Questioning Claims of Cross-Cultural Equivalence: the Case of Quality of Life Measurement

1. Questioning Claims of Cross-Cultural Equivalence: the Case of Quality of Life Measurement Katerini Tagmatarchi Storeng Maternal Health Group London School of Hygiene and Tropical Medicine

2. Introduction • Effectiveness of medical interventions is evaluated by quantitative assessment of specific outcomes • “Quality of life” (QoL) as one non-clinical patient-assessed outcome • Quality of life studies subsume studies of physical, psychological and social functioning • Little consensus about what quality of life means

3. History • In health research • Epidemiological shift towards chronic diseases • Changing attitudes and expectations towards health • Reconceptualisation of patient as consumer • Requirement that outcomes be measured for evaluation and resource allocation purposes

4. Objectives • To describe some of the assumptions upon which quality of life measurement is based • To consider some of the tensions of quantifying quality of life cross-culturally • To examine the limitations of quality of life measurement in the context of maternal health research • To propose some anthropological modifications to existing methods

5. IMMPACT and Quality of Life • Initiative for maternal mortality programme assessment (IMMPACT) • Quality of life of interest because of high levels of maternal illness and disability in developing countries • Critical review: QoL literature focuses on psychometric rigour, but there is insufficient focus on theoretical and conceptual issues (e.g. Bowden & Fox-Rushby 2003)

6. Defining Quality of Life: a Valid Construct? • Gill and Feinstein (1994) 15% of papers conceptually defined quality of life • Leplège and Hunt (1997) Variability across cultures, between patients, and in the same patient over time makes efforts to define quality of life impossible

7. Quality of Life Assumptions • Health is determined by the absence or presence of symptoms and disease • Quality of life as a construct is valid, important and ubiquitous across cultures • Those aspects of quality of life affected by health can be separated from overall quality of life: ‘health-related quality of life’ • Changes in quality of life are affected by changes in health status and by health care interventions • Quality of life instruments are culture free

8. Questioning the Assumptions • It is the meaning and significance of symptoms, not the symptoms per se, that have the potential of influencing quality of life • Instruments reflect the views of researchers • Few people limit their definition of quality of life to health • Ideas of health intrinsic to quality of life measurement conflict with variations in local ideas about health

9. Cross-Cultural Adaptation • Instruments adapted because of assumed value of international population norms of health • The choice of which instrument to adapt based on reputation and consensus rather than on consideration of cultural relevance • Universally applicable measures desirable from the point of view of standardisation and comparability – but at what cost?

10. Adapted or Equivalent • Cross-cultural equivalence: instruments measure the same thing in the same way in more than one culture • Hunt (1998): can ‘quality of life’ be defined and measured precisely enough to have scientific credibility across cultures? • Can versions of the same instrument in different languages be considered equivalent for the purpose of data aggregation?

11. Model of Equivalence • Conceptualequivalence: the way in which different populations conceptualise health and quality of life and the value they place on different domains of these concepts • Itemequivalence: the way in which domains are sampled • Semanticequivalence: the transfer of meaning across languages, and receiving a similar effect on respondents in different languages • Operational equivalence: the possibility of using a similar questionnaire format, instructions, mode of administration and measurement methods • Measurement equivalence: the extent to which the psychometric properties of different language versions of the same instrument are similar • Functional equivalence: the extent to which an instrument does what it is supposed to do equally well in two or more cultures. Herdman et al. (1997)

12. Maternal Health and Quality of Life • Many indicators equated with quality of life and a range of generic instruments used • Quality of life invoked as a meaningful outcome measure and descriptive term but no critical reflection on conceptual basis of quality of life

13. Maternal Health in Developing Countries • Use of QoL measures in maternal health largely restricted to industrialised countries • Prevalence of obstetric complications high in developing countries • Chronic morbidity and disability result from obstetric complications and have severe physical, psychological, social and cultural consequences

14. Cultural Aspects • Problematic to assume that quality of life implications of maternal ill health similar across cultures. Must consider: • Culturally constructed nature of women’s health • Gendered rules about expression of suffering • Structural constraints on health • Discordance between lay and professional views

15. Conclusions • Assessment of subjective perceptions and evaluations of health important • The reductionistic nature of quality of life measurement means that patients’ views are rarely included • General lack of conceptual and theoretical reflection, excessive focus on psychometric rigour, uncritical assumption of universal nature of health and quality of life problematic • May be sensible to refine the concept to be measured, acknowledge the limits of quantification, argue for the incorporation of more qualitative forms of evidence both in the formulation of quantitative measures and in the interpretation of findings, and assess ‘quality of life’ anthropologically.

16. Selected References • Bowden, A. and J. A. Fox-Rushby (2003). "A systematic and critical review of the process of translation and adaptation of generic health-related quality of life measures in Africa, Asia, Eastern Europe, the Middle East, South America." Social Science & Medicine57(7): 1289-306. • Gill, T. M. and A. R. Feinstein (1994). "A critical appraisal of the quality of the quality-of-life measurements." Journal of the American Medical Association272(8): 619-631. • Herdman, M., J. Fox-Rushby, et al. (1997). "'Equivalence' and the translation and adaptation of health-related quality of life questionnaires." Quality of Life Research6(3): 237-47. • Hunt, S. M. (1998). Cross-cultural issues in the use of quality of life measures in randomised controlled trials. Quality of Life Assessment in Clinical Trials. M. J. Staquet, R. D. Hayes and P. M. Fayers. Oxford, Oxford University Press: 51-67. • Leplège, A. and S. Hunt (1997). "The problem of quality of life in medicine." Journal of the American Medical Association278(1): 47-50.