Quality of Life
Three Words with Many Meanings
Donald L. Patrick
Global comparisons of health and health care systems drive a rising demand for health status and quality of life (QOL) measures for use in different cultures. Diagnostic criteria have become more international and treatments more standardized. Although provision and regulation of health care are still primarily a national responsibility international agreements on licensing and certification, on standards of care, and on applications of medical technology require evaluation through multinational clinical trials that aggregate data across countries. Also of growing interest are crosscultural comparisons to identify effective social and health policies that can be replicated in different nations. These global perspectives require outcome measures, including self-reported health and quality of life, that can be used to support claims, evaluate treatments, and monitor trends.
The demand for global measures is tempered by the recognition that wide differences exist in cultural notions of health and illness and in how different populations react to what is considered the same biological condition. A person's conception of what constitutes "disease" or "health" can his or her cultural traditions, language, and group mores as well as more individual characteristics such as age, gender, education level, and income. Consequently, data cannot be aggregated and crosscultural comparisons cannot be made without considering cultural content and striving for crosscultural comparability.
What is meant by crosscultural? For many parts of the world, crosscultural cannot be equated with crossnational because of ethnic diversity within national boundaries. The assumption of cultural comparability in measures derived from a single sample in a country may thus be invalid. In practice, however, the early development of a measure may begin within a single sample representing a nation, with extensions to different groups at a later date. It is one thing to claim cross-cultural validity for an instrument that has been tested in Europe and the United States; it is quite another to extend this claim to African or Asian cultures. The scope for cultural variation is almost limitless, and thus most efforts, focus on major languages with linguistic variations considered within each language.
Important considerations in development of measures are the crosscultural content, the meaning of different health and quality of life domains, the translation of measures from one language to another, and crosscultural validation. A key factor is the purpose of measurement (Table 1) for example, discriminating between the health status of different populations groups, evaluating change over time as in clinical trials or epidemiologic investigations, or predicting future health status such as mortality from self-perceived health status.
UW Contributions
Researchers in the Department of Health Services in the School of Public Health and Community Medicine are working on the translation, cultural adaptation, and simultaneous development of health and quality of life measures (Table 2). Translation converts a measure from the language in which it was developed to another language while retaining the original item content and meaning as closely as possible. Cultural adaptation involves an assessment of the intercultural relevance and conceptual equivalence of an original measure, with possibilities of changing the original measure for use crossculturally (Table 3). Simultaneous development is the concurrent development of equivalent versions of a measure in different languages and cultures.semantic equivalence, it was necessary to change this to "urinating or passing water," a more technical term in more common usage among young Americans. The term "attack" is a common British English term for an occurrence of herpes, whereas "outbreak" was used most commonly by U.S. focus group participants.
All development of crosscultural measures involves translation and linguistic validation because item wording and selection require agreement in one target language, even though more than one language group may contribute to the item pool. As an example, the University of Washington participated in a multinational project to develop a measure for evaluating the quality of life of persons with genital herpes, a significant public health concern with obvious ill effects on the quality of life of those infected with the virus. Draft items for the questionnaire were initially developed in the United Kingdom and then translated for use in validation studies in Denmark, France, Germany, Italy, Spain, and the United States. For all target languages, persons with genital herpes were interviewed to determine the cultural relevance of the measure and the translation. The herpes project illustrates that even using a British English measure in the United States requires a translation process. For example, the British English version used the expression "passing water," a term not common in American English. To achieve
Subjective reactions to symptoms and health conditions - the value assigned to health and living conditions, the relative importance and meaning of different conditions, and standards of behavior - show more cultural variation. These subjective perceptions, particularly values and preferences, define quality of life. The extent to which functional status and broader notions of quality of life have universal definitions and meaning across cultures is both a theoretical and empirical question. Differences between cultures on health and quality of life measures may be attributed to variation in the biological response, the cultural setting, the measurement constructs, or the measurement process itself.
Although subtle, these issues are important to consider prior to the use of measures in international studies. The herpes example also illustrates the difference between conceptual and semantic equivalence. Conceptual equivalence was difficult to achieve for the North American concept of "dating," a way of initiating intimate relationships, without counterpart in some European and non-European countries. To ensure crosscultural validity, quality of life issues in the herpes instrument dealing with relationships are worded as "personal relationships" with a parenthetical "intimate" in the American version. This type of trade-off is necessary in developing crosscultural instruments: some specificity and clarity are sacrificed to include an assessment for each culture. The final herpes measure has been used in international clinical trials that aggregate data from different countries for assessing and comparing the effects of pharmacologic treatment. How universal are concepts of health, quality of life?
Given that people everywhere engage in functional activities such as walking, sleeping, eating, and working, we can reasonably expect a measure assessing basic functions to produce valid crosscultural results. Difficulties arise, however, when example activities are used, such as "playing golf' or "walking a block," both phrases that are not relevant to all cultural or language groups. Somatic and psychological symptoms may be described similarly in different cultures.An example of cultural adaptation work at the UW is the development of a symptom battery and quality of life measure specific to urinary incontinence for use in clinical trials and patient care. We developed the urinary incontinence questionnaire (I-QOL) in Seattle by using qualitative interviews and focus groups with persons who met our diagnostic criteria. Once a field test of the I-QOL in the United States showed good measurement properties, we began the cultural adaptation process with the realization that changes in the U.S. version might be required. We adapted the measure into 18 predominantly European languages; to date, measurement validation studies have been conducted in France, Germany, Spain, and Sweden.
In each country, QOL and linguistic experts independently translated the I-QOL, tested these versions on patients with incontinence. and discussed the measure with urologists in several countries. Then, the UW team organ-ized a two-day "harmonization" meeting at which QOL experts from the participating countries gathered to assess the conceptual and semantic equivalence of items contained in the U.S. measure. The experts discussed translations, patient testing experiences, and all aspects of cultural adaptation. Each version of the measure was also translated back into American English to ensure equivalence in content and language.
This harmonization meeting uncovered several problems. The four-point response scale used in the United States was unacceptable to patients and consultants in the target languages so we adopted a five-point scale. Words such as incontinence and bladder proved impossible to translate, so colloquial definitions were added. To achieve cultural equivalence, items in the U.S. measure that used the phrase, "I worry" were adapted to "I'm afraid of," as worry did not have acceptable translations in all cultures. These and other changes required revalidation of the U.S. measure before aggregation of data in an international clinical trial.
We used a similar process to develop a measure for evaluating the quality of life of persons with irritable bowel syndrome. Before the U.S. validation trial, however, items were evaluated in four European languages for their conceptual and semantic equivalence. A harmonization meeting involved both item selection and cultural adaptation. Subsequent U.S. field trials were then conducted with the knowledge that language versions were already available in the target cultures.
World Health Organization Quality of Life instruments, now available in more than 23 languages worldwide, offer an example of simultaneous development. In the initial phases, focus groups were conducted in each of 15 centers to identify general issues relevant to QOL and to generate items. All items were translated into British English and an international team reduced more than 1,800 items to 1,000 that participants in the field centers ranked in order of importance. This process produced 236-item pilot versions that were pretested in all countries. Two instruments have resulted: WHOQOL-100 for evaluation of a wide range of concepts and domains and WHOQOL-Bref, a 26-item measure for administration when short versions are necessary. The WHOQOL-100 has also been used to evaluate changes in quality of life experienced by women and their partners after having a child.
Future Directions
It cannot be assumed that a questionnaire, however extensively tested in the originating county, will be valid and reliable once it has been translated. Taking measures developed solely within one culture and translating them to another culture without allowing for changes in the original measure, is increasingly being replaced by cultural adaptation or simultaneous development. Particularly with development of new measures, care is being taken to search for a universal core meaning to items within an instrument that can be applied in multiple languages. Based on experience with the VVH0Q0L instruments in Japan and China, our UW team is expanding efforts to incorporate Asian languages and cultures into worldwide assessments. We are also serving as a coordinating center for developing U.S. versions of the WHOQOL for different parts of the country and different cultural groups.Many measures show high agreement across cultures on the best "core" items that reflect health and quality of life, such as energy, and ability to conduct daily activities. Many cultures, however, retain distinct ways of expressing what is good health and quality of life. Maintaining conceptual and semantic equivalence requires time and money, particularly the participation of experienced consultants in quality of life and linguistics.
Surmounting the conceptual, methodological, and practical obstacles to crosscultural validation requires a higher level of cooperation and coordination of investigative sites in the different countries participating in instrument development. To improve standardization of item generation, translation, and validation procedures, agreement is necessary on field test protocols, adherence to these protocols, and frequent communication among sites on problems and solutions. A wider range of populations representing different subgroups of national populations need to be included in validation studies. Such studies are expensive, and development of crossculturally valid instruments requires considerable investment by study sponsors. Such investment will be necessary to achieve the standardization of measurement procedures and comparability and interpretation of outcomes.
Author
Donald L. Patrick, Ph.D., M.S.PH.
is a professor of health services and epidemiology, UW School of Public Health and Community Medicine. He spent 1995 on sabbatical in Lyon, France, working on crosscultural development of quality of life measures with MAPI Research Institute, INSERM. and the World Health Organization. During this time he also served as president of the International Society for Quality of Life Research.
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Created: 2/6/98 Updated: 7/15/99
