Table 2.
A. Before Propensity Score Weighting
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---|---|---|---|---|---|---|---|
Variables | No Coverage (n=2948) | Generic-only (n=1224) | LIS (n=9809) | ||||
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N | % | N | % | N | % | P-value | |
Female sex | 2123 | 72 | 879 | 72 | 7696 | 78 | <.001 |
Race | |||||||
Non-Hispanic White | 2809 | 95 | 1185 | 97 | 7401 | 75 | <.001 |
African American | 61 | 2 | 9 | 1 | 1037 | 11 | <.001 |
Hispanic | 51 | 2 | 21 | 2 | 1059 | 11 | <.001 |
Asian | 13 | 0 | 3 | 0 | 189 | 2 | <.001 |
Age | |||||||
65–74 | 696 | 24 | 363 | 30 | 3148 | 32 | <.001 |
75–84 | 1186 | 40 | 497 | 41 | 3799 | 39 | 0.2 |
≥ 85 | 1066 | 36 | 364 | 30 | 2862 | 29 | <.001 |
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Mean | SD | Mean | SD | Mean | SD | ||
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Zip Code Completion of College | 0.26 | 0.16 | 0.26 | 0.16 | 0.21 | 0.13 | <.001 |
Zip Code log of median household income | 10.69 | 0.35 | 10.68 | 0.34 | 10.5 | 0.34 | <.001 |
Prescription drug risk score | 1.23 | 0.34 | 1.27 | 0.35 | 1.28 | 0.36 | <.001 |
B. After Propensity Score Weighting†
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---|---|---|---|---|---|---|---|
Variables | No Coverage (n=2948) | Generic-only (n=1224) | LIS (n=9809) | ||||
| |||||||
N | % | N | % | N | % | P-value | |
Female sex | 2123 | 76 | 879 | 77 | 7696 | 77 | 0.15 |
Race | |||||||
Non-Hispanic White | 2809 | 82 | 1185 | 82 | 7401 | 82 | 0.88 |
African American | 61 | 8 | 9 | 7 | 1037 | 8 | 0.09 |
Hispanic | 51 | 7 | 21 | 8 | 1059 | 8 | 0.06 |
Asian | 13 | 2 | 3 | 2 | 189 | 1 | 0.25 |
Age | |||||||
65–74 | 696 | 30 | 363 | 30 | 3148 | 30 | 0.96 |
75–84 | 1186 | 39 | 497 | 39 | 3799 | 39 | 0.84 |
≥ 85 | 1066 | 30 | 364 | 30 | 2862 | 31 | 0.68 |
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Mean | SD | Mean | SD | Mean | SD | ||
| |||||||
Zip Code Completion of College | 0.22 | 0.30 | 0.22 | 0.48 | 0.22 | 0.17 | 0.61 |
Zip Code log of median household income | 10.59 | 0.75 | 10.57 | 1.14 | 10.58 | 0.42 | 0.08 |
Prescription drug risk score | 1.26 | 0.77 | 1.27 | 1.22 | 1.27 | 0.43 | 0.07 |
Abbreviations: LIS = low-income-subsidies
All numbers in panel B are adjusted using the inverse propensity score weights. Propensity scores were calculated using logistic regression models that predict the probability of being in a study group, controlling for beneficiary-level age, sex, race, and prescription drug hierarchical condition, and Zip Code level education and log of median household income.
To assess differences in baseline socio-demographic characteristics among beneficiaries in three different coverage groups, descriptive statistical analyses were performed using two-sided Chi-square test for categorical variables and Fisher’s two-sided F test for continuous variables.
We excluded those with end stage renal disease (n = 389) and outliers (n = 269) defined as data point more than 4 interquartile ranges (IQRs) below the 1st quartile or above the 3rd quartile.
Bold denotes statistically significant at α = 0.05.