Table 1.
Description of low back pain claimants (n=17 689) and those dispensed at least one gabapentinoid between 2010 and 2017
| Characteristic | Low back pain claimants | Low back pain claimants dispensed at least one gabapentinoid | ||
| N (%) | N (% back pain claims) | Prevalence ratio (95% CI) | P value | |
| Total | 17 689 (100) | 2608 (100) | ||
| Sex | ||||
| Female | 6301 | 876 (13.9) | 0.96 (0.89 to 1.04) | 0.474 |
| Male | 11 388 | 1732 (15.2) | 1.00 (ref) | – |
| Age group | ||||
| 15–24 years | 1514 (8.6) | 105 (6.9) | 0.77 (0.65 to 0.91) | 0.016 |
| 25–34 years | 3846 (21.7) | 520 (13.5) | 0.94 (0.86 to 1.02) | 0.260 |
| 35–44 years | 4492 (25.4) | 777 (17.3) | 1.02 0.94 to 1.09) | 0.771 |
| 45–54 years | 4724 (26.7) | 761 (16.1) | 1.00 (ref) | – |
| 55–64 years | 2878 (16.3) | 416 (14.5) | 0.93 (0.85 to 1.02) | 0.247 |
| 65 or more years | 235 (1.3) | 29 (12.3) | 0.94 (0.71 to 1.25) | 0.747 |
| Employer size | ||||
| Small | 4137 (23.4) | 672 (16.2) | 1.08 (1.00 to 1.16) | 0.148 |
| Medium | 7161 (40.5) | 1058 (14.8) | 1.00 (ref) | – |
| Large | 4805 (27.2) | 706 (14.7) | 1.02 (0.95 to 1.10) | 0.679 |
| Government | 679 (3.8) | 99 (14.6) | 1.06 (0.90 to 1.25) | 0.592 |
| Missing | 907 (5.1) | 73 (8.0) | – | – |
| Employment type | 1.02 (0.85 to 1.22) | 0.918 | ||
| Casual | 262 | 47 (17.9) | 1.00 (ref) | – |
| Full-time employee | 12 137 | 1869 (15.4) | 0.96 (0.87 to 1.06) | 0.532 |
| Part-time employee | 3071 | 417 (13.6) | 0.96 (0.88 to 1.06) | 0.576 |
| Others | 2219 | 275 (12.4) | ||
| Occupation (ASCO) | ||||
| Advanced clerical and service workers | 160 (0.9) | 14 (8.8) | 0.78 (0.52 to 1.19) | 0.369 |
| Associate professionals | 1778 (10.0) | 215 (12.1) | 0.98 (0.86 to 1.13) | 0.852 |
| Elementary clerical, sales and service workers | 714 (4.0) | 115 (16.1) | 1.12 (0.97 to 1.29) | 0.283 |
| Intermediate clerical, sales and service workers | 2259 (12.8) | 304 (13.5) | 0.96 (0.86 to 1.07) | 0.579 |
| Intermediate production and transport workers | 3476 (19.7) | 564 (16.2) | 1.02 (0.94 to 1.12) | 0.689 |
| Labourers and related workers | 3668 (20.7) | 553 (15.1) | 1.00 (ref) | – |
| Managers and administrators | 501 (2.8) | 96 (19.2) | 1.07 (0.90 to 1.26) | 0.569 |
| Professionals | 2008 (11.4) | 290 (14.4) | 1.07 (0.95 to 1.21) | 0.407 |
| Tradespersons and related workers | 3125 (17.7) | 457 (14.6) | 1.06 (0.97 to 1.16) | 0.377 |
| Socioeconomic status (IRSAD) | ||||
| Most advantaged | 3046 (17.2) | 354 (11.6) | 0.96 (0.88 to 1.05) | 0.535 |
| Middle three quintiles | 11 742 (66.4) | 1747 (14.9) | 1.00 (ref) | – |
| Most disadvantaged | 2868 (16.2) | 498 (17.4) | 0.99 (0.92 to 1.07) | 0.885 |
| Missing | 33 (0.2) | 9 (27.3) | – | – |
| Remoteness (ARIA) | ||||
| Major cities | 12 830 (72.6) | 1841 (14.3) | 1.00 (ref) | – |
| Inner regional | 4022 (22.7) | 647 (16.1) | 1.08 (1.01 to 1.15) | 0.122 |
| Outer regional and remote | 818 (4.6) | 115 (14.1) | 0.94 (0.81 to 1.09) | 0.562 |
| Missing | 19 (0.1) | 5 (26.3) | – | – |
| Dispensed opioid analgesics (N02) | ||||
| Dispensed an opioid analgesic(s) | 5541 (31.3) | 2365 (42.7) | 14.07 (12.18 to 16.24) | <0.001 |
| No opioid analgesics | 12 148 (68.7) | 243 (2.0) | 1.00 (ref) | |
| Dispensed anti-depressants (N06A) | ||||
| Dispensed an anti-depressant(s) | 2476 (14.0) | 1466 (59.2) | 2.24 (2.09 to 2.39) | <0.001 |
| No anti-depressants | 15 213 (86.0) | 1142 (7.5) | 1.00 (ref) | |
| Received any pain-related medicine* | – | – | – | |
| Dispensed any pain medicine | 6344 (35.9) | 2519 (39.7) | – | – |
| No other pain medicine (ie, excluding N02BF) | 11 345 (64.1) | 89 (0.8) | – | – |
*Medicine used for pain management included Anatomical Therapeutic Chemical (ATC) codes of M01 (anti-inflammatory and antirheumatic products, non-steroids), M02 (topical products for joint and muscular pain), M03 (muscle relaxants), N01 (anaesthetics), N02 (analgesics), N03 (anti-epileptics), N05 (psycholeptics), N06 (psychoanaleptics). ATC code of N06A are anti-depressants, and N02BF are gabapentinoids.
ARIA, Accessibility/Remoteness Index of Australia; ASCO, Australian Standard Classification of Occupations; IRSAD, Index of Relative Socio-economic Advantage and Disadvantage.