Assessing quality of life in palliative care settings: head-to-head comparison of four patient-reported outcome measures (EORTC QLQ-C15-PAL, FACT-Pal, FACT-Pal-14, FACT-G7)

A Randomized Controlled Trial of Betamethasone on Fatigue in Patients With Advanced Cancer

CONTEXT

Fatigue is one of the most uncomfortable physical symptoms seen in patients with advanced cancer. Previous studies have reported on the efficacy of corticosteroids from Western countries.

OBJECTIVES

To assess the effectiveness of 4mg betamethasone improving fatigue among Japanese patients with advanced cancer.

METHODS

A randomized, double-blind, placebo-controlled trial enrolled eligible patients with advanced cancer expected to survive 1-2 months, with an Eastern Cooperative Oncology Group Performance Status of 2-3, and experiencing fatigue according to the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-15-palliative criteria. Participants received twice-daily oral administration of 2 mg betamethasone (4 mg/d) or placebo for seven days, with fatigue assessed using EORTC QLQ-C15-PAL subscale and numerical rating scale (NRS) score (at baseline and day seven). The trial was registered under the University Hospital Medical Information Network (UMIN)000011913.

RESULTS

Among the 267 screened patients, 81 were eligible, of which 70 were evaluable (betamethasone, 33; placebo, 37). The mean difference in the EORTC-QLQ-C15-PAL fatigue subscale was -8.2 (95% CIs: -22.3, 0.0; P = 0.178) and in a NRS for fatigue was -1.2 (95% CIs: -2.5, -0.01; P = 0.048), respectively. Emotional function, appetite loss, and global-health were slightly better in the betamethasone group than in the placebo group.

CONCLUSION

The impact of betamethasone 4 mg/d on alleviating fatigue in patients with advanced cancer in the last weeks of life did not reach statistical significance in the EORTC-QLQ-C15-PAL as the primary endpoint, however, it was significant in the NRS, the secondary endpoint.

A Digital Platform (Telepalliation) for Patients in Palliative Care and Their Relatives: Protocol for a Multimethod Randomized Controlled Trial

BACKGROUND

The World Health Organization defines end-of-life palliative care as "prevention and relief of suffering, by means of early identification and impeccable assessment and treatment of pain and other problems, physical, psychosocial and spiritual." Over 20 million people worldwide are in need of palliative care. In Denmark, palliative care is given at a general and a specialist level. The general level comprises health care professionals (HCPs) who do not perform palliative care full-time. The specialist level comprises specialized palliative care (SPC), where HCPs perform palliative care full-time. In total, 20%-30% of patients who need palliative care are referred to SPC. Challenges with SPC include a short time span from referral to end of life, patients who are very ill and may therefore find it hard to travel to an outpatient clinic, and the SPC unit having a relatively small staff. The need for SPC is expected to rise, as the number of patients dying from terminal diseases is increasing. Telehealth has been successfully implemented in different home care settings, including palliative care.

OBJECTIVE

The aim of the study is to present the research design of the clinical testing of a telepalliation program by the use of a digital platform for patients in palliative care and their relatives.

METHODS

The telepalliation program will be conducted as a multimethod randomized controlled trial. The intervention group will follow the telepalliation program, while the control group will follow the traditional standard of care program for palliative care. The primary outcome of the study is increased quality of life. Secondary outcomes include enhanced sense of security; reduced experience of pain; satisfactory experiences of patients and relatives with the TelePal platform and degree of satisfaction in being a part of the program; experiences with the use of the TelePal platform on the part of HCPs and the professionals' experiences of being a part of the program; the use of a cross-sector communication platform and the telepalliation program by patients, relatives, and HCPs; and the projected lower cost of health care services. These outcomes will be assessed using questionnaires, data generated by digital technologies, and semistructured interviews.

RESULTS

The collection of data began in May 2021 and will be completed in August 2024. The results of the study will be published in peer-reviewed journals and presented at international conferences. Results from the telepalliation program are expected to be published by fall 2024.

CONCLUSIONS

The expected outcomes of the study are increased quality of life and increased sense of security. We also expect that the study will have a clinical impact on future telepalliation for those patients who are referred to a palliative team.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04995848; https://clinicaltrials.gov/study/NCT04995848.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/49946.

The Validity of Patient-Reported Outcome Measures of Quality of Life in Palliative Care: A Systematic Review

Importance: A recent systematic review and meta-analysis found that palliative care was not associated with improvement in quality of life (QOL) in terminal noncancer illness. Among potential reasons for a null effect, it is unclear if patient-reported outcome measures (PROMs) measuring QOL were derived or validated among populations with advanced life-limiting illness (ALLI). Objective: To systematically review the derivation and validation of QOL PROMs from a recent meta-analysis of randomized controlled trials (RCT) of palliative care interventions in people with terminal noncancer illness. Evidence Review: EMBASE, MEDLINE, and PsycINFO were searched from inception to January 8, 2023 for primary validation studies of QOL PROMs in populations with ALLI, defined as adults with a progressive terminal condition and an estimated median survival of less than or equal to one year. The primary outcome was the proportion of PROMs that were derived or validated in ≥1 ALLI population. Findings: Twenty-one unique studies of derivation (n = 13) and validation (n = 11, 3 studies evaluated both) provided data on 9657 participants (mean age 63 years, 50% female) across 15 unique QOL PROMs and subscales. Among studies of validation, 9 were in people with cancer (n = 2289, n = 5 PROMs), 1 in neurodegenerative disease (n = 23, n = 1 PROM), and 1 with mixed diseases (n = 248, n = 1 PROM). Across 15 QOL PROMs and subscales, 47% (n = 7) were derived or validated in an ALLI population. The majority of these seven PROMs were exclusively derived or validated among people with cancer (57%, n = 4). QOL PROMs such as Quality of Life at End of Life, EuroQoL-5 Dimension 5-level, and 36-item Short Form Survey demonstrated validity in more than one terminal noncancer illness. Conclusions: Most QOL PROMs that measured the effect of palliative care on QOL in RCTs were neither derived nor validated in an ALLI population. These findings raise questions about the inferences that palliative care does not improve QOL among people with terminal noncancer illness.

Validation of the FACT-G7 in patients with hematologic malignancies

Background

It is essential to evaluate the quality of life in patients with hematologic malignancies to reflect the therapeutic effect and prognosis, but lengthy assessments are often burdensome. The 7-Item Functional Assessment of Cancer Therapy-General (FACT-G7) is a brief, easy, and rapid index for evaluating quality of life. Nevertheless, there is no report about its application in Chinese patients with hematologic malignancies.

Objective

The purpose of this study was to validate the Chinese version of the FACT-G7 for patients with hematologic malignancies.

Methods

This study is a cross-sectional study. A total of 855 patients with hematologic malignancies completed the Functional Assessment of Cancer Therapy-General (FACT-G) and were scored the Eastern Cooperative Oncology Group Performance Status (ECOG-PS) by nurses. Cronbach's alpha, confirmatory factor analyses, Pearson's correlation, and one-way analysis of variance were conducted to evaluate internal consistent reliability, structural validity and concurrent validity.

Results

The FACT-G7 showed acceptable internal consistency, as indicated by a Cronbach's alpha of 0.73. The confirmatory factor analyses test for single-factor model fit for the FACT-G7 scale was almost adequate. The satisfactory correlations between the FACT-G7 and the FACT-G and its subscales, and ECOG-PS groups differed in FACT-G7 scores demonstrating concurrent validity.

Conclusion

This study suggested that the Chinese version of the FACT-G7 provides a useful and rapid measure for assessing quality of life in Chinese patients with hematologic malignancies, which providing a reference for further evaluation and care.

Patient-reported outcomes for people with diabetes: what and how to measure? A narrative review

Patient-reported outcomes (PROs) are valuable for shared decision making and research. Patient-reported outcome measures (PROMs) are questionnaires used to measure PROs, such as health-related quality of life (HRQL). Although core outcome sets for trials and clinical practice have been developed separately, they, as well as other initiatives, recommend different PROs and PROMs. In research and clinical practice, different PROMs are used (some generic, some disease-specific), which measure many different things. This is a threat to the validity of research and clinical findings in the field of diabetes. In this narrative review, we aim to provide recommendations for the selection of relevant PROs and psychometrically sound PROMs for people with diabetes for use in clinical practice and research. Based on a general conceptual framework of PROs, we suggest that relevant PROs to measure in people with diabetes are: disease-specific symptoms (e.g. worries about hypoglycaemia and diabetes distress), general symptoms (e.g. fatigue and depression), functional status, general health perceptions and overall quality of life. Generic PROMs such as the 36-Item Short Form Health Survey (SF-36), WHO Disability Assessment Schedule (WHODAS 2.0), or Patient-Reported Outcomes Measurement Information System (PROMIS) measures could be considered to measure commonly relevant PROs, supplemented with disease-specific PROMs where needed. However, none of the existing diabetes-specific PROM scales has been sufficiently validated, although the Diabetes Symptom Self-Care Inventory (DSSCI) for measuring diabetes-specific symptoms and the Diabetes Distress Scale (DDS) and Problem Areas in Diabetes (PAID) for measuring distress showed sufficient content validity. Standardisation and use of relevant PROs and psychometrically sound PROMs can help inform people with diabetes about the expected course of disease and treatment, for shared decision making, to monitor outcomes and to improve healthcare. We recommend further validation studies of diabetes-specific PROMs that have sufficient content validity for measuring disease-specific symptoms and consider generic item banks developed based on item response theory for measuring commonly relevant PROs.

Considerations for Pain Assessments in Cancer Patients: A Narrative Review of the Latin American Perspective

Cancer incidence in Latin America is lower than in Europe or the United States but morbidity and mortality rates are disproportionately high. A barrier to adequate pain control is inadequate pain assessment, which is a relatively easy and inexpensive metric. The objective of this narrative review is to describe pain assessment for cancer patients in Latin America. Cultural factors may influence pain perception, including contextualizing pain as noble or natural suffering and aspects of what is now called "spiritual pain." Unlike other painful conditions, cancer pain may be strongly associated with existential fear, psychosocial distress, anxiety, and spiritual concerns. Pain assessment allows not just quantification of pain intensity but may elucidate pain mechanisms involved or psychosocial aspects that may color the pain. Many current pain assessment instruments capture only pain intensity, which is but one aspect of the pain experience; some have expanded to include functional assessments, mental health status evaluations, and quality of life metrics. A quality-of-life assessment may be appropriate for cancer patients since chronic pain can severely impact function, which can in turn create a vicious cycle by exacerbating pain. The incidence of cancer in Latin America is expected to increase in the ensuing years. Better pain assessment and clinician education are needed to help manage pain in this large and growing patient population.

Effect of Perioperative Palliative Care on Health-Related Quality of Life Among Patients Undergoing Surgery for Cancer: A Randomized Clinical Trial

Importance

Involvement of palliative care specialists in the care of medical oncology patients has been repeatedly observed to improve patient-reported outcomes, but there is no analogous research in surgical oncology populations.

Objective

To determine whether surgeon-palliative care team comanagement, compared with surgeon team alone management, improves patient-reported perioperative outcomes among patients pursuing curative-intent surgery for high morbidity and mortality upper gastrointestinal (GI) cancers.

Design, Setting, and Participants

From October 20, 2018, to March 31, 2022, a patient-randomized clinical trial was conducted with patients and clinicians nonblinded but the analysis team blinded to allocation. The trial was conducted in 5 geographically diverse academic medical centers in the US. Individuals pursuing curative-intent surgery for an upper GI cancer who had received no previous specialist palliative care were eligible. Surgeons were encouraged to offer participation to all eligible patients.

Intervention

Surgeon-palliative care comanagement patients met with palliative care either in person or via telephone before surgery, 1 week after surgery, and 1, 2, and 3 months after surgery. For patients in the surgeon-alone group, surgeons were encouraged to follow National Comprehensive Cancer Network-recommended triggers for palliative care consultation.

Main Outcomes and Measures

The primary outcome of the trial was patient-reported health-related quality of life at 3 months following the operation. Secondary outcomes were patient-reported mental and physical distress. Intention-to-treat analysis was performed.

Results

In total, 359 patients (175 [48.7%] men; mean [SD] age, 64.6 [10.7] years) were randomized to surgeon-alone (n = 177) or surgeon-palliative care comanagement (n = 182), with most patients (206 [57.4%]) undergoing pancreatic cancer surgery. No adverse events were associated with the intervention, and 11% of patients in the surgeon-alone and 90% in the surgeon-palliative care comanagement groups received palliative care consultation. There was no significant difference between study arms in outcomes at 3 months following the operation in patient-reported health-related quality of life (mean [SD], 138.54 [28.28] vs 136.90 [28.96]; P = .62), mental health (mean [SD], -0.07 [0.87] vs -0.07 [0.84]; P = .98), or overall number of deaths (6 [3.7%] vs 7 [4.1%]; P > .99).

Conclusions and Relevance

To date, this is the first multisite randomized clinical trial to evaluate perioperative palliative care and the earliest integration of palliative care into cancer care. Unlike in medical oncology practice, the data from this trial do not suggest palliative care-associated improvements in patient-reported outcomes among patients pursuing curative-intent surgeries for upper GI cancers.

Trial Registration

ClinicalTrials.gov Identifier: NCT03611309.

Treatment patterns and out-of-hospital healthcare resource utilisation by patients with advanced cancer living with pain: An analysis from the Stop Cancer PAIN trial

BACKGROUND

About 70% of patients with advanced cancer experience pain. Few studies have investigated the use of healthcare in this population and the relationship between pain intensity and costs.

METHODS

Adults with advanced cancer and scored worst pain ≥ 2/10 on a numeric rating scale (NRS) were recruited from 6 Australian oncology/palliative care outpatient services to the Stop Cancer PAIN trial (08/15-06/19). Out-of-hospital, publicly funded services, prescriptions and costs were estimated for the three months before pain screening. Descriptive statistics summarize the clinico-demographic variables, health services and costs, treatments and pain scores. Relationships with costs were explored using Spearman correlations, Mann-Whitney U and Kruskal-Wallis tests, and a gamma log-link generalized linear model.

RESULTS

Overall, 212 participants had median worst pain scores of five (inter-quartile range 4). The most frequently prescribed medications were opioids (60.1%) and peptic ulcer/gastro-oesophageal reflux disease (GORD) drugs (51.6%). The total average healthcare cost in the three months before the census date was A$6,742 (95% CI $5,637, $7,847), approximately $27,000 annually. Men had higher mean healthcare costs than women, adjusting for age, cancer type and pain levels (men $7,872, women $4,493, p<0.01) and higher expenditure on prescriptions (men $5,559, women $2,034, p<0.01).

CONCLUSIONS

In this population with pain and cancer, there was no clear relationship between healthcare costs and pain severity. These treatment patterns requiring further exploration including the prevalence of peptic ulcer/GORD drugs, and lipid lowering agents and the higher healthcare costs for men.

TRIAL REGISTRATION

ACTRN12615000064505. World Health Organisation unique trial number U1111-1164-4649. Registered 23 January 2015.

Symptom experience and care needs of Turkish palliative care patients

BACKGROUND

Nurses need to focus on supporting patients' quality of life, supporting their families, reducing the morbidity rate, providing psychosocial support services to improve symptom management and delivering high-quality care.

AIM

This study aimed to determine the symptom experience and care needs of Turkish patients who received inpatient treatment in palliative care units.

METHODS

This descriptive research was conducted between May 2019 and May 2020. The study sample was composed of 200 palliative care patients selected using a convenience-purposive sampling method. The personal and disease-related characteristics were collected using the Patient Information Survey and the Functional Assessment of Chronic Illness Therapy-Palliative Care scale.

FINDINGS

The mean age of the sample was 75±15 years, and 56.5% were women. The patients' overall quality of life scores were below average (mean 84.05±19.44). The functional wellbeing and other concerns subscales of the scale were affected the most adversely. The Physical Wellbeing subscale was affected minimally, while the Emotional Wellbeing and Social Wellbeing subscales were affected moderately. Conclusion: The palliative care patients mostly needed support for the prevention and management of infections, management of respiratory distress and swallowing problems, dealing with confusion and improving compliance with treatment. The low quality of life scores emphasise the importance of urgent interventions for improving the functional wellbeing and symptom management in these patients.

Cross-cultural translation and adaptation of Functional Assessment of Cancer Therapy – Multiple Myeloma tool – MM1 and LEU3 – for Portuguese

Objective

To describe of the translation from English to Portuguese and adaption process of subitems of the Functional Assessment of Cancer Therapy – Multiple Myeloma.

Methods

In the first phase, translations from English into Portuguese of two subitems of Functional Assessment of Cancer Therapy – Multiple Myeloma were performed. Subsequently, a consensus and back translation were conducted, and, finally, translation and back translations were reviewed by four independent bilingual experts. In the second phase, the translated subitems were applied, along with a questionnaire, to 10 native Portuguese speakers patients with multiple myeloma.

Results

There was a recognition of the translation process in its first version applied to 10 patients with multiple myeloma, whose reported no difficult to understand the translated and validated instrument. Patients also did not find the content irrelevant or offensive, and they did not suggested changes.

Conclusion

The subitems of the Functional Assessment of Cancer Therapy – Multiple Myeloma were translated from English into Portuguese following the proposed methodology and there was not need of readjustments. This process allowed this instrument of quality of life, which is widely known to be beneficial in the management of patients with multiple myeloma, to be used among our population.

Measuring quality of life in older people with cancer

PURPOSE OF REVIEW

The number of individuals aged 65+ with cancer will double in the next decade. Attention to quality of life (QOL) is imperative to identify relevant endpoints/outcomes in research and provide care that matches individual needs. This review summarizes recent publications regarding QOL measurement in older adults with cancer, considering implications for research and practice.

RECENT FINDINGS

QOL is a complex concept and its measurement can be challenging. A variety of measurement tools exist, but only one specific to older adults with cancer. QOL is frequently measured as functional health, adverse symptoms, and global QOL, thus only capturing a portion of this concept. Yet successful QOL intervention for older adults requires drawing from behavioral and social dimensions.Growing interest in comprehensive geriatric assessment (CGA) and patient-reported outcomes (PROs) provides important opportunities for measuring QOL. Recommendations for use of CGAs and PROs in clinical practice have been made but widespread uptake has not occurred.

SUMMARY

QOL is important to older adults and must be central in planning and discussing their care. It is modifiable but presents measurement challenges in this population. Various domains are associated with decline, survival, satisfaction with life, coping, and different interventions. Measurement approaches must fit with intention and capacity to act within given contexts.

The effects of guided imagery and hand massage on wellbeing and pain in palliative care: Evaluation of a pilot study

BACKGROUND

This study aims to measure the effect of guided imagery and hand massage on self-rated wellbeing and pain for palliative care patients.

METHODS

This study adopted a quasi-experimental one-group pre-test post-test design. The sample consisted of n = 20 adult palliative care patients who received one session of guided imagery and hand massage. Self-reported levels of wellbeing and pain were measured on a scale of 0-10 before and after the intervention. Results were analyzed using a one-tailed sign test in SPSS Software.

RESULTS

The intervention elicited a statistically significant improvement in self-reported levels of wellbeing (p = .029) and pain (p = .001). Feedback from participants showed the intervention was helpful and relaxing.

CONCLUSION

The intervention had an immediate positive effect on wellbeing and pain among palliative care patients. Considering the promising results of this pilot study, guided imagery and hand massage should be studied further in the palliative care setting.

Head-to-Head Comparison of the Psychometric Properties of 3 Carer-Related Preference-Based Instruments

OBJECTIVES

To compare the psychometric properties of the Adult Social Care Outcomes Toolkit for carers (ASCOT-Carer), the Carer Experience Scale (CES), and the Care-related Quality of Life (CarerQol) to inform the choice of instrument in future studies.

METHODS

Data were derived from a 2018 online survey of informal carers in Australia. Reliability was assessed via internal consistency (Cronbach alpha, α) and test-retest reliability (intraclass correlation coefficient, ICC) for respondents who self-reported no change in their quality of life as a carer over 2 weeks. Convergent validity was evaluated via predetermined hypotheses about associations (Spearman's rank correlation) with existing, validated measures. Discriminative validity was assessed based on the ability of the carer-related scores to distinguish between different informal care situations (Mann-Whitney U, Kruskal-Wallis one-way analysis of variance).

RESULTS

Data from 500 carers were analyzed. The ASCOT-Carer demonstrated a higher degree of internal consistency, possibly due to a unidimensional structure, and test-retest reliability than the CarerQol and CES (α = 0.87, 0.65, 0.59; ICC, 0.87, 0.67, 0.81, respectively). All 3 instruments exhibited convergent validity and detected statistically significant associations between carer-related scores and different informal care situations, except for the CarerQol-7D and sole carer status.

CONCLUSIONS

The ASCOT-Carer, CarerQol, and CES performed reasonably well psychometrically; the ASCOT-Carer exhibited the best psychometric properties overall in this sample of Australian informal carers. Findings should be used in conjunction with consideration of research goals, carer population, targeted carer-related constructs, and prevailing perspectives on the economic evaluation to inform choice of instrument in future studies.

Validation of the 7-item Functional Assessment of Cancer Therapy-General (FACT-G7) as a short measure of quality of life in patients with advanced cancer

BACKGROUND

Assessing quality of life is essential for individuals with advanced cancer, but lengthy assessments can be burdensome. The authors investigated the psychometric characteristics of the FACT-G7, a 7-item quality-of-life measure derived from the Functional Assessment of Cancer Therapy-General (FACT-G) scale, in advanced cancer.

METHODS

Data were obtained from outpatients with advanced cancer who were enrolled in a randomized controlled trial of early palliative care. At baseline, 228 intervention participants and 233 control participants (N = 461) completed the FACT-G and measures of symptom severity, quality of life near the end of life, problematic medical communication, and satisfaction with care. Follow-up measures were administered monthly for 4 months.

RESULTS

The FACT-G7 showed good internal consistency (Cronbach α = .72-.80), and its single-factor structure was supported. It correlated strongly with the FACT-G total, physical, and functional indices and with symptom severity (absolute r = 0.73-0.92); more moderately with the FACT-G emotional index and with symptom impact and preparation for the end of life (r = .40-.71); and least with the FACT-G social/family index and with relationship with health care provider, life completion, problematic medical communication, and care satisfaction measures (absolute r = .26-.44). Eastern Cooperative Oncology Group performance status groups differed on FACT-G7 scores, as expected (all P < .001). Improvements in FACT-G7 scores in the intervention group compared with the control group at 3-month (P = .049) and 4-month (P = .034) follow-up supported responsiveness to change and somewhat greater sensitivity than the FACT-G scores.

CONCLUSIONS

The FACT-G7 is a valid, brief measure particularly of the physical and functional facets of quality of life. It may enable rapid quality-of-life assessments in patients with advanced cancer.

A Multicenter, Randomized Controlled Trial of Perioperative Palliative Care Surrounding Cancer Surgery for Patients and Their Family Members (PERIOP-PC)

Background: Despite positive outcomes associated with specialist palliative care (PC) in diverse medical populations, little research has investigated specialist PC in surgical ones. Although cancer surgery is predominantly safe, operations can be extensive and unpredictable perioperative morbidity and mortality persist, particularly for patients with upper gastrointestinal (GI) cancers. Objectives and Hypotheses: Our objective is to complete a multicenter, randomized controlled trial comparing surgeon-PC co-management with surgeon-alone management among patients pursuing curative-intent surgery for upper GI cancers. We hypothesize that perioperative PC will improve patient postsurgical quality of life. This study and design are based on >8 years of engagement and research with patients, family members, and clinicians surrounding major cancer surgery and advance care planning/PC for surgical patients. Methods: Randomized controlled superiority trial with two study arms (surgeon-PC team co-management and surgeon-alone management) and five data collection points over six months. The principal investigator and analysts are blinded to randomization. Setting: Four, geographically diverse, academic tertiary care hospitals. Data collection began December 20, 2018 and continues to December 2020. Participants: Patients recruited from surgical oncology clinics who are undergoing curative-intent surgery for an upper GI cancer. Interventions: In the intervention arm, patients receive care from both their surgical team and a specialist PC team; the PC is provided before surgery, immediately after surgery, and at least monthly until three months postsurgery. Patients randomized to the usual care arm receive care from only the surgical team. Main Outcomes and Measures: Primary outcome: patient quality of life. Secondary outcomes: patient: symptom experience, spiritual distress, prognostic awareness, health care utilization, and mortality. Caregiver: quality of life, caregiver burden, spiritual distress, and prognostic awareness. Intent-to-treat analysis will be used. Ethics and Dissemination: This study has been approved by the institutional review boards of all study sites and is registered on clinicaltrials.gov (NCT03611309, First received: August 2, 2018).