Approximately 1 437 180 new cancer cases were diagnosed in the United States in 2008.1 For those patients receiving chemotherapy, studies have shown that despite recent advances in antiemetic therapy, approximately 38% to 64% of patients develop chemotherapy-induced nausea and vomiting (CINV).2-4 Based on patient testimony, these symptoms are among the most commonly reported symptoms during chemotherapy and impact the patients' lives in the arena of ability to function, quality of life, and fulfillment of chemotherapy treatments.2,4-10 Research has shown that patients receiving chemotherapy report nausea and vomiting to be among the most distressing and feared symptoms.11-13 Fear of this experience may cause patients to withdraw from potentially beneficial treatment.
Nausea, vomiting, and retching, although related, are actually 3 distinct symptoms. Definitions provided by Rhodes and McDaniel14 in 2001 clearly articulate the uniqueness of each symptom as follows:
- Nausea is an unpleasant sensation experienced in the back of the throat and the epigastrum that may or may not result in the expulsion of material from the stomach.
- Vomiting involves the actual forceful upward expulsion of contents from the stomach.
- Retching is the attempt to expel contents of the stomach without actually bringing anything up.14
Therefore, to adequately address the patient's experience with these symptoms requires each symptom to be measured independently.
Useful assessment of the symptoms requires more than just an accounting of its presence-yes or no. To obtain the information needed for focused interventions, the assessment must be comprehensive and requires a clear sense of other aspects of the symptom experience.
The nausea, vomiting, and retching experience of patients receiving chemotherapy can be separated into 3 periods. Some patients experience pre, or anticipatory, nausea and vomiting prior to the initiation of chemotherapy. Osoba and colleagues15 report that patients who experience pre or anticipatory nausea have a higher incidence of nausea and vomiting during and after chemotherapy. Patients often experience acute nausea, vomiting, and retching occurring during the first 24 hours following chemotherapy. Research has also shown that as many as 50% to 60% of the patients who receive moderately or highly emetogenic chemotherapy also experience delayed nausea and vomiting, which can continue for days following treatment.5 The majority of the information available for each period focuses only on nausea and vomiting. Comprehensive assessments are needed to determine if all periods should also be addressed for retching.
Chemotherapy-induced nausea and vomiting has been shown to greatly impact perceived quality of life during treatment. The intensity of this impact appears to be at least somewhat related to certain characteristics of the experience, including duration, frequency, severity, and distress, as well as the consequences of the experienced symptoms. This is especially true for those patients who experience delayed nausea and vomiting.5 Reducing the length and severity of CINV helps patients retain their ability to maintain normal life functions including caring for themselves and sustaining their relationships with others.6 Failure to effectively treat nausea and vomiting may lengthen hospital stays16; increase medical complications such as malnutrition, dehydration, and electrolyte imbalances; and contribute to physical and mental deterioration.17 As indicated above, information regarding this aspect of retching is less well known than for nausea and vomiting.
Nurses play a significant role in identifying and managing chemotherapy-induced nausea, vomiting, and retching (CINVR) symptoms, yet the process for accomplishing this is complex. Previously, the primary authors conducted a performance improvement project aimed at improving the management of nausea and vomiting related to high-dose chemotherapy on an inpatient bone marrow transplant unit. This project provided the groundwork and identified the need for tools to accurately measure CINVR.18 Such tools must be able to accurately measure the symptoms of interest in a reliable manner. In addition, the tools must be realistic to use in the practice setting-either research or clinical, especially as symptom management research moves into the clinical arena. The usefulness of an effective assessment tool can help engage patients in the process of evaluating treatment experiences. In clinical practice, tools will facilitate the involvement of patients in the monitoring and individualization of their own care. It can also enhance patient-provider communication and shared decision making in the practice setting. This patient-centered approach can reduce the intensity and distress of the symptom experience and potentially lead to improved health outcomes.19
Tools have been available for many years to assist care providers in monitoring the frequency, severity, and duration of CINVR symptoms. However, trying to understand these symptoms remains a challenge for many health care professionals. This is related to both the subjectivism of the symptoms9 and the number of tools available. In addition, it is now understood that the interaction of 2 or more of these symptoms has a greater affect on an individual than the total power achieved by each symptom working separately.20 Unfortunately, many tools do not include all 3 symptoms. In addition, others lack documentation regarding reliability and validity. Therefore, the desire is to identify a tool that is clear, concise, and clinically useful (so as to not burden the patient or the provider), as well as able to provide valid and reliable data for the evaluation of interventions for evidence-based practice.
The purpose of this literature review was to conduct a thorough evaluation of available CINVR assessment tools. This information will provide clinicians and researchers with a comprehensive examination of the various instruments available, including period evaluated, type of questions posed, and aspects of each symptom measured. The information can then be used by health care professionals to evaluate the individual components of each tool and determine the most appropriate one for their setting.
The search for CINV tools began with a review of nationally recognized oncology Web sites for information related to the topic. These Web sites included the American Cancer Society, Oncology Nursing Society, National Comprehensive Cancer Network, and Multinational Association of Supportive Care in Cancer (MASCC) for information related to our topic. The search was then expanded using MEDLINE/CINAHL and CINAHL/EBSCO, and Cochrane databases using the following keywords: nausea, vomiting, retching, CINV, measurement, tool, symptom experience, symptom distress, symptom occurrence, symptom assessment, quality of life, cancer, oncology, emesis, and scale.
The search period spanned from 1980 to 2009. Initially, 412 abstracts were identified; these were narrowed to 123 abstracts that discussed tools available in an English version. Searches were then conducted to seek information regarding documentation of tool reliability and validity, tool use in the adult oncology population, and availability of the tool in print form in order that it could be evaluated. To complete the search, a hand search through the reference lists of retrieved articles was also completed.
Initial review of the selected articles provided the content for development of the components that would guide the evaluation of all of the tools. The acceptance of the components was validated based on the clinical experience of the authors as well as the findings of an earlier performance improvement project examining nausea and vomiting in high-dose chemotherapy patients.18 Each tool was then critiqued for the inclusion of measures of duration, frequency, severity, and distress for each of the 3 symptoms: nausea, vomiting, and retching. Reviewers also recorded the number of questions that addressed nausea, vomiting, and retching; the period queried; and the scale used for the assessment. Relevant notes were added in a comment fashion to guide the final critique process.
The initial focus was placed on tools that were developed to assess only nausea, vomiting, and/or retching symptoms. Later, the process was expanded to include several widely used, oncology-related, quality-of-life and ability-to-function tools. The intent was to review how the identified symptoms of CINVR were addressed in these larger tools. Final inclusion of a tool for evaluation involved availability of the tool in English, ability to use the tool in a clinical practice setting, and the tool's capability to provide data that could be used to evaluate evidence-based practice. The goal was to find self-report tools, ideally with the potential of being able to reproduce for use in electronic documentation. Tool length was taken into consideration to avoid additional burden for this potentially nauseated and fatigued patient population and to respect time constraints of the care providers. The ideal instrument needs to be clear and concise, yet provide useful information not only for the clinical setting but also for research.
The comprehensive literature search yielded more than 20 instruments that addressed nausea, vomiting, and retching (Table). Some of the instruments had more than 1 version in the literature. The versions may have included additional items, used different scales, or demonstrated evidence of evolution over time. Although the importance of addressing overall quality-of-life issues is widely recognized in the oncology population, the purpose of this review was narrowed to evaluating only the CINVR symptom experience. Therefore, when broader oncology tools such as the Organization for Research and Treatment of Cancer QLQ-C3024 were examined, only the items that addressed CINVR were reviewed. Twenty-four tools evaluating nausea were identified that met the inclusion criteria. Thirteen tools measured vomiting as a separate experience. Only 3 tools included a separate assessment of retching. The number of CINVR-related questions in each tool ranged from 2 to 17. The most detailed tools included assessment of frequency, duration, severity, and distress caused by these symptoms. For the final selection of assessment tools to be included in this review, earlier original versions of tools were added only if they varied significantly from the most current version available. Information regarding the validity and reliability information available is also included in the Table. The amount of information available regarding the validity and reliability of the tools included in this review varied greatly. Often, articles would make reference to the established validity and reliability without providing details of the data available.
Of the 24 tools that addressed nausea in the oncology population, many were designed to focus on the patient's more broad functional status or quality-of-life issues. One tool, the Morrow Assessment of Nausea and Emesis,33 specifically asked questions regarding pretreatment nausea. Another tool, the MASCC Antiemesis Tool,34 individually addressed both acute and delayed nausea and vomiting. By completing the assessment on multiple days, the other tools could be used to capture these data for the different phases. All but one of the tools included were developed to be used as self-report questionnaires, although assistance could be provided for those who are weak or unable to read or complete on their own. One tool, the Behavioral Observation tool, requires nurses to assess the patient's experience and report patient behaviors. The research using this tool did not find it to be as sensitive as self-report tools, but it may be a reasonable alternative when a patient is not able to communicate verbally with staff about his/her experience.22
Four characteristics of nausea typically were measured including duration, frequency, severity, and associated distress. Duration was measured by asking the patient if they had experienced nausea and/or the number of hours that nausea was experienced during the time frame addressed. Frequency was measured as the number of nausea episodes during the same period. Severity was measured using a categorical rating scale, usually Likert-type, such as none, mild, moderate, or severe. Some used a visual analog scale (VAS) or numerical rating scale (NRS). A clear exception to this pattern is the Nausea Questionnaire,39 which ranks descriptors based on the position of the word within each set. In addition, the Common Toxicity Criteria23 examines both nausea and vomiting separately, in relation to the symptom's influence on a patient's ability to maintain oral intake or need for intravenous fluid replacement. Distress, when included, is most often measured using Likert-type scales ranging from none to severe distress or discomfort. Some tools address distress by how patients perceive the symptom's impact on their daily/social functioning or quality of life.
Vomiting as a separate physical experience was addressed in 13 of the 24 tools that met the inclusion criteria. Duration is measured in both number of hours and as yes/no questions. Frequency is measured by the number of vomiting episodes in the specified period. The time frame addressed ranges from the past 12 hours to during the past week. Three tools inquire regarding the number of vomiting episodes the patient experienced in the past 12 to 24 hours. In the Index of Nausea, Vomiting, and Retching (INVR),32 the vomiting assessment addresses volume as measured in cups. The Common Toxicity Criteria23 includes assessing the need for intravenous fluids or total parenteral nutrition and the potential for life-threatening consequences. Severity is addressed in 4 tools using 4- to 6-point Likert scales. Distress produced by vomiting is evaluated in 6 tools, with questions ranging from asking about a specific emetic episode to the distress caused by vomiting in the past week. The Functional Living Index-Emesis6 and Osoba Nausea and Vomiting Module8 addressed the effect of vomiting on the patient's ability to perform life functions. The MASCC Antiemesis Tool includes both acute and delayed vomiting in conjunction to the acute and delayed nausea as indicated above.
Only 3 tools ask specific questions regarding retching. The Osoba Nausea and Vomiting Module8 includes 5 separate Likert-type questions to assess the impact of retching on daily functioning and patient well-being. The INVR inquires regarding the number of retching episodes in the previous 12 hours and the distress felt by these episodes. The Behavioral Observation tool asks the care providers if they have witnessed the patient retching. The duration and severity of retching were included as part of the instrument review; however, because they were not found on the tools examined, those 2 columns were not included in the Table in the section on retching.
Twelve tools address the past week to as far back as the previous chemotherapy cycle. Three of the tools reviewed were developed to utilize 3- to 6-day recalls. Three tools address the previous 24-hour period. Three tools address the immediate present to the previous 12-hour period. The other tools are either nonspecific in their evaluation period, or it was stated they could be adapted to meet the user's needs.
The CINVR experience is composed of 3 separate symptoms. To obtain a complete understanding of the patient's total experience, each symptom requires evaluation. Nursing plays a crucial role in the assessment and management of these symptoms. To impact the patient's experience, nurses need to have the tools available to help them assess each symptom in a timely manner. Early and accurate assessment can lead the way to timely, patient-specific interventions and minimize the symptom experience. This review indicates that the tools available vary in the comprehensiveness of their assessment of all 3 symptoms, with retching being included least often and in less detail. In fact, because of this limited presence in the assessments, the relevance of information collected regarding retching is not well known.
Four aspects of nausea were assessed: duration, frequency, severity, and associated distress. Because of the subjective nature of the experience, nausea may be the most difficult symptom for care providers to measure. However, research has shown that it has a stronger negative impact on quality of life than vomiting5; thus, it is critical to include in assessments. Questions related specifically to vomiting evaluated 5 components: duration, frequency, volume, severity, and distress. Few tools looked at all of the components. Although some of the instruments assess retching together with vomiting, retching was seldom assessed as its own symptom. When retching was addressed, the focus was on frequency and its associated distress. Assessing retching as a separate symptom may help identify and quantify the total experience of chemotherapy patients. When asked about their chemotherapy experience, patients may not report having had an emetic episode if no matter was expelled. This has the potential of reducing assessment information. By separating out the retching experience, care providers may develop a more complete understanding of the patient's experience. Adequately addressing the frequency, severity, and duration of each of these symptoms positively impacts the patient's quality of life, their ability to maintain normal life functions, and their ability to maintain relationships with others.5-8
Timely and complete assessments are essential because research has shown that most health care professionals significantly underestimate the incidence and severity of nausea, especially when it is delayed. The periods addressed in the questions varied greatly and ranged from the time of assessment to the past treatment experience, with many of the tools using recall to address long periods. It has been reported that these extended recall periods provide quality information when addressing chemotherapy's impact on a patient's health-related quality of life.45 However, a real-time or 12- to 24-hour recall time frame would facilitate more timely interventions, making these tools better suited for the acute-care clinical practice setting. In the outpatient setting, the period needs to address whatever time frame is relevant to the current phase of treatment.
Three types of scales were used most frequently. The VAS often uses 0- to 100-mm visual line anchored by verbal descriptors. Numerical rating scales use a unidimensional line, with evenly spaced numerical markings, and verbal categorical scales (VCSs), such as Likert-type scales. The VAS requires patients to convert a subjective sensation to a mark on a straight line provided on the assessment tool. It is extremely difficult to identically reproduce this line and therefore difficult to analyze data obtained for use in research studies. The VAS can also be difficult to explain to patients and must be administered on paper or electronically. The NRS can be administered either verbally or graphically and has been found to be similar in sensitivity to the VAS. It can be more easily understood by patients and is able to generate data that can be statistically analyzed. The VCS asks for level of agreement with a particular statement, usually rating the experience as mild, moderate, or severe. A study done by Borjeson and colleagues46 found good agreement between VAS and VCR when assessing nausea intensity. However, the study did find that the VAS was more sensitive to detecting early changes in patient-reported nausea. Scales using a VCS often require less patient teaching and are easier for clinicians and researchers to interpret.47 More recently, a similar study was done regarding various assessment tools for pain. The authors' recommendations were to use the NRS when needing a clinically practical tool that could also be used for audits and research.48 Clinicians can also take into account the current measurement scale already in use in their clinical setting. If the VAS or NRS is already used for pain assessment in their organization, it may be more patient friendly to use the same scale to assess CINVR.
Severity of the symptom is often measured as the intensity of the experience. Symptom distress takes into account the physical and emotional suffering related to an individual's response to the symptom.43 Tools also used the terms troublesome and bothersome to address the distress of a symptom. Research has shown that the level of distress does not always correlate with the frequency or intensity of a symptom.49
Symptom distress is defined as the degree of physical or mental discomfort reported by a patient in relation to a specific symptom.21 It is viewed by some to be the total response to symptom intensity and frequency.43 However, it is not always limited to the symptom's intensity, frequency, or duration. Other factors also influence the patient's perceived distress, including the meaning of the illness and other life events.50 In addition, duration of symptom experience also influences perceived distress. A mild/moderate symptom that persists over a lengthy period can be perceived as more distressing than a single more severe episode.51 Also, experiencing multiple symptoms at once can result in increased symptom distress.21 It is the emotional response derived from that symptom that prompts a person to take action and/or implement coping and behavioral skills. Timely interventions and involving the patient in the management of his/her care can aid in reducing symptom distress and improve patient outcomes.19
Although a thorough literature review was conducted to search for complete and concise CINVR tools available to be used in the practice setting, no single best tool was identified. Only the tools developed by Rhodes32provide a separate assessment of all 3 symptoms. The period in question is the previous 12 hours, which makes it applicable for real-time symptom management. Rhodes and McDaniel32 demonstrate the tool's ability to be used in both paper and computerized charting. The INVR utilizes a 5-point Likert-type scale; although this has not been shown to be as sensitive to early changes as the VAS, it has been found to be clinically useful and easy for patients to understand. There have been various versions of this tool published. The INRV32 revised in 1996 addresses the frequency and distress associated with all 3 symptoms: nausea, vomiting, and retching. It is interesting that distress, not severity, is assessed in real-time symptom management. It could be viewed as unusual to ask a vomiting patient to rate the distress of vomiting as it is occurring. Severity questions may be better received, and the distress lessened by adequate, timely interventions.
Future work regarding mechanisms involved in the 3 symptoms addressed will require selection of a valid and reliable instrument that adequately addresses all components of the symptom(s) being studied. The purpose of this literature review was to examine the CINVR tools available and to explore the specific components of each. As the medical community continues its development and integration of information technology and the translation of research into the clinical setting, it will be important to adapt a CINVR assessment tool that could be utilized in both paper and computerized charting. Tools to be considered for clinical use should incorporate evaluation of all 3 symptoms of nausea, vomiting, and retching as separate experiences of oncology patients. Correct timing of measurements is essential for symptom management. An ideal CINVR tool would evaluate the symptom experience as close to real-time as possible. The information gathered from this tool, used in combination with a detailed antiemetic algorithm, could help clinicians improve the CINVR experience. A well-developed CINVR tool would be valuable in both the high-paced clinical setting and at the same time provide detailed-enough information needed for research studies. The high-quality data collected could then be used to help support evidence-based practices and compare the effectiveness of new interventions.
It is also important to minimize the potential for additional burden being placed on patients by the use of lengthy assessment tools. Further investigation should be done to determine if the information gathered in these tools is truly necessary for symptom management. Some of the larger tools developed for research or larger quality-of-life evaluations provide valuable retrospective reviews of the entire chemotherapy experience but would be too time consuming and burdensome for patients to complete several times per day. Questions posed in these tools may help assess a patient's quality of life and functional ability but may not be essential for the real-time management of symptoms in the clinical setting. Taking this into account may help reduce the number of questions a potentially nauseated person has to answer during an examination and respect the time constraints of the nursing staff. However, the literature search has shown that additional reliability and validity testing may need to be done to support the use of the tools selected and to assess their sensitivity to detecting subtle differences in symptom management.
1. American Cancer
Society. Cancer Facts and Figures 2008
. Accessed October 2, 2009.
2. Grunberg SM, Deuson RR, Mavros P, et al. Incidence of chemotherapy-induced nausea
after modern antiemetics. Cancer
3. Lindley C, Goodin S, McCune J, et al. Prevention of delayed chemotherapyinduced nausea
after moderately high to highly emetogenic chemotherapy: comparison of ondansetron, prochlorperazide, and dexamethasone. Am J Clin Oncol
4. Cohen L, de Moor CA, Eisenberg P, et al. Chemotherapy-induced nausea
: incidence and impact on patient quality of life
at community oncology
settings. Support Care Cancer
5. Bloechl-Daum B, Deuson RR, Marvos P, et al. Delayed nausea
continue to reduce patient's quality of life
after highly and moderately emetogenic chemotherapy despite antiemetic treatment. J Clin Oncol
6. Decker GM, DeMeyer ES, Kisko DL. Measuring the maintenance of daily life activities using the Functional Living Index-Emesis
in patients receiving moderately emetogenic chemotherapy. Support Oncol
7. Glaus A, Knipping C, Morant R. Chemotherapy-induced nausea
in routine practice: a European persective. Support Cancer Care
8. Martin CG, Rubenstein EB, Elting LS, et al. Measuring chemotherapy-induced nausea
: psychometric properties of Quality of Life
9. Miller M, Kearney N. Chemotherapy-related nausea
- past reflections, present practice and future management. Eur J Cancer Care
10. Oliver IN. Update on anti-emetics for chemotherapy-induced emesis
. Intern Med J
11. De Boer-Dennert M, de Wit R, Schmitz P, et al. Patient perceptions of the side-effects of chemotherapy: the influence of 5-HT3 antagonists. Br J Cancer
12. Lindley C, Thomason T, Klauder D, et al. Perceptions on chemotherapy side effects. Cancer
versus noncancer patients. Cancer Pract
13. Sun CC, Bodurka DC, Weaver CB, et al. Ranking and symptom assessments of side effects from chemotherapy: insights from experienced patients with ovarian cancer
. Support Care Cancer
14. Rhodes VA, McDaniel R. Nausea
, and retching
: complex problems in palliative care. CA Cancer J Clin
15. Osoba D, Zee B, Pater J, et al. Determinants of post chemotherapy nausea
in patients with cancer
. J Clin Oncol
16. Pendergrass K. Options in the treatment of chemotherapy-induced emesis
. Cancer Pract
17. Hamadani M, Chaudhary L, Awan FT, et al. Management of platinum-based chemotherapy-induced acute nausea
: is there a superior serotonin receptor antagonist? J Oncol Pharmacol Pract
18. Wood J, Eilers J. Nausea
in the hematopoietic stem cell transplant population. Poster presented at the State of the Art Nursing Conference; April 2006; Omaha, Nebraska.
19. Robinson JH, Callister LC, Berry JA, et al. Patient-centered care and adherence: definitions and applications to improve outcomes. J Am Acad Nurse Pract
20. Molassiotis A, Stricker CT, Eaby B, et al. Understanding the concept of chemotherapy-related nausea
: the patient experience. Eur J Cancer Care
21. Rhodes VA, McDaniel RW, Homan SS, et al. An instrument to measure symptom experience
: symptom occurrence
and symptom distress
. Cancer Nurse
22. Chapko MK, Syrjala KL, Bush N, et al. Development of a behavioral measure of mouth pain, nausea
, and wellness for patients receiving radiation and chemotherapy. J Pain Symptom Manage
Care Nova Scotia. Guidelines for the management of nausea
. Accessed October 2, 2009.
24. EORTC Study Group on Quality of Life
. EORTC QLQ-C30 (version 3). European Organization for Research and Treatment of Cancer
. Accessed October 2, 2009.
25. Ferreira K, Kimura M, Teixeira J, et al. Impact of cancer
-related symptom synergisms on health-related quality of life
and performance status. J Pain Symptom Manage
26. Chang VT, Hwang SS, Feuerman M. Validation of the Edmonton Symptom Assessment Scale
27. Baba K, Fransson P, Lindh J. Use of a modified ESAS in cancer
patients: a pilot study of patient and staff experience. Int J Palliat Nurs
28. Philip J, Smith WB, Craft P, Lickiss N. Concurrent validity of the modified Edmonton Symptom Assessment
System with the Rotterdam Symptom Checklist and the Brief Pain Inventory. Support Care Cancer
29. Cella DF, Tulsky DS, Gray G, et al. The functional assessment of cancer
: development and validation of the general measure. J Clin Oncol
30. Schipper H, Clinch J, McMurray A, et al. Measuring the quality of life
patients: the Functional Living Index-Cancer
: development and validation. J Clin Oncol
31. Martin AR, Carides AD, Pearson JD, et al. Functional relevance of antiemetic control: experience using the FLIE questionnaire in a randomized study of the NK-1 antagonist aprepitant. Eur J Cancer
32. Rhodes VA, McDaniel RW. The Index of Nausea
, and Retching
: a new format of the Index of Nausea
. Oncol Nurs Forum
33. Morrow GR. The assessment of nausea
: past problems, current issues, and suggestions for future research. Cancer
34. Multinational Association of Supportive Care in Cancer
. A quick guide to the MASCC Antiemesis Tool
. Accessed October 2, 2009.
35. Molassiotis A, Coventry PA, Stricker CT, et al. Validation and psychometric assessment of a short clinical scale
to measure chemotherapy-induced nausea
: the MASCC Antiemesis Tool
. J Pain Symptom Manage
36. Cleeland CS, Mendoza TR, Wang XS, et al. Assessing symptom distress
patients: the M.D. Anderson Symptom Inventory. Cancer
37. Portenoy RK, Thaler HT, Kornblith AB, et al. The Memorial Symptom Assessment Scale
: an instrument for the evaluation of symptom prevalence, characteristics and distress. Eur J Cancer
38. Chang VT, Hwang SS, Feuerman M, et al. The Memorial Symptom Assessment Scale
Short Form (MSAS-SF). Cancer
39. Muth ER, Stern RM, Thayer JF, et al. Assessment of the multiple dimensions of nausea
: the Nausea
Profile (NP). J Psychosom Res
40. Melzack R, Rosberger Z, Hollingsworth ML, et al. New approaches to measuring nausea
. Can Med Assoc J
41. Choo S, Knong K, Lim W, et al. Electro acupuncture for refractory acute emesis
caused by chemotherapy. J Altern Complement Med
42. Stein KD, Denniston M, Baker F, et al. Validation of a Modified Rotterdam Symptom Checklist for use with cancer
patients in the United States. J Pain Symptom Manage
43. Fu MR, McDaniel RW, Rhodes VA. Measuring symptom occurrence
and symptom distress
: development of the symptom experience
index. J Adv Nurs
44. Samarel N, Leddy SK, Greco K, et al. Developing and testing of the Symptom Experience Scale
. J Pain Symptom Manage
45. Osoba D, Bezjak A, Brundage M, et al. Evaluating health-related quality of life
clinical trials: the National Cancer
Institute of Canada Clinical Trials Group experience. Value Health
46. Borjeson S, Hursti TJ, Peterson C, et al. Similarities and differences in assessing nausea
on a verbal category scale
and a visual analogue scale
. Cancer Nurs
47. Jaeschke R, Singer J, Guyatt GH. A comparison of seven-point andvisual analogue scales. Data from a randomized trial. Control Clin Trials
48. Williamson A, Hoggart B. Pain: a review of three commonly used pain scales. J Clin Nurs
49. Lough M, Lindsey A, Shinn J. Impact of symptom distress
frequency and symptom distress
on self-reported quality of life
in heart transplant recipients. Heart Lung
50. McClement SE, Woodgate RL, Degner L. Symptom distress
in patients with cancer
. Cancer Nurs
51. Kirkova J, Davis MP, Walsh D, et al. Cancer symptom assessment
instruments: a systematic review. J Clin Oncol