A Multifactorial Approach to Evaluating Disparities in Outcomes after Major Surgery in Disadvantaged Older Persons - Major surgery is a common event in the lives of community-living older persons, with a 5-year cumulative inci- dence of 13.8%, representing nearly 5 million persons aged 65 years or older in the US. This value will in- crease substantially in the coming years based on the projected doubling of this age group to 98 million by 2060. As our society ages, it is also becoming increasingly diverse, with growing proportions of racial/ethnic minorities and other disadvantaged groups. Yet, despite the public health imperative, disparities in outcomes after major surgery in disadvantaged older persons are poorly understood. Prior research has generally relied on large administrative datasets and, hence, has usually been restricted to disadvantaged populations defined only by individual-level demographic characteristics, a small number of short-term outcomes, and a limited set of explanatory variables. To address current gaps in knowledge, and build the evidence for action, a more ro- bust approach is needed that focuses on multiple disadvantaged populations of older persons, emphasizes the importance of social contextual factors in defining the scope and complexity of disadvantage, includes a larger array of geriatric-specific outcomes that are clinically meaningful, evaluates a comprehensive set of explana- tory variables that include modifiable patient-centered variables, and assesses the use of post-surgical pallia- tive treatments such as hospice. The overarching objective of this proposal is to identify and elucidate sources of potential disparities in outcomes after major surgery in disadvantaged older populations, defined on the ba- sis of individual-level and social contextual factors. Building on our prior work, we will use high-quality data from the National Health and Aging and Trends Study (NHATS), an ongoing nationally representative longitudi- nal study that includes 7,600+ community-living persons aged 65+ years with oversampling of Blacks, compre- hensive annual assessments with patient-centered phenotypic data that are not available in administrative da- tasets, cohort replenishment at 5-year intervals, and linkages to Medicare and geographic data. This unique resource will permit a series of innovative longitudinal analyses at the patient level that will complement sys- tems-based research on the quality of surgical care. We will rigorously test three distinct but related hypothe- ses: (1) disparities after major surgery in older persons will be observed consistently for multiple outcomes across multiple disadvantaged populations; (2) for each disadvantaged population, these disparities in out- comes will be largely attributable to a set of patient-centered variables, including several that are potentially modifiable; and (3) similar disparities will be observed in the use of hospice but will not be as easily explained. By taking a comprehensive, multifactorial, and multilevel approach that emphasizes the importance of social contextual factors, the proposed research will build the evidence that is essential to understanding the mecha- nisms of potential disparities in outcomes after major surgery. These actionable results will inform novel inter- ventions, collaborations, and policies designed to improve these outcomes in disadvantaged older persons.
