Quick answer
Whenever possible, with a validated questionnaire. Questionnaires take the form of single symptom or cluster scales. Where no suitable questionnaire is available, simple numerical rating scales and visual analogue scales (VAS) have been effective in identifying treatment effects.
Symptoms and HRQoL
The relationship between symptoms and HRQoL is complex and only partially understood. Highly salient symptoms such as intense pain clearly have an influence on HRQoL,1 and there is evidence that number of symptoms can sometimes serve as an indicator of overall HRQoL.2 At the same time, however, dimensions of HRQoL such as social and spiritual wellbeing can remain stable, or even improve, in the face of worsening symptoms.3 These findings underline the need to include assessment of symptoms within a range of domains in most cases where HRQoL is an endpoint of interest. However, there may be instances where measuring symptoms will be sufficient without broader HRQoL assessment. One example would be a trial where the primary objective is to improve a symptom that requires detailed assessment and for which the impact on HRQoL has already been established in the literature.
Symptom assessment
Evolution
A wide range of symptom scales are available for use in research. Many of these scales were developed for clinical practice, and many have limited validity and reliability despite being commonly used in clinical trials. A number of measures have been based on the graded toxicity scales developed by the World Health Organization,4 the National Cancer Institute 5 and US oncology groups (e.g., RTOG, ECOG, SWOG) – all of which continue to be widely used in cancer clinical trials (see http://www.accessdata.fda.gov/scripts/cder/onctools/toxicity.cfm for a selection of these scales). Toxicity scales reflect the traditional preference for clinician ratings of the signs of disease on grounds that this is more ‘objective’ – and therefore reliable - than assessments based on patients’ report. However, there is increasing recognition that assessment should also include some measure of “symptom burden” – that is, patient experience of symptoms and the ways in which these impact on everyday functioning. Unfortunately, to date, there is no standard approach to combining signs and subjective descriptors and, in many cases, the different elements are not clearly defined.6
HRQoL measures
Most cancer-specific HRQoL questionnaires include symptom subscales among the dimensions they assess. The widely-used EORTC QLQ and FACIT suites, for example, include symptoms common across cancers in their core measures and add further symptoms specific to each cancer type or treatment mode in dedicated modules. Some symptoms, such as alopecia, as yet have no dedicated patient-report scale available and are typically assessed only within the larger context of HRQoL questionnaires such as the Breast Cancer Chemotherapy Questionnaire (BCQ),7 FACT-B (Breast) 8 and GLQ-8.9
Measures from the EORTC QLQ and FACIT suites include examples of ‘symptom cluster scales’ that assess groups of symptoms which tend to co-occur. The widespread use of validated symptom cluster scales across trials would ensure systematic assessment of symptoms and offer the potential for standardisation.10 Symptom cluster scales also have the advantage that they may identify symptoms that were not known to be an issue in a particular disease or treatment and therefore would not have been selected for assessment using a single-symptom scale. A good example of this is fatigue, which is frequently emphasised by cancer patients but often overlooked by clinicians because treatment options are limited. Symptoms may cluster together in the presence of certain cancer types or treatment modes because of common or closely related underlying pathologies. Other symptoms, such as fatigue and pain are prevalent across cancers for a range of reasons and vary in their relationships to one another.11
Click HERE for a summary of the symptoms included in five commonly-used and validated symptom cluster questionnaires. Of these questionnaires, the Symptom Distress Scale (SDS) 12 has been used most extensively in cancer clinical trials. But all except the Patient Disease and Treatment Assessment (DATA) Form have been rated as “moderate” to “good” against criteria devised by Kirkova et al. (2006) 13 relating to comprehensiveness, ease of understanding, reliability, validity, time taken to complete, and capacity to inform decision making and facilitate symptom management. The 48-item Patient DATA Form 14 is a relatively new measure for which validation data has yet to be published but which is the most comprehensive to date, includes brief assessment of physical, emotional and overall wellbeing and impacts on daily functioning, and was developed in Australia. A 24-item Patient DATA Form also exists and has been validated in patients with hepatocellular carcinoma.15 The 48-item Patient DATA Form is the only symptom cluster scale to include an item that asks patients to identify any symptoms that may have been missed by the scale – a practice that is especially important for patients in the palliative phase.16
Single-symptom assessment
Where one particular symptom has been highlighted in the literature as prevalent and important - especially where this is targeted in a trial’s objectives - it may be appropriate to choose a measure that focuses on this symptom alone. Some symptoms, such as pain, are multidimensional, and are likely to benefit from detailed assessment whenever they are anticipated to have a significant impact. Other complex symptoms, such as dyspnoea, defy assessment by a single questionnaire; choice of assessment therefore will depend on the purpose of the study and the component of dyspnoea that forms the focus.17
Click HERE for information on validated self-report symptom assessment scales. Whenever possible, symptom-specific scales and HRQoL measures have been included that have demonstrated treatment effects in cancer clinical trials.
Where a validated self-report scale is not available, researchers have tended to use a Visual Analogue Scale (VAS) or Linear Analogue Self Assessment (LASA) scale 18 of their own devising. VAS/LASAs consist of a single line, usually 10 cm long, that is assumed to represent the full spectrum of potential experience of a given symptom. The scale is anchored on its left end with a phrase that indicates the absence of the symptom or symptom burden (e.g. “none”, “not at all”) and on its right with a phrase that indicates the worst possible severity (e.g., “as bad as I can imagine”). Patients are then asked to mark the line at a point that represents the status of a particular symptom on this continuum. VAS/LASAs have often proven to be effective in identifying a treatment effect, sometimes even when validated measures have lacked similar sensitivity or responsiveness.17, 19
A systematic review of scales used to measure physical symptoms in children and adolescents is offered by Linder (2005).20
Assessments of depression and anxiety are discussed in more detail in our FAQ on Measuring psychological distress in people with cancer.
References
1. Strang P, Qvarner H. Cancer-related pain and its influence on quality of life. Anticancer Research. Jan-Feb 1990;10(1):109-112.
2. Chang VT, Hwang SS, Feuerman M, Kasimis BS. Symptom and quality of life survey of medical oncology patients at a veterans affairs medical center: a role for symptom assessment. Cancer. Mar 1 2000;88(5):1175-1183.
3. Brady MJ, Peterman AH, Fitchett G, Mo M, Cella D. A case for including spirituality in quality of life measurement in oncology. Psycho-Oncology. Sep-Oct 1999;8(5):417-428.
4. World Health Organization. WHO handbook for reporting results of cancer treatment. Geneva World Health Organization; 1979.
5. National Cancer Institute Cancer Therapy Evaluation Program. Common toxicity criteria manual, Version 2: NCI; June 1 1999.
6. Sonis ST, Elting LS, Keefe D, et al. Perspectives on cancer therapy-induced mucosal injury: pathogenesis, measurement, epidemiology, and consequences for patients. Cancer. May 1 2004;100(9 Suppl):1995-2025.
7. Levine M, Guyatt G, Gent M, et al. Quality of life in stage II breast cancer: an instrument for clinical trials. J Clin Oncol. 1988;6(12):1798-1810.
8. Brady MJ, D.F C, Mo F, et al. Reliability and validity of the Functional Assessment of Cancer Therapy-Breast (FACT-B) quality of life instrument. Journal of Clinical Oncology. 1997;15:974-986.
9. Coates A, Glasziou P, McNeil D. On the receiving end--III. Measurement of quality of life during cancer chemotherapy. Annals of Oncology. 1990;1:213-217.
10. Paice JA. Assessment of symptom clusters in people with cancer. Journal of the National Cancer Institute. 2004;Monographs.(32):98-102.
11. Kaasa S, Loge JH, Knobel H, Jordhoy MS, Brenne E. Fatigue. Measures and relation to pain. Acta Anaesthesiologica Scandinavica. Oct 1999;43(9):939-947.
12. McCorkle R, Young K. Development of a symptom distress scale. Cancer Nursing. 1978;1(5):373-378.
13. Kirkova J, Davis MP, Walsh D, et al. Cancer symptom assessment instruments: a systematic review.[erratum appears in J Clin Oncol. 2006 Jun 20;24(18):2973]. Journal of Clinical Oncology. Mar 20 2006;24(9):1459-1473.
14. Stockler MR, O'Connell R, Nowak AK, et al. Effect of sertraline on symptoms and survival in patients with advanced cancer, but without major depression: a placebo-controlled double-blind randomised trial.[see comment][erratum appears in Lancet Oncol. 2007 Jul 8;8(7):574]. Lancet Oncology. Jul 2007;8(7):603-612.
15. Nowak AK, Cebon J, Hargreaves C, et al. Assessment of health-related quality of life and patient benefit as outcome measures for clinical trials in hepatocellular carcinoma. Asia-Pacific Journal of Clinical Oncology. 2008;4:55-67.
16. Hoekstra J, Vernooij-Dassen MJFJ, de Vos R, Bindels PJE. The added value of assessing the 'most troublesome' symptom among patients with cancer in the palliative phase. Patient Education & Counseling. Feb 2007;65(2):223-229.
17. Mancini I, Body JJ. Assessment of dyspnea in advanced cancer patients.[see comment]. Supportive Care in Cancer. Jul 1999;7(4):229-232.
18. Priestman TJ, Baum M. Evaluation of quality of life in patients receiving treatment for advanced breast cancer. Lancet. Apr 24 1976;1(7965):899-900.
19. Fairclough DL, Gagnon DD, Zagari MJ, Marschner N, Dicato M, Epoetin Alfa Study G. Evaluation of quality of life in a clinical trial with nonrandom dropout: the effect of epoetin alfa in anemic cancer patients. Quality of Life Research. Dec 2003;12(8):1013-1027.
20. Linder LA. Measuring physical symptoms in children and adolescents with cancer. Cancer Nursing. Jan-Feb 2005;28(1):16-26.
NOTE: When citing information or advice obtained from PoCoG's Quality of Life Office Frequently Asked Questions, please use the following citation:
Psycho-oncology Co-operative Research Group (PoCoG) (2008). Quality of Life Office (online resource).
Last updated: 2 July 2012