Factors Associated with Health Literacy among People Living with HIV: A Narrative Review

two factors. Abstract Health literacy is an important topic in people living with human immune deficiency virus (HIV). This review examined factors associated with health literacy among people living with HIV. We searched the literature available from PubMed and Scopus-Elsevier. Compound terms “health literacy” and “HIV health literacy” were employed to retrieve the relevant literature. The terms were typed in the following fields: article title, abstract and key words through the Boolean operator “AND”. We limited our searches to articles published in the period between 1993 and 2017 and in the English language. Factors associated with health literacy were critically reviewed and categorized. A total of 40 articles met inclusion criteria and were included in this literature review. They were clinical trials (n = 28), cross-sectional (n = 10) and pilot (n = 2) studies. The majority of the studies (68.42%) were conducted in the United States (US), while the rest were conducted in Africa. Whether gender plays a role in health literacy among people living with HIV was inconclusive. Factors associated with HIV health literacy among people living with HIV included education, age, and race. These factors could be used to predict the level of health literacy among people living with HIV. Further research conducted in other geographical regions is needed, given limited generalizability of these published articles’ results.

Most of the previous studies on health literacy among people living with HIV were conducted in the US and Africa. 3,20 Nonetheless, the findings may not be generalizable to other geographical regions with differences in socioeconomic characteristics, cultural aspects and local healthcare policies. A primary objective of this review was to provide a critical analysis of factors associated with health literacy among people living with HIV.

Methods
This article was a narrative literature review of publications, such as articles, case reports and books on health literacy and people living with HIV/AIDS. We searched for literature from PubMed and Scopus-Elsevier. Compound terms "health literacy" and "HIV health literacy" were used to retrieve the relevant literature. The terms were typed in the following fields: article title, abstract and keywords through the Boolean operator "AND". We limited our searches to the time period between 1993 and 2017 and to articles written in the English language. Factors associated with health literacy were critically reviewed and categorized. Gaps in research and implications on clinical practice are discussed at the end of this article.

Results and Discussion
Of the 74 identified articles, 40 met our criteria. Most of the articles belonged to the subject areas of the "Medicine," "Nursing," and "Social Science" fields. Articles included in the literature review were 28 clinical trials, 10 cross-sectional, and 2 pilot studies, and mainly involved non-representative and/or convenience samples. Of these studies, 68.42% were conducted in the United States and the rest in Africa.

Education
Low health education levels were significantly associated with limited health literacy. 29,30 Kalichman and Rompa 31 (1999) examined health literacy in 339 patients living with HIV and found that those with limited health literacy had a lower level of formal education, compared to those with higher health literacy. A study of individuals with HIV on ART demonstrated that HIV patients, who graduated from college, had higher reading-literacy skills, higher CD4 count and lower viral load than those who graduated from a high school. A strong predictor of antiretroviral medication adherence was health literacy and the number of years of academic study. 7,29 The relationship between education, health numeracy and health literacy in individuals with HIV was found in an earlier study. 9,31 One study examined health literacy, health numeracy and their association with an education level among 184 patients, of which 54% were African-American. 32 Health literacy was assessed by the Test of Functional Health Literacy in Adults (TOFHLA) and health numeracy by the numeracy scale of TOFHLA. The study found a significant relationship between levels of education, levels of health literacy, health numeracy and medication adherence. The study concluded that education was an important factor for patients with HIV in African-American communities.

Gender
An association between gender and health literacy is inconclusive. Gakumo et al. 32 compared levels of health literacy between men and women. Findings showed that women had a better performance of reading and comprehension of health information than men, while men had significantly higher scores than women in numeracy skills. Waldrop-Valverd et al. studied the health literacy of 204 participants with HIV and found that female participants were more likely to have higher health literacy levels than male participants. 33 They also examined the links of health literacy, health numeracy and HIV-medication management among participants in the Southeastern US. Reading comprehension was used to measure health literacy and the applied problems subscale of the Woodcock Johnson-III Tests of Achievement was used to measure health numeracy. Results show that men scored higher than women on the numeracy skills, while health literacy levels were not different between men and women. Men also performed better than women in understanding HIV medication information. Accordingly, men were more likely to comprehend and act on medical instructions than women.

Aging
Compared to the general population, the elderly seem to have lower levels of health literacy. 1 Over two-thirds of the US people aged 60 years or above have limited health literacy. 32 The Short Test of Functional Health Literacy was used by Gazmararian et al. 4 to test the health literacy of Medicare participants from all over the US (n = 3260). Their findings revealed that 53.9% of Spanish-language speakers and 33.9% of English-language speakers aged 65 or above had limited health literacy. 2,33 Intellectual disabilities and education levels were related to health literacy as well. Even though the two factors were controlled, health literacy still dwindled considerably with age. 4 Murphy et al. 34 conducted one of the first studies on health literacy in teenagers with HIV and found no relationship between health literacy and antiretroviral adherence in this population (n = 186; mean age 20.5 years). Drainoni et al. 35 (2008) reported that a relationship between increasing age and lower health literacy had been found, while some other studies did not find such a correlation. 13,28,30,35 By 2015, approximately half of HIV patients in developed countries where antiretroviral medication is accessible were 50 years and older. Since increasing age leads to an augment of comorbidities in adults with HIV, 36 aging patients will need to abide by a significant number of medical recommendations. Coping with more information can result in difficulties, especially for thousands of adults with HIV who are undergoing neurological operations which may cause trouble with reasoning and planning. 12,36 Therefore, it is important that more details be provided describing how health literacy and health numeracy, as well as intellectual disability, tend to affect health conditions in a rising population.

Race
Osborn et al. 14 studied associations of health literacy, medication adherence and race. The researchers used the Rapid Estimate of Adult Literacy in Medicine to measure health literacy. 36 All participants engaged in the examination were required to read a list of medical terms aloud (e.g., "prescription", "medication", "pill") and scoring was based on correctness of pronunciation. The researchers found that, among the participants (n = 204; 45% African American), race was not a significant factor with respect to level of health literacy, although African-American patients were reportedly more non-adherent to their HIV medications than their Caucasian counterparts. 14 Waldrop-Valverde et al. 18 studied the relationship of race to health literacy and medication adherence among African-American HIV patients (n = 207) at an infectious-disease clinic and an AIDS drug-assistance program. Health literacy was evaluated by reading the comprehension subscale of the TOFHLA. 37 The study showed that health literacy among African-Americans was less than their non-African American counterparts, especially since African-Americans followed medication instructions less correctly and their HIV-medication management was lower than their non-African American counterparts. Thus, racial disparities may be an important predictor of health literacy skills among African-Americans in their self-management and medication adherence.
Even though the majority of HIV studies that referred to racial differences in health literacy have focused on African-Americans, early studies had also mentioned disparities in the Latino population. Drainoni et. al. 35 examined a high-risk sample of individuals with HIV (n = 231) and demonstrated that Latinos were four times as likely to have low health literacy as Caucasians. Also, those whose native language is Spanish, as compared to native speakers of English, had lower health literacy. Health literacy with respect to specific racial groups has been addressed in the literature, as well. 38

Gaps in research
The study was reviewed with attention to factors associated with health literacy among people living with HIV. Factors associated with HIV health literacy have important implications for HIV research in a clinical setting. Even though recent data have been studied for factors associated with general health literacy, the data pertaining to factors associated to HIV literacy was limited. Sufficient knowledge of the factors associated with HIV health literacy can be applied to clinical use. For instance, we will be able to develop instruments to measure HIV health literacy, modify the factors associated with limited health literacy and predict health outcomes.

Implication on clinical practice
The factors associated with health literacy among HIV patients have important implications for clinical practice. Even though recent studies have examined the interrelationship of health literacy, factors associated with health literacy and health outcomes, much work will be needed in order to approach a complete grasp of the nature of HIV. In particular, HIV health literacy test development, intervention methods and studies of factors associated with health literacy studies are going to be essential.
The absence of non-abstract examples in terms of health and medicine is still a problem in the use of general literacy instruments. 39,40 HIV-targeted health literacy instruments would be much more suitable to health outcomes and would work more effectively than general instruments. While it is not encouraging that certain instruments, mainly those that emphasize HIV literacy, are scarce, it is fortunate that there are two HIV health literacy instruments which can be used as surrogates. HIV health literacy research should focus on factors associated with health literacy and developing interventions that can improve health outcomes, not only in medication adherence, but also in decision-based laboratory evaluations.

Limitations
This narrative review of the literature has its limitations. First, most of the HIV research mentioned in this review were conducted among westerners and African HIV patients, while only a few studies involved Asian HIV patients. Second, the majority of the mentioned HIV health literacy studies did not include a significant number of participants over 50 years old, limiting the ability to draw age-group comparisons. This deficiency constitutes an important gap that needs to be addressed, as the aging population living with HIV continues to grow.

Conclusion
Health literacy has an important role to play in the successful use of health information, accessing health care services, one's self-care of chronic conditions and maintaining health and well-being. The factors associated with health literacy among HIV patients have important implications for clinical practices that can be applied to measuring health literacy and predicting health outcomes. This study demonstrated that education, gender, age and race among living HIV patients were associated with levels of health literacy and should be considered for HIV care in clinical practice. Further research on HIV health literacy is needed, conducted in different geographical areas with differences in socioeconomic characteristics, cultures and local health policies.