Phase 1 Literature Review

Rationales For Selecting Phase I of HSU For This Dissertation.

First, all of the modified and expanded Phases of the HSU retained the predisposing, enabling, and need components (determinants of individuals) as essential elements that can directly influence healthcare service utilization behaviors. This means that the determinants of individuals from Phase I capture essential elements of the HSU. So, this dissertation focused on the most central key factors of the HSU.

Second, several researchers have argued that immigrants’ health service utilization in the host country could be influenced thoroughly by social structural characteristics of individuals (e.g., employment, insurance, income status, and education; Kuo & Porter, 1998; Myers &

Rodriguez, 2003; Tan, 2009; Trimble, 2003). So, the components of social structure (in the predisposing component) and accessibility to healthcare service (e.g., number of clinic visits; in the enabling component) would be important to examine immigrants’ health service utilization.
Third, the availability of valid and reliable measures of Phase I predisposing, enabling, and need components may facilitate empirical tests of the theoretical frame. Elements added in later Phases of the HSU have a smaller body of empirical evidence behind them. Many studies on breast cancer preventive behaviors use demographic characteristics (e.g., age, race, and marital status) as predisposing characteristics, healthcare resources (e.g., usual sources of healthcare) as enabling characteristics, and perceived and evaluated health status (e.g., number of comorbidities) as need components (e.g., Chen, 2009; Lee-Lin, Nguyen, Pedhiwala, Dieckmann, & Menon, 2015; Walter & Schonberg, 2014). This means that conceptualization and operationalization of the key components of Phase I have been accepted by other scholars, and it has been repeatedly evaluated and replicated (Aday, Andersen, & Fleming, 1980).
Fourth, the Phase I model can be applied not only to improve accessibility to healthcare services of individuals, but it also can lead to policy implications. According to Andersen (2001), to promote equitable healthcare access and envision effective interventions, components of the model should have a high level of mutability (e.g., be changeable by social work intervention). Some of the determinants of Phase I are mutable (Gochman, 1997): especially, enabling factors (Aday & Andersen, 1981).
Last, the California Health Interview Survey (CHIS) data, which was used for this dissertation research, mainly include the predisposing, enabling, and need components rather than macro level measures (e.g., healthcare delivery system, or environmental factors) or cognitive measures (e.g., health beliefs). Therefore, Phase I is a more feasible model for this dissertation compared to other phases of the HSU.

Limitations of Phase I of HSU
Phase I needs to increase its generalizability for more diverse populations including immigrants (Andersen, 1995).

Phase I of HSU is not sensitive to ethnic differences that are associated with individuals’ situational or environmental components (Moon, Lubben, & Villa, 1998; Tan, 2009), because Phase I (like all other Phases of HSU) considered ethnicity as a simple predisposing demographic predictor. Most studies using HSU with diverse target populations (e.g., male and female veterans, American Indians, African Americans, or Asian immigrants) proposed that HSU has very limited generalizability, especially for ethnic minority populations (Bradley et al., 2002; Song et al., 2010). Integrating both universal factors and ethnic specific components may enhance the generalizability: some part should cover overall populations regardless of ethnicity or immigrant status of individuals, and the other part should cover unique elements associated with minority populations (Choi, 2011). However, none of the Phases of HSU have incorporated unique components such as acculturation for immigrant populations. Rather, the HSU explains a broad level of demographic (e.g., SES) and social factors (e.g., family or community resources) as predisposing or enabling factors of individuals. Researchers agree that Phase I is not sensitive to the diverse cultural and acculturation barriers/protectors in health care (Moon et al., 1998; Wallace, Levy-Storms, Kington, & Andersen, 1998). Andersen and colleagues (Andersen et al., 2011) also argued that despite the rapid growth of the Asian populations in the U.S., few studies determined cultural influences on Asian populations’ health behaviors or health outcomes. Therefore, it was essential to modify Phase I to investigate the relationships between acculturation and the healthcare utilization behavior of individuals (Choi, 2011). The acculturation measures were added to the predisposing

components.