Table 1.
Baseline characteristics: after match
| Characteristics | RP (n = 4633) | non-RP (n = 4633) | P valuea | Standardized difference | ||
|---|---|---|---|---|---|---|
| Demographic characteristics | ||||||
| Age (mean, SD) | 62.07 | 12.60 | 62.02 | 12.16 | 0.8262 | 0.45 |
| Female (n, %) | 2900 | 62.59 | 2889 | 62.36 | 0.8250 | 0.49 |
| Region (n, %) | ||||||
| Midwest | 849 | 18.33 | 901 | 19.45 | 2.87 | |
| Northeast | 675 | 14.57 | 677 | 14.61 | 0.6556 | 0.12 |
| South | 2711 | 58.52 | 2656 | 57.33 | 2.40 | |
| West | 398 | 8.59 | 399 | 8.61 | 0.08 | |
| Adherence in pre-index period (mean, SD) | ||||||
| MPR | 82.43 | 18.63 | 82.57 | 19.39 | 0.6910 | 0.77 |
| Refill timing (days) | 8.77 | 14.61 | 8.84 | 13.55 | 0.7971 | 0.51 |
| Prescription counts in pre-index period (mean, SD) | ||||||
| Unique HTN Rx classes (n) | 0.62 | 0.79 | 0.62 | 0.79 | 0.8183 | 0.44 |
| Unique HTN Rxs (n) | 0.64 | 0.82 | 0.63 | 0.82 | 0.7718 | 0.55 |
| Unique non-HTN Rx classes (n) | 4.41 | 3.62 | 4.47 | 3.75 | 0.4224 | 1.55 |
| Unique non-HTN Rxs (n) | 4.61 | 3.89 | 4.68 | 4.05 | 0.3072 | 1.97 |
| Comorbidity in pre-index period | ||||||
| Cardiovascular CDS Ib,c (mean, SD) | 1.38 | 1.69 | 1.37 | 1.67 | 0.8649 | 0.33 |
| Non-cardiovascular CDS IIb,d (mean, SD) | 2.24 | 2.25 | 2.27 | 2.30 | 0.5337 | 1.25 |
| Other diseases (n, %) | ||||||
| Renal disease | 2 | 0.04 | 3 | 0.06 | 1.0000 | 0.93 |
| End-stage renal disease | 1 | 0.02 | 1 | 0.02 | 1.0000 | 0.00 |
| Cystic fibrosis | 2 | 0.04 | 1 | 0.02 | 1.0000 | 1.20 |
| Liver failure | 7 | 0.15 | 9 | 0.19 | 0.8036 | 1.04 |
| Transplantation | 0 | 0.00 | 1 | 0.02 | – | – |
| Thyroid disorders | 587 | 12.67 | 592 | 12.78 | 0.8987 | 0.32 |
| Pain and inflammation | 837 | 18.07 | 828 | 17.87 | 0.8180 | 0.51 |
| Pain | 1020 | 22.02 | 1009 | 21.78 | 0.7957 | 0.57 |
| Depression | 928 | 20.03 | 911 | 19.66 | 0.6730 | 0.92 |
| Psychotic illness | 78 | 1.68 | 84 | 1.81 | 0.6771 | 0.99 |
| Bipolar disorder | 4 | 0.09 | 3 | 0.06 | 1.0000 | 0.79 |
| Human immunodeficiency virus | 114 | 2.46 | 102 | 2.20 | 0.4368 | 1.72 |
| Anxiety and tension | 613 | 13.23 | 565 | 12.20 | 0.1094 | 3.11 |
Notes:
t-test for continuous variables and Chi-square test for categorical variables;
CDS is calculated by assigning a weight (score) to each drug class to correspond to disease complexity and severity. It is an aggregate of the assigned weights based on medication use, but not on frequency of use;
CDS I is derived based on hypertensive (excluding valsartan-hydrochlorothiazide claims) and cardiac medications, by assigning scores suggested by Von Korff et al.21 Range (0–7);
CDS II is derived based on medications of epilepsy, tuberculosis, rheumatologic conditions, hyperlipidemia, malignancies, Parkinson’s disease, diabetes, glaucoma, ulcer, respiratory illness, gout, acne, migraines, Crohn’s disease, and coronary disease by assigning scores suggested by Von Kroff et al.21 Range (0–27) Standardized difference = 100 * (x1 − x2)/√ {(s12 + s22)/2}, where x1 = mean of group 1, x2 = mean of group 2, s1 = standard deviation of group 1, and s2 = standard deviation of group 2.
Abbreviations: CDS, chronic disease score; ESRD, end-stage renal disease; HIV, human immunodeficiency virus; HTN, hypertension; MPR, medication possession ratio; RP, reminder packaging; Rx, prescription; SD, standard deviation; non-RP, without reminder packaging.