Health care contact days in older adults enrolled in SWOG cancer clinical trials.

64 Background: Health care contact days—days with health care contact outside the home—are a measure of how much of a patient’s life is consumed by health care. This number of contact days are especially relevant for older adults with advanced cancer facing limited survival. One concern is that patients with different sociodemographic and clinical backgrounds may be at particular risk of increased contact days. Thus, there is a critical need to understand factors associated with contact days. Methods: We linked data from 6 SWOG trials in advanced cancer to Medicare claims data. These trials encompassed a variety of primary cancer types [prostate (S9916, S0421), lung (S0003, S0124, S0819), and pancreas (S0205)]. Health care contact days (days with ambulatory, emergency department, inpatient, or facility-based care) in the first 12 months were calculated using Medicare database files. A day with >1 source of contact counted as 1. We examined sociodemographic (age, race, ethnicity, sex, insurance status, rurality, area deprivation index) and clinical (prognostic risk, cancer type, performance status) predictors of contact days, using negative binomial regression, with a log link and clustering by study ID, including an offset variable for duration of observation. We examined predictors in univariate and multivariable analysis. We report relative risk (RRs) estimates and 95% CI. Results: We included 1,429 patients (median age, 71 years, 7.6% Black, 2.7% Hispanic, 21.4% female, and 23.5% rural residence). Of these, 741 (51.9%) patients died in the first year. The median number of contact days was 48, out of a median of 350 days of observation. At a trial level, median percentage of contact days ranged from 14% (prostate) to 27% (lung). The most common sources of contact days were ambulatory clinician visits (median=17), tests (median=12), and treatments (median=11). In multivariable regression, factors associated with increased contact days included increasing age (per year, RR=1.02 [1.01-1.02], p<.001), insurance status (Medicare alone or with Private or Medicaid insurance, vs Military/VA, none, or other insurance, RR=2.47 [2.16-2.83], p<.001), higher prognostic risk score (RR=1.14 [1.04-1.25], p=.004), and type of cancer (pancreas, RR=1.69 [1.51-1.89] and lung, RR=1.69 [1.54-1.85] vs prostate, p<.001 for both). Conclusions: This novel linkage of trial and claims data to evaluate contact days and associated factors found that older trial participants spent up to one in four days with health care contact. Ambulatory appointments were the most common source of contact days. Encouragingly, rural residence and neighborhood deprivation were not associated with contact days, increasing confidence that participants from diverse geographic areas may receive equitable care in trials. These data highlight the frequency of contact days for trial participants, while identifying factors to consider when benchmarking contact days.