Table 2.
Baseline Characteristics of Patients with Fibromyalgia Initiating FDA-Approved Medications, 2006–2014
| Characteristics | Pregabalin (N = 1043) | Duloxetine (N = 1281) | Milnacipran (N = 326) | P value |
|---|---|---|---|---|
| Age, yrs | .31 | |||
| Mean ± SD | 50.0 ± 11.6 | 49.6 ± 11.4 | 49.0 ± 11.1 | |
| Age category, yrs, N (%) | .71 | |||
| 18–34 | 98 (9.4) | 136 (10.6) | 31 (9.5) | |
| 35–44 | 206 (19.8) | 264 (20.6) | 74 (22.7) | |
| 45–54 | 381 (36.5) | 428 (33.4) | 113 (34.7) | |
| 55–64 | 278 (26.7) | 366 (28.6) | 88 (27.0) | |
| 65+ | 80 (7.7) | 87 (6.8) | 20 (6.1) | |
| Sex, N (%) | <.05a | |||
| Male | 132 (12.7) | 143 (11.2) | 17 (5.2) | |
| Female | 911 (87.3) | 1138 (88.8) | 309 (94.8) | |
| Insurance type, N (%) | .51 | |||
| Commercial | 956 (91.7) | 1185 (92.5) | 305 (93.6) | |
| Medicare | 87 (8.3) | 96 (7.5) | 21 (6.4) | |
| Race, N (%) | .82 | |||
| Native American | 2 (0.2) | 5 (0.4) | 1 (0.3) | |
| Asian | 7 (0.7) | 12 (0.9) | 4 (1.2) | |
| Black | 58 (5.6) | 61 (4.8) | 17 (5.2) | |
| Pacific Islander | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| White | 778 (74.6) | 948 (74.0) | 238 (73.0) | |
| Unknown | 177 (17.0) | 226 (17.6) | 53 (16.3) | |
| Ethnicity, N (%) | .88 | |||
| Hispanic | 49 (4.7) | 58 (4.5) | 13 (4.0) | |
| Not Hispanic | 817 (78.3) | 997 (77.8) | 260 (79.8) | |
| Unknown | 177 (17.0) | 226 (17.6) | 53 (16.3) | |
| Region, N (%) | .16 | |||
| Northeast | 147 (14.1) | 235 (18.4) | 59 (18.1) | |
| North Central | 206 (19.8) | 242 (18.9) | 69 (21.2) | |
| South | 551 (52.8) | 638 (49.8) | 158 (48.5) | |
| West | 139 (13.3) | 166 (13.0) | 40 (12.3) | |
| Charlson Comorbidity score, mean ± SD | 0.65 ± 1.02 | 0.66 ± 1.01 | 0.55 ± 0.80 | .20 |
| Charlson comorbidities, N (%) | ||||
| AIDS/HIV | 0 (0.0) | 0 (0.0) | 0 (0.0) | N/A |
| Any malignancyb | 11 (1.1) | 23 (1.8) | 0 (0.0) | <.05a |
| Cerebrovascular disease | 41 (3.9) | 72 (5.6) | 9 (2.8) | <.05a |
| Chronic pulmonary disease | 153 (14.7) | 203 (15.9) | 52 (16.0) | .71 |
| Congestive heart failure | 29 (2.8) | 30 (2.3) | 4 (1.2) | .28 |
| Dementia | 1 (0.1) | 0 (0.0) | 0 (0.0) | .52 |
| Depression | 266 (25.5) | 418 (32.6) | 72 (22.1) | <.0001a |
| Diabetes without chronic complications | 37 (3.6) | 25 (2.0) | 6 (1.8) | <.05a |
| Charlson comorbidities, N (%) | ||||
| Diabetes with chronic complications | 145 (13.9) | 154 (12.0) | 33 (10.1) | .16 |
| Hemiplegia or paraplegia | 2 (0.2) | 10 (0.8) | 1 (0.3) | .13 |
| Metastatic solid tumor | 0 (0.0) | 0 (0.0) | 0 (0.0) | N/A |
| Mild liver disease | 47 (4.5) | 69 (5.4) | 22 (6.8) | .25 |
| Moderate or severe liver disease | 1 (0.1) | 1 (0.1) | 0 (0.0) | 1.00 |
| Myocardial infarction | 4 (0.4) | 4 (0.3) | 2 (0.6) | .61 |
| Peptic ulcer disease | 12 (1.2) | 16 (1.3) | 3 (0.9) | .93 |
| Other comorbidities, N (%) | ||||
| Fatigue | 345 (33.1) | 530 (41.4) | 145 (44.5) | <.0001a |
| Hypertension | 347 (33.3) | 449 (35.1) | 112 (34.4) | .67 |
| Generalized anxiety disorder | 44 (4.2) | 83 (6.5) | 17 (5.2) | .05 |
| Migraine/headache | 301 (28.9) | 391 (30.5) | 95 (29.1) | .67 |
| Musculoskeletal pain disorders | 430 (41.2) | 523 (40.8) | 140 (42.9) | .78 |
| Neuropathic pain disorders | 47 (4.5) | 52 (4.1) | 12 (3.7) | .80 |
| Gastrointestinal disorders | 251 (24.1) | 312 (24.4) | 79 (24.2) | .99 |
| Obesity | 90 (8.6) | 160 (12.5) | 38 (11.7) | <.05a |
| Epilepsy | 16 (1.5) | 14 (1.1) | 2 (0.6) | .43 |
| Sleep disorder | 183 (17.6) | 271 (21.2) | 70 (21.5) | .06 |
| Medication use, N (%) | ||||
| Fibromyalgia medications | ||||
| Pregabalin | N/A (N/A) | 29 (2.3) | 2 (0.6) | N/A |
| Duloxetine | 54 (5.2) | N/A (N/A) | 9 (2.8) | N/A |
| Milnacipran | 6 (0.6) | 7 (0.6) | N/A (N/A) | N/A |
| Antidepressants | 639 (61.3) | 785 (61.3) | 200 (61.4) | 1.0000 |
| Tetracyclic antidepressants | 130 (12.5) | 150 (11.7) | 31 (9.5) | .36 |
| Tricyclic antidepressants | 160 (15.3) | 218 (17.0) | 63 (19.3) | .21 |
| SSRIs | 380 (36.4) | 499 (39.0) | 108 (33.1) | .11 |
| SNRIs | 167 (16.0) | 124 (9.7) | 45 (13.8) | <.05a |
| Antimigraine (triptans) | 122 (11.7) | 133 (10.4) | 34 (10.4) | .58 |
| Benzodiazepines | 431 (41.3) | 527 (41.1) | 141 (43.3) | .78 |
| Gabapentin | 249 (23.9) | 283 (22.1) | 60 (18.4) | .11 |
| NSAIDs, nonselectiveb | 417 (40.0) | 512 (40.0) | 131 (40.2) | .99 |
| Skeletal muscle relaxants | 520 (49.9) | 577 (45.0) | 155 (47.6) | .07 |
| Sedative/hypnotics | 242 (23.2) | 271 (21.2) | 68 (20.9) | .44 |
| Oral corticosteroids | 510 (48.9) | 585 (45.7) | 147 (45.1) | .24 |
| Topical corticosteroids | 181 (17.4) | 206 (16.1) | 44 (13.5) | .25 |
| Opioids, long acting | 99 (9.5) | 102 (8.0) | 37 (11.4) | .12 |
| Opioids, short acting | 795 (76.2) | 887 (69.2) | 232 (71.2) | <.05a |
| Topical analgesics | 69 (6.6) | 87 (6.8) | 22 (6.8) | .98 |
NOTES: Results are reported as number and percentage, unless otherwise specified. Regions were defined using US Census regions as Northeast: ME, NH, VT, MA, CT, RI, NY, PA, NJ; North Central: ND, MN, WI, MI, SD, NE, KS, IA, MO, IL, IN, OH; South: TX, OK, AR, LA, MS, TN, KY, AL, GA, SC, NC, FL, VA, WV, DC, MD, DE; and West: WA, OR, ID, MT, WY, UT, CO, AZ, NM, NV, CA.
a
Significant at P <.05.
b
Including lymphoma and leukemia, except for malignant neoplasm of skin.
FDA indicates US Food and Drug Administration; N/A, not available; NSAIDs, nonsteroidal anti-inflammatory drugs; SD, standard deviation; SNRI, serotonin and norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor.