Optimism may moderate screening mammogram frequency in Medicare: A longitudinal study

Abstract

Higher trait optimism and/or lower cynical hostility are associated with healthier behaviors and lower risk of morbidity and mortality, yet their association with health care utilization has been understudied. Whether these psychological attitudes are associated with breast cancer screening behavior is unknown. To assess the association of optimism and cynical hostility with screening mammography in older women and whether sociodemographic factors acted as mediators of these relationships, we used Women's Health Initiative (WHI) observational cohort survey data linked to Medicare claims. The sample includes WHI participants without history of breast cancer who were enrolled in Medicare Parts A and B for ≥2 years from 2005-2010, and who completed WHI baseline attitudinal questionnaires (n = 48,291). We used survival modeling to examine whether screening frequency varied by psychological attitudes (measured at study baseline) after adjusting for sociodemographic characteristics, health conditions, and healthcare-related variables. Psychological attitudes included trait optimism (Life Orientation Test-Revised) and cynical hostility (Cook Medley subscale), which were self-reported at study baseline. Sociodemographic, health conditions, and healthcare variables were self-reported at baseline and updated through 2005 as available. Contrary to our hypotheses, repeated events survival models showed that women with the lowest optimism scores (i.e., more pessimistic tendencies) received 5% more frequent screenings after complete covariate adjustment (p < .01) compared to the most optimistic group, and showed no association between cynical hostility and frequency of screening mammograms. Sociodemographic factors did not appear to mediate the relationship between optimism and screenings. However, higher levels of education and higher levels of income were associated with more frequent screenings (both p < .01). We also found that results for optimism were primarily driven by women who were aged 75 or older after January 2009, when changes to clinical guidelines lead to uncertainty about risks and benefits of screening in this age group. The study demonstrated that lower optimism, higher education, and higher income were all associated with more frequent screening mammograms in this sample after repeated events survival modeling and covariate adjustment.

Figure 1

Flowchart of cohort creation. Notes: Censorship rates in 2005 and 2006 are lower because women were required to have at least 2 years of Medicare claims starting in 2005, so censorship in these first 2 years was due to breast cancer diagnosis alone.

Figure 2

Screening mammography timelines in survival models. Notes: the figure above provides examples of potential individual participant timelines and how these timelines are interpreted for survival models. Intervals with diagonal lines are included in the analyses; those with dots are excluded from analyses because they follow either death or a breast cancer diagnosis. Screening mammograms (designated with a black “X”) are considered events, and survival models assess how the hazard for the event (screening mammogram) differs for women with, for example, least vs most optimism scores. A diagnosis of breast cancer or death (both designated with a square) are terminal end points, meaning that the individual is no longer eligible for the event. “Censored” start and end points indicate that the exact date of the previous or subsequent screening mammogram (the event) is unknown, for example, at the beginning of the observation period, and at the end of the study follow-up period. Diagnostic mammograms are considered definite start points (they re-set a woman's clock for a potential new screening at that exact time); however, they are considered censored end-points (they are not the screening event of interest, so they function similar to ending an eligible follow-up window). In the figure above, Timeline A represents a woman with 2 screening mammograms during her follow up, and ends at the study end (censored end point). Timelines B and C include diagnostic mammograms as well as screening mammograms. Timelines D and E show a case where follow-up is ended due to breast cancer diagnosis (D) or death (E). Finally, Timeline F shows a case where a woman has no events during her entire follow-up period and until the study ends.

Figure 3

Distribution of attitudes by race/ethnicity and SES variables.