Table 1.
Clinical and Demographic Characteristics of Epilepsy and Comparison Cohorts
| Characteristic | CPRD | SAIL Databank | ||
|---|---|---|---|---|
| Epilepsy Cohort (n = 44 678) |
Comparison Cohort (n = 891 429) |
Epilepsy Cohort (n = 14 051) |
Comparison Cohort (n = 279 365) |
|
| Male, No. (%) | 22 961 (51.4) | 458 008 (51.4) | 7716 (51.1) | 142, 526 (51.0) |
| Age at entry, median (IQR), y | 41 (25-60) | 40 (25-60) | 44 (24-62) | 43 (24-62) |
| Level of deprivation, No. (%)a | ||||
| 1 (Least deprived) | 7621 (17.0) | 178 850 (20.1) | 2202 (15.7) | 52 305 (18.7) |
| 2 | 8878 (19.9) | 194 644 (21.8) | 2314 (16.4) | 50 635 (18.1) |
| 3 | 8565 (19.2) | 178 281 (20.0) | 3059 (21.8) | 61 063 (21.9) |
| 4 | 9723 (21.8) | 179 831 (20.2) | 2997 (21.3) | 56 110 (20.1) |
| 5 (Most deprived) | 9826 (22.0) | 158 696 (17.8) | 3468 (24.7) | 58 849 (21.1) |
| Missing | 65 (0.1) | 1127 (0.1) | 11 (0.1) | 403 (0.1) |
| Previous diagnoses, No. (%) | ||||
| Alcohol misusea | 2682 (6.0) | 12 056 (1.4) | 936 (6.7) | 5823 (2.1) |
| Anxietya | 7195 (16.1) | 104 532 (11.7) | 2452 (17.5) | 34 486 (12.3) |
| Bipolar disordera | 465 (1.0) | 3293 (0.4) | 143 (1.0) | 1066 (0.4) |
| Depressiona | 9096 (20.4) | 123,989(13.9) | 2930 (20.9) | 39 953 (14.3) |
| Eating disordera | 548 (1.2) | 5849 (0.7) | 183 (1.3) | 2025 (0.7) |
| Migrainea | 3081 (6.9) | 46 150 (5.2) | 1058 (7.5) | 14 299 (5.1) |
| Neuropathic pain | 1578 (3.5) | 30 763 (3.5) | 961 (6.8) | 18 253 (6.5) |
| Personality disordera | 836 (1.9) | 3675 (0.4) | 307 (2.2) | 1996 (0.7) |
| Schizophreniaa | 1273 (2.9) | 6711 (0.8) | 377 (2.7) | 2584 (0.9) |
| Self-harma | 3563 (8.0) | 23 248 (2.6) | 1050 (7.5) | 9140 (3.3) |
| Substance misusea | 2972 (6.7) | 11 923 (1.3) | 1122 (8.0) | 6661 (2.4) |
| Prior prescription at baseline, No. (%) | ||||
| Antidepressanta | 11 175 (25.0) | 171 866 (19.3) | 4043 (28.8) | 27 104 (20.4) |
| Antipsychotica | 6823 (15.3) | 88 433 (9.9) | 1843 (13.1) | 19 655 (7.0) |
| Anxiolytic or hypnotica | 14 562 (32.6) | 124 898 (14.0) | 4938 (35.1) | 42 137 (15.1) |
| Lithium carbonate or lithium citratea | 162 (0.4) | 1982 (0.2) | 61 (0.4) | 642 (0.2) |
| Opioida,b | 14 355 (32.1) | 252 308 (28.3) | 6603 (47.0) | 100 331 (35.9) |
| Follow-up time, median (IQR), ya | 4.0 (1.4-8.4) | 5.1 (2.1-9.3) | 6.9 (2.9-10.3) | 7.7 (3.6-10.9) |
| New diagnoses during follow-up, No. (%) | ||||
| Alcohol misusea | 784 (1.8) | 9321 (1.1) | 296 (2.1) | 3887 (1.4) |
| Anxietya | 2901 (6.5) | 45 429 (5.1) | 1069 (7.6) | 19 495 (7.0) |
| Bipolar disordera | 204 (0.5) | 1595 (0.2) | 69 (0.5) | 535 (0.2) |
| Depressiona | 2858 (6.4) | 46 189 (5.2) | 1081 (7.7) | 18 892 (6.8) |
| Eating disordera | 383 (0.9) | 3796 (0.4) | 176 (1.3) | 1667 (0.6) |
| Migraine | 975 (2.2) | 17 155 (1.9) | 331 (2.4) | 6536 (2.3) |
| Neuropathic pain | 1217 (2.7) | 23 349 (2.6) | 729 (5.2) | 14 540 (5.2) |
| Personality disordera | 212 (0.5) | 963 (0.1) | 92 (0.7) | 706 (0.3) |
| Schizophreniaa | 465 (1.0) | 2861 (0.3) | 213 (1.5) | 1879 (0.7) |
| Self-harma | 846 (1.9) | 6497 (0.7) | 322 (2.3) | 3382 (1.2) |
| Substance misusea | 1913 (4.3) | 25 016 (2.8) | 315 (2.2) | 3518 (1.3) |
| Reason for end of follow-up, No. (%)a | ||||
| Death identified using ONS | 6599 (14.7) | 62 903 (7.1) | 2143 (15.3) | 23 540 (8.4) |
| Practice stopped contributing | 7175 (16.0) | 170 882 (19.1) | 6330 (45.0) | 60 484 (21.7) |
| Study ended | 16 623 (37.2) | 403 717 (45.3) | 5578 (39.7) | 195 341 (69.9) |
| Patient transferred out of practice | 14 281 (32.0) | 253 927 (28.5) | NA | NA |
Abbreviations: CPRD, Clinical Practice Research Datalink; IQR, interquartile range; NA, not applicable; ONS, Office for National Statistics; SAIL, Secure Anonymised Information Linkage.
a
Significant difference between epilepsy and comparison cohorts (P < .05).
b
Includes single prescriptions of an opioid for short-term pain relief (eg, tablets containing a combination of codeine phosphate [8 mg] and acetaminophen [500 mg]).