A clinical trial was conducted to test the efficacy of nifedipine, a new drug for reducing chest pain in patients with angina severe enough to require hospitalization. The duration of the study was 14 days in the hospital unless the patient was withdrawn prematurely from therapy, was discharged from the hospital, or died prior to this time. Patients were randomly assigned to either nifedipine or propranolol and were given the same dosage of each drug in identical capsules at level 1 of therapy. If pain did not cease at this level of therapy or if pain recurred after a period of pain cessation, then the patient progressed to level 2, whereby the dosage of each drug was increased according to a pre-specified schedule. Similarly, if pain continued or recurred at level 2, then the patient progressed to level 3, whereby the dosage of the anginal drug was increased again. Patients randomized to either group received nitrates in any amount deemed clinically appropriate to help control pain.
The main objective of the study was to compare the degree of pain relief with nifedipine vs. propranolol. A secondary objective was to better understand the effects of these agents on other physiologic parameters, including heart rate and blood pressure. Data on these latter parameters are given in Data Set NIFED.DAT (at www.cengagebrain.com); the format of this file is shown in Table 5.3
Compare graphically the effects of the treatment regimens on heart rate and blood pressure. Do you notice any difference between treatments?
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Fundamentals of Biostatistics
- A deficiency of the trace element selenium in the diet can negatively impact growth, immunity, muscle and neuromuscular function, and fertility. The introduction of selenium supplements to dairy cows is justified when pastures have low selenium levels. Authors of a research paper supplied the following data on milk selenium concentration (mg/L) for a sample of cows given a selenium supplement (the treatment group) and a control sample given no supplement, both initially and after a 9-day period. Initial Measurement Treatment Control 11.2 9.1 9.6 8.7 10.1 9.7 8.5 10.8 10.3 10.9 10.6 10.6 11.7 10.1 9.7 12.3 10.8 8.8 10.3 10.4 10.4 10.9 11.2 10.4 9.4 11.6 10.6 10.9 10.7 8.4 After 9 Days Treatment Control 138.3 9.3 104 8.7 96.4 8.7 89 10.1 88 9.6 103.8 8.6 147.3 10.2 97.1 12.2 172.6 9.3 146.3 9.5 99 8.2 122.3 8.9 103 12.5 117.8 9.1 121.5 93 (a) Use the given data for the treatment group to determine if there…arrow_forwardA deficiency of the trace element selenium in the diet can negatively impact growth, immunity, muscle and neuromuscular function, and fertility. The introduction of selenium supplements to dairy cows is justified when pastures have low selenium levels. Authors of a research paper supplied the following data on milk selenium concentration (mg/L) for a sample of cows given a selenium supplement (the treatment group) and a control sample given no supplement, both initially and after a 9-day period. Initial Measurement Treatment Control 11.3 9.1 9.7 8.7 10.1 9.7 8.5 10.8 10.4 10.9 10.7 10.6 11.8 10.1 9.8 12.3 10.6 8.8 10.4 10.4 10.2 10.9 11.3 10.4 9.2 11.6 10.7 10.9 10.8 8.2 After 9 Days Treatment Control 138.3 9.4 104 8.8 96.4 8.8 89 10.1 88 9.7 103.8 8.7 147.3 10.3 97.1 12.3 172.6 9.4 146.3 9.5 99 8.3 122.3 8.9 103 12.5 117.8 9.1 121.5 93 (a) Use the given data for the treatment group to determine if…arrow_forwardA recent study on the effects of Tamiflu looked into whether the antiviral medication can reduce the duration of the flu or not. To test this, researchers selected sample of 42 individuals recently diagnosed with the flu. Twenty-one of these individuals were given a placebo, and their average flu durations was 12.6 days (SD = 1.88). The remaining 21 subjects were given Tamiflu, and their average flu duration was 11.4 days (SD = 1.58). Did Tamiflu make reduce the duration of the flu? What is the effect size for this difference? state the null and alternavive hypthesis, aplha level of 0.05 please text the null hypthesis and draw the rejction regionarrow_forward
- Vermont maple sugar producers sponsored a testing program to determine the benefit of a potential new fertilizer regimen. A random sample of 27 maple trees in Vermont were chosen and treated with one of three levels of fertilizer suggested by the chemical producer. In this experimental setup, nine trees (three in each of three climatic zones) were treated with each fertilizer level and the amount of sap produced (in mL) by the trees in the subsequent season was measured. The results are presented in the following table. Southern Zone Central Zone Northern Zone 76.2 80.4 74.2 79.4 87.9 86.9 84.5 85.2 80.1 Low fertilizer Medium 87.0 95.1 93.0 98.2 94.7 96.2 88.4 90.4 922 fertilizer High 84.2 87.5 83.1 90.3 89.9 93.2 81.4 84.7 82.2 fertilizer Estimate the main effects of fertilizer levels and climatic zone, and their interactions. b. Construct an ANOVA table. You may give ranges for the P-values. Test the hypothesis that there is no interaction between fertilizer levels and climatic zone.…arrow_forwardA study was designed "to determine if application of duct tape is as effective as cryotherapy (liquid nitrogen applied to the wart for 10 seconds every 2 to 3 weeks) in the treatment of common warts." The researchers randomly divided 51 patients into two groups. The 26 patients in group 1 had their warts treated by applying duct tape to the wart for 6.5 days and then removing the tape for 12 hours, at which point the cycle was repeated for a maximum of 2 months. The 25 patients in group 2 had their warts treated by cryotherapy for a maximum of six treatments. Once the treatments were complete, it was determined that 85% of the patients in group 1 and 60% of the patients in group 2 had complete resolution of their warts. The researchers concluded that duct tape is significantly more effective in treating warts than cryotherapy. What is the research objective? What is the population being studied? What is the sample? What are the descriptive statistics? What are the conclusions of the…arrow_forwardA study was conducted to examine the effect of diet cola consumption on calcium levels in women. A sample of 16 healthy women aged 18 to 40 were randomly assigned to drink 24 ounces of either diet cola or water. Their urine was collected for three hours after ingestion of the beverage and calcium excretion (in mg) was measured. The data are stored in ColaCalcium.arrow_forward
- Researchers interested in lead exposure due to car exhaust sampled the blood of 52 police officers subjected to constant inhalation of automobile exhaust fumes while working traffic enforcement in a primarily urban environment. The blood samples of these officers had an average lead concentration of 124.32 µg/l and a SD of 37.74 µg/l; a previous study of individuals from a nearby suburb, with no history of exposure, found an average blood level concentration of 35 µg/l. Based on your preceding result, without performing a calculation, would a 99% confidence interval for the average blood concentration level of police officers contain 35 µg/l? Based on your preceding result, without performing a calculation, would a 99% confidence interval for this difference contain 0? Explain why or why not.arrow_forwardThe dose-response effect is best described as A. when similar studies produce similar results B. when all other possible causes are ruled out. C. when the value of the response variable changes in a meaningful way with the dosage of the suspected cause.arrow_forwardA researcher would like to examine how the chemical tryptophan, contained in foods such as turkey, can reduce mental alertness. A sample of n = 9 college students is obtained, and each student’s performance on a familiar video game is measured before and after eating a traditional Thanksgiving dinner including roasted turkey. The average mental alertness score dropped by MD= 14 points after the meal with SS= 1152 for the difference scores. a. Is there is significant reduction in mental alertness after consuming tryptophan versus before? Use a one-tailed test with α = .05. b. Compute r2 to measure the size of the effect.arrow_forward
- A survey of 90 recently delivered women on the rolls of a county welfare department revealed that 27 had a history of intrapartum or postpartum infection. Can we conclude that the population proportion with a history of intrapartum or postpartum infection is significantly less than or equal to 0.25? Let alpha = 0.05.arrow_forwardS-adenosyl methionine (SAM-e) is a naturally occurring compound in human cells that is thought to have an effect on depression symptoms. Suppose that a researcher is interested in testing SAM-e on patients who are struggling with HIV. She obtains a sample of n = 25 patients and asks each person to take the suggested dosage each day for 4 weeks. At the end of the 4-week period, each individual takes the Beck Depression Inventory (BDI), which is a 21-item, multiple-choice self-report inventory for measuring the severity of depression. The scores from the sample produced a mean of M = 26.3 with a standard deviation of s = 1.01. In the general population of HIV patients, the standardized test is known to have a population mean of μ = 27.1. Because there are no previous studies using SAM-e with this population, the researcher doesn’t know how it will affect these patients; therefore, she uses a two-tailed single-sample t test to test the hypothesis. The critical t scores (the values…arrow_forwardA biochemist is testing the effect of a new antibiotic on a particulararrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill