Differences between husbands and wives in colonoscopy use: Results from a national sample of married couples

Marriage is linked to improved colorectal cancer-related health, likely in part through preventive health behaviors, but it is unclear what role spouses play in colorectal cancer screening. We therefore determine whether self-reported colonoscopy rates are correlated within married couples and the characteristics of spouses associated with colonoscopy use in each partner. We use US nationally-representative 2010 data which includes 804 male-female married couples drawn from a total sample of 3137 community-dwelling adults aged 55-90years old. Using a logistic regression model in the full sample (N=3137), we first find married men have higher adjusted colonoscopy rates than unmarried men (61% versus 52%, p=0.023), but women's rates do not differ by marital status. In the couples' sample (N=804 couples), we use a bivariate probit regression model to estimate multiple regression equations for the two spouses simultaneously as a function of individual and spousal covariates, as well as the adjusted correlation within couples. We find that individuals are nearly twice as likely to receive a colonoscopy if their spouse recently has had one (OR=1.94, 95% CI: 1.39, 2.67, p<0.001). Additionally, we find that husbands have higher adjusted colonoscopy rates whose wives are: 1) happier with the marital relationship (65% vs 51%, p=0.020); 2) more highly educated (72% vs 51%, p=0.020), and 3) viewed as more supportive (65% vs 52%, p=0.020). Recognizing the role of marital status, relationship quality, and spousal characteristics on colonoscopy uptake, particularly in men, could help physicians increase guideline adherence.