Table 1.
Characteristics of MS Patients Included in the Study Cohort
| Variable, n (%) | Initiation Population for Time-Trend Analysis | Calendar Time-Matched Sample for Predictors Analysis | Switching Population for Time-Trend Analysis | Calendar Time-Matched Sample for Predictors Analysis | ||
|---|---|---|---|---|---|---|
| Total (N = 7,576) | Oral Initiators (n = 422) | Injectable Initiators (n = 3,176) | Total (N = 1,342) | Oral Switchers (n = 408) | Injectable Switchers (n = 408) | |
| Demographics | ||||||
| Age, years | ||||||
| 18-49 | 4,698 (62.0) | 272 (64.5) | 2,025 (63.8) | 862 (64.2) | 267 (65.4) | 257 (63.0) |
| 50-64 | 2,730 (36.0) | 141 (33.4) | 1,079 (34.0) | 451 (33.6) | 126 (30.9) | 143 (35.0) |
| ≥ 65 | 148 (2.0) | 9 (2.1) | 72 (2.3) | 29 (2.2) | 15 (3.7) | 8 (2.0) |
| Females | 5,681 (75.1) | 320 (75.8) | 2,320 (73.3) | 1,006 (75.1) | 300 (73.7) | 287 (70.9) |
| Regiona | ||||||
| Midwest | 822 (10.9) | 27 (6.4) | 242 (7.6) | 122 (9.1) | 36 (8.8) | 25 (6.1) |
| Northeast | 2,567 (33.9) | 124 (29.4) | 1,373 (43.2) | 454 (33.8) | 118 (28.9) | 162 (39.7) |
| South | 2,701 (35.7) | 182 (43.1) | 981 (30.9) | 494 (36.8) | 165 (40.4) | 140 (34.3) |
| West | 1,336 (17.6) | 82 (19.4) | 513 (16.2) | 243 (18.1) | 84 (20.6) | 78 (19.1) |
| Treatment for MS-associated symptomsb | ||||||
| Dalfampridine | 203 (2.7) | 31 (7.3) | 121 (3.8) | 103 (7.7) | 40 (9.8) | 52 (12.7) |
| Continence treatment | 364 (4.8) | 16 (3.8) | 130 (4.1) | 81 (6.0) | 24 (5.9) | 18 (4.4) |
| Fatigue treatment | 921 (12.2) | 46 (10.9) | 339 (10.7) | 181 (13.5) | 61 (15) | 36 (8.8) |
| Erectile dysfunction treatment | 75 (1.0) | 6 (1.4) | 19 (0.6) | 25 (1.9) | 8 (2.0) | 6 (1.5) |
| Neuralgia or muscle spasm treatment | 2,369 (31.3) | 155 (36.7) | 969 (30.5) | 528 (39.3) | 155 (38) | 164 (40.2) |
| Injectable steroids | 833 (11.0) | 350 (11.0) | 53 (12.6) | 197 (14.8) | 59 (14.5) | 80 (19.6) |
| Oral high-dose steroidsc | 192 (2.5) | 21 (5.0) | 98 (3.1) | 56 (4.2) | 19 (4.7) | 24 (5.9) |
| Comorbid diagnosis and health care use | ||||||
| Seizures | 209 (2.8) | 16 (3.8) | 125 (3.9) | 53 (4.0) | 22 (5.4) | 22 (5.4) |
| Depression | 1,242 (16.4) | 112 (26.5) | 544 (17.1) | 316 (23.6) | 99 (24.3) | 102 (25.0) |
| Gastrointestinal symptoms | 963 (12.7) | 97 (23.0) | 531 (16.7) | 282 (21) | 102 (25.0) | 95 (23.3) |
| Hematological conditions | 97 (1.3) | 10 (2.4) | 51 (1.6) | 28 (2.1) | 7 (1.7) | 14 (3.4) |
| Liver diseases | 62 (0.8) | 7 (1.7) | 40 (1.3) | 27 (2.0) | 11 (2.7) | 11 (2.7) |
| Hypertension | 1,524 (20.1) | 102 (24.2) | 692 (21.8) | 327 (24.4) | 101 (24.8) | 92 (22.5) |
| Diabetes | 414 (5.5) | 29 (6.9) | 200 (6.3) | 89 (6.6) | 33 (8.1) | 25 (6.1) |
| Cardiovascular diseasesd | 373 (4.9) | 30 (7.1) | 200 (6.3) | 98 (7.3) | 33 (8.1) | 28 (6.9) |
| Infectionse | 370 (4.9) | 20 (4.7) | 141 (4.4) | 69 (5.2) | 25 (6.1) | 18 (4.4) |
| Any hospitalization in previous 6 months | 463 (6.1) | 29 (6.9) | 228 (7.2) | 87 (6.5) | 18 (4.4) | 26 (6.4) |
| Any neurologist consultation in previous 6 months | 6,069 (80.1) | 325 (77.0) | 2,365 (74.5) | 1,126 (83.9) | 323 (79.2) | 344 (84.3) |
| Any occupational or physical therapy visits in previous 6 months | 292 (3.9) | 14 (3.3) | 107 (3.4) | 73 (5.4) | 19 (4.7) | 33 (8.1) |
| Any emergency department visits in previous 6 months | 1,218 (16.1) | 82 (19.4) | 520 (16.4) | 212 (15.8) | 59 (14.5) | 57 (14.0) |
aRegion missing for approximately 2% of patients.
bIncontinence treatment included desmopressin, botulinum toxin, oxybutynin, and tolterodine; fatigue treatment included amantadine, modafinil, armodafinil, and methylphenidate; erectile dysfunction treatment included sildenafil citrate, tadalafil, and vardenafil; and neuralgia or muscle spasm treatment included carbamazepine, gabapentin, lamotrigine, phenytoin, pregabalin, baclofen, diazepam, clonazepam, dantrolene, and tizanidine.
cOral high-dose steroids were defined by a cumulative dose of oral steroid equivalent to more than 1,000 mg of prednisone.
dCardiovascular diseases included ischemic heart diseases, cerebrovascular events, or chronic heart failure.
eInfections included serious bacterial infections (meningitis, encephalitis, cellulitis, endocarditis, pneumonia, pyelonephritis, osteomyelitis, and bacteremia) and opportunistic infections (tuberculosis, systemic candidiasis, cryptococcosis, and aspergillosis) or herpes zoster in the 6 months before DMD initiation or switch.
DMD = disease-modifying drug; MS = multiple sclerosis.