An analysis of the construct validity and responsiveness of the ICECAP-SCM capability wellbeing measure in a palliative care hospice setting

Abstract

Background For outcome measures to be useful in health and care decision-making, they need to have certain psychometric properties. The ICECAP-Supportive Care Measure (ICECAP-SCM), a seven attribute measure (1. Choice, 2. Love and affection, 3. Physical suffering, 4. Emotional suffering, 5. Dignity, 6. Being supported, 7. Preparation) developed for use in economic evaluation of end-of-life interventions, has face validity and is feasible to use. This study aimed to assess the construct validity and responsiveness of the ICECAP-SCM in hospice inpatient and outpatient settings. Methods A secondary analysis of data collated from two studies, one focusing on palliative care day services and the other on constipation management, undertaken in the same national hospice organisation across three UK hospices, was conducted. Other quality of life and wellbeing outcome measures used were the EQ-5D-5L, McGill Quality of Life Questionnaire – Expanded (MQOL-E), Patient Health Questionnaire-2 (PHQ-2) and Palliative Outcomes Scale Symptom list (POS-S). The construct validity of the ICECAP-SCM was assessed, following hypotheses generation, by calculating correlations between: (i) its domains and the domains of other outcome measures, (ii) its summary score and the other measures’ domains, (iii) its summary score and the summary scores of the other measures. The responsiveness of the ICECAP-SCM was assessed using anchor-based methods to understand change over time. Statistical analysis consisted of Spearman and Pearson correlations for construct validity and paired t-tests for the responsiveness analysis. Results Sixty-eight participants were included in the baseline analysis. Five strong correlations were found with ICECAP-SCM attributes and items on the other measures: four with the Emotional suffering attribute (Anxiety/depression on EQ-5D-5L, Psychological and Burden on MQOL-E and Feeling down, depressed or hopeless on PHQ-2), and one with Physical suffering (Weakness or lack of energy on POS-S). ICECAP-SCM attributes and scores were most strongly associated with the MQOL-E measure (0.73 correlation coefficient between summary scores). The responsiveness analysis (n = 36) showed the ICECAP-SCM score was responsive to change when anchored to changes on the MQOL-E over time (p < 0.05). Conclusions This study provides initial evidence of construct validity and responsiveness of the ICECAP-SCM in hospice settings and suggests its potential for use in end-of-life care research.

Methodological challenges and potential solutions for economic evaluations of palliative and end-of-life care: A systematic review

“…The majority were published in the past 10 years ( N = 59 (70%)). The largest group of first authors (41%) was affiliated with institutions in the UK, 15,16,20,22,26,34 –61 followed by the USA (13%). 62 –71 Study types and their focus varied widely, including systematic reviews and meta-analyses, 17,26,41,52 –54,72,73 qualitative studies 35,36,40,44,49,50,51,58,74 and studies describing, for example, the development and/or concept of an outcome measure, testing its validity.…”

“…In total, we identified challenges that can be grouped into nine themes, with most of the studies relating to three of them: ambiguity in the selection of outcomes, 16,17,20 –22,26,34 –50,62,63,72,74–88 , non-standardised measurement and valuation of costs, 15,17,26,40 –42,47,51 –57,61,64,65,73,85,89 –93 and narrow costing perspective app-lied. 17,20,…”

“…In total, we identified challenges that can be grouped into nine themes, with most of the studies relating to three of them: ambiguity in the selection of outcomes, 16,17,[20][21][22]26,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50]62,63,72,[74][75][76][77][78][79][80][81][82][83][84][85][86][87][88] , non-standardised measurement and valuation of costs, 15,17,26,[40][41][42]47,[51][52][53]…”

“…35 Aligning with the capability approach, these measures concentrate on domains related to achieving a good life and good death for patients and their relatives. 35,45,50 Although several psychometric validation studies on the ICECAP-SCM have been recently published, 36,48,49,75 more comparative research is needed in this area. 45,50 Another measure is the Palliative Care Yardstick, which aims to assign a higher value to end-of-life care 22 and address dimensions such as caregiver impact 47 and valuation problems.…”

“…While the discussions regarding the most suitable outcome measurement instrument are ongoing, there has been a noticeable increase in psychometric validation studies focusing on specific tools like the ICECAP-SCM. 48,49,118,119 This growing body of research provides valuable information about the suitability and validity of such tools. Both in terms of challenges and potential solutions, the list of recommendations is not exhaustive.…”