Marital Quality and Physical Illness: A Latent Growth Curve Analysis

K. A. S. WICKRAMA, FREDERICK 0. LORENZ, AND RAND D. CONGER Iowa State University GLEN H. ELDER, JR. University of North Carolina* Using latent growth curves, this study investigates the association between intraindividual changes in marital quality and physical illness for 364 wives and husbands in the rural Midwest. The results reveal that both the initial level of and the change in the marital quality of husbands and wives correlate with the initial level of and the change in physical health, after controlling for the influence of work stress, education, and income. Additional analyses imply that psychological wellbeing and behaviors that are health risks mediate or explain this association. The results provide stronger evidence for the association between marital quality and physical illness for both husbands and wives than has been obtained from cross-sectional studies or from longitudinal studies that have been limited to the investigation of interindividual differences. Key Words: marital quality, physical illness. Previous research demonstrates a significant association between marital roles and physical health (Gove, Hughes, & Style, 1983; Ross, Mirowsky, & Goldsteen, 1990). Few scholars, however, have examined how the degree of marital quality, rather than simply the status of being married, relates to physical well-being (Marcenes & Sheham, 1992). Yet subjective experience in the marital role may be a more powerful predictor of health status than is role occupancy (Barauch & Barnett, 1986). Gove and Umberson (1985), for example, found that intimate relationships are strongly related to overall well-being. Another limitation in previous research is that most of the studies focusing on the association between marital quality and health have examined only mental health (Lorenz, Conger, Montague, & Wickrama, 1993). In this study, we extend earlier research by investigating the correlation of marital quality, as indicated by marital stability, satisfaction, and happiness in the relationship, with physical illness, as reported by 364 wives and husbands who have been married long. In addition to examining the empirical relationship between marital quality and physical health, our study also addresses two important methodological issues largely neglected in previous research. First, earlier studies have focused on the correspondence between the levels of marital quality and physical health. We were able to locate only one study that has examined the relationship between interindividual changes in marital quality and changes in physical health (Booth & Johnson, 1994). No research in this area has investigated individual differences in intraindividual change in marriage and health, even though the investigation of change should explain individual growth or decline over time. Instead, prior studies of health and social relations have inferred intraindividual change from interindividual differences in levels of attributes (Lorenz & Wickrama, 1994). Actually monitoring the correspondence between changes in social relations and changes in health status provides stronger evidence for the dynamic association between those attributes, at least in comparison with the correspondence that can be obtained from interindividual differences in levels of marital quality and physical health at one point in time (McArdle, 1986; Patterson, 1983, Rogosa, Brandt, & Zimowski, 1982). Most important, none of the earlier studies that we have been able to identify has used individual trajectories of change to examine the systematic relationship between marital quality and physical wellbeing. In examining how the dynamics of marriage might affect changes in health status, it is important to note that changes in personal attributes across several points in time can take either linear or nonlinear forms. When true individual change follows interesting and even nonlinear trajectories, traditional analytical methods (correlational and covariant) are unlikely to reveal the intricacies of individual change (Willet & Sayer, 1994). …