Figure 2 shows the results of a univariate analysis of the HRQOL and education gap between couples. In terms of HRQOL for husbands, there was no significant difference between husband TE vs wife LLSE when the husband had a higher education level than the wife, compared to no education gap. Meanwhile, the husband USVE vs wife LLSE group was not significantly different from the husband TE vs wife LLSE group. Significant differences were shown between the other groups. Similar results were also found when husbands had lower education levels than their wives.
As for the HRQOL of wives, when the wife's education level was higher than that of the husband, there was no significant difference between the wife TE vs husband LLSE group and the no gap group. The following groups also showed the same results: the wife TE vs husband LLSE group and the wife USVE vs husband LLSE group, the wife TE vs husband LLSE group and the wife TE vs husband USVE group. When the education level of the wife is lower than that of the husband, it is important to note that there are also significant differences between the wife LLSE vs husband TE group and the wife USVE vs husband TE group.
Figure 2 Univariate analysis of educational gap between couples and HRQOL
Table 2 shows differences in the distribution of HRQOL for husbands and wives for other control variables. Respondents who were younger, no multimorbidity, working, and had higher levels of household wealth (both husband and wife) had better HRQOL. As for husbands, respondents who live in cities, do not drink alcohol, or smoke scored higher. Regarding wives, respondents who lived in rural areas, drank alcohol, and did not smoke scored higher. This implies that the control variables included in the study were appropriate.
Table 2 Univariate analysis of other independent variables and HRQOL
Models 1-3 in Table 3 show the analysis results of husband's HRQOL. Firstly, Model 1 indicates that husbands who have an educational gap with their wives (whether higher or lower) score higher. Model 2 indicates that husbands with higher education levels than their wives have higher HRQOL compared to those without an education gap. Model 3 indicates that there is no significant difference in the HRQOL between husband LLSE vs wife TE compared to the absence of education gap.
Models 4-6 show the analysis results of wife's HRQOL, and the results also indicate that there is no significant difference in HRQOL between wife TE vs husband LLSE compared to no education gap. Comparisons between other groups found a significant positive relationship between the education gap in couples and the wife's HRQOL. In summary, the educational gap between couples could significantly improve their HRQOL, except for the case of husband LLSE vs wife TE.
An interesting discovery is also worth further analysis. Research has found that smoking has different effects on the HRQOL of husbands and wives, respectively. Research shows that there is no significant association between husband smoking and HRQOL, while wife smoking has lower HRQOL scores.
Table 3 Regression analysis results of marital education gap and health-related quality of life
Figure 3 shows the results of the quantile regression analysis. For the husband's HRQOL, when the husband's education level is higher than the wife's, the improvement level of the education gap on the husband's HRQOL is higher in the low quantile of HRQOL. When the education level of the husband is lower than that of the wife, the downward trend is not obvious. The Quantile regression of wife's HRQOL also showed a similar trend.
Figure 3(a) Quantile regression results of education gap and husband's HRQOL
Figure 3(b) Quantile regression results of education gap and Wife's HRQOL