Findings
Older age, living without a partner, and having a low educational level were independently associated with increased emotional loneliness among older adults. Women living with a partner were more prone to emotional loneliness than men living with a partner. Older age and having a low educational level were associated with increased social loneliness. Men living without a partner were more prone to social loneliness than men living with a partner.
Results of a meta-analysis (10) showed that older age was associated with increased overall loneliness in studies among participants with a mean age >80 years, but not among participants with a mean age of 60-80 years. In our study, among participants with a mean age of almost 80 years, older age was associated with increased emotional loneliness and with increased social loneliness (borderline significance). Further research could examine possible differences in age-related factors associated with emotional and social loneliness, and their onset. The death of a partner may primarily be associated with emotional loneliness, whereas leaving paid employment and decreasing out-door mobility could be age-related factors primarily associated with social loneliness (33).
Some studies report sex differences in loneliness, however these findings are inconsistent (10, 15). In our study, women living with a partner were more prone to emotional loneliness than men living with a partner. This is in line with findings of Dykstra and Fokkema (34), whose study showed that married men were less prone to emotional loneliness than married women. Pinquart and Sorensen (10) identified a stronger association between female sex and increased loneliness in studies including married participants, compared to studies among single, widowed or divorced participants. Therefore, distinguishing between emotional and social loneliness in future studies, and testing for interactions between sex and living situation or marital status, may clarify the association between sex and loneliness.
Previous studies found that not having a partner, widowhood, and living alone were associated with increased overall loneliness (4, 10, 13, 35). In line with results of previous studies (15, 18), living without a partner was associated with increased emotional loneliness. In addition, living without a partner was associated with increased social loneliness among men. Again, this corresponds to findings of Dykstra and Fokkema (34), as results of their study showed that divorced men had a greater vulnerability to social loneliness than divorced women.
In Croatia, living without a partner was not associated with increased emotional loneliness. The association between living situation and loneliness may be influenced by cultural norms and values, affecting individual expectations of family members (36). Further research is needed to explain cross-country differences in the association between living situation and emotional loneliness. Descriptive statistics on emotional loneliness distinguishing between participants living with/ without children are provided in Additional Table 5.
In line with previous studies, having a low educational level was associated with increased emotional and social loneliness (4, 10, 15, 35). Older adults with a low educational level are more likely to live in disadvantaged socioeconomic circumstances, which have been associated with chronic stress and a decreased quality of social relations (37). In addition, living in disadvantaged socioeconomic circumstances has been associated with reduced opportunities for participation in social activities (4).
In contrast to previous findings (38, 39), having a migration background was not associated with loneliness. Social loneliness was reported more frequently by participants with a migration background, but there was no independent association. This may have differed between immigrant groups, depending on their command of the local language and the magnitude of cultural differences (38). However, in our study the number of participants with a migration background was too low to distinguish between groups.
In the study population some participants only reported the presence of one type of loneliness, while others reported the presence of both types of loneliness. To explore whether the associations were different when only one type of loneliness was reported, or when both types of loneliness were reported, we performed additional analyses in which we compared these groups with older adults experiencing neither emotional or social loneliness (Additional Table 3 and 4). The directions of the associations for exclusive emotional loneliness and exclusive social loneliness were similar. With regard to the simultaneous experience of emotional and social loneliness, the results were most similar to the results of emotional loneliness
Data used in this study indicate that the proportion of older persons experiencing exclusive or combined emotional and social loneliness varies between European countries (Additional Table 3). Hansen and Slagsvold (35) suggest cross-country differences in the risk of late-life loneliness can be explained by macro-level inequalities in health, socioeconomic status, marital status, and social integration. In addition, cross-country differences may be explained by differences in social welfare, demographic composition, and cultural norms and values (36).
Methodological considerations
A strength of this study was the relatively high average age of the study population. Older adults living in urban areas in Southern, Western and Eastern European countries were represented in the sample, which has increased the external validity of the results. Using a broader and a stricter definition of loneliness yielded similar results, indicating that the findings are applicable to older adults experiencing loneliness at different intensities
Nevertheless, several limitations need to be considered when interpreting the findings. First, a sampling bias cannot be ruled out. Older adults with poor health may have been less likely to participate in the UHCE study (27), participants living with a partner and participants with a migration background were more often excluded from the population for analyses due to missing data. This has reduced the representativeness of the sample, and should be considered when the findings are generalized. Secondly, although previous studies reported good psychometric properties of the De Jong-Gierveld Loneliness Scale among culturally diverse groups, in our study the internal consistency of the emotional loneliness sub scale was relatively low in the United Kingdom and Greece; we suggest further methodological studies regarding the measurement of loneliness in European countries.
Thirdly, the number of participants with a migration background was relatively low, and several sub groups in the interaction analyses were small, which may have resulted in a lack of statistical power to evaluate differences. Future studies should expand upon the findings using longitudinal designs with large and varied samples of older adults. Lastly, causal directions of the associations between socio-demographic characteristics and loneliness could not be examined. Longitudinal research is needed to evaluate (bi-)directional associations between living situation, educational level, migration background and loneliness.
Implications for policy and practice
Our findings may be used to identify target groups for intervention strategies aimed at the emotional or social dimension of loneliness. As mentioned above, Bouwman and Van Tilburg (25) have distinguished four intervention goals. Based on the results of this study, we hypothesize that intervention strategies aiming 1) to build or to strengthen a social network, and intervention strategies aiming 2) to increase a sense of belonging could in particular be beneficial for older adults, for men living without a partner, and for older adults with a low educational level. Intervention strategies aiming 3) to increase a sense of meaning, and intervention strategies aiming 4) to increase intimacy in relationships could in particular be beneficial for older adults of higher age, for older adults living without a partner, for women living with a partner, and for older adults with a low educational level. Future studies need to evaluate which intervention strategies are most effective in reducing emotional and/ or social loneliness (22).