Disparities in seasonal influenza vaccine uptake and language preference among Hispanic US adults: an analysis of the 2017–2020 BRFSS

Methods

We performed a cross-sectional analysis utilizing data from the 2017 through 2020 BRFSS cycles. BRFSS is a nationally representative, telephone-based survey, administered annually by the CDC and state health departments in each of the 50 states, the District of Columbia, and select US territories. BRFSS extracts health behavior and disease conditions from all noninstitutionalized individuals. To estimate population estimates, BRFSS incorporates complex sampling design and utilizes ranking weights to account for survey noncoverage, nonresponse, and the probability of being sampled given geographic location, age, race, and sex [12].

Participants included in our study self-reported to be of Hispanic ethnicity and responded to the question “Are you Hispanic, Latino/a, or Spanish origin? ” as either “Yes” or “No.” Responses of “unsure” or “refused” were excluded from analysis. Individuals who answered “Yes” or “No” to receiving an influenza vaccine were included in our study, and those who refused to respond or answered “unsure” were excluded. Further, the participant’s language was determined by the version of the BRFSS survey administered—the English or Spanish version—as has been utilized in previous studies [13]. BRFSS provides a variable of sex (male or female) and a calculated age variable with categories of below 65 and equal to or greater than 65 years. Therefore, respondents met the inclusion criteria if they were Hispanic, aged 18 years or greater, and completed the survey in either English or Spanish.

Results

Annually, the Hispanic population included in the study was predominantly aged 18–64—between 88.4% (n=33,050) and 89.4% (n=32,625; Table 1). The lowest percentage of Hispanic US adults of all ages who received influenza shots was in 2018 (25.3%; n=10,036) and the highest was in 2020 at (34.8%; n=12,496). These years (2018 and 2020) also represent the lowest and highest rates of vaccine uptake among the younger age groups (Figure 1). Lastly, Hispanic US adults ages 65 years and over had the highest percentage of influenza shots received in 2017 (57.8%; n=2,865), while 2018 had the lowest (50.1%; n=2,546). Rates of seasonal influenza vaccine uptake among Hispanic US adults stratified by language, sex, and age are shown in Table 2. In 2018, 2019, and 2020, there was a statistically significant difference in uptake in English-preferring women when compared to Spanish-preferring women ages 18to 64 (p=0.002, p=0.011, and p<0.001, respectively). Higher influenza vaccine uptake of Spanish-preferring women ages 18 to 64 was seen only in 2018 (27.5%; n=1919) in comparison to English-preferring women (23.4%; n=2,401). On the contrary, English-preferring women ages 18 to 64 had higher percentages of influenza vaccine uptake in 2019 (35.6%; n=3,040) and 2020 (38.6%; n=3,810) than Spanish-preferring women in 2019 (31.9%; n=2094) and 2020 (32.2%; n=1819). English-preferring men aged 18 to 64 showed higher percentages of influenza vaccine uptake compared to Spanish-preferring men in 2017 (27.3%; n=2,292), 2019 (28.1%; n=2,249), and 2020 (30.2%; n=2,760), each of which were significantly different.

Figure 1:

Trends in seasonal influenza vaccine uptake by language and sex among US Hispanic adults. The data were extracted from the 2017 to 2020 Behavior Risk Factor Surveillance System (BRFSS).

English- and Spanish-preferring women aged 65 and older showed a difference in influenza vaccine uptake only in 2018 (p=0.009), whereas Spanish-preferring women aged 65 years and older had a higher percentage of influenza vaccine uptake (51.2%; n=677) compared to English-preferring women (42.7%; n=772). There was no statistically significant difference for English-and Spanish-preferring men aged 65 and older (Table 2).

Discussion

Overall, we found that Hispanic individuals over the age of 65 were much more likely to have received an influenza vaccine between 2017 and 2020 compared to younger individuals. Our findings show a dip among all groups in 2018, which rebounded among all groups in 2019. In 2020, all groups, with the exception of younger Spanish-preferring Hispanic men, increased vaccine uptake or remained at 2019 levels. Notably, this increase in vaccine uptake corresponded with the onset of the SARS-CoV-2 pandemic. Further, our results show that Hispanic individuals who were English-preferring had greater seasonal influenza vaccine uptake rates in the latter 2 years of our study for both sexes in the younger age group. We also noted that in 2018, older Spanish-preferring women were more likely to be influenza-vaccinated over older English-preferring women. This finding was reversed for the younger age group of women, where Spanish-preferring women had less seasonal influenza vaccine uptake than their English-preferring counterparts.

The literature on seasonal influenza vaccine uptake rates for those who prefer to speak a different language than English is sparse. Compared to results from Link et al. [9], which found influenza vaccine uptake from 2001 through 2005 ranging from 52.7 to 58.3% among Hispanic US adults, we found that vaccine uptake remains similar nearly 15 years later. Conversely, Pearson et al. [5] found that influenza vaccine uptake among older Spanish-preferring Hispanics ranged from 44.5% (n=3,330) to 46.0% (n=5,125). Our more recent findings show that influenza vaccine uptake among Spanish-preferring men and women has increased in the past 15 years—ranging from 51 to 60% of these individuals receiving an influenza shot. Our findings show higher rates of influenza vaccine uptake compared to these earlier studies, which may be attributed to increased public health efforts within Spanish-speaking communities as well as an overall expanded acceptance of influenza vaccines within the American population [14]. Our findings also highlight outcomes based on sex and age, including a younger age group (18–64 years), whereas previous research has mainly focused only on individuals 65+ years without further categorization. Further, recommendations for future research would be to investigate whether certain regions face disproportionate disparity in regard to vaccine uptake, and to possibly compare vaccine uptake among Hispanic population densities.

Barriers related to vaccine uptake, such as the language barrier, have been shown to increase vaccine hesitancy particularly in the younger Hispanic population, and this may be partly due to marginal Hispanic representation in the medical field and studies [15]. Hernandez et al. [16] found that vaccine information was seen as more trustworthy by college-aged Hispanic women when the information was administered by a race-concordant medical professional. Increasing Hispanic representation and media coverage of Hispanic healthcare professionals disseminating research information and the experiences of Hispanic vaccine recipients may lead to greater vaccine trust in the Hispanic community [15], especially among Spanish-preferring younger men. Overcoming the language barrier is a necessary responsibility to promote vaccine uptake in order to help reduce morbidity, mortality, and healthcare costs.

Interventions to bridge the language gap would not only improve healthcare but also could help provide economic relief from influenza-associated costs. A study by Molinari et al. [17] found that an estimated 610,660 years’ worth of life was lost due to influenza in 2003, with an additional loss of $16.3 billion due to influenza-related expenses. Another study found that vaccinating children, the elderly, at-risk patients, and pregnant women could prevent hospitalizations and has proven to be a cost-saving strategy for influenza-related expenses [18]. This reveals the importance of increasing seasonal influenza vaccine uptake not only for decreasing mortality and improving healthcare, but also for mediating costs and alleviating economic expenditures. By reforming healthcare complications related to the language barrier, we believe that the rate of influenza vaccine uptake will improve, leading to an ultimate reduction in mortality and economic grief imposed by influenza annually.

Language barriers have been shown to impede access to care and result in suboptimal relationships between providers and clients [19]. Therefore, it is important to address the language barrier in order to promote seasonal influenza vaccine uptake by providing access to Spanish translated medical resources and medically trained translators or interpreters in healthcare settings [20]. The use of professionally trained medical interpreters increases patient satisfaction [21], quality of care, and patient compliance, while decreasing adverse events [22], hospital stays, and readmission rates [23]. Incorporating linguistic training in the education of medical and healthcare disciplines would likely reduce disparities in influenza vaccine uptake [20].

Conclusions

In summary, we found that following a dip in 2018, influenza vaccine uptake among Hispanic individuals in the United States increased through 2020 despite the COVID-19 pandemic. However, disparities exist between English- and Spanish-preferring Hispanic individuals and age groups by influenza vaccine status. Given these differences, language barriers may play a role in whether specific groups received influenza vaccines. Thus, increased use of medical translators in healthcare settings, incorporation of linguistic medical education courses, and culture-concordant public health messaging are needed to reduce these disparities. In turn, these strategies may reduce influenza-related healthcare expenses, overall morbidity, and mortality.