Confidence Intervals In everyday terms, a confidence interval is the range of values around a sample statistic (such as mean or proportion) within which clinicians can expect to get the same results if they repeat the study protocol or intervention, including measuring the same outcomes the same ways. As you ask yourself, "Will I get the same results if I use this research?", you must address the precision of study findings, which is determined by the Confidence Interval. If the CI around the sample statistic is narrow, you can be confident you will get close to the same results if you implement the same research in your practice. Consider the following example. Suppose that you did a systematic review of studies on the effect of tai chi exercise on sleep quality, and you found that tai chi affected sleep quality in older people. If, according to your study, you found the lower boundary of the CI to be .49, the study statistic to be 0.87, and the upper boundary to be 1.25, this would mean that each end limit is 0.38 from the sample statistic, which is a relatively narrow CI. (UB + LB)/2 = Statistic [(1.25 + .49)/2 = .87] Keep in mind that a mean difference of 0 indicates there is no difference; this CI does not contain 0. Therefore, the sample statistic is statistically significant and unlikely to occur by chance. Because this was a systematic review, and tai chi exercise has been established from the studies you assessed as helping people sleep, based on the sample statistics and the CI, clinicians could now use your study and confidently include tai chi exercises among possible recommendations for patients who have difficulty sleeping. Now you can apply your knowledge of CIs to create your own studies and make wise decisions about whether to base your patient care on a particular research finding. Initial Post Instructions Thinking of the many variables tracked by hospitals and doctors' offices, confidence intervals could be created for population parameters (such as means or proportions) that were calculated from many of them. Choose a topic of study that is tracked (or that you would like to see tracked) from your place of work. Discuss the variable and parameter (mean or proportion) you chose, and explain why you would use these to create an interval that captures the true value of the parameter of patients with 95% confidence. Consider the following: How would changing the confidence interval to 90% or 99% affect the study? Which of these values (90%, 95%, or 99%) would best suit the confidence level according to the type of study chosen? How might the study findings be presented to those in charge in an attempt to affect change at the workplace? Follow-Up P Welcome to Week 6! You may begin posting on Monday, October 7, 2019 for credit. This week, we will be discussing confidence intervals in the health field. According to Holmes et al. (2017), when we have only a single sample, the sample mean is the best estimate of the population mean, μ. However, we do not expect the sample mean to be equal to the population mean, because there is likely to be some sampling error. Therefore, in order to make an inference about the population mean, we need some way to describe how well we expect it to be represented by the sample mean. The most common method for doing this is by way of confidence intervals. A precise calculation shows that if the distribution of sample means is normal with a mean of μ, then 95% of all sample means lie within 1.96 standard deviations of the population mean; for our purposes in this book, we will approximate this as 2 standard deviations. A confidence interval is a range of values likely to contain the true value of the population mean. Two important formula to know. margin of error is = E = 1.96s/sqrt(n), where s is the standard deviation of the data and n is the number of items in the data. Confidence interval formula is from the mean adding and subtracting the margin of error. Reference: Holmes, A., Illowsky, B., & Dean, S. (2017). Introductory Business Statistics. Houston, TX: OpenStax CNX. Retrieved from https://openstax.org/details/books/introductory-business-statistics (Links to an external site.)Links to an external site. Using your own research, and/or the textbook, respond to the discussion question. Remember to use an outside resource in the main post, which needs to be on or before Wednesday. Don’t forget to look over the discussion rubric as a reference when you are writing your discussion posts. If you have any questions, please post in the Q&A forum or email me: Let’s get started! Rn-BSN stats class Example: Discussion post Professor Cartwright and Class, According to the textbook, “A confidence interval is another type of estimate but, instead of being just one number, it is an interval of numbers. The interval of numbers is a range of values calculated from a given set of sample data” (Holmes, Illowsky & Dean, 2017). For example, if we have a confidence value of 95%, then approximately 95 of the 100 samples we used will have a population value. In healthcare, there are many measures that are kept track of. One thing the ED focuses on it TPA administration time for non-hemorrhagic strokes. The national goal is under 60 minutes, but our hospital goal is under 45 minutes. Let’s say the TPA administration times for the month of September were 21, 25, 36, 44, 72, & 90 minutes. There are 6 samples. The sample mean would be 48, and the standard deviation is 27.4153. With a confidence level of 95%, we can assume the population mean is between 26.1 and 69.9 based on 6 samples. With a confidence level of 90%, we can assume the population mean is between 29.6 and 66.4 based on 6 samples. There is a little bit of a difference between the two but not much. I feel like the 95% CI would be the most accurate because it is more confident numbers. “The correct interpretation of a confidence interval is based on repeated sampling. If we repeatedly sample and construct confidence intervals, 95% of the confidence intervals will contain the true population mean; 5% will not” (CCN, 2019). I think this is important when reviewing data because we can see how accurately we are doing. It is also important for everyone to understand CI, so when results are read, we can understand what they mean. “CI is usually found in the results section of a paper and provide the reader with an opportunity to draw conclusions about the importance of the size or strength of the results (Clarke, 2012). Tiffany Loy References: Chamberlain College of Nursing. (2019). MATH225N. Week 6: Confidence Interval. Downers Grove, IL: DeVry Education Group. Clarke, J. (2012). BMJ Journals. What is a CI? Evidence-Based Nursing 2012;15:66. https://ebn.bmj.com/content/15/3/66.info Holmes, A., Illowsky, B., & Dean, S. (2017). Introductory Business Statistics. Houston, TX: OpenStax CNX. https://openstax.org/details/books/introductory-business-statisticsLinks to an external site.