631680 research-article2016
CNU0010.1177/1474515116631680European Journal of Cardiovascular NursingBjørnnes et al.
EUROPEAN SOCIETY OF CARDIOLOGY ®
Original Article
The impact of an educational pain management booklet intervention on postoperative pain control after cardiac surgery
European Journal of Cardiovascular Nursing 1–10 © The European Society of Cardiology 2016 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1474515116631680 cnu.sagepub.com
Ann Kristin Bjørnnes1, Monica Parry2, Irene Lie3, Morten Wang Fagerland4, Judy Watt-Watson2, Tone Rustøen5, Audun Stubhaug6 and Marit Leegaard7
Abstract Background: Relevant discharge information about the use of analgesic medication and other strategies may help patients to manage their pain more effectively and prevent postoperative persistent pain. Aims: To examine patients’ pain characteristics, analgesic intake and the impact of an educational pain management booklet intervention on postoperative pain control after cardiac surgery. Concerns about pain and pain medication prior to surgery will also be described. Methods: From March 2012 to September 2013, 416 participants (23% women) were consecutively enrolled in a randomized controlled trial. The intervention group received usual care plus an educational booklet at discharge with supportive telephone follow-up on postoperative day 10, and the control group received only usual care. The primary outcome was worst pain intensity (The Brief Pain Inventory – Short Form). Data about pain characteristics and analgesic use were collected at 2 weeks and at 1, 3, 6 and 12 months post-surgery. General linear mixed models were used to determine between-group differences over time. Results: Twenty-nine percent of participants reported surgically related pain at rest and 9% reported moderate to severe pain at 12 months post-surgery. Many participants had concerns about pain and pain medication, and analgesic intake was insufficient post-discharge. No statistically significant differences between the groups were observed in terms of the outcome measures following surgery. Conclusion: Postoperative pain and inadequate analgesic use were problems for many participants regardless of group allocation, and the current intervention did not reduce worst pain intensity compared with control. Further examination of supportive follow-up monitoring and/or self-management strategies post-discharge is required. Keywords Cardiac surgery, postoperative pain, pain management education, analgesic intake, randomized controlled trial
1D epartment
of Research and Development, Division of Emergencies and Critical Care, Oslo University Hospital, Norway and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway 2Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Canada 3Department of Cardiothoracic Surgery, Oslo University Hospital, Ullevål/Center for Patient Centered Heart and Lung Research, Department of Cardiothoracic Surgery, Division of Cardiovascular and Pulmonary Diseases, Oslo University Hospital, Norway 4Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Norway
5Department
of Research and Development, Division of Emergencies and Critical Care, Oslo University Hospital and Institute of Health and society, Department of Nursing Science, University of Oslo, Norway 6Department of Pain Management and Research, Oslo University Hospital and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway 7Oslo and Akershus University College of Applied Sciences, Faculty of Health Sciences, Institute of Nursing, Norway Corresponding author: Ann Kristin Bjørnnes, Oslo University Hospital, Ullevål, P.O. Box 4956 Nydalen, 0424 Oslo, Norway. Email: [email protected]
Downloaded from cnu.sagepub.com at CHINESE UNIV HONG KONG LIB on February 22, 2016
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European Journal of Cardiovascular Nursing
Introduction In 2014, over 3500 cardiac surgeries were performed in Norway,1 and persistent postoperative pain was identified as an important health care issue after discharge.2 Uncontrolled acute postoperative pain continues to be the most frequently reported problem following cardiac surgery3 and is consistently found to be a predictor of both the presence and/or severity of persistent postoperative pain.4–6 The prevalence has ranged from 10% to 60% at 12 months after surgery,2,4,5 and in a more recent Canadian study (n = 1247), 10% of patients continued to report persistent non-anginal postoperative pain at 2 years following cardiac surgery.6 Early discharge leaves little time for patients to learn strategies for effective pain management, and an increasing number of cardiac surgical patients are recovering at home without the supervision of a health care provider after cardiac surgery.7,8 Relevant discharge information about pain relief and the use of analgesic medication may assist patients to manage their pain after hospital discharge.7,9 Although patients may be prescribed adequate doses of analgesics, their concerns and beliefs about analgesia and related adverse effects may prevent them from taking them and having adequate pain management.10 Rashid et al.11 found that patients who were afraid of longterm harm and addiction took as little analgesic as possible and did not adhere to recommended analgesic regimes. Rather than using analgesics, patients preferred to limit their activity in order to manage their postoperative pain.12 Although health care providers have an obligation to educate patients and prescribe sufficient medication for acute pain, they also may hold similar concerns about pain and pain medication, which can contribute to inadequate pain management for patients.13 Written information set in the context of the particular illness is reported to help patients to make decisions about whether to take analgesia for their pain.14 Increased knowledge of analgesic effects improves adherence to analgesic therapy,15 and adherence to prescribed medication reduces pain.16 A variety of educational interventions for different outcome measures including pain relief after cardiac surgery have been tested,17 but the effectiveness of these interventions is uncertain due to the large heterogeneity in methods and design. Two more recent Cochrane reviews3,18 suggested that interventions that provide written educational information as a single component may be ineffective for improving adherence or enhancing clinical outcomes. When used in combination with other interventions, such as self-management skills training or counseling, there is some evidence to suggest improved knowledge and adherence to prescribed analgesic regimes.3,18,19 In a review of technology-assisted self-management interventions for persistent pain,20 12 studies used telephone follow-up as an
adjunct to written self-help materials, and five studies (n = 2539) demonstrated significant improvement in one or more pain-relevant variables. Even when the telephone call was short, reduction in pain intensity was demonstrated. Veronovici et al.21 also reported standardized education self-help materials (i.e. booklets and videos) improved selfmanagement post-cardiac surgery discharge if used in combination with face-to-face or telephone follow-up. Two previous, independent Norwegian studies – one qualitative study22 (n = 10) and one mixed-method study8 (n = 185) – demonstrated the need for improvement and greater standardization of discharge information regarding pain management after cardiac surgery. In both studies, participants expressed a substantial amount of uncertainty regarding prescribed medications and had insufficient information at discharge. The purpose of this study was to examine patients’ pain characteristics, analgesic intake and the impact of an educational pain management booklet intervention on postoperative pain control after cardiac surgery. We hypothesized that participants who received an intervention pain management booklet plus one follow-up supportive phone call would have less worst pain intensity (primary outcome) and related interference with daily activities (secondary outcomes) compared with a control group following hospital discharge from cardiac surgery. Participants’ concerns about pain and pain medication prior to surgery were also examined.
Methods A randomized controlled trial (RCT) was used to evaluate the effects of a standardized pain management booklet and a 10-day follow-up telephone call intervention on worst pain intensity after cardiac surgery (ClinicalTrials.gov: NCT01976403). The Regional Committee for Medical and Health Research Ethics, Health Region South-East, Norway, approved the study prior to participant recruitment. All participants provided written informed consent to participate and the study conforms with the principles as outlined in the Declaration of Helsinki.23 Patients >18 years of age, able to read and write Norwegian and scheduled for elective coronary artery bypass surgery (CABG) and/or valve surgery were consecutively invited to participate in the study from March 2012 through to September 2013. Participants were excluded if they spent more than 12 hours in the intensive care unit, were not anticipated to be home to receive the follow-up telephone call at 10 days following cardiac surgery or were predicted to be unable to care for themselves after hospital discharge. Recruitment was conducted in two separate cardiothoracic surgical units at a regional hospital in Oslo, Norway. Combined, these units offer services to 55% of the total Norwegian population. Length of stay at the regional
Downloaded from cnu.sagepub.com at CHINESE UNIV HONG KONG LIB on February 22, 2016
3
Bjørnnes et al. hospital was usually 3–4 days, and when stable, patients were transferred to a local community hospital for an additional 1–3 days prior to discharge home. Total length of hospital stay (regional and local community) was 5–7 days. When the surgical date was confirmed, eligible participants received written information about the study with standard preoperative information about the routines related to the surgical procedure (i.e. mobilization and the importance of communicating pain) from the cardiac surgery waitlist managers. When admitted for surgery, all eligible patients met with a designated study nurse in order to receive more information about the study and to ask questions. Interested patients signed the consent form and completed baseline questionnaires. Participants were then randomly assigned by the study nurse to either the control or intervention group using the Medinsight computerized randomization service that was developed and administrated by Oslo University Hospital at the Institute for Cancer Genetics and Informatics. Randomization was stratified by unit, and all participants and nurses (except the research team) were blinded to group assignment until after discharge from the hospital. All participants received a sealed envelope containing a prepaid, addressed return envelope and a questionnaire to be completed at 2 weeks after surgery and discharge from the regional hospital. All participants were instructed to open the sealed envelope after their discharge to home from their local community hospital. At postoperative day 10, all participants were contacted by telephone by a designated member of the research team in order to answer general questions regarding the study and to ensure that they had received and opened the sealed envelope. Further prepaid, addressed return envelopes and questionnaires were mailed to all participants prior to the data collection points at 1, 3, 6 and 12 months after surgery.
Control group The control group received standard discharge care, which included a 10-minute talk with the nurse/doctor on the day of discharge from the regional hospital that included general information about the physical recovery after surgery. Patients were invited to ask questions and encouraged to continue with paracetamol as a treatment for pain following discharge. At postoperative day 10, patients in the control group also received a brief phone call to ensure adherence.
Intervention group Participants in the intervention group received standard discharge care as described for the control group, plus a pain management education intervention, with the latter consisting of: 1) a booklet entitled Pain Relief After Your Surgery, originally developed by Watt-Watson et al.24,25;
and 2) a discussion about the content of the booklet during the supportive follow-up telephone call at 10 days after cardiac surgery. The booklet was translated from English and modified for use in Norway in collaboration with the author of the original version. Current clinical practice guidelines and results from focus group interviews with Norwegian nurses regarding pain management in patients undergoing cardiac surgery26 were incorporated into the Norwegian version of the booklet. The booklet emphasized four key concepts of effective pain management: 1) the importance of good pain relief following cardiac surgery; 2) how and when to ask for help with pain management following discharge; 3) pain relief methods, including pharmacological and non-pharmacological approaches; and 4) common concerns preventing patients seeking help with pain and/or taking analgesics. The booklet was written to be understood by the general public. Participants were blinded to group assignment until they opened the sealed envelope given at discharge. Although the booklet was not discussed at discharge, participants were given an opportunity to ask questions about the content of the booklet during the follow-up telephone call made by a designated member of the research team. All participants who expressed problems related to managing their pain were encouraged to contact their physician.
Measures At baseline, several exploratory outcomes were assessed. Information about age, sex, marital status, education level and income was collected using a demographic questionnaire. Additional data about number of comorbidities were collected via the Self-Administered Comorbidity Questionnaire (SCQ-16).27 The SCQ-16 included 15 common comorbidities and one optional condition, with the total number of comorbidities ranging from 0 to 16. Respondents indicated (yes/no) whether they had the comorbid condition. The SCQ-16 has a test–retest reliability of 0.94,27 and De-loyde et al.28 have recently demonstrated high concordance between patient self-report of comorbidities and medical record review.
Primary outcome The primary outcome for this trial was worst pain intensity at rest in the previous 24 hours measured using an 11-point numerical rating scale (NRS) grading from 0 (no pain) to 10 (the worst pain imaginable) using the Brief Pain Inventory – Short Form (BPI-SF) questionnaire.29 Both the reliability and internal validity of the BPI-SF have been demonstrated previously,30 and in the Norwegian validation study among cardiac surgery patients, the results indicated good internal consistency, with Cronbach’s alpha coefficients of between 0.84 and 0.94.31
Downloaded from cnu.sagepub.com at CHINESE UNIV HONG KONG LIB on February 22, 2016
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European Journal of Cardiovascular Nursing
Secondary outcomes Secondary outcomes included pain-related interference with activities (BPI – Interference [BPI-I] subscales),31 patients’ concerns about pain and pain medication (Barriers Questionnaire [BQ])32,33 and self-report of pharmacological management in the previous week. The BPI-I included seven interference subscales with 11-point NRSs (0 = no interference, 10 = interferes completely) in order to rate pain-related interference in everyday activities (i.e. general activity, mood, walking ability, work, relationships with other people, sleep and enjoyment of life). Validated in a Norwegian sample,34 the BQ included seven items, each having a six-point rating from 0 (completely disagree) to 5 (completely agree). Scores ranged from 0 to 35, and higher scores indicated more concerns about pain and pain medication.33 Additional exploratory data included assessing pain location on a body outline diagram and one NRS for the degree of pain relief from pain treatments or medications in the previous 24 hours using the BPI-SF (0 = no relief, 100 = complete relief). Participants completed the items from the BPI-SF and self-reported their analgesic intake at 2 weeks and at 1, 3, 6 and 12 months after surgery. At baseline, participants were asked about the presence and location of pain in the week prior to surgery.
Sample size Approximately 1000 patients undergo cardiac surgery (CABG, valve surgery or both) at the regional hospital each year.1 Sample size calculation was based on previous studies24,25 with the original booklet, where an effect size of 0.2 was considered to be clinically significant. A sample size of 208 per group would achieve 80% power to detect an effect size of 0.2 at the p
CNU0010.1177/1474515116631680European Journal of Cardiovascular NursingBjørnnes et al.
EUROPEAN SOCIETY OF CARDIOLOGY ®
Original Article
The impact of an educational pain management booklet intervention on postoperative pain control after cardiac surgery
European Journal of Cardiovascular Nursing 1–10 © The European Society of Cardiology 2016 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1474515116631680 cnu.sagepub.com
Ann Kristin Bjørnnes1, Monica Parry2, Irene Lie3, Morten Wang Fagerland4, Judy Watt-Watson2, Tone Rustøen5, Audun Stubhaug6 and Marit Leegaard7
Abstract Background: Relevant discharge information about the use of analgesic medication and other strategies may help patients to manage their pain more effectively and prevent postoperative persistent pain. Aims: To examine patients’ pain characteristics, analgesic intake and the impact of an educational pain management booklet intervention on postoperative pain control after cardiac surgery. Concerns about pain and pain medication prior to surgery will also be described. Methods: From March 2012 to September 2013, 416 participants (23% women) were consecutively enrolled in a randomized controlled trial. The intervention group received usual care plus an educational booklet at discharge with supportive telephone follow-up on postoperative day 10, and the control group received only usual care. The primary outcome was worst pain intensity (The Brief Pain Inventory – Short Form). Data about pain characteristics and analgesic use were collected at 2 weeks and at 1, 3, 6 and 12 months post-surgery. General linear mixed models were used to determine between-group differences over time. Results: Twenty-nine percent of participants reported surgically related pain at rest and 9% reported moderate to severe pain at 12 months post-surgery. Many participants had concerns about pain and pain medication, and analgesic intake was insufficient post-discharge. No statistically significant differences between the groups were observed in terms of the outcome measures following surgery. Conclusion: Postoperative pain and inadequate analgesic use were problems for many participants regardless of group allocation, and the current intervention did not reduce worst pain intensity compared with control. Further examination of supportive follow-up monitoring and/or self-management strategies post-discharge is required. Keywords Cardiac surgery, postoperative pain, pain management education, analgesic intake, randomized controlled trial
1D epartment
of Research and Development, Division of Emergencies and Critical Care, Oslo University Hospital, Norway and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway 2Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Canada 3Department of Cardiothoracic Surgery, Oslo University Hospital, Ullevål/Center for Patient Centered Heart and Lung Research, Department of Cardiothoracic Surgery, Division of Cardiovascular and Pulmonary Diseases, Oslo University Hospital, Norway 4Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Norway
5Department
of Research and Development, Division of Emergencies and Critical Care, Oslo University Hospital and Institute of Health and society, Department of Nursing Science, University of Oslo, Norway 6Department of Pain Management and Research, Oslo University Hospital and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway 7Oslo and Akershus University College of Applied Sciences, Faculty of Health Sciences, Institute of Nursing, Norway Corresponding author: Ann Kristin Bjørnnes, Oslo University Hospital, Ullevål, P.O. Box 4956 Nydalen, 0424 Oslo, Norway. Email: [email protected]
Downloaded from cnu.sagepub.com at CHINESE UNIV HONG KONG LIB on February 22, 2016
2
European Journal of Cardiovascular Nursing
Introduction In 2014, over 3500 cardiac surgeries were performed in Norway,1 and persistent postoperative pain was identified as an important health care issue after discharge.2 Uncontrolled acute postoperative pain continues to be the most frequently reported problem following cardiac surgery3 and is consistently found to be a predictor of both the presence and/or severity of persistent postoperative pain.4–6 The prevalence has ranged from 10% to 60% at 12 months after surgery,2,4,5 and in a more recent Canadian study (n = 1247), 10% of patients continued to report persistent non-anginal postoperative pain at 2 years following cardiac surgery.6 Early discharge leaves little time for patients to learn strategies for effective pain management, and an increasing number of cardiac surgical patients are recovering at home without the supervision of a health care provider after cardiac surgery.7,8 Relevant discharge information about pain relief and the use of analgesic medication may assist patients to manage their pain after hospital discharge.7,9 Although patients may be prescribed adequate doses of analgesics, their concerns and beliefs about analgesia and related adverse effects may prevent them from taking them and having adequate pain management.10 Rashid et al.11 found that patients who were afraid of longterm harm and addiction took as little analgesic as possible and did not adhere to recommended analgesic regimes. Rather than using analgesics, patients preferred to limit their activity in order to manage their postoperative pain.12 Although health care providers have an obligation to educate patients and prescribe sufficient medication for acute pain, they also may hold similar concerns about pain and pain medication, which can contribute to inadequate pain management for patients.13 Written information set in the context of the particular illness is reported to help patients to make decisions about whether to take analgesia for their pain.14 Increased knowledge of analgesic effects improves adherence to analgesic therapy,15 and adherence to prescribed medication reduces pain.16 A variety of educational interventions for different outcome measures including pain relief after cardiac surgery have been tested,17 but the effectiveness of these interventions is uncertain due to the large heterogeneity in methods and design. Two more recent Cochrane reviews3,18 suggested that interventions that provide written educational information as a single component may be ineffective for improving adherence or enhancing clinical outcomes. When used in combination with other interventions, such as self-management skills training or counseling, there is some evidence to suggest improved knowledge and adherence to prescribed analgesic regimes.3,18,19 In a review of technology-assisted self-management interventions for persistent pain,20 12 studies used telephone follow-up as an
adjunct to written self-help materials, and five studies (n = 2539) demonstrated significant improvement in one or more pain-relevant variables. Even when the telephone call was short, reduction in pain intensity was demonstrated. Veronovici et al.21 also reported standardized education self-help materials (i.e. booklets and videos) improved selfmanagement post-cardiac surgery discharge if used in combination with face-to-face or telephone follow-up. Two previous, independent Norwegian studies – one qualitative study22 (n = 10) and one mixed-method study8 (n = 185) – demonstrated the need for improvement and greater standardization of discharge information regarding pain management after cardiac surgery. In both studies, participants expressed a substantial amount of uncertainty regarding prescribed medications and had insufficient information at discharge. The purpose of this study was to examine patients’ pain characteristics, analgesic intake and the impact of an educational pain management booklet intervention on postoperative pain control after cardiac surgery. We hypothesized that participants who received an intervention pain management booklet plus one follow-up supportive phone call would have less worst pain intensity (primary outcome) and related interference with daily activities (secondary outcomes) compared with a control group following hospital discharge from cardiac surgery. Participants’ concerns about pain and pain medication prior to surgery were also examined.
Methods A randomized controlled trial (RCT) was used to evaluate the effects of a standardized pain management booklet and a 10-day follow-up telephone call intervention on worst pain intensity after cardiac surgery (ClinicalTrials.gov: NCT01976403). The Regional Committee for Medical and Health Research Ethics, Health Region South-East, Norway, approved the study prior to participant recruitment. All participants provided written informed consent to participate and the study conforms with the principles as outlined in the Declaration of Helsinki.23 Patients >18 years of age, able to read and write Norwegian and scheduled for elective coronary artery bypass surgery (CABG) and/or valve surgery were consecutively invited to participate in the study from March 2012 through to September 2013. Participants were excluded if they spent more than 12 hours in the intensive care unit, were not anticipated to be home to receive the follow-up telephone call at 10 days following cardiac surgery or were predicted to be unable to care for themselves after hospital discharge. Recruitment was conducted in two separate cardiothoracic surgical units at a regional hospital in Oslo, Norway. Combined, these units offer services to 55% of the total Norwegian population. Length of stay at the regional
Downloaded from cnu.sagepub.com at CHINESE UNIV HONG KONG LIB on February 22, 2016
3
Bjørnnes et al. hospital was usually 3–4 days, and when stable, patients were transferred to a local community hospital for an additional 1–3 days prior to discharge home. Total length of hospital stay (regional and local community) was 5–7 days. When the surgical date was confirmed, eligible participants received written information about the study with standard preoperative information about the routines related to the surgical procedure (i.e. mobilization and the importance of communicating pain) from the cardiac surgery waitlist managers. When admitted for surgery, all eligible patients met with a designated study nurse in order to receive more information about the study and to ask questions. Interested patients signed the consent form and completed baseline questionnaires. Participants were then randomly assigned by the study nurse to either the control or intervention group using the Medinsight computerized randomization service that was developed and administrated by Oslo University Hospital at the Institute for Cancer Genetics and Informatics. Randomization was stratified by unit, and all participants and nurses (except the research team) were blinded to group assignment until after discharge from the hospital. All participants received a sealed envelope containing a prepaid, addressed return envelope and a questionnaire to be completed at 2 weeks after surgery and discharge from the regional hospital. All participants were instructed to open the sealed envelope after their discharge to home from their local community hospital. At postoperative day 10, all participants were contacted by telephone by a designated member of the research team in order to answer general questions regarding the study and to ensure that they had received and opened the sealed envelope. Further prepaid, addressed return envelopes and questionnaires were mailed to all participants prior to the data collection points at 1, 3, 6 and 12 months after surgery.
Control group The control group received standard discharge care, which included a 10-minute talk with the nurse/doctor on the day of discharge from the regional hospital that included general information about the physical recovery after surgery. Patients were invited to ask questions and encouraged to continue with paracetamol as a treatment for pain following discharge. At postoperative day 10, patients in the control group also received a brief phone call to ensure adherence.
Intervention group Participants in the intervention group received standard discharge care as described for the control group, plus a pain management education intervention, with the latter consisting of: 1) a booklet entitled Pain Relief After Your Surgery, originally developed by Watt-Watson et al.24,25;
and 2) a discussion about the content of the booklet during the supportive follow-up telephone call at 10 days after cardiac surgery. The booklet was translated from English and modified for use in Norway in collaboration with the author of the original version. Current clinical practice guidelines and results from focus group interviews with Norwegian nurses regarding pain management in patients undergoing cardiac surgery26 were incorporated into the Norwegian version of the booklet. The booklet emphasized four key concepts of effective pain management: 1) the importance of good pain relief following cardiac surgery; 2) how and when to ask for help with pain management following discharge; 3) pain relief methods, including pharmacological and non-pharmacological approaches; and 4) common concerns preventing patients seeking help with pain and/or taking analgesics. The booklet was written to be understood by the general public. Participants were blinded to group assignment until they opened the sealed envelope given at discharge. Although the booklet was not discussed at discharge, participants were given an opportunity to ask questions about the content of the booklet during the follow-up telephone call made by a designated member of the research team. All participants who expressed problems related to managing their pain were encouraged to contact their physician.
Measures At baseline, several exploratory outcomes were assessed. Information about age, sex, marital status, education level and income was collected using a demographic questionnaire. Additional data about number of comorbidities were collected via the Self-Administered Comorbidity Questionnaire (SCQ-16).27 The SCQ-16 included 15 common comorbidities and one optional condition, with the total number of comorbidities ranging from 0 to 16. Respondents indicated (yes/no) whether they had the comorbid condition. The SCQ-16 has a test–retest reliability of 0.94,27 and De-loyde et al.28 have recently demonstrated high concordance between patient self-report of comorbidities and medical record review.
Primary outcome The primary outcome for this trial was worst pain intensity at rest in the previous 24 hours measured using an 11-point numerical rating scale (NRS) grading from 0 (no pain) to 10 (the worst pain imaginable) using the Brief Pain Inventory – Short Form (BPI-SF) questionnaire.29 Both the reliability and internal validity of the BPI-SF have been demonstrated previously,30 and in the Norwegian validation study among cardiac surgery patients, the results indicated good internal consistency, with Cronbach’s alpha coefficients of between 0.84 and 0.94.31
Downloaded from cnu.sagepub.com at CHINESE UNIV HONG KONG LIB on February 22, 2016
4
European Journal of Cardiovascular Nursing
Secondary outcomes Secondary outcomes included pain-related interference with activities (BPI – Interference [BPI-I] subscales),31 patients’ concerns about pain and pain medication (Barriers Questionnaire [BQ])32,33 and self-report of pharmacological management in the previous week. The BPI-I included seven interference subscales with 11-point NRSs (0 = no interference, 10 = interferes completely) in order to rate pain-related interference in everyday activities (i.e. general activity, mood, walking ability, work, relationships with other people, sleep and enjoyment of life). Validated in a Norwegian sample,34 the BQ included seven items, each having a six-point rating from 0 (completely disagree) to 5 (completely agree). Scores ranged from 0 to 35, and higher scores indicated more concerns about pain and pain medication.33 Additional exploratory data included assessing pain location on a body outline diagram and one NRS for the degree of pain relief from pain treatments or medications in the previous 24 hours using the BPI-SF (0 = no relief, 100 = complete relief). Participants completed the items from the BPI-SF and self-reported their analgesic intake at 2 weeks and at 1, 3, 6 and 12 months after surgery. At baseline, participants were asked about the presence and location of pain in the week prior to surgery.
Sample size Approximately 1000 patients undergo cardiac surgery (CABG, valve surgery or both) at the regional hospital each year.1 Sample size calculation was based on previous studies24,25 with the original booklet, where an effect size of 0.2 was considered to be clinically significant. A sample size of 208 per group would achieve 80% power to detect an effect size of 0.2 at the p
