Table 1.
Baseline characteristics of the study population
| Characteristic | PSP N=9851 | Non-PSP N=7520 | P-valuea |
|---|---|---|---|
| Age (years), mean ± SD | 45.6±13.3 | 46.4±13.9 | <0.001 |
| Male, n (%) | 3817 (38.7) | 2935 (39.0) | 0.71 |
| Household income, n (%) | |||
| $0–$49,999 | 1694 (17.2) | 1486 (19.8) | <0.001 |
| $50,000–$99,999 | 2778 (28.2) | 2106 (28.0) | 0.78 |
| >$100,000 | 2402 (24.4) | 1480 (19.7) | <0.001 |
| Unknown | 2977 (30.2) | 2448 (32.6) | <0.001 |
| Expected patient copay, mean ± SD | $344±$1601 | $627±$2042 | <0.001 |
| $0–$25, n (%) | 7685 (78.0) | 4183 (55.6) | <0.001 |
| $26–$100, n (%) | 902 (9.2) | 1581 (21.0) | <0.001 |
| $101–$500, n (%) | 437 (4.4) | 586 (7.8) | <0.001 |
| $501–$1000, n (%) | 150 (1.5) | 225 (3.0) | <0.001 |
| $1001–$2000, n (%) | 160 (1.6) | 195 (2.6) | <0.001 |
| >$2000, n (%) | 517 (5.2) | 750 (10.0) | <0.001 |
| Calendar year, n (%) | |||
| 2015 | 6152 (62.5) | 5146 (68.4) | <0.001 |
| 2016 | 3699 (37.5) | 2374 (31.6) | <0.001 |
| Primary plan, n (%) | |||
| Commercial | 3794 (38.5) | 475 (6.3) | <0.001 |
| Employer group | 584 (5.9) | 703 (9.3) | <0.001 |
| Third party administrator | 27 (0.3) | 47 (0.6) | <0.001 |
| Pharmacy benefit manager | 1887 (19.2) | 2432 (32.3) | <0.001 |
| Cash | 180 (1.8) | 361 (4.8) | <0.001 |
| Processors | 41 (0.4) | 71 (0.9) | <0.001 |
| Unspecified or missing | 3338 (33.9) | 3431 (45.6) | <0.001 |
| Initial claim at specialty pharmacy, n (%)b | 7443 (75.6) | 3938 (52.4) | <0.001 |
| Charlson Comorbidity Index, mean ± SD | 0.38±0.70 | 0.47±0.84 | <0.001 |
| Indications, n (%) | |||
| Inflammatory bowel disease | 4046 (41.1) | 2446 (32.5) | <0.001 |
| Rheumatoid arthritis | 2475 (25.1) | 2254 (30.0) | <0.001 |
| Psoriasis | 1844 (18.7) | 1412 (18.8) | 0.92 |
| Psoriatic arthritis | 813 (8.3) | 750 (10.0) | <0.001 |
| Ankylosing spondylitis | 246 (2.5) | 304 (4.0) | <0.001 |
| Hidradenitis suppurativa | 314 (3.2) | 217 (2.9) | 0.25 |
| Uveitis | 113 (1.1) | 137 (1.8) | <0.001 |
Notes: aWilcoxon rank-sum tests and chi-square tests were used to compare continuous and categorical variables, respectively. bDefined as a pharmacy type of mail order/specialty.
Abbreviations: PSP, patient support program; SD, standard deviation.