A practical Approach to analyzing health care data: HIM 333 Chapter 5 Analysing continuous variables: ONE SAMPLE T-TEST Use this data for questions 1-4 1) Calculate a t-test statistic for a facility who would like to compare a month sample of their coding times in minutes per record against their company's benchmark of 30 minutes per record coding time. The alpha level will be set at 0.05. The mean coding time from the facility's sample was 28.25 minutes. The sample size was 51 records. The calculated standard deviation was 5 minutes. 2) What would the degrees of freedom and the critical t-value be for the problem above? 3) Based on the information found in questions 11 & 12, would you reject or not reject (accept) the null hypothesis? CONFIDENCE INTERVAL 4) Calculate a Confidence Interval for the data above. PAIRED T-TEST 5) A weight loss clinic is introducing a new diet regimen. They took a sample of 25 patients and weighed them before and after the diet regimen was completed. The mean difference in their weights was 10.5 pounds. The standard deviation of the differences was found to be 4 pounds. Calculate the paired t-test statistic. TWO SAMPLE 6) When running a two sample test, how is the test statistic usually calculated? 7) If you ran a two sample test and found that your t critical two tail value was 3.56 and that your t Statistic value was 2.45. Would you reject or not reject (accept) the null hypothesis? ANOVA 8) What does the abbreviation SS stand for? 9) What does variation 'between groups' mean? 10) What does variation 'within groups' mean? Chapter 6 :Analysing Relationship between two variables: 1)As nurses gain more experience, they should be able to establish IV access in less tries. In order to quantify that relationship, an analyst selected a sample of 8 nurses. For the subjects sampled, the years of experience and average number of tries to establish IV access was collected. The data from the study appear in the table below: Subject Experienc e Number of Tries 20 15 30 24 16 28 14 21 168 21 xx y y 2 3 1 2 4 1 3 3 19 2.375 (3 dec) xx 2 y y 2 (6 dec) y y ( xx ) (3 decimals) 1 2 3 4 5 6 7 8 Sum Average a) What is the formula for Pearson's r Correlation Coefficient? b) Find the Pearson's r Correlation Coefficient for the data. (Show work out to three decimal places) c) Does this data correlate? If so, is it negative or positive and what can we conclude from this data? 1) When would you use the Spearman's Rho as opposed to the Pearson's r? 2) Spearman's Rho a) What is the formula for Spearman's Rho? b) Define each variable in the formula. C) Calculate the Spearman's Rho for the set of data given. Subject 1 2 3 4 5 Charges (X) 15,000 20,000 10,000 15,000 25,000 LOS (Y) 1.0 6.0 1.0 2.0 5.0 Rank X Rank Y Rank X- Rank Y (Rank X- Rank Y)2 3) When would you use a t-test for correlation? 4) T-test for Correlations a) State the formula for the t-test. b) Define each variable. c) Test the hypothesis that the correlation between nursing experience and tries to obtain IV access is zero at the 0.05 level. (Reference Data from Problem 5) Calculate the t-test statistic. Use the alpha level and degrees of freedom to determine if this value is acceptable. - Alpha level: Degrees of Freedom: Critical Value: Would you Reject or Accept the null hypothesis? 5) In the least squares method of simple linear regression, what is the goal when drawing your line of \"best fit\" or regression line? A practical Approach to analyzing health care data: HIM 333 Chapter 5 Analysing continuous variables: ONE SAMPLE T-TEST Use this data for questions 1-4 1) Calculate a t-test statistic for a facility who would like to compare a month sample of their coding times in minutes per record against their company's benchmark of 30 minutes per record coding time. The alpha level will be set at 0.05. The mean coding time from the facility's sample was 28.25 minutes. The sample size was 51 records. The calculated standard deviation was 5 minutes. 2) What would the degrees of freedom and the critical t-value be for the problem above? 3) Based on the information found in questions 11 & 12, would you reject or not reject (accept) the null hypothesis? CONFIDENCE INTERVAL 4) Calculate a Confidence Interval for the data above. PAIRED T-TEST 5) A weight loss clinic is introducing a new diet regimen. They took a sample of 25 patients and weighed them before and after the diet regimen was completed. The mean difference in their weights was 10.5 pounds. The standard deviation of the differences was found to be 4 pounds. Calculate the paired t-test statistic. TWO SAMPLE 6) When running a two sample test, how is the test statistic usually calculated? 7) If you ran a two sample test and found that your t critical two tail value was 3.56 and that your t Statistic value was 2.45. Would you reject or not reject (accept) the null hypothesis? ANOVA 8) What does the abbreviation SS stand for? 9) What does variation 'between groups' mean? 10) What does variation 'within groups' mean? Chapter 6 :Analysing Relationship between two variables: 1)As nurses gain more experience, they should be able to establish IV access in less tries. In order to quantify that relationship, an analyst selected a sample of 8 nurses. For the subjects sampled, the years of experience and average number of tries to establish IV access was collected. The data from the study appear in the table below: Subject Experienc e Number of Tries 20 15 30 24 16 28 14 21 168 21 xx y y 2 3 1 2 4 1 3 3 19 2.375 (3 dec) xx 2 y y 2 (6 dec) y y ( xx ) (3 decimals) 1 2 3 4 5 6 7 8 Sum Average a) What is the formula for Pearson's r Correlation Coefficient? b) Find the Pearson's r Correlation Coefficient for the data. (Show work out to three decimal places) c) Does this data correlate? If so, is it negative or positive and what can we conclude from this data? 1) When would you use the Spearman's Rho as opposed to the Pearson's r? 2) Spearman's Rho a) What is the formula for Spearman's Rho? b) Define each variable in the formula. C) Calculate the Spearman's Rho for the set of data given. Subject 1 2 3 4 5 Charges (X) 15,000 20,000 10,000 15,000 25,000 LOS (Y) 1.0 6.0 1.0 2.0 5.0 Rank X Rank Y Rank X- Rank Y (Rank X- Rank Y)2 3) When would you use a t-test for correlation? 4) T-test for Correlations a) State the formula for the t-test. b) Define each variable. c) Test the hypothesis that the correlation between nursing experience and tries to obtain IV access is zero at the 0.05 level. (Reference Data from Problem 5) Calculate the t-test statistic. Use the alpha level and degrees of freedom to determine if this value is acceptable. - Alpha level: Degrees of Freedom: Critical Value: Would you Reject or Accept the null hypothesis? 5) In the least squares method of simple linear regression, what is the goal when drawing your line of \"best fit\" or regression line