Running head STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N.docx
- 1. Running head: STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 1 Statistical Analysis Project on Post-Operative Nausea and Vomiting Brenda Venvertloh Olivet Nazarene University Statistics BSN 198/MATH 120 Dr. Dan Green September 15, 2015
- 2. Certification of Authorship: I certify that I am the author of this paper and that any assistance I received in its preparation is fully acknowledged and disclosed in the paper. I have also cited any sources from which I used data, ideas, or words, either quoted directly or paraphrased. I also certify that this paper was prepared by me specifically for the purpose of this assignment. Your Signature: Brenda Venvertloh RN, CAPA STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 2 Abstract The purpose of this case-controlled observational study is to determine if the proportion of men or women experience post-operative nausea and vomiting after general anesthesia more often than the opposite gender. Post-operative nausea and vomiting
- 3. proves to be very debilitating for many patients. The population of this study is all outpatient surgical patients who receive general anesthesia. Data was obtained through random samples of patients that received general anesthesia for outpatient procedures at a hospital based surgical center. Permission was granted by the manager of the surgical department to use the data for statistical purposes for this assignment. No personal or demographic information was used to protect the confidentiality of the patients. This paper will discuss statistical methods used to analyze the data collected for this project. Results will be revealed through graphs and statcrunch computations. My hypothesis is that women experience post-operative nausea/vomiting at a higher proportion than men. This hypothesis is based on observations and experience as a nurse with years of experience in perianesthesia nursing.
- 4. STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 3 Statistical Analysis Project on Post-operative Nausea/Vomiting Introduction Post-operative nausea and vomiting after general anesthesia proves to be very debilitating for many patients. In fact, according to the American Society of Perianesthesia nurses, post- operative nausea and vomiting is the most common complication after general anesthesia that affects one third of all surgical patients each year (McLaughlin, 2010). Due to the fact that this complication may lead to unanticipated or prolonged hospital stays, it is important to identify high risk patients in order to be pro-active in prevention and treatment of post-operative nausea and vomiting. This statistical analysis project focuses on the topic of post-operative nausea and
- 5. vomiting, with the specific question being, which gender is affected by post-operative nausea and vomiting after general anesthesia at a higher proportion, men or women? I hypothesize that women experience post-operative nausea and vomiting after general anesthesia at a higher proportion than men. The information gained from this project could be supportive of evidence based practice recommendations in regards to post-operative nausea and vomiting. “It remains one of the most predictable indicators of prolonged postoperative stays, unplanned admissions and delayed return to activities of daily living and employment”(Sites et al., 2014, p. 12-13). Negative outcomes can certainly occur due to post-operative nausea and vomiting as well. Complications from post- operative nausea and vomiting cost health care providers and insurers millions of dollars per year (Sites et al., 2014). Post-operative nausea and vomiting may also have a huge impact on patient satisfaction scores. Patients that are affected by post-operative nausea and vomiting are not as likely to remember the good aspects of their care. The purpose
- 6. of this project is to identify which gender is affected at a higher proportion so nurses may identify and advocate for STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 4 preventative measures to be taken in order to lower the post- operative nausea and vomiting statistics. METHODS Participants The population of this statistical analysis project is all patients who have outpatient surgery with general anesthesia. The sample was a subset of 50 female individuals and 50 male individuals who had outpatient surgery with general anesthesia at a hospital based surgery center. The samples were selected randomly out of all outpatients who had general anesthesia in a two week period at a hospital based surgery center. The exclusion criteria were patients that were to be admitted after surgery and patients who only had local
- 7. anesthesia. Materials A follow-up phone call form was used to collect the data for this project. Outpatients are notified by the surgery center nurses the day after surgery. Patients are asked several questions regarding their experience with surgery, their care at the surgery center, and any complications they may be experiencing. Two questions on the form address post-operative nausea and vomiting. The only question that was used in the data collection for this project was, “Did you experience any nausea or vomiting after surgery?” Procedure First of all, I determined the objective to conduct my statistical analysis project. I have worked in perianesthesia nursing for a number of years and have observed that it seems women tend to experience post-op nausea and vomiting more frequently than men. I thought it would be interesting to analyze whether this is true in a study of patients in the department that I work in. Then, I determined this would be a case-control study, meaning
- 8. that this was retrospective in STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 5 nature. I had to look at data that had already been collected, the follow-up phone call form. The only thing required of the subjects in this study was to respond and answer the question regarding post-operative nausea and vomiting when the follow- up phone call was made. Since it would be impossible for me to conduct research on the entire population, I decided to collect a random sample of data from 50 men and 50 women to analyze. As I have learned in this course, larger sample sizes show more congruency in relation to the normal population. To obtain the random sample, I collected all follow-up call sheets from a 2 week period and divided them into a group of women forms and a group of men forms. I had another nurse randomly select 50 from each group, essentially like “drawing out of a hat”. Each form had a random chance of being chosen. Next, I tallied how many positive responses for post-
- 9. operative nausea and vomiting for each gender. The data collected for my statistical analysis project included qualitative variables since gender is a qualitative variable. I also calculated the data into percentages, meaning that the statistical methods used to perform inference had to be appropriate to population proportion, not µ. (Sullivan & Woodbury, 2015). RESULTS At face value, the results from my sample populations showed that women experience post-operative nausea and vomiting at a higher proportion than men. 16 out of 50 women reported nausea/vomiting after general anesthesia, which computes to 32%. Only 6 men out of 50 reported nausea/vomiting after general anesthesia, which computes to 12%. Statcrunch was used to construct the following graphical displays. A bar graph was used to show the comparison of positive responses of nausea/vomiting for each gender. Pie charts were also used as a visual to compare the percentages of post-operative nausea/vomiting for each gender.
- 10. STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 6 GRAPHICAL DISPLAYS – Pie Charts STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 7 GRAPHICAL DISPLAY - Bar Graph Positive Responses to Post-Operative N/V In order to apply the results from my sample to the entire population, inferential statistical analysis had to be done. Using statcrunch, I have determined a 95% confidence interval for each gender, and performed hypothesis testing to determine the
- 11. difference between two population proportions at the level of significance of alpha = 0.01. Requirements for constructing the inferential statistics of confidence levels and testing the hypothesis are as follows: 1. The samples were obtained using simple random sampling. 2. n1p1 (1-p1) ≥10 and n2p2 (1-p2) ≥10,sample and proportion 1 being women, sample and proportion 2 being men. Computations are as follows: women – 50(.32)(1-.32)=10.88 which is greater than 10 STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 8 men- 50(.12)(1-.12)=5.28 which is not greater than 10 3. n1≤0.05N1, meaning that the sample size of 50 women who had outpatient surgery with general anesthesia is less than the entire population of women who had outpatient surgery with general anesthesia. This proves the same for men using the same formula, n2≤0.05N2 (Sullivan & Woodbury, 2015).
- 12. Using statcrunch, the following confidence intervals were computed for each gender. 95% confidence interval results: N2, MEN p : Proportion of successes Method: Standard-Wald Proportion Count Total Sample Prop. Std. Err. L. Limit U. Limit p 6 50 0.12 0.045956501 0.029926913 0.21007309 95% confidence interval results: N1, WOMEN p : Proportion of successes Method: Standard-Wald Proportion Count Total Sample Prop. Std. Err. L. Limit U. Limit p 16 50 0.32 0.06596969 0.19070178 0.44929822 Hypothesis test results: Women p1 and Men p2 p1 : proportion of successes for population 1 p2 : proportion of successes for population 2 p1 - p2 : Difference in proportions H0 : p1 - p2 = 0 HA : p1 - p2 > 0 Difference Count1 Total1 Count2 Total2 Sample Diff. Std. Err. Z-Stat P-value p1 - p2 16 50 6 50 0.2 0.082849261 2.4140227 0.0079
- 13. This means that we are 95% confident that the population proportion of men who experience nausea and vomiting following outpatient surgery with general anesthesia falls between .03 and .21. Also, we are 95% confident that the population proportion of women who experience nausea and vomiting following outpatient surgery with general anesthesia falls STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 9 between .19 and .45. Since the P-value of 0.0079 is less than the level of significance at the alpha level of 0.01, the null hypothesis would be rejected. This means that there is sufficient evidence that the population proportion of women who have outpatient surgery with general anesthesia experience post-operative nausea and vomiting at a higher proportion than men (Sullivan & Woodbury, 2015). According to the results of this study, my hypothesis was correct. Minimal data was
- 14. obtained due to time constraints and to protect the confidentiality of the sample patients. As mentioned earlier, the men’s sample did not meet one of the requirements for the inferential statistical testing. Also, there are many lurking variables that could skew the results of this study. Examples of lurking variables could be the general health of the patient, any previous history of post-op nausea/vomiting, history of motion sickness, the experience of the nurse caring for the patient post-operatively, under reporting of post- operative nausea/vomiting during the follow-up phone call, and the anesthesia provider’s aggressiveness in prevention of post-operative nausea/vomiting-operative nausea and vomiting. There is much literature surrounding the benefits of decreasing post-operative nausea and vomiting, but less information on how to manage it. For this reason, future research should focus on patient characteristics such as age, gender, and comorbidities which could potentially provide guidance for management of post-operative nausea and vomiting (Deitrick et al., 2015). In the
- 15. future, it would be very beneficial to be able to collect and analyze data regarding age ranges affected by post-operative nausea and vomiting. STATISTICAL ANALYSIS PROJECT ON POST-OPERATIVE N/V 10 References Deitrick, C. L., Mick, D. J., Lauffer, V. L., Prostka, E., Nowak, D., & Ingersoll, G. (2015, February). A Comparison of Two Differing Doses of Promethazine for the Treatment of Postoperative Nausea and Vomiting. Journal of Perianesthesia Nursing, 30(1), 5-13. McLaughlin, M. (2010). Perianesthesia Nursing Standards and Practice Recommendations. New Jersey: American Society of Perianesthesia Nurses. Sites, D. S., Johnson, N. T., Miller, J. A., Torbush, P. H., Hardin, J. S., Knowles, S. S., Creech Tart, R. (2014, February). Controlled Breathing With or Without Peppermint
- 16. Aromatherapy for Postoperative Nausea and or/Vomiting Symptom Relief: A Randomized Controlled Trial. Journal of Perianesthesia Nursing, 29(1), 12-19. Sullivan, M., & Woodbury, G. (2015). Interactive Statistics: Informed Decisions Using Data. Boston, MA: Pearson. Running head: YOUR RUNNING HEAD 1 YOUR RUNNING HEAD 2 Title page as seen in APA format.
- 17. Certification of Authorship: I certify that I am the author of this paper and that any assistance I received in its preparation is fully acknowledged and disclosed in the paper. I have also cited any sources from which I used data, ideas, or words, either quoted directly or paraphrased. I also certify that this paper was prepared by me specifically for the purpose of this assignment. Your Signature: Abstract The abstract summarizes the problem, participants, hypotheses, methods used, results and conclusions using 150 – 250 words. Notice, this is not indented as a paragraph would be. (Insert a new page) The Title is Centered and Double Spaced in Upper and Lower Case Letters Introduction Notice how there’s not a double double space after the title. This is your introduction. The introduction states the topic and the main questions to be explored. The researchers supply background information by discussing past or related research on the topic. The researchers explain how their study will relate or add to past research on the topic. The researchers state their initial hypotheses. Methods Participants Explain who was in your experiment (sample). Materials What type of form or tool did you use to gather your data? (Surveys, if used should be included in an Appendix) Procedure Explain the process of the experiment. What did the subjects
- 18. have to do? The experiment is laid out step by step, with time transitions like “then” and “next.” Results What statistical methods did you use? This is where you would include graphical displays and statistical tests AND their interpretation. Example: Recurrent kidney stones were more than twice as likely among males as females, as illustrated in Figure 1. (pie graph) A 95% confidence interval of the recurrence rate in males was (.34,.56) versus (.17, .33) for females. It appears that…. A hypothesis test was performed to test the difference in the stone rates by gender, revealing that the difference was highly significant (p < 003)… Include your Statcrunch output for any confidence intervals or hypothesis tests in an appendix. Discussion What did your study show? Did this match your hypothesis? What were the drawbacks to your study? Were there any limitations to your study that would affect the reliability of the results. For example, was the sample size too small, not random, or in some other way not ideally representative of the population?. Was there any potential bias? Were there any other difficulties that limited the validity of the study. Were there possible lurking variables that affected the outcome? What do you suggest for future study? Insert a new page so your reference page ALWAYS starts on a new page just in case you add something to the body of the paper. References Once your cursor is here, go to the paragraph setting to set up your page as double spaced and hanging indent (located under ‘special’). Now you type your reference. The minute you hit Enter Your next reference will start at the left margin. Running head: YOUR RUNNING HEAD 1
- 19. Title page as seen in APA format. Certification of Authorship: I certify that I am the author of this paper and that any assistance I received in its preparation is fully acknowledged and disclosed in the paper. I have also cited any sources from which I used data, ideas, or words, either quoted directly or paraphrased. I also certify that this paper was prepared by me specifically for the purpose of this assignment. Your Signature: