CHICAGO—While the main objective in caring for cancer patients has been to prolong life and to focus on short-term and long-term survival, more recent efforts include considerations of health-related quality of life (QOL).[1,2] The World Health Organization defines QOL as “not merely the absence of disease but a state of physical, emotional, and social well being.”[3]
Evaluation of QOL involves assessments of a wide spectrum of human functioning, including emotional response to cancer and treatment, physical activity, and the impact of the specific cancer on physical and psychological capacities. QOL now constitutes an important part of study for epidemiology, clinical trials, and health services research.
From a cancer surveillance perspective, information about health-related QOL is important because it provides indicators for trends in cancer treatments and their impact on patients’ lives. From a clinical trialist’s perspective, QOL outcomes are increasingly included as endpoints in oncology clinical trials.[2] Finally, from the perspective of health services research, health-related QOL is considered a major part of medical outcomes research, since a cancer patient’s life is a highly dynamic experience.[4]
Since many oncology treatments do not cure cancer but can extend life for long periods of time, it is wise to examine all aspects of disease burden to allow accurate assessment of therapeutic progress.
Although many clinical trials, outcomes studies, and epidemiology studies now include health-related QOL assessments for persons with many different types of cancer, efforts that include large numbers of racial/ethnic minorities are rare.
Most of the questionnaires used to assess QOL in clinical settings are written in English and are tailored for relatively highly educated, white populations. The content and format of the questionnaires can act as a barrier that immediately precludes numerous cancer patients from socioeconomically and ethnically diverse populations, or whose first language is not English.
In recent years, this problematic situation has gained attention and motivated researchers to begin drafting instruments that allow for accurate evaluation of populations that speak languages other than English and who have different daily life circumstances.
In addition, QOL measurement in cancer patients can present further challenges when the disease has markedly affected physical, role, social, and emotional functioning, making adherence to self-administered questionnaires difficult.
In this article, we focus on the work of three researchers who presented papers at the 1999 Robert H. Lurie Comprehensive Cancer Center Health Policy Symposium: Frank Baker, MD, of the American Cancer Society; David Cella, PhD, of the Evanston/Northwestern Healthcare System and Northwestern University; and Sara J. Knight, PhD, of the VA Chicago Healthcare System/Lakeside Division and Northwestern University.
All three have been actively involved in developing appropriate methods for evaluating the QOL of patients with cancer in culturally diverse populations.
Cultural Equivalence
Dr. Frank Baker’s research is based on the practical observation that QOL measurement in cancer patients from lower socioeconomic and minority backgrounds presents numerous chal-lenges.[5] His work has focused on delivering information regarding the cultural equivalence of QOL instruments so that they may be used across culturally diverse populations.
In one study he described, only a minority of the different QOL measures demonstrated adequate reliability and validity for black and Hispanic populations. It was further shown that the family functioning dimension was particularly difficult to address across the different cultural backgrounds, because of widely variant attitudes toward this domain.
Dr. Baker’s research is novel, since most QOL instruments include predominantly middle-class white cohorts and since normative QOL data on specific populations, categorized by socioeconomic status, cultural identity, and literacy level, generally are not available.
In response to this issue, the appropriateness of several existing QOL instruments has been evaluated and new methods developed for assessing QOL in minority populations.
Dr. Baker and his colleagues have identified five main areas of QOL testing that make up the core elements required to evaluate a person’s physical and psychological health state.
The first is cultural equivalence, which refers to whether the items in the questionnaires are relevant to the specific lifestyle background of the population.
Another important aspect of determining instrument validity is semantic equivalence, referring to the way questions are worded. Questions should be presented in Spanish to a Spanish-speaking group of patients. It is also critical that the phrases be written in the everyday language of the cohort, because people may use different dialects and have different Spanish literacy levels.
Technical equivalence determines whether the different QOL instruments are actually measuring the same aspects of health.
Finally, criteria equivalence and conceptual equivalence, as ascertained by statistical method analyses, ensure that the same ideas are being examined across cultures.
Dr. Baker’s research includes analyses of various aspects of QOL testing for several instruments that are administered to patients with various types of cancer. To achieve cultural equivalence among the various QOL surveys and eliminate potential interviewer bias, Dr. Baker suggests that the operational aspects of the research incorporate several safety guidelines.
Interviewers are trained nurses, usually from a similar background as the patient. This may allow the patient to feel slightly more comfortable in the interview setting and to give more candid responses.
The interviews are structured so that they are easy to understand and are administered face-to-face rather than over the telephone, to further reduce discomfort of the participants.
In addition, the interviewers evaluate the entire process and provide essential feedback to help improve the patient/interviewer interaction.
Developing Better QOL Measures
Dr. David Cella’s research is dedicated to developing better, more relevant, and more culturally appropriate QOL measures,[6,7] including the Functional Assessment of Cancer Therapy-General Scale (FACT-G) (the fourth version is currently used), a 27-item questionnaire written at the third-grade level.
Dr. Cella and his colleagues have shown that there are no significant differences in the validity of the FACT-G between high-literacy and low-literacy populations or between interview-assisted or self-administration assessment methods.
In another 3-year National Cancer Institute funded study, the Bilingual Intercultural QOL project, Dr. Cella’s team translated the English FACT into Spanish and tested its reliability. Translation from one language to another, however, does not always guarantee that meaning is preserved. As a result, QOL assessments for cohorts made up of Hispanics using the Spanish version of a test cannot be compared with those obtained from cohorts of whites.
Furthermore, Dr. Cella has pointed out that the conception of QOL is embedded within any given culture, and, therefore, it is impossible to expect any measure of QOL to be void of cultural influence.[8] Nonetheless, the research indicates that we can expect a good QOL instrument to be “culture equivalent.”
Dr. Cella’s presentation stemmed from his previous work on these issues and focused on cultural differences that affect the validity of QOL questionnaires as well as the low-literacy issues surrounding quality of health care.
