Background
Palliative care aims to improve the quality of life (QOL) of patients through the early detection and treatment of their symptoms [
1]. Thus, the assessment of patients’ QOL is essential when evaluating the outcome of palliative care. Nevertheless, assessment of QOL may be difficult in patients with advanced cancer due to the number and severity of symptoms they experience. To reduce the burden on patients, patient-reported outcomes (PROs) instruments in palliative care should be brief, cover the main symptoms and problems, and at the same time avoid content of limited relevance.
The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 15 Palliative Care (QLQ-C15-PAL) is an abbreviated 15-item version of the EORTC Quality of Life Questionnaire Core 30 (QLQ-C30), which is one of the most widely used, validated, translated and published instruments for assessing symptoms and QOL in cancer patients [
2]. The QLQ-C15-PAL contains the items of the QLQ-C30 which were identified as the most important for palliative care, based on interviews with health care professionals and patients [
3], and on statistical analyses using item response theory [
4,
5]. This development process secures that studies may compare their results obtained from the QLQ C15-PAL with studies using the original QLQ-C30 questionnaire [
3]. In addition, the QLQ-C15-PAL has been successfully validated and translated in several countries [
6‐
14], including Spanish-speaking countries [
15,
16].
The Chilean-Spanish version of the QLQ-C30 and some modules have been validated before [
17,
18]. A few studies have used the QLQ-C30 to evaluate patients’ QOL in oncology research [
19‐
22], but no instruments have been validated for measuring symptoms and QOL in patients receiving palliative care in Chile. When the QLQ-C15-PAL was developed, its content validity was evaluated by health care professionals and patients from six European countries [
3]. However, because of differences between these European countries and Chile in their health care systems, including how palliative care is organized, and the availability of palliative care services, it would be relevant to investigate the content validity of the QLQ-C15-PAL in Chilean population. In Chile most palliative care services are in the public health care system, but some services are fully private. Although Chile has the highest number of palliative care services in Latin America [
23], Chile still has a fewer number of palliative services compared to the Western European countries. In 2013, the ratio of services to the population in Chile was 1: 808,000, which is lower compared to the six European countries with a ratio of services to the population between 1: 48,000 (in the United Kingdom), and 1: 122,000 (in Denmark) [
24]. Therefore, we aimed to investigate the content validity of the QLQ-C15-PAL questionnaire with patients and health care professionals from palliative care services in Chile, replicating the methods used previously to shorten the items of the QLQ-C30 among European patients in palliative care [
3].
Methods
Patients and health care professionals
This cross-sectional study was conducted from October to November 2017 with participants from the palliative care services of four public hospitals in Santiago in Chile. We planned to recruit at least 10 patients and 10 heath care professionals (HCPs) from each palliative care service.
Outpatients with advanced cancer undergoing palliative care treatment, with knowledge of their diagnosis, and who had given informed consent were eligible. Patients who were too ill to participate in interviews, and non-native Spanish speakers were excluded. HCPs with their main job in palliative care were eligible. For patients, the primary cancer site was registered, occupation and years of experience were registered for HCPs, and demographic characteristics were collected for all participants.
Questionnaires
The Chilean-Spanish version of the QLQ-C30 questionnaire (version 3) was used for this study, and was obtained from the EORTC Quality of Life Department in Brussels. The QLQ-C30 consists of 30 items distributed in five functional scales measuring physical, emotional, role, cognitive and social functioning; three symptoms scales measuring fatigue, pain, nausea/vomiting; one scale measuring “global health and quality of life status”, and six single items measuring sleeping difficulties, dyspnea, constipation, lack of appetite, financial difficulties, and diarrhea. All items are rated on 4-points Likert scales that range from 1 (not at all) to 4 (very much), with the exception of the global health/quality of life scale, which is rated from 1 (very poor) to 7 (excellent) [
25,
26].
The QLQ-C15-PAL is an abbreviated version of the QLQ-C30, which was developed for patients in palliative care preserving the main advantages of the original questionnaire. The QLQ-C30 was shortened to 15 items by omitting items of the QLQ-C30 that were considered inappropriate or not highly relevant in palliative care by patients and health care professionals in interviews, [
3] and by shortening multi-item scales of QLQ-C30 using item response theory [
4,
5]. Four scales, i.e., physical functioning, emotional functioning, nausea/vomiting and fatigue, were shortened retaining the items that best predicted scores on the original scales. Due to the low relevance reported in the interviews, the two-item global QOL scale was reduced to one item by omitting overall health, and five scales/items were completely omitted (social, role and cognitive functioning scales, diarrhea and financial difficulties items).
Procedure for interviews
To validate the content of the QLQ-C15-PAL questionnaire, we conducted semi-structured interviews following the procedure originally used to develop a shortened version of the QLQ-C30 for palliative care patients [
3], and the EORTC Quality of Life Group Guidelines for developing questionnaire modules [
27]. The purpose of these interviews was to identify the most relevant issues for patients in palliative care among those included in the EORTC QLQ-C30 in order to investigate whether the QLQ-C15-PAL also has the appropriate content for use in Chile.
Patients were asked to respond to the Chilean-Spanish version of the QLQ-C30 during individual interviews by a trained researcher. The interviewer then invited patients to comment on how well the QLQ-C30 items “evaluated the outcome of the palliative care they received”. Patients were asked to comment on the QLQ-C30 items in terms of relevance, appropriateness, relative importance, and breadth of coverage. The relevance of each item was rated using the response categories 1 “not at all”, 2 “a little”, 3 “quite a bit” and 4 “very much”. If an item was rated 1 or 2, patients were asked to report the reasons, e.g., “Why do you consider this question not or only a little relevant?”. The appropriateness was measured asking patients to identify items they perceived as inappropriate or upsetting. The relative importance was evaluated asking patients to select the 10 most important items when evaluating the success of palliative care. The breadth of coverage was assessed asking patients to report additional issues that were relevant for them but not covered by the QLQ-C30.
An identical interview was followed for HCPs, but they were required to comment on how well the QLQ-C30 items “evaluated the outcome of palliative care in general”, i.e., not for a specific patient, but for patients admitted to palliative care in general. HCPs were asked to comment on relevance, appropriateness, relative importance, and breadth of coverage of the QLQ-C30 items, using the same procedure as described above.
Statistical analysis
Participants’ characteristics were expressed as proportions for categorical variables, and as means, standard deviations, medians and ranges for continuous variables. The mean relevance score of each item was calculated after transforming the responses to 0–100 scales with 0 corresponding to “not at all” and 100 to “very much” [
26]. The proportion of participants rating each item as “inappropriate or upsetting” and selecting each item as one of the 10 most important were calculated. The proportion of participants who selected at least one of the items from each multi-item scale as one of the 10 most important was also calculated. Single items and multi-item scales were ranked according to the proportion of patients and HCPs selecting them as among the 10 most important. This ranking named ‘importance percentage’ was calculated as the average: (percentage of patients + percentage of HCPs)/2; although the sample of patients was larger than HCP sample, both received equal weight. Furthermore, this ranking was used to compare the relative importance of the scales and items as perceived by Chilean patients/HCPs with the results of the original study [
3]. HCPs were divided in two subgroups, i.e., “physicians” and “other HCPs” to explore differences between the rating of relevance and importance for each dimension of the QLQ-C30, tested by Mann-Whitney U Test. Qualitative data obtained from the interviews were categorized into responses about the lack of relevance in selected items, and the need to include other issues in the questionnaire, respectively. A
p value < 0.05 was considered statistically significant. Analyses were performed using the statistical software Statistical Package for the Social Sciences (SPSS) version 23.
Discussion
In this study, we performed a content validation of the QLQ-C15-PAL with 48 patients and 35 HCPs from four palliative care services in Chile, replicating the methodology of a previous study conducted in six European countries [
3]. In general, our results were similar to that study, confirming the content validity of the QLQ-C15-PAL questionnaire, but we made important observations that will be discussed later.
Of the 10 function/symptom scales included in the QLQ-C15-PAL questionnaire, eight were selected among the 10 most important dimensions to include in the assessment of palliative care in Chile, i.e., pain, physical functioning, sleeping difficulties, emotional functioning, nausea/vomiting, fatigue, lack of appetite and constipation. Responses about the five shortened scales from the original QLQ-C30 to form the QLQ-C15-PAL were comparable to the Groenvold et al. study [
3]. Physical functioning and fatigue scales were particularly important scales by patients, whereas emotional functioning, nausea/vomiting and global health status/QOL scales were essential for HCPs. Most of the items of these scales that were finally retained in the QLQ-C15-PAL, were also selected by our respondents as relevant issues to measure the outcome of palliative care.
The most important dimension selected by the participants was pain (96%), which has been recognized in the literature as one of the most prevalent symptoms reported by advanced cancer patients in palliative care [
28,
29]. Other dimensions frequently selected as important were physical functioning (89%), sleeping difficulties (80%), emotional functioning (78%), nausea/vomiting (57%), fatigue (56%) and social functioning (49%). These dimensions were previously identified as prevalent palliative needs in a study investigating the content validity of PROs instruments in palliative care, by comparing patient reported symptoms and problems to what was registered in the medical records [
30]. Although social and role functioning were excluded in the development of the QLQ-C15-PAL due to the lack relevance reported in the original study [
3], in our study these dimensions were selected as the most important by 49 and 43% of respondents respectively, principally HCPs selected social functioning in relation to family life of patients, and patients selected role functioning in relation to their limitations at work. Patients’ concern about their role in the family, the social support they received from family, and personal challenges related to work have been reported before by a palliative care service in a small qualitative study conducted in Chile [
31].
Qualitative data corresponding to additional issues not covered by the questionnaire showed that HCPs reported twice as many topics as patients did. A reason may be that HCPs have the perspective of many patients while patients focus on their own situation. Further, the breadth of coverage question was asked at the end of the interview, hence, some patients may have been too fatigued to give comprehensive responses. The main additional issues reported in our study were satisfaction with care, emotions and psychological support. In contrast, additional issues related with existential and spiritual issues were frequently reported by Groenvold et al. [
3]. Further research is needed to evaluate which aspects not covered by the QLQ-C15-PAL may be relevant for a comprehensive measurement of the QOL in Chilean palliative care patients, e.g., a social dimension. While social support for patients in palliative care and their families has been recommended by the Chilean Ministry of Health [
32], as well as international organizations [
1,
33], social needs do not seem to be covered by current palliative care in Chile, as only one of the four palliative care services in this study had a social worker in their teams.
The qualitative data was useful to identify unexpected linguistics issues in the dyspnea and constipation items, since 33 and 20% of the participants reported that these questions were not well formulated or were difficult to understand. A list with the comments about these two items was submitted to the Translation Unit of the EORTC Quality of Life Department for possible revision of the translation of these items. After their analysis both items were modified in the Chilean versions of the QLQ-C30, and the QLQ-C15-PAL questionnaires.
We recognize some limitations related to this study. First, we did not evaluate statistically the psychometric properties of the QLQ-C15-PAL in Chilean patients; however, it has been extensively validated in previous international studies [
6‐
13]. Second, we planned to recruit at least 10 HCPs from each palliative care service, but half of the services investigated had less than 10 professionals in their teams. Nevertheless, we had no missing data for the study analysis, since the participants were accompanied by the researcher during their self-assessment of the QLQ-C30 or were assisted if necessary.
Conclusions
The EORTC QLQ-C15-PAL showed good content validity in the assessment of symptoms and QOL of advanced cancer patients. Additionally, we identified linguistic issues in the dyspnea and constipation items that were revised by the EORTC group. This questionnaire may help clinicians, and researchers to initiate palliative care interventions that may improve QOL of patients. Therefore, we recommend the use of the EORTC QLQ-C15-PAL in patients receiving palliative care in Chile. More research is needed to add a social dimension for a comprehensive assessment of patients’ QOL in Chile.
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