This study explored the individual association between housework activities, sleep duration and self-reported health, and additionally examined the combined associations of total housework and sleep duration on self-reported health among elderly men and women in selected high-income countries. As far as we know, this is the first study to analyze these interactive associations among elderly men and women in six European countries and the US using time use data. On the descriptive level, our study showed that elderly women allocate more time to routine and repetitive housework such as cleaning and cooking, whereas elderly men tend to devote more time to occasional tasks such as gardening and maintenance. Interestingly, both routine and occasional housework activities were positively associated with health among elderly men and women, but the magnitude of the association varied. Regarding time spent on total housework activities, there were gender and cross-country differences. Women spent more time than men in housework activities, consistent with previous literature [
11,
12]. However, we observed a cross-country variation in time devoted to these activities. The result as shown in Additional file
2: Table S1 revealed that elderly women in the southern European countries and Germany allocated most time to total housework activities. In contrast, men’s total housework activities were about 2 h per day less than that of women in the southern European countries. Meanwhile, the difference in housework among older men and women was approximately 1 h per day in Germany. Gender differences in the allocation of time especially for housework may to some extent be explained by cultural and social norms [
34]. These norms may shape total work distribution and time use patterns of the various task of life among men and women. For instance, in the southern European countries where gender roles are still shaped in a more traditional way [
34], women devote a significant amount of time to housework activities while the amount of time devoted to other time use activities may be reduced.
Housework activities, sleep hours and health
Although gender inequality in time allocation to housework activities exists [
15,
16], we found that time devoted to the three broad categories of housework activities were positively associated with health among elderly women and men. Our findings of the association between routine housework activities (cleaning, cooking and shopping) and health contrast with a recent study conducted in China. Wen et al. [
26] found no significant association of cooking, cleaning and grocery shopping and health among older men, but washing clothes and house cleaning were negatively associated with health among women. Meanwhile, our results corroborate a longitudinal study of 2761 older Americans aged 65 years [
35]. Glass et al. [
35] found productive housework activities such as cooking, shopping and gardening to be associated with lower risk of mortality. To these effects, we note that the three broad categories of housework activities involve some form of physical activities which may be beneficial to health among older adults [
36]. Gardening and maintenance activities may increase fitness level and muscle strength because they require some form of physical exertion such as carrying equipment for repair works, lawn mowing, shoveling, digging holes and carrying soil. Previous studies have also stressed the health benefits of gardening for older adults; such benefits include physical health, psychological health, cognitive ability, and low risk of depression [
37,
38]. Park et al. [
39] recently reported that gardening has a positive effect on the blood lipid profiles, blood pressure and level of inflammatory markers in blood.
We also found a positive association between childcare and health status among older people. Although the amount of time devoted to childcare activities among the elderly is very small compared to young adults [
6], caregiving support, especially caring for grandchildren, has been linked with good psychosocial health [
40,
41]. Ku et al. [
41] found that grandparenting was positively associated with good self-reported health and lower risk of depression. However, in some instances, more time devoted to childcare among older adults may have a negative impact on their physical or mental health [
42], especially among custodial grandparents [
43,
44].
Regarding time devoted to total housework hours, the result showed a positive association with health status among both genders. The few studies that examined the effects of total time spent on housework and health among elderly men have given inconsistent results [
26,
35,
45,
46]. Lawlor et al. [
46] reported that heavy housework was not associated with reduced likelihood of being overweight among British women aged 60 to 79 years.
Among the working population, unequal division of household labor has been linked with adverse health outcomes especially among women [
19,
21]. One main hypothesis that has been advanced to explain these gender-specific inequalities in health is the “double burden” of work hypothesis. It has been postulated that the combination of paid market work and domestic work may be more stressful for women than men [
47], which may affect women’s health negatively [
19,
48]. Research findings [
6,
34] indicate that the patterns and distribution of time use vary largely among the elderly and the working population. Therefore, the elderly may not have the same time constraints of combining both paid work and household activities like the working-age adults. In this case, the “double burden” of work hypothesis might lose its premise in explaining the effect of total housework on health among elderly men and women. In our view, housework activities by the older population can be perceived as domestic leisure activities [
12] and forms of domestic physical activities [
38] rather than “work overload”, given a changed time availability after retirement. Hence, there is overall evidence for a positive association between housework activities and health status among elderly men and women.
Regarding sleep duration and self-reported health, we found a U-shaped association where both short (<7 h) and long (>8 h) sleep duration were negatively associated with self-reported health for both genders, consistent with prior findings [
49‐
52]. The magnitude of the association was greater for long in comparison with short sleep duration. No significant difference in sleep duration was found between men and women within-countries, but there were cross-national variations (Additional file 2: Table S1). Currently, it is unclear whether older men or older women actually sleep longer on average [
53‐
55]. Nevertheless, both elderly men and women allocate more time to sleep than any other time use activity [
6,
24]. This time use pattern is expected among older individuals due to the increasing incidence of adverse health conditions [
6]. Conversely, both short and long sleep duration have been found to be associated with adverse health outcomes including diabetes mellitus [
55,
56] obesity [
57,
58], osteoporosis [
59] and hypertension [
60]. Furthermore, recent studies suggest that both short and long sleep duration are associated with increased mortality rates [
23,
61]. Considering gender, a cohort study by Ikehara et al. [
62] showed a U-shaped association between sleep duration and all-cause mortality for both men and women. Even though our data does not permit examining the association with mortality, previous studies have consistently shown a strong relationship between self-reported health and mortality [
63,
64].
While the assessment of gender differences in housework and sleep duration with health status was informative, our study further examined the combined associations, as they provide information about a potentially important interactive gender effect. The results showed that the interactive associations between housework, sleep duration and self-reported health vary by gender. Among men, the combination of longest housework hours with either short or long sleep duration yielded a strong positive association with self-reported health. On the contrary, a combination of longest housework hours with either short or long sleep duration yielded a negative association on self-reported health among women. The result suggests that regardless of sleep duration, less housework was associated with poor health status among both genders.
There is no prior evidence of the combined association of sleep duration and time devoted to housework on health status. Nonetheless, Kiosses and Alexopoulos [
65] found that older adults who report higher levels of depression devote less time to housework and other instrumental activities of daily living (IADL) such as shopping and meal preparation. This negative association can be explained by little or no physical or mental energy associated with less housework, as physical inactivity has been found to play a significant role in the development of chronic diseases [
66]. As discussed above, short and long sleep durations have also been linked to poor health [
55,
56], therefore our findings of the combined effects may be attributed to the negative correlations between less housework, poor sleep and health. Regarding long housework hours and sleep duration, we observed a different pattern among both genders (Fig.
1a and
b). For men, long hours of housework was associated with good health status regardless of sleep duration, whereas these very long hours of housework combined with either short or long sleep was negatively associated with health among women. In fact, these patterns suggest that long housework hours is less sensitive to elderly men’s health [
67] since the impact of long housework and health status appeared to be least influenced by sleep duration.
Limitations and strengths
Our study has some limitations. First, the cross-sectional design of the study prevents conclusions about causality because the association between sleep duration, housework hours and self-reported health may be reciprocal. Second, this study relied on subjective measures to assess duration of sleep, housework and health. However, time use estimates of daily activities have been found to be more accurate and reliable in time use surveys than survey estimates [
68,
69]. Notwithstanding, we acknowledge that sleep disturbance [
70], may impinge on sleep quality and duration [
71], but sleep quality cannot be assessed with time use surveys [
24]. Thus, future research should explore objective and sophisticated time use data collection technologies such as smart-phone apps and actigraphy. Third, due to data availability and constrains, we used diary data of time use surveys that have been collected at different points in time with different modes of data collection in the chosen countries, but evaluation studies suggest that these differences do not affect the comparability of the data [
11]. Despite these limitations, this current study provides an initial overview of housework activities, sleep duration and their correlations with self-reported health of the population aged 65+ years using a large-scale, homogeneous and comparative set of time use data in Europe as well as the US.