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Back Pain Treatment In a study designed to test the effectiveness of paracetamol (or acetaminophen) as a treatment for lower back pain, 1643 patients were randomly assigned to one of three groups: (1) the 547 subjects in the placebo group were given pills containing no medication; (2) 350 subjects were in a group given pills with paracetamol taken at regular intervals; (3) 546 subjects were in a group given pills with paracetamol to be taken when needed for pain relief. (See “Efficacy of Paracetamol for Acute Low-Back Pain,” by Williams, et al., Lancet, doi: 10.1016/S0140-6736(14)60805-9.) Is this study an experiment or an observational study? Explain.
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- List the sample space of each experiment. Picking a one-digit numberarrow_forwardSeattle Grace Medical Center. As part of a long-term study of individuals 65 years of age or older, doctors at the Seattle Grace Medical Center in Washington state investigated the relationship between state of residence and depression. A sample of 60 individuals, all in reasonably good health, was selected; 20 individuals were residents of Texas, 20 were residents of Washington state, and 20 were residents of South Carolina. Each of the individuals sampled was given a standardized test to measure depression. The data collected follow; higher test scores indicate higher levels of depression. These data are contained in the attached data file SeattleGrace1. A second part of the study considered the relationship between state of residence and depression for individuals 65 years of age or older who had a chronic health condition such as diabetes and/or high blood pressure. A sample of 60 individuals with such conditions was identified. Again, 20 were residents of Texas, 20 were residents…arrow_forwardSeattle Grace Medical Center. As part of a long-term study of individuals 65 years of age or older, doctors at the Seattle Grace Medical Center in Washington state investigated the relationship between state of residence and depression. A sample of 60 individuals, all in reasonably good health, was selected; 20 individuals were residents of Texas, 20 were residents of Washington state, and 20 were residents of South Carolina. Each of the individuals sampled was given a standardized test to measure depression. The data collected follow; higher test scores indicate higher levels of depression. These data are contained in the attached data file SeattleGrace1. A second part of the study considered the relationship between state of residence and depression for individuals 65 years of age or older who had a chronic health condition such as diabetes and/or high blood pressure. A sample of 60 individuals with such conditions was identified. Again, 20 were residents of Texas, 20 were residents…arrow_forward
- Seattle Grace Medical Center. As part of a long-term study of individuals 65 years of age or older, doctors at the Seattle Grace Medical Center in Washington state investigated the relationship between state of residence and depression. A sample of 60 individuals, all in reasonably good health, was selected; 20 individuals were residents of Texas, 20 were residents of Washington state, and 20 were residents of South Carolina. Each of the individuals sampled was given a standardized test to measure depression. The data collected follow; higher test scores indicate higher levels of depression. These data are contained in the attached data file SeattleGrace1. A second part of the study considered the relationship between state of residence and depression for individuals 65 years of age or older who had a chronic health condition such as diabetes and/or high blood pressure. A sample of 60 individuals with such conditions was identified. Again, 20 were residents of Texas, 20 were residents…arrow_forwardIn a clinical trial of 2198 subjects treated with a certain drug, 26 reported headaches. In a control group of 1661 subjects given a placebo, 22 reported headaches. Denoting the proportion of headaches in the treatment group by p, and denoting the proportion of headaches in the control (placebo) group by Pc the relative risk is p/pc. The relative risk is a measure of the strength of the effect of the drug treatment. Another such measure is the odds ratio, which is the ratio of the odds in favor of a headache for the treatment group to the odds in favor of a headache for the control (placebo) group, found by evaluating . The relative risk and odds ratios are commonly used in medicine and epidemiological studies. Find the relative risk and odds ratio for the headache data. What do the results suggest about the risk of a headache from the drug treatment? Pt/(1-Pt) Pc/(1-Pc)arrow_forwardA magazine reported on the "... treatment-emergent adverse events that occurred in 2% or more patients treated with a new medicine and with incidence greater than placebo in the treatment of depression, OCD, or bulimia." In the study, patients took the new medicine and patients were given placebo. Identify the a. treatment group, b. control group, and c. treatments.arrow_forward
- Do cell phones increase drivers' reaction times while driving? A 2003 American Journal of Health Education study investigated the effects of cell phone use on reaction time. In the study, 60 participants were randomly selected and placed into one of two groups: the cell phone group or the control group. Those in the control group participated in the experiment with no distractions, whereas those in the cell phone group had access to text documents on a cell phone. Participants in each group were then asked to take a computerized reaction time test. Researchers then recorded each subject's reaction time in seconds. The table shows the results of the experiment. Group Populationmean Samplesize Samplemean Sample standarddeviation Phone up n=30 x¯P=0.546 sx=0.213 Control uc n=30 x¯C=0.356 sx=0.245 df=56.900 Suppose the researchers wish to examine at a significance level of alpha=0.05 if the mean reaction time for phone users is larger than the mean reaction time for the…arrow_forwardThe national Center for Health Services found that 26% of men aged 20 years or older suffer from hypertension and 31.5% of women aged 20 years or older are hypertensive. A random sample of 150 of each gender was selected from recent hospital records and the following results were obtained. Can you conclude that a higher percentage of women have high blood pressure? Men: 43 patients had high blood pressure Women: 52 patients had high blood pressurearrow_forwardSigall and Ostrove (1975) did an experiment to assess whether the physical attractiveness of a defendant on trial for a crime had an effect on the severity of the sentence given in a mock jury trials. Each of the participants in this study was randomly assigned to one of the following three treatment groups; every participant received a package that described a burglary and gave background information about the accused person. The three treatment groups differed in the type of information that they were given about the accused person’s appearance. Members of Group 1 were showing a photo of an attractive person; members of Group 2 were shown a photograph of an unattractive person; members of Group 3 saw no photograph. Some of their results are described here. Each participant was asked to assign a sentence (in years) to the accused person; the researchers predicted that more attractive persons would receive shorter sentences. a)Prior to assessment of the outcome, the researchers did a…arrow_forward
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