Algunos ejemplos de reactivos

Socioeconomic factors are mainly education level, occupation, and income (Lampert & Kroll 2009); however, regarding medication adherence, the WHO (Sabaté 2003) also includes gender, age, ethnicity, and social support. Regarding gender, some studies suggest that male kidney transplant

recipients are more likely to be non-adherent (Kiley et al. 1993; Chisholm et al. 2005; Rosenberger et al. 2005; Chisholm et al. 2007; Denhaerynck et al. 2007; Griva et al. 2012), while others place the higher risk of non-adherence with female recipients (Hilbrands et al. 1995; Gheith et al. 2008). However, most research studies found no association between gender and degree of medication adherence in international settings (Vasquez et al. 2003; Butler et al. 2004b; Chisholm et al. 2005; Russell et al. 2010) or European settings (Bunzel & Laederach-Hofmann 2000; Vlaminck et al. 2004; Gremigni et al. 2007; Germani et al. 2011; Lennerling & Forsberg 2012; Massey et al. 2013). A systematic review (Denhaerynck et al. 2005) supports the conclusion of no association between gender and medication adherence.

Much research has also been conducted on the association between age and medication adherence. Studies have shown that younger age is often associated with non-adherence (Raiz et al. 1999; Rudman et al. 1999; Bunzel & Laederach-Hofmann 2000; Butler et al. 2004b; Denhaerynck et al. 2007; Gremigni et al. 2007; Takemoto et al. 2007; Gelb et al. 2010; Griva et al. 2012), and that adherence increases with age (Chisholm et al. 2007; Lin et al. 2011; Massey et al. 2013). This findings were also confirmed by the systematic review (Denhaerynck et al. 2005). Although this finding applies to children and especially adolescents, an age group that has been excluded from the present review, it also holds for young adults, with evidence

Conflicting studies have found that older kidney transplant recipients may display a greater extent of non-adherence to medication than their younger peers (Chisholm et al. 2005; Chisholm-Burns et al. 2008a). This

phenomenon may be attributed to general cognitive and physical declines over the age of 60 years (Chisholm-Burns et al. 2008a). However, the issue is inconclusive, as many studies have found no association between

adherence and age in kidney transplant recipients (Vasquez et al. 2003; Vlaminck et al. 2004; Russell et al. 2010; Germani et al. 2011; Lennerling & Forsberg 2012; Tielen et al. 2014).

Some research has been conducted on the relationship between ethnicity and medication adherence. While most studies found no association

(Vasquez et al. 2003; Vlaminck et al. 2004; Chisholm et al. 2005; Russell et al. 2010; Massey et al. 2013; Tielen et al. 2014), some found that African Americans may be less adherent than white Americans (Schweizer et al. 1990; Kiley et al. 1993; Chisholm et al. 2007). These findings, however, can be attributed to the lower average socioeconomic status of African Americans compared with white Americans, rather than to ethnicity.

No conclusive association could be established between education level and non-adherence following renal transplantation. While some studies suggest that higher levels of education are associated with better adherence or vice versa (Rudman et al. 1999; Chisholm et al. 2007; Griva et al. 2012), other research found no significant association (Vasquez et al. 2003; Denhaerynck et al. 2005; Germani et al. 2011; Massey et al. 2013; Tielen et al. 2014).

Employment status and household income, as two of the three major factors contributing to socioeconomic status, have been studied extensively, but no conclusions could be drawn. Some research has found better socio-

economic status to be associated with better adherence (Schweizer et al. 1990; Lin et al. 2011) and unemployment to be more common in non-

adherent persons (Kiley et al. 1993). However, it is unclear whether this may be explained by a financial inability to afford IM (Schweizer et al. 1990; Gordon et al. 2009) or a general low income of non-adherent kidney

transplant recipients (Chisholm et al. 2005), as some research from the USA suggests. In contrast, other studies have found no association between adherence and socioeconomic status (Vasquez et al. 2003; Denhaerynck et al. 2005; Russell et al. 2010; Germani et al. 2011; Massey et al. 2013; Tielen et al. 2014), or have found that employment may lead to less adherent

behaviour (Griva et al. 2012).

Much research has been conducted on social support and medication adherence. In research settings, social support is often conceptualised as being provided by a spouse or partner, but may also come from other family members, friends, acquaintances, colleagues, or neighbours (Taylor 2011). Research on this topic concludes that marriage or living as a couple is a protecting factor for non-adherence (De Geest et al. 1995; Bunzel &

Laederach-Hofmann 2000; Butler et al. 2004b; Lin et al. 2011; Lennerling & Forsberg 2012). This conclusion is supported by studies, including a

systematic review, that stress the importance of subjective feelings of being socially supported as a crucial factor for adherent behaviour (Denhaerynck et al. 2005; Scholz et al. 2012), and by other qualitative studies (Gordon et al. 2009; Tong et al. 2011). Rosenberger et al. (2005) have also found that more non-adherers complain about a lack of social support than adherers, and Vlaminck et al. (2004) use low social support as predictor for non-adherence.

In contrast to these findings, other research found no association between social support and medication adherence (Russell et al. 2010; Germani et al. 2011; Massey et al. 2013), with some even suggesting that people living in relationships may be more likely to be non-adherent (Griva et al. 2012) or that participants with perceived social support display a larger extent of non- adherence than other persons (Kiley et al. 1993).