Running Head: PAIN CONTRACTS 1. Pain Contracts in Post-Operative Joint Patients

Transcription

1 Running Head: PAIN CONTRACTS 1 Pain Contracts in Post-Operative Joint Patients

2 PAIN CONTRACTS 2 Pain Contracts in Post-Operative Joint Patients Problem Overview Introduction to the Problem Pain is a compound, subjective feeling which encompasses multiple domains. In fact, 77-98% of patients experience post-operative pain, with up to 50% reporting moderate pain (Lin, 2011; Wong, Lin, Lee, & Liu, 2012). Pain control directly correlates with functional status. If patients have uncontrolled pain, they are unable to fully participate in physical and/or occupational therapy. This results in a longer hospitalization and ultimately, a longer recovery period. Greater physical independence comes with early discharge and home rehabilitation, therefore proper pain control is necessary for the best patient outcomes (Murphy, et al., 2011). Although nutritional status, hemoglobin levels, pre-operative status, and other factors play a role in recovery, pain control is essential for functionality (Murphy, et al., 2011). By initiating pain contracts in the post-operative hip and knee total arthroplasty patients, healthcare providers can have a better understanding of individual pain goals and expectations in the postoperative period. As an easy, inexpensive intervention, pain contracts give patients a feeling of control in their care, as well as the ability to verbalize any concerns in regards to pain control. This would allow for increased control in the immediate post-surgical period. Review of the Literature Many studies have been conducted implementing non-pharmacological interventions in an effort to increase pain control in post-operative patients. It is understood the sympathetic nervous system (SNS) is involved in pain as evidenced by changes in blood pressure and pulse in response to painful stimuli (Editorial, 2011). However, much less information is available regarding the autonomic nervous system s (ANS) role in pain response. Studies have shown

3 PAIN CONTRACTS 3 stimulation of the vagus nerve is capable of reducing acute pressure pain but not thermal or mechanically induced pain (Editorial, 2011, p. 542). More research is needed to fully understand the role of the ANS in acute pain development and the span for analgesic treatment (Editorial, 2011). Pain is a multi-modal feeling; it is important to understand its physiological effect on the body before delving in to its subjective side. Payne, et al. (2010) looked at incorporating pain contracts or agreements in patients with chronic pain to reduce opioid abuse. Interestingly, the number of patients with chronic pain exceeds those with diabetes, heart disease, and cancer combined (Payne, et al., 2010, p. 5). Unfortunately, it is difficult to determine how many of these patients with chronic pain abuse the use of opioid therapy for pain relief. In this study, the pain contracts were used for the provider to explain his/her expectations of the patient and the conditions in which the provider will prescribe opioid medication (Payne, et al., 2010). A positive outcome could not be reached in this particular instance as many believed the initiation of a pain contract/agreement in this study was discriminatory and resulted in a lack of trust between patient and provider. However, in the present study, pain contracts were used to incorporate the patient into the care plan in an effort to allow healthcare providers to fully understand expectations and goals in regards to pain management as verbalized by the patient. Murphy, et al. (2011) studied the effects of dispensing information booklets to hip fracture patients in the early post-operative period to improve early mobilization. Similar to initiating a pain contract, educating patients via an information booklet allows them to become more involved in their care and rehabilitative care. This study contained a control group which received usual care and two experimental groups. One group received an information booklet that contained basic post-operative information, while the other group s booklet contained more

4 PAIN CONTRACTS 4 detailed, comprehensive information (Murphy, et al., 2011). The researcher s theory proposes the earlier functional status is regained, the more economically friendly the hospitalization expenditure is, and the rate of re-hospitalization decreases (Murphy, et al., 2011). Although the improvements in mobility status changed, they did not reach statistical significance. However, it should be noted that the experimental group who received a booklet containing basic information had the greatest improvements (Murphy, et al., 2011). The ability of energy, via thermal therapy, to increase patient s pain thresholds in postoperative total knee arthroplasty patients was studied (Wong, et al., 2012). A sample size of 41, with 21 in the control group and 20 in the thermal therapy experimental group found no statistical significance between the groups in pain measurement (Wong, et al., 2012). Although, the results were not statistically significant, decreases in pain measurement were present. Music therapy is one of many non-pharmacological interventions that have been implemented in post-operative patients with pain in an effort to reduce the overall pain experience. Research has shown that music causes a decrease in heart and respiratory rates, enhances relaxation, and reduces anxiety while improving mood (Vaajoki, Pietila, Kankkunen, & Vehvilainen-Julkunen, 2011). However, no statistical significance was found overall in pain intensity between the experimental and control groups at any of the studied post-operative dates in 168 subjects (Vaajoki, et al., 2011). Lin (2011) looked at the effects of relaxation therapy for patients undergoing joint replacement surgery. Because surgery is a stressful event for most patients, anxiety is a preoperative and post-operative concern for those deals with the patient s care. If the patient is overly anxious, then a decline in overall health status can occur prolonging the recovery period (Lin, 2011). In this study, patients listened to a 10-minute audio tape via headphones twice a day,

5 PAIN CONTRACTS 5 at the same time each day, for three post-operative days. There were 93 total participants with 45 in the experimental group and 48 in the control group. The difference in severity of pain was found to not be of statistical significance. However, via the ANOVA test, differences in systolic blood pressure between the two groups was statistically significant (Lin, 2011). Although not all results found statistical significance, pain was reduced in the patients who underwent relaxation therapy. Non-pharmacological pain management can reduce the emotional effect of pain, enhance adjustment and make patients believe they can control their pain, thus reducing pain and promoting sleep (Lin, 2011, p. 601). While many of the above non-pharmacological studies did not find statistically significant evidence, all of them found some decrease in pain in the experimental groups. Furthermore, in the present study, the pain contract is used as a method to understand patient s conceived idea of pain, along with what they consider manageable. The pain contract is used as a simple, non-pharmacological measure to guide the healthcare providers and aide in the proper interventions for pain control in the post-operative period. Research Question Does the implementation of a pain contract in total hip and knee arthroplasty patients increase pain control in the post-operative period? Methodology Target Population Participants in this study were from the orthopedic unit of St. Alexius Medical Center in Hoffman Estates, Illinois. A census of 195 patients were included in the study. Inclusion criteria consisted of being scheduled for a total joint arthroplasty, having surgery between May 2012 and October 2012, and the ability to understand and verbalize pain according to the visual analog

6 PAIN CONTRACTS 6 scale (VAS) with faces. In most cases, a pain contract was initiated with those who attended the pre-operative joint class. This allowed for random assignment to the control group (n=80) and the experimental group (n=115), since patients had the option to attend the class or not. Patients with a history of a previous total joint replacement surgery were excluded from the pre-operative class, and were assigned to the control group. Sampling Method A census was used for this study as the overall population was quite small. In an effort to avoid false results, the census was used to compensate for any cases that fell out. This means that not all hip and knee total arthroplasty patients were included in the data set as not all patients had completed audits at the four pain-audit check points in the post-operative period. At n=195, power should easily reach the acceptable level at.80 because n>30. This means there is an 80% probability of achieving statistically significant results. Furthermore, for all tests run in this study, α=0.05 was used for the error rate. This number was further derived using Bonferroni s correction. Bonferroni s correction adjusts the p-value (α=0.05) when multiple statistical tests are being run on the same data set (David Walker, personal communication, April 15, 2013). Therefore, because five chi-square tests were run to answer the hypothesis, the p-value was changed to α=0.01. The dependent variable (DV) is pain control in the post-operative period while the independent variable (IV) is the pain contract. The patient s subjective assessment of pain on the VAS scale is a potential intervening variable. For the sake of this study, it is assumed pain is a subjective feeling to each individual patient and each patient correctly verbalized his/her pain at the requested time.

7 PAIN CONTRACTS 7 Data Collection Data was collected over a six-month span (May 2012-October 2012) on all total hip and knee arthroplasty patients. Recorded data included: attendance at the pre-operative class, pain contract initiation, the pain audit, and functional status (ability to ambulate 100 feet by discharge). A pain audit was completed on each of these patients upon arrival to the unit, six hours post-arrival to the unit, 24-hours post-arrival to the unit, and at the time of discharge. For this study, pain control is defined as verbalizing pain as tolerable at all four checkpoints. Tolerable pain is defined as pain rated at or below the numerical pain goal per the patient. The pain goal in the control group was initiated upon arrival to the floor from recovery. The experimental group set pain goals at the pre-operative class when filling out the pain contracts. All variables in the study are nominal level data. Since pain is a subjective experience, the use of nominal level data inhibited formulation of any grey areas. After reviewing all pain audits, if pain was controlled at the specified time, then yes was recorded. If pain was not controlled, then no was recorded. This also helped control any variables that could have intervened with the study and cause extraneous results. Likewise, a pain contract was utilized or it was not. It is noted that some patients are excluded from the pre-operative class (annotated as 3 ) because they have had a previous total joint replacement surgery. However, these patients still had the option of attending the class. Furthermore, any missing data was recorded as discrete missing data, annotated as 999. Statistical Methods Once coded, data were analyzed via the Statistical Package for Social Sciences (SPSS) version 19.0 for Windows. As stated previously, an α of 0.01 after Bonferroni s correction adjustment was used for all statistical tests.

8 PAIN CONTRACTS 8 A chi-square test of independence was used to determine if there is an association between pain contracts and post-operative pain in total hip and knee replacement patients. The following assumptions are used in a chi-square test of independence: 1. At least 75% of the cells have expected frequencies 5 in any sized table. All cells in all tables have expected frequencies 1 (David Walker, personal communication, April 8, 2013). 2. In a 2x2 table only, if <75% of the cells have expected frequencies <5, the Yates Continuity Correction is used. If only 1 out of the 4 cells has a count <5, the χ 2 is statistically significant and Yates is not, use the chi-square due to the conservative natures of Yates (David Walker, personal communication, April 8, 2013). 3. If an observed count equals 0 or an expected frequency is <1 in a cell in a 2x2 table only, an alternative χ 2 is used, call Fisher s Exact Test (David Walker, personal communication, April 8, 2013). Descriptive statistics including skewness, kurtosis, and standard deviation were not measured to ensure normality of the data as they would be irrelevant due to the data s nominal level nature. Barcharts were analyzed to depict the data pictorially. A 2x2 contingency table was used five times to answer the research question by running the chi-square test for independence. Standard residuals were run to indicate any influential cells that may have driven statistical significant results more than others. A standard residual finding >2 (positive or negative) defines a specific cell contributing more to statistical significant results than other cells (David Walker, personal communication, April 8, 2013).

9 PAIN CONTRACTS 9 The null hypothesis for the research question is that there is not an association between pain contracts and post-operative pain. The alternative hypothesis is that there is an association between pain contracts and post-operative pain. Hₒ: χ 2 =0 χ 2 = (O-E) 2 /E H 1 : χ 2 0 df= (rows-1)(columns-1) Analysis Results Five chi-square tests of independence were conducted to answer the proposed research question: Does the implementation of a pain contract in total hip and knee arthroplasty patients increase pain control in the post-operative period? The results from the chi-square tests are depicted and explained below. Figure 1 The first chi-square test (Figure 1) looked at pain upon arrival to the orthopedic floor from the recovery room following surgery. The first assumption was met, since greater than 75%

10 PAIN CONTRACTS 10 of the cells had expected frequencies 5 and all cells in the table had expected frequencies 1. Therefore, the chi-square test for independence was run. Statistical significance was not found as the p-value = 0.112, which is not greater than α=0.01. After looking at the chi-square distribution table, the critical value is 6.63 at the 0.01 level with 1 degree of freedom (Gravetter & Wallnau, 2011). Therefore, the sample value is not beyond the critical value 6.63 and we fail to reject the Hₒ that there is not an association between pain contracts and post-operative pain control. The standardized residuals are not > 2 in any of the cells, which means there are no particular cells that drove the findings more than others. Figure 2 The second chi-square test (Figure 2) looked at pain six hours post-arrival to the floor from recovery. The first assumption was again met as greater than 75% of the cells had expected frequencies 5 and all cells in the table had expected frequencies 1. Therefore, the chi-square test for independence was ran as the other assumptions were not met to run a different chi-square test. Statistical significance was not found as the p-value = 0.196, which is not greater than

11 PAIN CONTRACTS 11 α=0.01. The critical value remains 6.63 at the 0.01 level with 1 degree of freedom. Therefore, the sample value is not beyond the critical value 6.63 and we fail to reject the Hₒ that there is not an association between pain contracts and post-operative pain control. The standardized residuals are not > 2 in any of the cells, which means no particular cells influenced the findings more than others. Figure 3 An alternative test, called Yates Continuity Correction was conducted for the third test (Figure 3). This is because the second assumption was met. That is, less than 75% of the cells have expected frequencies <5. More than 1 of the 4 cells have expected frequencies <5, so the second part of the assumption does not pertain to the data in this instance. Statistical significance was not found as p=0.623, which is not greater than α=0.01. The sample value=0.242 is not greater than the critical value =6.63, and therefore we fail to reject the Hₒ that there is not an association between pain contracts and post-operative pain control. Similar to the previous two

12 PAIN CONTRACTS 12 tests, none of the standardized residuals are >2. Thus, there are no particular cell drivers in this instance either. Figure 4 The fourth test (Figure 4) required running Fisher s Exact Test after looking at the assumptions. Two cells contained expected counts <1 and the table is 2x2, thus the alternative χ 2 test, Fisher s Exact Test, was used. The other assumptions did not apply to this situation. The p- value =0.410, which is not greater than α=0.01. Therefore, we did not find statistical significance and fail to reject the Hₒ that there is not an association between pain contracts and post-operative pain control. Like the above four tests, none of the standardized residuals were >2 so, neither of the cells were more influential than the others.

13 PAIN CONTRACTS 13 Figure 5 The final chi-square test (Figure 5) looked at pain control upon overall from arrival to the floor after surgery to the time of discharge. The first assumption was met as greater than 75% of the cells had expected frequencies 5 and all cells in the table had expected frequencies 1. The other two assumptions did not apply to the data in this set. Therefore, the chi-square test for independence was utilized. Statistical significance was not found as the p-value = 0.035, which is not greater than α=0.01.the sample value is not beyond the critical value 6.63 and we fail to reject the Hₒ that there is not an association between pain contracts and post-operative pain control. The standardized residuals are not > 2 in any of the cells, which delineates that none of the cells contribute to the results more than the others. None of the tests conducted reached statistical significance; therefore effect size was not calculated.

14 PAIN CONTRACTS 14 Limitations A limitation to this study is that it requires pain to be an objective finding when it is a subjective experience. Therefore, it was assumed that nurses could correctly assess the patient s ability to adequately verbalize their pain when asked and relate it to their overall pain goal. If members of the healthcare team correctly noted each patient s pain goal and recorded their specific pain level at the assessed times, there should be little room for error to occur. Nominal level data, either yes or no answers, were used to help reduce the risk of variance in this instance. There was also a difference in sample size between the control and experimental groups. The experimental group was larger (n=115) than the control group (n=80), which allowed the experimental group a greater opportunity to show a statistically significant difference from the control group in regards to overall pain control in the post-operative period. Since the chi-square test for independence was run five times, the Type I error rate may have inflated. Bonferroni s correction adjusted the overall p-value to decrease the instance of increased Type I error. The chi-square test of independence does not show directionality, magnitude, or causality of an association. This can be seen as a limitation at it cannot give any detail in regards to an association between and independent and dependent variable. Discussion, Conclusions, and Recommendations Although statistical significance was not found in any of the chi-square tests for independence, interesting and applicable information was produced. For instance, a post-hoc point of interest was found. If the chi-square test for independence was only ran one time looking at pain control overall in the post-operative period, α=0.05, and statistical significance would be present. It is also interesting to look at each barchart depicted above in the results section. Pain is

15 PAIN CONTRACTS 15 controlled much more often than not judging by the substantially larger amount of green shown in the barcharts. Regardless of whether a pain contract is in place, pain is still controlled much more often than it is not. It is interesting to note that 29% of patients without a pain contract could not answer that their pain was controlled throughout the entire post-operative period at the four checkpoints. Only 13% of patients with a pain contract in place did not have pain control at each of the four pain audit times. This is a 16% difference, which is not statistically significant, but should still be noted. There are several clinical implications found from these findings. Overall, St. Alexius Medical Center does well with pain control in the post-operative period for total hip and knee arthroplasty patients. It would be beneficial to study the same data in surrounding area hospitals, taking a sample from a larger population to run the chi-square test again. Perhaps, statistical significance would be found. A longer research period may provide different results as well. Moreover, pain control is an important variable to control in post-operative patients. Lack of pain control decreases patient satisfaction, which decreases overall hospital scores and affects reimbursement. Although the results were not found to be statistically significant, a substantial increase (16%) in pain control was found with the use of a pain contract. This allows room for improvement and might dictate a non-pharmacological measure that is worth investigating. Implementation of pain contracts has shown some improvement in post-operative pain control. More research needs to be conducted regarding their overall effect on post-operative pain control.

16 PAIN CONTRACTS 16 References Editorial. (2011). The role of the autonomic nervous system in acute surgical pain processing what do we know? Anaesthesia, 66, Gravetter, F., & Wallnau, L. (2011). Essentials of statistics for the behavioral sciences(7 th ed.). Belmont, CA: Thompson Wadsworth. Lin, P. (2011). An evaluation of the effectiveness of relaxation therapy for patients receiving joint replacement surgery. Journal of Clinical Nursing, 21, doi: /j x Murphy, S., Conway, C., McGrath, N., O Leary, B., O Sullivan, M., & O Sullivan, D. (2011). An intervention study exploring the effects of providing older adult hip fracture patients with an information booklet in the early postoperative period. Journal of Clinical Nursing, 20, doi: /j x Payne, R., Anderson, E., Arnold, R., Duensing, L., Gilson, A., Green, C., Haywood Jr., C., Passik, S., Rich, B., Robin, L., Shuler, N., & Christopher, M. (2010). A rose by another name: pain contracts/agreements. The American Journal of Bioethics, 10(11), doi: / Vaajoki, A., Pietila, A., Kankkunen, P., & Vehvilainen-Julkunen, K. (2011). Effects of listening to music on pain intensity and pain distress after surgery: an intervention. Journal of Clinical Nursing, 21, doi: /j x Wong, C., Lin, L., Lee, H., & Liu, C. (2012). The analgesic effect of thermal therapy after total knee arthroplasty. The Journal of Alternative and Complementary Medicine, 18(2), doi: /acm