Validity and reliability of the English and translated Chinese versions of the Integrated Palliative care Outcome Scale (IPOS) in Singapore

Abstract

Context Measurement of patient-centred outcomes enables clinicians to focus on patient and family priorities and enables quality of palliative care to be assessed. Objectives This study aimed to evaluate the validity and reliability of the English and translated Chinese versions of the Integrated Palliative care Outcome Scale (IPOS) among advanced cancer patients in Singapore. Methods IPOS was forward and backward translated from English into Chinese. Structural validity was assessed by confirmatory factor analysis; known-group validity by comparing inpatients and community patients; construct validity by correlating IPOS with Edmonton Symptom Assessment System-revised (ESAS-r) and Functional Assessment of Cancer Therapy–General (FACT-G); internal consistency by Cronbach’s alpha; inter-rater reliability between patient and staff responses; test-retest reliability of patient responses between two timepoints. Results One hundred eleven English-responding and 109 Chinese-responding patients participated. The three-factor structure (Physical Symptoms, Emotional Symptoms and Communication and Practical Issues) was confirmed with Comparative Fit Index and Tucker-Lewis-Index > 0.9 and Root Mean Square Error of Approximation < 0.08. Inpatients scored higher than outpatients as hypothesised. Construct validity (Pearson’s correlation coefficient, r ≥ |0.608|) was shown between the related subscales of IPOS and FACT-G and ESAS-r. Internal consistency was confirmed for total and subscale scores (Cronbach’s alpha≥0.84), except for the Communication and Practical Issues subscale (Cronbach’s alpha = 0.29–0.65). Inter-rater reliability (Intra-class correlation coefficient [ICC] ≤ 0.43) between patient and staff responses was insufficient. Test-retest reliability was confirmed with Intra-class correlation coefficient ICC = 0.80 (English) and 0.88 (Chinese) for IPOS Total. Conclusion IPOS in English and Chinese showed good validity, good internal consistency, and good test-retest reliability, except for the Communication and Practical Issues subscale. There was poor inter-rater reliability between patients and staff.

Validity and Reliability of the Integrated Palliative Care Outcome Scale in Asian Heart Failure Patients

“…The first item “What have been your main problems or concerns over the past three days?” required participants to report their main problems and concerns in free text. The IPOS used in this study 21 had an additional descriptor (health, financial, well-being etc.) for the first item, to provide participants with an additional context for answering this question.…”

“… 20 In an earlier study, the team culturally adapted the IPOS for cancer patients in Singapore. 21 This was done through an iterative process of cognitive interviews with patients to adapt the IPOS items in accordance with existing guidelines. 22…”

“…However, as patients with HF have a different prevalence of symptoms and needs compared to patients with cancer, 7 this study aimed at evaluating the validity and reliability of the culturally adapted IPOS 21 in patients with HF in Singapore.…”

Intra-rater reliability and feasibility of the HexCom advanced disease complexity assessment model

“… 16 As for the Integrated Palliative care Outcome Scale (IPOS), good test-retest reliability has been reported for the subscales physical symptoms (intra-class correlation coefficient [ICC] = 0.77) and emotional symptoms (ICC = 0.72), and moderate for the subscale communication and practical issues (ICC = 0.53). 17 With respect to the Palliative Care Outcomes Collaboration Symptom Assessment Scale (PCOC SAS), Daveson found a weighted kappa of 0.6 (CI 95% 0.54–0.63) for the pain item. 18 Similarly, for the Japanese version of the STAS-J, which was also analyzed using hypothetical cases, a weighted kappa of 0.64–0.85 was reported.…”

Translation and cultural adaptation of the Integrated Palliative care Outcome Scale for Dementia (IPOS-Dem) to Swedish

“…Based on POS and POS-S (a symptom module), The Integrated Palliative care Outcome Scale (IPOS) was developed [ 6 ]. IPOS has been translated into several languages, including Chinese [ 7 ], Italian [ 8 ], Estonian [ 9 ], French [ 10 ], Czech [ 11 ], Turkish [ 12 ], Portuguese [ 13 ] and Japanese [ 14 ]. A Swedish version of IPOS has been developed by Beck et al [ 15 ] and has now been partly implemented in specialised palliative care in Sweden.…”