Spousal education and frailty trajectories among Chinese older adults: A national longitudinal study

•Higher spousal education is negatively associated with own frailty level in later life, especially among older adults who are already frail.•The differences in frailty level between older adults whose spouses had less than a junior high school education and those whose spouses had a junior high school education or above, respectively, and older adults whose spouses had no formal education far exceeded the minimal clinically important difference threshold for the frailty level.•However, the frailty trajectory differences across spousal education levels narrow with increasing age.•The protective impact of a highly educated spouse against frailty did not vary by gender or own education.