 Total 200 400 600 100 200 We want to know whether the study findings give evidence of a significant difference of the number of deaths between the different groups. Set up the alternative hypothesis (H, : The distribution of the categorical variable is not as given by the null hypothesis (lack of fit) At least ones of the means is different from the others O The two categorical variables are dependent The distribution of the categorical variable is not…
The following is data about the hemoglobin concentrations of volunteers collected at sea level and at an altitude of 11000 feet. sea level concentrations = [14.70 , 15.22, 15.28, 16.58, 15.10 , 15.66, 15.91, 14.41, 14.73, 15.09, 15.62, 14.92]11000 feet concentrations = [14.81, 15.68, 15.57, 16.59, 15.21, 15.69, 16.16, 14.68, 15.09, 15.30 , 16.15, 14.76] There are two alternative scenarios about the way the data were obtained. In scenario 1, there are 12 volunteers who lived for a month at sea level, at which time blood was drawn and the data in "sea level concentrations" dataset were obtained. Subsequently, all 12 volunteers were moved to 11000 ft and after a month the data in the "11000 feet concentrations" dataset obtained. There is a one to one correspondence between the numbers in the two datasets, that is the first numbers correspond to volunteer1, the second numbers to volunteer2 etc. In scenario 2, the "sea level concentrations" dataset is a random sample obtained from 12…
A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in a cohort of 600 adults participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table. Death No Death Total None 40 100 140 Mild 40 100 140 Moderate 20 100 120 Severe 100 100 200 Total 200 400 600 We want to know whether the study findings give evidence of a significant difference of the number of deaths between the different groups. The observed test statistic is 3.610 42.857 5.476 8.075
A study was made of 1,057 cases of poisoning in children treated as inpatients at Milwaukee Children's Hospital from 1962 through 1968. Data on date of occurrence, age and sex of the child, and type of agent involved were recorded and analyzed by standard statistical methods. Poisoning was due to ingestion of aspirin in 35 per cent of the children studied and to the ingestion of hydrocarbon distillates in 18 per cent. A statistically significant male dominance was found for ingestion of hydrocarbons; age-specific peaks were found for some categories. Trends as to the relative and absolute frequencies of each specific poison from one year to the next were noted; possible reasons for increasing or decreasing trends are discussed. Is this study descriptive or inferential? Explain your answer. What are the variables used in the study? In your opinion, what level of measurement was used to obtain the data from the variables? Does the article define the population? If so, how is it…
A random survey of health issues, conducted by the Department of Public Health of the Commonwealth of Massachusetts, examined the results from the state's seven largest cities. These cities were selected on the basis of their diverse racial and ethnic populations. The percentage of adults with diabetes in each city in the survey is given in the following table. City Boston Worcester Springfield Lowell Fall River Lawrence NewBedford Adults withDiabetes (%) 4.2 5.2 9.1 5.7 8.1 7.9 6.3 Find the average percentage of adults with diabetes in these seven cities. (Round your answer to two decimal places.) %What is the standard deviation for these data? (Round your answer to two decimal places.) %
2. [modified from page 76 #3] Coughlin et al. examined the breast and cervical screening practices of Hispanic and non-Hispanic women in counties that approximate the U.S. southern border region. The study used data from the Behavioral Risk Factor Surveillance System surveys of adults age 18 years or older conducted in 1999 and 2000. The table below reports the number of observations of Hispanic and non-Hispanic women who had received a mammogram in the past 2 years cross-classified with marital status. Marital Status Currently Married Divorced or Separated Widowed Never Married or Living As an Unmarried Couple Total Hispanic 319 130 88 41 578 Non-Hispanic 738 329 402 95 1564 Total 1057 459 490 136 2142 a) We select at random a subject who had a mammogram. What is the probability that she is widowed? b) We select at random a subject who had a mammogram and learn that she is Hispanic. With that information, what is the probability that she is married? e) Def two vents in this space that…

SEE MORE QUESTIONS

Recommended textbooks for you

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

Elementary Statistics: Picturing the World (7th E…

Statistics

ISBN:

9780134683416

Author:

Ron Larson, Betsy Farber

Publisher:

PEARSON

The Basic Practice of Statistics

Statistics

ISBN:

9781319042578

Author:

David S. Moore, William I. Notz, Michael A. Fligner

Publisher:

W. H. Freeman

Introduction to the Practice of Statistics

Statistics

ISBN:

9781319013387

Author:

David S. Moore, George P. McCabe, Bruce A. Craig

Publisher:

W. H. Freeman

SEE MORE TEXTBOOKS