Table 3.
Racial/Ethnic Inequities in Adherence to and Discontinuation of Orally-administered Antimyeloma Therapy
| Adherencea | Discontinuationa | Time to Discontinuationa,b | ||||
|---|---|---|---|---|---|---|
| Effect of Racec | SES-Adjustedd | Effect of Racec | SES-Adjustedd | Effect of Racec | SES-Adjustedd | |
| All Enrollees | ||||||
| Non-Hispanic/Latinx White | Ref | Ref | Ref | Ref | Ref | Ref |
| Non-Hispanic/Latinx Black or African American | 0.98 (0.85–1.13) | 1.09 (0.94–1.27) | 0.94 (0.81–1.09) | 0.82 (0.70–0.97) | 0.99 (0.84–1.17) | 0.85 (0.71–1.03) |
| Hispanic/Latinx | 1.12 (0.95–1.31) | 1.22 (1.03–1.46) | 1.01 (0.85–1.20) | 0.94 (0.77–1.15) | 1.05 (0.86–1.28) | 0.90 (0.71–1.13) |
| Asian or Pacific Islander | 0.87 (0.70–1.07) | 0.90 (0.73–1.12) | 0.99 (0.80–1.23) | 0.94 (0.74–1.18) | 1.03 (0.80–1.32) | 0.92 (0.70–1.20) |
| Full Subsidy Enrollees | ||||||
| Non-Hispanic/Latinx White | Ref | Ref | Ref | Ref | Ref | Ref |
| Non-Hispanic/Latinx Black or African American | 0.96 (0.73–1.25) | 1.02 (0.77–1.34) | 1.00 (0.80–1.24) | 0.98 (0.78–1.23) | 1.00 (0.77–1.29) | 0.98 (0.75–1.28) |
| Hispanic/Latinx | 1.14 (0.88–1.46) | 1.13 (0.87–1.48) | 0.95 (0.74–1.21) | 1.01 (0.77–1.32) | 0.86 (0.65–1.15) | 0.91 (0.66–1.26) |
| Asian or Pacific Islander | 0.95 (0.70–1.28) | 0.87 (0.63–1.20) | 0.96 (0.71–1.29) | 1.01 (0.74–1.39) | 0.81 (0.57–1.16) | 0.88 (0.61–1.28) |
| Non-subsidy Enrollees | ||||||
| Non-Hispanic/Latinx White | Ref | Ref | Ref | Ref | Ref | Ref |
| Non-Hispanic/Latinx Black or African American | 1.10 (0.92–1.30) | 1.19 (0.99–1.42) | 0.73 (0.57–0.95) | 0.67 (0.51–0.88) | 0.74 (0.56–0.98) | 0.64 (0.48–0.86) |
| Hispanic/Latinx | 1.14 (0.88–1.48) | 1.19 (0.92–1.55) | 1.02 (0.74–1.41) | 1.03 (0.74–1.42) | 1.14 (0.81–1.60) | 1.13 (0.80–1.61) |
| Asian or Pacific Islander | 0.78 (0.55–1.12) | 0.78 (0.55–1.11) | 0.88 (0.60–1.30) | 0.95 (0.64–1.40) | 0.97 (0.64–1.47) | 1.05 (0.69–1.60) |
Abbreviations: SES, socioeconomic status
Risk ratios and 95% confidence intervals are presented for adherence and discontinuation within 180 days of treatment initiation and hazard ratios and 95% confidence intervals are presented for time to discontinuation. 3,091 patients were included in the analysis of adherence and discontinuation within 180 days of treatment initiation and 3,563 patients were included in the analysis of time to discontinuation.
The all enrollees independent effect of race and SES-adjusted models were stratified by marital status, bone loss, and age at diagnosis; and marital status, bone loss, age at diagnosis, and high school education, respectively, since the proportionality assumption was not satisfied for these variables. Similarly, the full subsidy enrollees and non-subsidy enrollees models were stratified by bone loss; and age at diagnosis, marital status, and year of diagnosis, respectively.
In accordance with the Institute of Medicine’s definition of disparities, we assessed the independent effect of race/ethnicity by only controlling for health status (age at diagnosis, sex, marital status, clinical characteristics, and prior health service use).
We adjusted for urbanicity and census tract-level SES and SES-related factors (median household income, poverty level, high school education, and English proficiency) to determine if observed racial/ethnic differences in treatment use were attenuated.