Measuring what matters to older persons for active living: part I content development for the OPAL measure across four countries.

AIMS: Many older persons do not think of themselves as "patients" but as persons wishing to live as actively as possible for as long as possible. However, most health-related quality of life (HRQL) measures were developed for use with clinical populations. The aim of this project was to fill that gap and to develop, for international use, a measure of what matters to older persons as they age and seek to remain as active as possible, Older Persons for Active Living (OPAL). METHODS: For content development, interviews about active living were conducted with older persons from Canada, USA, UK, and the Netherlands in English, French, Spanish and Dutch, respectively with subsequent thematic analysis and harmonization. RESULTS: Analyses of transcripts from 148 older persons revealed that active living was a "way of being" and not merely doing activities. Saturation was reached and a total of 59 content areas were identified. After grouping similar "ways" together and after conducting a consensus rating of importance, 19 unique and important "ways" remained. In some languages, formulating was challenging for three of the 19, resulting in changes to two English words and dropping two other words, yielding a final list of 17 "ways of being" with harmonized wording in 4 languages. CONCLUSION: This study underscores the significance of listening to older adults and highlights the importance of considering linguistic and cultural nuances in measure development.

Measuring what matters to older persons for active living: part II cross-sectional validity evidence for OPAL measure across four countries.

INTRODUCTION: Through interviews with 148 older persons from four countries and in four languages, the content for a 17-item measure of active living was developed. The purpose of this paper is to present further evidence of the extent to which this new measure, Older Persons Active Living (OPAL), is "fit-for-purpose" for measuring the extent of active living at one point in time. METHODS: A cross-sectional study was carried out on a population aged 65 + and living independently, drawn from a participant panel, HostedinCanada, sampling people from Canada, United States, United Kingdom, and Netherlands. The survey instrument comprised the OPAL questionnaire rated on importance and frequency, sociodemographics, and information on physical and mental function. The argument-based approach to validity framed the analyses. Logistic regression, structural equation modeling, ordinary least-squares regression, and correlation were used to generate estimates for parameters underpinning validity evidence. RESULTS: A total of 1612 people completed the survey, 100 to 400 people across the 6 country-language strata. The proportion of people rating the items as extremely or quite important ranged from 60 to 90%, with no important differences between men and women and few differences between strata. A single-factor structure was supported. The ordinality of the response options justified an additive total score yielding a near normal distribution (mean: 33.1; SD: 11.5; range 0-51). Correlations with other measures of converging constructs were of moderate strength (~ 0.50), and differences across groups known to affect functioning and health were observed, suggesting a Miminal Important Difference (MID) of 6 out of 51. CONCLUSION: The results of this study provide evidence that the 17-item OPAL measure is fit for the purpose of estimating the extent to which older persons are living actively at one point in time.