Table 2.
Descriptive statistics of the data set and results of the univariate statistical analyses
| All patients prescribed pregabalin | Groups of patients with average doses | Unadjusted P value | Bonferroni adjusted P value | ||
| ≤600 mg/day | >600 mg/day | ||||
| n (%)/M (SD) | n (%)/M (SD) | n (%)/M (SD) | |||
| Patient characteristics | |||||
| Gender | |||||
| Male | 21 004 (39.6) | 20 468 (39.2) | 536 (61.1) | <0.001 | <0.001 |
| Female | 32 045 (60.4) | 31 704 (60.8) | 341 (38.9) | ||
| Age (years) | |||||
| 12–17 | 22 (0.0) | 22 (0.0) | 0 (0.0) | <0.001 | <0.001 |
| 18–29 | 867 (1.6) | 782 (1.5) | 85 (9.7) | ||
| 30–39 | 1996 (3.8) | 1808 (3.5) | 188 (21.4) | ||
| 40–49 | 4472 (8.4) | 4271 (8.2) | 201 (22.9) | ||
| 50–59 | 9434 (17.8) | 9252 (17.7) | 182 (20.8) | ||
| 60–69 | 9768 (18.4) | 9677 (18.5) | 91 (10.4) | ||
| ≥70 | 26 490 (49.9) | 26 360 (50.5) | 130 (14.8) | ||
| Place of residence | |||||
| Urban area | 23 862 (45.0) | 23 413 (44.9) | 449 (51.2) | <0.001 | 0.004 |
| Rural area | 29 119 (54.9) | 28 694 (55.0) | 425 (48.5) | ||
| Approved indications | |||||
| Epilepsy | 1968 (3.7) | 1882 (3.6) | 86 (9.8) | <0.001 | <0.001 |
| Generalised anxiety disorder | 3068 (5.8) | 2958 (5.7) | 110 (12.5) | <0.001 | <0.001 |
| Neuropathic pain | 39 829 (75.1) | 39 249 (75.2) | 580 (66.1) | <0.001 | <0.001 |
| Neuropathic pain (broad definition) | 42 120 (79.4) | 41 505 (79.6) | 615 (70.1) | <0.001 | <0.001 |
| Multiple | 3293 (6.2) | 3186 (6.1) | 107 (12.2) | <0.001 | <0.001 |
| None of the indications recorded in the records | 9283 (17.5) | 9098 (17.4) | 185 (21.1) | 0.005 | 0.135 |
| Medical preconditions with increased risk of abuse | |||||
| Substance use disorders | 6414 (12.1) | 6049 (11.6) | 365 (41.6) | <0.001 | <0.001 |
| Addictive disorder drug (alcohol) | 43 (0.1) | 41 (0.1) | 2 (0.2) | 0.345 | 1.000 |
| Addictive disorder drug (tobacco) | 2 (0.0) | 2 (0.0) | 0 (0.0) | 1.000 | 1.000 |
| Addictive disorder drug (opioids) | 258 (0.5) | 182 (0.3) | 76 (8.7) | <0.001 | <0.001 |
| Drugs with potential for abuse | |||||
| Benzodiazepine | 9665 (18.2) | 9367 (18.0) | 298 (34.0) | <0.001 | <0.001 |
| Opioids | 23 886 (45.0) | 23 527 (45.1) | 359 (40.9) | 0.015 | 0.386 |
| Psychostimulants | 288 (0.5) | 263 (0.5) | 25 (2.9) | <0.001 | <0.001 |
| Contemporaneous prescription of gabapentin | 2973 (5.6) | 2890 (5.5) | 83 (9.5) | <0.001 | <0.001 |
| Prescription networks and structural characteristics | |||||
| Number of prescriptions | 6.34 (3.28) | 6.23 (2.91) | 12.70 (10.17) | <0.001 | <0.001 |
| Number of prescribers (physicians) | 1.79 (1.03) | 1.77 (0.89) | 3.12 (3.91) | <0.001 | <0.001 |
| Number of prescribers (practices) | 1.59 (0.87) | 1.57 (0.73) | 2.86 (3.61) | <0.001 | <0.001 |
| Medical specialty of initial prescriber | |||||
| GP | 32 911 (62.0) | 32 344 (62.0) | 567 (64.7) | 0.010 | 0.256 |
| Anaesthesiology | 1935 (3.6) | 1908 (3.7) | 27 (3.1) | ||
| Orthopaedics | 1209 (2.3) | 1192 (2.3) | 17 (1.9) | ||
| Neuroscience | 4292 (8.1) | 4223 (8.1) | 69 (7.9) | ||
| Neurology | 5039 (9.5) | 4984 (9.6) | 55 (6.3) | ||
| Psychiatry and psychotherapy | 2341 (4.4) | 2289 (4.4) | 52 (5.9) | ||
| Other | 5322 (10.0) | 5232 (10.0) | 90 (10.3) | ||
| Proportion of specialists among prescribers | 0.31 (0.40) | 0.31 (0.40) | 0.31 (0.38) | 0.300 | 1.000 |
| Care density among physicians* | 47.97 (70.61) | 48.29 (70.67) | 33.23 (66.43) | <0.001 | <0.001 |
| Care density among practices* | 17.42 (35.77) | 17.54 (35.84) | 12.90 (32.76) | 0.149 | 1.000 |
| Maximal geographical distance (km) | 6.86 (26.63) | 6.71 (26.24) | 15.98 (43.27) | <0.001 | <0.001 |
*Care density was calculated as the average number of shared patients among all pairs of providers per patient and was calculated for patients with at least two prescribers (physicians/practices).
GP, general practitioner.