The present study aimed to explore the mechanisms which may explain the educational inequalities in TV viewing among Australian older adults. Education was inversely associated with TV viewing, confirming results shown in previous studies [14–17]. The current results showed that these educational inequalities in TV viewing were partly mediated by certain ecological factors, namely BMI, personal safety, neighbourhood aesthetics, and the number of televisions in the house.
BMI had the highest proportion (4.5%) of mediation (which was still relatively low), suggesting that less educated older adults are likely to have higher BMI scores, which in turn may result in higher levels of TV viewing. However, reverse causality between BMI and TV viewing is also possible: low educated individuals who watch more TV, might be at risk of higher BMI scores. In an Australian sample of adult women aged 18–65 years, weight status was also found to be a significant mediator of the association between education and TV viewing . The present finding might suggest that future programs focusing on weight management in less educated older adults might help reduce educational inequalities in TV viewing. However, longitudinal studies are needed to be able to ascertain the direction of the effect.
A second group of factors that were found to be partial mediators (similarly representing relatively low percentages) were the environmental factors. Less educated older adults had lower scores for perceptions of the social (personal safety) and physical (neighbourhood aesthetics) environment consistent with other studies [38, 39], which was also related with higher levels of TV viewing. Less educated adults may be more likely to live in deprived neighbourhoods. As such neighbourhoods may be (perceived as) unsafe and unattractive , time spent outdoors might be replaced by sedentary indoor activities, including TV viewing. However, longitudinal studies are needed to confirm the direction of relationships and exclude the possibility that those who watch more TV have less positive perceptions about their neighbourhood. Present findings suggest that targeting perceived environmental variables in less educated older adults might reduce the educational differences in TV viewing. For example, feelings about safety, violence and crime can be addressed in less educated older adults, together with attractiveness (e.g. rubbish, noise) of neighbourhoods. In the present study, proximal social factors (e.g. social participation) did not contribute to explaining the association between education and TV viewing. The normative nature of TV viewing might be one explanation for this as older adults (and their proximal social environment) are possibly not aware of the health consequences of TV viewing. Including an educational-based component to interventions aimed at reducing sedentary behaviour may be useful in order to increase awareness and knowledge of sedentary behaviours, such as TV viewing. Only one other study has assessed the mediating role of ecological factors in the association between education and TV viewing . In contrast to our findings, that study suggested to focus on intrapersonal (enjoyment of TV viewing and weight status) and social (social cohesion and social support from friends for physical activity) strategies. Physical environmental factors were not important in mediating the relationship between education and TV viewing in 18–65 year-old Australian women . The discrepancies in findings between the studies are most likely resulting from the different samples studied. This highlights the need for more research investigating the mediating role of ecological factors on the relationship between education and TV viewing, conducted in various study groups.
The number of televisions in the house (physical environmental factor) was likely to be higher in less educated older adults, also explaining higher levels of TV viewing. The fact that less educated individuals had more televisions might seem unexpected, as lower educated individuals are more likely to have a lower income and consequently less resources to buy televisions . However, lower educated adults often buy technological media devices to feel themselves part of the society . Considering the findings of the current study, future interventions might focus on the discouragement of multiple indoor entertainment devices and products, such as TV’s, DVD’s etc. and encourage physical activity equipment at home. The number of televisions in the house was also found to be a significant mediator of the association between maternal education and children’s TV viewing . However, no comparable studies in adults were found.
In summary, the current findings suggest that targeting weight status and (perceived) environmental factors may be a useful approach for limiting TV viewing among older adults with a lower education. Perceptions of the neighbourhood environment may not reflect reality in older adults. Therefore, potential future intervention strategies might include community initiatives to improve personal safety (e.g. by organizing neighbourhood watch) and aesthetics in the neighbourhood.
Limitations of the present study should be acknowledged. Firstly, the data is self-reported which may result in recall and social desirability bias . However, measures were derived from published sources with acceptable validity and reliability levels [21, 28, 32–35]. Including the use of more objective measures, such as accelerometers or inclinometers, to assess sedentary behaviour, as well as objective measures of the environment [e.g. GIS (Geographic Information System) data] may be an important component of future studies. Although perceptions of the environment are valuable as they impact on behaviour, Ball and colleagues found that there may be relatively poor agreement between perceived and objective measures of physical activity environments . Secondly, the cross-sectional nature of the design does not permit causality of the investigated relationships to be examined. Thirdly, the modest response rate should be taken into account, however there was variation in the demographic and physical activity characteristics of participants. Finally, the list of potential mediators was limited to the present factors tested, and therefore the mediating role of other potential factors (e.g. psychosocial constructs such as self-efficacy, cognitive variables such as intention, other individual factors such as functional status, or other sedentary activities such as computer use)  needs to be examined. These factors may differ according to education and might also be associated with TV viewing.
A major strength of this study is that it is the first to examine the underlying mechanisms in the association between education and TV viewing among older adults. Further, the large, random sample of older adults living in both rural and urban neighbourhoods was adequately powered to detect associations after controlling for a number of covariates. Finally, the inclusion of measures that assessed physical and social environmental factors specifically linked to sedentary behaviour was a strength of this study since little previous research has utilised such measures.