摘要：Objectives. We examined the association of language proficiency vs language preference with self-rated health among Asian American immigrants. We also examined whether modeling preference or proficiency as continuous or categorical variables changed our inferences. Methods. Data came from the 2002–2003 National Latino and Asian American Study (n = 1639). We focused on participants' proficiency in speaking, reading, and writing English and on their language preference when thinking or speaking with family or friends. We examined the relation between language measures and self-rated health with ordered and binary logistic regression. Results. All English proficiency measures were associated with self-rated health across all models. By contrast, associations between language preference and self-rated health varied by the model considered. Conclusions. Although many studies create composite scores aggregated across measures of English proficiency and language preference, this practice may not always be conceptually or empirically warranted. Despite the popularity of language as a correlate of morbidity, no clear consensus exists about its meaning or measurement. Two overlapping perspectives influence research in this area. The first perspective posits that language is a proxy for acculturation. 1 A common assumption is that acculturation represents immigrants' incorporation of the host society's norms, a perspective sometimes known as the unilinear view. For example, Suarez and Pulley argued that “acculturation is the adoption of attitudes, values, and behaviors (including language ability) of the dominant … culture.” 2 (p41) In this sense, language reflects a broad concept that signifies a fundamental evolution in one's way of thinking and acting. 3 Language clearly plays a key role in how researchers operationalize acculturation. Zane and Mak found that 18 of 21 acculturation scales measured language, yet only 8 measured cultural traditions and only 5 measured cultural values. 4 According to the second perspective, language may be viewed more narrowly as the ability to communicate, reflecting a skill that may or may not reflect one's culture. For example, English is an official language of the Philippines, Guyana, and England, yet few would argue that these countries share a unified culture. Hence, language may not completely mark cultural adoption, at least not in the ways commonly assumed in the literature. These dual issues of English language proficiency and language preference are often considered as interchangeable concepts within public health. This is most clearly seen in scales that aggregate items pertaining to proficiency and preference. 4 , 5 Yet there are important practical and theoretical reasons to disentangle these concepts. For instance, one person may adamantly prefer Vietnamese but still be highly proficient in English, whereas another person may prefer English but not be very fluent in it. Further, proficiency and preference may influence health through different mechanisms. Poor English proficiency may restrict one's employment opportunities, limit social interactions, increase experiences with discrimination, and impede access to services. 6 – 9 Hence, English proficiency relates to one's skill with a tool (i.e., language) that may directly influence access to health care (e.g., communication between client and clinician) and potentially broader social determinants of illness (e.g., socioeconomic position). Language preference is more ambiguous, reflecting one's underlying cultural values, social networks, political ideology, or construction of social identity. 1 , 2 , 10 Preference for English may be influenced by English ability, but not necessarily. Three main viewpoints arise from the literature. The first contends that preference for English is an indicator of immigrants' adoption of unhealthy “American” lifestyles. 11 , 12 For instance, Asian Americans who prefer to use English show higher odds of smoking and drinking than those who prefer Asian languages. 13 The second viewpoint argues that preference for English marks greater acceptance of health-promoting practices, such as cancer screenings and physical activity. 14 – 16 Thus, the first viewpoint predicts that greater English proficiency is associated with increased risk of illness whereas the second predicts the opposite. The third viewpoint posits that English preference does not mark cultural adoption but rather proxies for English proficiency and barriers to access. 17 The measurement of language preference and proficiency also varies across studies. Notably, studies are inconsistent in using language measures: some studies use them as continuous variables and others as categorical variables. Many prefer the categorical approach. For example, 1 study compared those who spoke English most often against those who spoke some other language most often. 18 Another study created 3 categories, distinguishing between those who spoke only English, those who spoke English and another language equally, and those who spoke only another language. 11 Yet another study examined 5 categories. 19 An advantage of the categorical approach is that the categories may be easily communicated and interpreted if reasonable cutpoints are used. For instance, the categorical variable “limited English proficiency,” often defined as speaking English not well or not at all, conveys a clear and consistent meaning across studies. 20 , 21 However, important information can be lost and statistical power diminished when continuous measures are categorized. These types of issues have been raised in many other contexts (e.g., continuous blood pressure readings vs clinical cutpoints of normal, high, or hypertensive; self-rated health as an ordinal or dichotomous variable). 22 Further, single-item measures may be unreliable or inadequately represent all of the dimensions underlying language preference or English proficiency (i.e., low content validity). Some studies therefore prefer to use continuous items and scales. 4 , 5 , 23 Finally, some studies create odd mixtures of continuous and categorical variables. For example, one study dichotomized 5 language items, summed them, and then turned the summed “scale” into 3 categories. 24 This heterogeneity raises questions about how researchers should model language items. Because the choice of modeling strategy is often constrained by the items available or the statistical distribution of the items, there should be no singular approach for all situations. However, it would be informative to examine how the choice of modeling may influence the conclusions reached regarding these language measures. In this study, we investigated 2 major questions: (1) Are there advantages to disaggregating versus aggregating measures of English proficiency and language preference? (2) Do we draw similar conclusions if we use continuous measures versus categorical measures? We first examined individual questions related to English proficiency and language preference. We next created scales of these items. We then evaluated whether these measures performed similarly if we modeled them as continuous measures or as categorical measures. We tested how these language measures correlate with self-rated health. We focused on self-rated health because many studies have examined the relationship of proficiency versus preference with self-rated health 20 , 21 , 24 – 26 and because self-rated health is often considered a useful marker of one's overall health appraisal that often correlates with morbidity. 27 – 30
