Table 2.
Demographics, comorbidities, and pharmacotherapy in the study and reference populations.
| Study population (n = 411) Cohort 1 |
All SCS implants (n = 1082) Cohort 2 |
SWESPINE (n = 83,786) Cohort 3 |
Healthy controls (n = 2055) Cohort 4 |
Data source(s) | |||||
|---|---|---|---|---|---|---|---|---|---|
| Mean or percent | SE or count | Mean or percent | SE or count | Mean or percent | SE or count | Mean or percent | SE or count | ||
| Age at index (y) | 52.3 | 0.6 | 47.1 | 0.3 | 57.7 | 16.1 | 52.3 | 0.2 | NPR |
| Follow-up time (y) | 4.7 | 0.7 | 4.4 | 0.4 | 5.1 | 2.9 | N/A | N/A | RAY & SWESPINE |
| Sex | NPR & RTP | ||||||||
| Male | 45% | 186 | 44% | 480 | 49% | 40,738 | 45% | 925 | |
| Female | 55% | 225 | 56% | 602 | 52% | 43,048 | 55% | 1130 | |
| Income (000, €) | 21.1 | 0.6 | 21.6 | 0.6 | 24.8 | 0.2 | 29.4 | 1.2 | LISA |
| Birth country | LISA | ||||||||
| Sweden | 87% | 356 | 86% | 931 | 85% | 71,428 | 81% | 1665 | |
| Europe, except Sweden | 7% | 31 | 9% | 99 | 10% | 8,172 | 8% | 164 | |
| Other | 6% | 24 | 5% | 52 | 5% | 4,186 | 11% | 226 | |
| Education level | LISA | ||||||||
| Primary education | 21% | 85 | 19% | 201 | 23% | 19,538 | 13% | 267 | |
| Secondary education | 55% | 227 | 58% | 629 | 48% | 39,911 | 43% | 884 | |
| Post-secondary/postgraduate education | 22% | 91 | 22% | 242 | 28% | 4,186 | 44% | 904 | |
| Employment status | LISA | ||||||||
| Employed | 42% | 174 | 47% | 508 | 53% | 44,311 | 70% | 1438 | |
| Not employed | 58% | 237 | 53% | 574 | 47% | 39,475 | 30% | 617 | |
| Elixhauser comorbidity index | 1 | 0.1 | 0.8 | 0 | 0.9 | 1.4 | 0.3 | 0.1 | NPR |
| Prior spine surgery | 47% | 191 | 40% | 443 | N/A | N/A | <1% | N/A | SWESPINE & NPR |
| Pharmacotherapy | PDR | ||||||||
| Nonopioid pain medication usage* | 51% | 211 | 45% | 484 | 47% | 39,077 | 5% | 102 | |
| Antidepressant medication usage* | 42% | 173 | 46% | 494 | 17% | 13,972 | 9% | 185 | |
| Any opioid usage* | 60% | 245 | 55% | 594 | 45% | 37,788 | 4% | 82 | |
| Strong opioid usage* | 27% | 110 | 27% | 288 | 19% | 15,695 | 1% | 13 | |
| Weak opioid usage | 40% | 164 | 36% | 394 | 35% | 29,091 | 3% | 66 | |
*
At least 1 drug dispensation in the prior 3 months before index date.
LISA, national register on labor market and educational level data; NPR, the national patient register; PDR, the prescribed drug register; RAY, a local therapy specific register on invasive neurostimulation; RTP, the register of the total population; SE, standard error; SWESPINE, the national register on spine surgery.