Principles Of Biostatistics 3rd Edition Marcello Pagano, Kimberlee Gauvreau, Heather Mattie - Solutions

Thirty-five patients with Ischemic heart disease, a suppression of blood flow to the heart, took part in a series of tests designed to evaluate the perception of pain. In one part of the study, the patients exercised until they experienced angina or chest pain; time until the onset of angina and
In a study conducted in Italy, 10 patients with hypertriglyceridemia were placed on a low-fat, high-carbohydrate diet. Before the start of the diet, cholesterol and triglyceride measurements were recorded for each subject [274].(a) Construct a two-way scatter plot for these data. (b) Does there
If a test of hypothesis indicates that the correlation between two random variables is not significantly different from 0, does this necessarily imply that the variables are Independent? Explain.
How does the Spearman rank correlation differ from the Pearson correlation?
What are the strengths and limitations of the Pearson correlation coefficient?
When investigating the relationship between two continuous random variables, why is it Important to start by creating a scatter plot of the data?
Intimate partner violence (IPV) toward a woman either before or during her pregnancy has been documented as a risk factor for the health of both the mother and her unborn child. A study conducted in the postnatal wards of a public hospital in Bangladesh examined the relationship between experience
Since the role of rescue breathing in cardiopulmonary resuscitation was uncertain, a randomized study was conducted to compare survival to hospital discharge among in- dividuals experiencing out-of-hospital cardiac arrest when bystanders were instructed to perform chest compression plus rescue
Two different questionnaire formats designed to measure alcohol consumption - one encompassing all types of food in the diet and the other specifically targeting alcohol use - were compared for males and females between 50 and 65 years of age living in a particular community [270]. For each of the
A study was conducted to determine whether geographic variations in the use of medical and surgical services could be explained in part by differences in the appropriateness with which physicians use these services [269]. One concern might be that a high rate of inappropriate use of a service is
In a study of HIV infection among women entering the New York State prison system, 475 inmates were cross-classified with respect to HIV seropositivity and their histories of intravenous drug use [268]. These data are saved in a dataset called prison. The indicators of seropositivity are saved
The data below were taken from a study investigating the associations between sponta- neous abortion and various risk factors including alcohol use [267].(a) For each level of alcohol consumption, estimate the probability that a woman who becomes pregnant will undergo a spontaneous abortion. (b)
In France, a study was conducted to investigate potential risk factors for ectopic preg- nancy [266]. Of the 279 women who experienced ectopic pregnancy, 28 had suffered from pelvic inflammatory disease. Of the 279 women who did not, 6 had suffered from pelvic inflammatory disease.(a) Construct a 2
In a study of the risk factors for invasive cervical cancer that was conducted in Germany, the following data were collected relating smoking status to the presence or absence of cervical cancer [265].(a) Estimate the odds ratio of invasive cervical cancer for smokers versus nonsmokers. (b)
In an effort to evaluate the health effects of air pollutants containing sulfur, individuals living near a pulp mill in Finland were questioned about various symptoms following a strong emission released in one particular month [264]. The same subjects were ques- tioned again four months later
In response to a study suggesting a link between lack of circumcision and cervical cancer, an investigation was conducted to assess the accuracy of reported circumcision status [263]. Before registering at a cancer institute, all patients were asked to fill out a questionnaire. For males, the data
Suppose that you are interested in investigating the association between retirement status and heart disease. One concern might be the age of the subjects: an older person is more likely to be retired, and also more likely to have heart disease. In one study, therefore, 127 victims of cardiac
The following table compiles data from six studies designed to investigate the accuracy of death certificates. The causes of death listed on 5373 death certificates were compared to autopsy results. Of those considered, 3726 certificates were confirmed to be accurate, 783 either lacked information
In a survey conducted in Italy, physicians with different specialties were questioned regarding the surgical treatment of early breast cancer [260]. In particular, they were asked whether they would recommend radical surgery regardless of a patient's age (R), conservative surgery only for younger
A study was conducted to evaluate the relative efficacy of supplementation with calcium versus calcitriol in the treatment of postmenopausal osteoporosis [259]. Calcitriol is an agent that has the ability to increase gastrointestinal absorption of calcium. A number of patients withdrew from this
The following data come from a study designed to investigate drinking problems among college students [258]. A group of students were asked whether they had ever driven an automobile while drinking. Four years later, after the legal drinking age had been raised, a different group of college
Consider the chi-square distribution with 17 degrees of freedom. (a) What proportion of the area under the curve lies to the right of x = 33.41? (b) What proportion of the area under the curve lies to the left of x = 27.59? (c) What value of x cuts off the upper 10% of the distribution?
Consider the chi-square distribution with 2 degrees of freedom. (a) What proportion of the area under the curve lies to the right of x = 9.21? (b) What proportion of the area under the curve lies to the right of x= 7.38? (c) What value of xcuts off the upper 10% of the distribution?
How can the use of a restricted rather than a random sample affect the results of an analysis?
How does the null hypothesis evaluated using McNemar's test differ from that evaluated by the chi-square test?
Describe the properties of the chi-square probability distribution.
How does the chi-square test statistic use the observed frequencies in a contingency table to determine whether an association exists between two nominal random variables?
The data set lowbwt contains information for a sample of 100 low birth weight infants born in two teaching hospitals in Boston, Massachusetts [81]. Indicators of a maternal diagnosis of preeclampsia during the pregnancy-a condition characterized by high blood pressure and other potentially serious
Intimate partner violence (iv) toward a woman either before or during her pregnancy has been documented as a risk factor for the health of both the mother and her unborn child. A study conducted in the postnatal wards of a public hospital in Bangladesh examined the relationship between experience
A randomized study compared death or severe neurodevelopmental impairment at age 2 years for preterm infants receiving either the drug erythropoietin (a neuroprotective agent) or placebo within 24 hours of birth [248]. Data are contained in the dataset erythro. Treatment group is saved under the
Patients with craniopharyngioma - a rare, noncancerous type of brain tumor- are at Increased risk of cardiovascular mortality [247]. A study was conducted to estimate the prevalence of metabolic syndrome (MetS), a known risk factor for cardiovascular disease, in a combined Dutch-Swedish population
Suppose you are interested in investigating factors that affect the prevalence of tubercu- losis among intravenous drug users. In a group of 97 individuals who admit to sharing needles, 24.7% had positive tuberculin skin test results; among 161 drug users who deny sharing needles, 17.4% had
A study was conducted to Investigate the use of community-based treatment programs among Medicaid beneficiaries suffering from severe mental illness [245]. The study Involved assigning a sample of 311 patients to a prepaid medical plan and a sample of 310 patients to the traditional Medicaid
Suppose you are interested in determining whether the advice given by a physician during a routine physical examination is effective in encouraging patients to stop smoking. In a study of current smokers, one group of patients was given a brief talk about the hazards of smoking and was encouraged
You plan to conduct a study to compare the prevalence of electronic cigarette use in the past 30 days by high school students in grade 10 to the prevalence in grade 12.You do not have any information about prevalence in either group. You intend to conduct a two-sided, two-sample test of proportions
You plan to conduct a study to compare the prevalence of electronic cigarette use in the past 30 days by high school students in grade 10 to the prevalence in grade 12.Based on a previous study, you assume that the prevalence of e-cigarette use among students in grade 12 is 25%. You intend to
You plan to conduct a study to estimate the prevalence of electronic cigarette use in the past 30 days by high school students in grade 10.You postulate that prevalence will be around 20%. (a) If you wish to estimate prevalence to within +5% using a 95% confidence interval- meaning that the length
In a French study Investigating the effectiveness of the drug mifepristone (RU 486) for terminating early pregnancy, 488 women were administered mifepristone followed 48 hours later by a single dose of a second drug, misoprostol. In 473 of these women, the pregnancy was terminated and the conceptus
In a random sample of 746 Individuals being treated In Veterans Affairs primary care clinics, 86 were determined to have post-traumatic stress disorder (ers) by diagnostic Interview [242]. (a) What is a point estimate for p, the proportion of Individuals with PTSD among the population being treated
Incidence is defined as the proportion of Individuals at risk for some condition who go on to develop that condition during a specified period of time. In the United States, the Incidence of homelessness over a one-year period for military veterans being treated at a speciality mental health clinic
In the United States, the probability that a 40-year-old female will develop coronary heart disease during her lifetime is 0.32 [240]. Suppose that you select a random sample of stze 40 from this population. (a) For the sample of size 40, what is the probability that 5 or fewer of the females will
One way to construct a 95% confidence interval for a population proportion p is to begin with the probability statementand solve for p. (a) Rewrite the probability statement by squaring all three terms inside the inequality above. (b) Note that (-1.96)2 = (1.96)2, and therefore the expression
Explain the difference between the risk difference and the risk ratio as measures of the association between a binary exposure variable and a binary outcome.
When might it be appropriate to use the normal approximation to the binomial distribu- tion? How is it used?
The dataset lowbwt contains measurements for a sample of 100 low birth weight infants born in two teaching hospitals in Boston, Massachusetts [81]. The values of Apgar score - an index of neonatal asphyxia or oxygen deprivation-recorded five minutes after birth are saved under the variable name
The nursing home occupancy rates for each state in the United States in 2015 are saved in the dataset nursing home [15]. For each state, the vartable occupancy is the percentage of beds occupied (number of nursing home residents per 100 nursing home beds), and region contains the region of the
A study was conducted to investigate whether females who do not have health insurance coverage are less likely to be screened for breast cancer than those who do, and whether their disease is more advanced at the time of diagnosts [230]. The medical records for a sample of individuals who were
A study was conducted to evaluate the effectiveness of a work site health promotion program in reducing the prevalence of cigarette smoking. Thirty-two work sites were randomly assigned to either implement the health program or to make no changes for a period of two years. The promotion program
The characteristics of low birth weight children dying of sudden Infant death syndrome were examined for both females and males. The ages at time of death for samples of 11 female infants and 16 males are provided in the dataset sids.dta [228]. (a) Construct box plots of age at time of death by
Nineteen individuals with asthma were enrolled in a study investigating the respiratory effects of sulfur dioxide. During the study, two measurements were obtained for each subject. The first was the increase in specific airway resistance - a measure of bron- choconstriction from the time when the
The data below are taken from a study that compares adolescents who have bulimia to adolescents without bulimia who have similar body compositions and levels of physical activity. The data consist of measures of daily caloric intake for random samples of 23 bulimic adolescents and 15 adolescents
We are interested in examining the effects of the transition from fetal to postnatal cir- culation among premature infants. For each of 14 healthy newborns, respiratory rate is measured at two different times: once when the child is less than 15 days old, and again when he or she is more than 25
Refer to the resting energy expenditure (ER) data for patients with cystic fibrosis and healthy individuals matched to the patients on age, sex, height and weight that was provided in Table 13.1 [220]. We previously used the sign test to evaluate the null hypothesis that the median difference in
What are the advantages and disadvantages of using ranks rather than continuous mea- surements to conduct tests of hypothesis?
How do the assumptions of the Wilcoxon rank sum test differ from those underlying the two-sample test?
How does the Wilcoxon signed-rank test differ from the sign test?
What are the advantages and disadvantages of using the sign test to analyze paired observations?
How do nonparametric tests differ from parametric ones?
The data set lowbwt contains information for a sample of 100 low birth weight infants born in two teaching hospitals in Boston, Massachusetts [81]. Systolic blood pressure measurements are saved under the variable name sbp and indicators of sex - where I represents a male and 0 a female-under the
For the study discussed in the text which investigates the effect of carbon monoxide exposure on patients with coronary artery disease, baseline measures of pulmonary function were examined across the three medical centers which enrolled patients. Another characteristic that you might wish to
A study was conducted to assess the performance of outpatient substance abuse treatment centers. Three different types of units were evaluated: private for-profit (FP), private not- for-profit (NFP), and public. Among the performance measures considered were minutes of individual therapy per
One of the goals of the Edinburgh Artery Study was to investigate the risk factors for peripheral arterial disease among persons 55 to 74 years of age. You wish to compare mean LDL cholesterol levels, measured in mmol/liter, among four different populations of subjects: patients with intermittent
A study of patients with insulin-dependent diabetes was conducted to investigate the effects of cigarette smoking on renal and retinal complications. Before examining the results of the study, you wish to compare the baseline measures of systolic blood pressure across four different subgroups:
Consider the F distribution with 3 and 30 degrees of freedom. (a) What proportion of the area under the curve lies to the right of F = 5.24? (b) What proportion of the area under the curve lies to the left of F = 2.92? (c) What value of F cuts off the upper 2.5% of the distribution? (d) What value
Consider the F distribution with 8 and 16 degrees of freedom. (a) What proportion of the area under the curve lies to the right of F = 2.09? (b) What value of F cuts off the upper 1% of the distribution? (c) What proportion of the area under the curve lies to the left of F = 4.52?
Describe the purpose of the Bonferroni correction for multiple comparisons.
What are the properties of the F distribution?
What is the idea behind the one-way analysis of variance? What two measures of variation are being compared?
When testing the equality of several population means, what problems arise if you attempt to perform all possible pairwise two-sample t-tests?
The Bayley Scales of Infant Development provide scores on two indices-the Psychomotor Development Index (ex) and the Mental Development Index (MDI)-which can be used to assess a child's level of functioning at approximately one year of age. As part of a study Investigating the development and
The data set lowbwt contains Information for a sample of 100 low birth weight infants born in two teaching hospitals in Boston, Massachusetts [81]. Measurements of systolic blood pressure are saved under the variable name sbp and indicators of sex with 1 representing a male and 0 a female-under the
A crossover study was conducted to Investigate whether oat bran cereal helps to lower serum cholesterol levels in hypercholesterolemic males [214]. Fourteen such individuals were randomly placed on a diet which included either oat bran or corn flakes. After two weeks, their low-density lipoprotein
A study was conducted to compare physical and psychological characteristics of monozy- gotic (identical) twins [213]. One question of Interest was whether brain volume differed by birth order. The dataset twins contains total brain volumes measured in cm for 10 pairs of monozygotic twins. The brain
You wish to compare health-related quality of life as measured by the mental component summary (MCS) score of the Medical Outcomes Study se-36 questionnaire for patients with fibromyalgia undergoing two different treatment regimens. In the general population, MCS scores are normally distributed
Investigators are designing a study to compare forced vital capacity - the maximum amount of air which can be forcibly exhaled from the lungs after fully inhaling - for females between 30 and 35 years of age who smoke at least 10 cigarettes per day and females in the same age group who smoke fewer
In the study of adults undergoing liver transplantation who completed the Medical Out- comes Study se-36 questionnaire six months after surgery, we previously compared the mental component summary MCS score for Individuals receiving usual care versus those treated with exercise and dietary
You plan to conduct a study evaluating an anti-smoking campaign in a large public high school. Prior to Implementation of the campaign, you will enroll a sample of students who are all self-reported smokers, and record the number of cigarettes smoked on the day prior to study enrollment. Two months
In an investigation of pregnancy-induced hypertension, one group of females with this disorder was treated with low-dose aspirin, and a second group was given a placebo [212]. A sample consisting of 23 females who received aspirin has mean arterial blood pressure 111 mm Hg and standard deviation 8
A study was conducted to determine whether an expectant mother's cigarette smoking has any effect on the bone mineral content of her otherwise healthy child [211]. A sample of 77 newborns whose mothers smoked during pregnancy has mean bone mineral content * = 0.098 g/cm and standard deviation s =
The data below come from a study that examines the efficacy of saliva cotinine as an Indicator for exposure to tobacco smoke. In one part of the study, seven subjects - none of whom were heavy smokers and all of whom had abstained from smoking for at least one week prior to the study-were each
Suppose you are interested in determining whether exposure to the organochlorine DOT. which has been used extensively as an Insecticide for many years, is associated with breast cancer in women. As part of a study which investigated this issue, blood was drawn from a sample of women diagnosed with
What is the rationale for using a pooled estimate of the variance in the two-sample t-test?
When can you use the two-sample t-test? When must the modified version of the test be applied?
Explain the concept of paired data. In certain situations, what might be the advantage of using paired samples to compare populations rather than independent samples?
What is the main difference between paired and independent samples of observations?
The Bayley Scales of Infant Development yield scores on two Indices - the Psychomotor Development Index (PD) and the Mental Development Index (MDI) - which can be used to assess a child's level of functioning in each of these areas at approximately one year of age. Among normal healthy Infants,
A researcher is planning a study to investigate whether a six-month diet and exercise program will change total body bone mineral content (TBBMC) among females 20 to 29 years of age. If the diet and exercise program has no impact on bone mineral content, the mean change would be equal to 0%. A
In Norway, the distribution of birth weights for full-term infants whose gestational age Is 40 weeks is approximately normal with mean = 3500 grams and standard deviation = 430 grams [177]. An Investigator plans to conduct a study to determine whether the birth weights of full-term babies whose
Over the years, the Food and Drug Administration of the United States (PDA) has worked very hard to avoid making type II errors. A type II error occurs when the FDA approves a drug which is not both safe and effective. Despite the agency's efforts, however, bad drugs do on occasion get through to
Percentages of Ideal body weight were determined for 18 randomly selected insulin- dependent diabetics and recorded below [187]. A percentage of 120 means that an Individual weighs 20% more than his or her ideal body weight, a percentage of 95 means that the Individual weighs 5% less than the
The population of male industrial workers in London who have never experienced a major coronary event has mean systolic blood pressure 136 mm Hg and mean diastolic blood pressure 84 mm Hg [198]. You might be interested in determining whether these values are the same as those for the population of
Body mass index is calculated by dividing a person's weight by the square of his or her height; it is a measure of the extent to which the Individual is overweight. For the population of middle-aged men who later develop diabetes mellitus, the distribution of baseline body mass indices is
E. canis infection is a tick-borne disease of dogs that is sometimes contracted by humans. Among Infected humans, the distribution of white blood cell counts has an unknown mean and a standard deviation or. In the general population, the mean white blood cell count is 7250/mm [75]. It is believed
The distribution of diastolic blood pressures for the population of female diabetics between the ages of 30 and 34 has an unknown mean Hd and standard deviation = 9.1 mm Hg. It may be useful to physicians to know whether the mean of this population is equal to the mean diastolic blood pressure of
List four factors that affect the power of a test.
Explain the analogy between type I and type II errors in a test of hypothesis and the false positive and false negative results which occur in diagnostic testing.
Describe the two types of errors that can be made when conducting a test of hypothesis.
Under what circumstances might you use a one-sided test of hypothesis rather than a two-sided test?
Briefly explain the relationship between confidence intervals and hypothesis testing.
What is a p-value? What does the p-value mean in words?

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Principles Of Biostatistics 3rd Edition Marcello Pagano, Kimberlee Gauvreau, Heather Mattie - Solutions

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