There is increasing recognition that psychosocial care, with its goal of relieving emotional distress and promoting well-being, is an essential component of the comprehensive care of patients diagnosed with cancer. Heightened distress is common1 and is associated with worse health-related quality of life (HRQoL),2 poorer adherence to treatment recommendations,3 and poorer survival in patients with cancer.4 Yet, evidence indicates that heightened distress often goes unrecognized.5
NCCN recommends that all patients be routinely screened for distress at appropriate intervals during the cancer trajectory,6 and the Distress Thermometer (DT) has been shown to be an effective screening tool in identifying distress in patients with cancer.6,7 The one-item DT was originally published by Roth et al8 in 1998, and appears in the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) accompanied by a Problem List (PL), which categorizes sources of distress. The DT is widely used in the supportive and palliative care of patients with cancer across a diverse range of settings and various populations,9 and is systematically validated across countries and cultures.10–15 However, there are several challenges to translating these instruments. One such challenge with the DT is the translation of the core concept itself; for example, there is no relevant corresponding Swedish term for distress.
Several studies12,16,17 have tested the validity of the DT with the Hospital Anxiety and Depression Scale (HADS), also using HADS to determine specificity and sensitivity for identifying clinical cases.18 Based on a validation study examining a Swedish translation of an earlier version of the DT (version 1.2004) in relation to HADS, Thalén-Lindström et al17 suggested that, with a cutoff threshold for significance of ≥4, the DT is valid for screening purposes and has the ability to measure changes in distress over time.
Although most studies tested the validity of the DT, few studies have validated the PL. The PL consists of a list of 39 items regarding responses to cancer and its treatment, which are categorized into 5 PL areas measuring practical, family, emotional, spiritual/religious, and physical problems.9 The PL also includes 1 open-ended item that allows respondents to indicate other problems not included in the list. Less is known about how these problems are associated with each other. To the best of our knowledge, no studies have validated the PL using the EORTC core quality-of-life questionnaire (QLQ-C30) function scales.
In patients with colorectal cancer (CRC), significant negative relationships have been found between mental health outcomes, as measured by HADS, and HRQoL, as measured using the QLQ-C30.19 However, the association between distress, measured with the DT, and HRQoL, measured by QLQ-C30, is less known, as is whether the DT can identify individuals with poor, moderate, or excellent HRQoL.
The main objectives of this study were to examine measurement validity and reliability with respect to the DT/PL in a Swedish population of patients diagnosed with CRC. We specifically examined construct validity, internal consistency reliability (ICR), and convergent and discriminant validity, by addressing the following questions:
Do the PL items cluster in a manner that is consistent with the PL areas?
What is the ICR of the PL areas and what are their correlations with the DT?
How do the PL items correlate with the HRQoL domains of the QLQ-C30?
To what extent does the DT distinguish groups of people with poor, moderate, or excellent HRQoL?
The authors wish to acknowledge all patients who participated in this study.
The authors have disclosed that they have no financial interests, arrangements, affiliations, or commercial interests with the manufacturers of any products discussed in this article or their competitors.
Grants supporting this research were received from University of Gothenburg Centre for Person-centred Care and the Health & Medical Care Committee of the Regional Executive Board in Region Västra Götaland. This research was undertaken, in part, thanks to funding from the Canada Research Chairs program. Dr. Sawatzky holds a Canada Research Chair (Tier 2) in Patient-Reported Outcomes.
SkarsteinJAassNFossaSD. Anxiety and depression in cancer patients: relation between the Hospital Anxiety and Depression Scale and the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire. J Psychosom Res2000;49:27–34.
KennardBDStewartSMOlveraR. Nonadherence in adolescent oncology patients: preliminary data on psychological risk factors and relationships to outcome. J Clin Psychol Med Settings2004;11:31–39.
SteelJLGellerDAGamblinTC. Depression, immunity, and survival in patients with hepatobiliary carcinoma. J Clin Oncol2007;25:2397–2405.
FallowfieldLRatcliffeDJenkinsV. Psychiatric morbidity and its recognition by doctors in patients with cancer. Br J Cancer2001;84:1011–1015.
HollandJCDeshieldsTLAndersenB. NCCN Clinical Practice Guidelines in Oncology: Distress Management. Version 2.2018. Accessed: March 8 2018. To view the most recent version of these guidelines visit NCCN.org.
RothAJKornblithABBatel-CopelL. Rapid screening for psychologic distress in men with prostate carcinoma: a pilot study. Cancer1998;82:1904–1908.
HollandJCBultzBD. The NCCN Guideline for distress management: a case for making distress the sixth vital sign. J Natl Compr Canc Netw2007;5:3–7.
BulliFMiccinesiGMaruelliA. The measure of psychological distress in cancer patients: the use of Distress Thermometer in the Oncological Rehabilitation Center of Florence. Support Care Cancer2009;17:771–779.
GrassiLJohansenCAnnunziataMA. Screening for distress in cancer patients: a multicenter, nationwide study in Italy. Cancer2013;119:1714–1721.
MartinezPGaldonMJAndreuY. The Distress Thermometer in Spanish cancer patients: convergent validity and diagnostic accuracy. Support Care Cancer2013;21:3095–3102.
GesslerSLowJDaniellsE. Screening for distress in cancer patients: is the distress thermometer a valid measure in the UK and does it measure change over time? A prospective validation study. Psychooncology2008;17:538–547.
Thalén-LindströmALarssonGHellbomM. Validation of the Distress Thermometer in a Swedish population of oncology patients; accuracy of changes during six months. Eur J Oncol Nurs2013;17:625–631.
AaronsonNKAhmedzaiSBergmanB. The European Organization for Research and Treatment of Cancer QLQ-C30: a quality-of-life instrument for use in international clinical trials in oncology. J Natl Cancer Inst1993;85:365–376.
BorghedeGKarlssonJSullivanM. Quality of life in patients with prostatic cancer: results from a Swedish population study. J Urol1997;158:1477–1485; discussion 1486.
FinneySJDiStefanoC. Non-normal and categorical data in structural equation modeling. In: HancockGMuellerR eds. Structural Equation Modeling: A Second Course. Greenwich, CT: Information Age Publishing; 2006:269–314.
VandenbergRJLanceCE. A review and synthesis of the measurement invariance literature: suggestions, practices, and recommendations for organizational research. Organ Res Methods2000;3:4–70.
ZumboBDGadermannAMZeisserC. Ordinal versions of coefficients alpha and theta for Likert rating scales. J Mod Appl Stat Methods2007;6:21–29.
ReeveBBWyrwichKWWuAW. ISOQOL recommends minimum standards for patient-reported outcome measures used in patient-centered outcomes and comparative effectiveness research. Qual Life Res2013;22:1889–1905.
Group AS. Health-related quality of life and psychological distress among cancer survivors in Southeast Asia: results from a longitudinal study in eight low- and middle-income countries. BMC Med2017;15:10.