Table 2.
Univariate associations at 12-month follow-up between candidate predictors and the two outcomes; non-substantial improvement in disability and arm pain. Regression coefficient and odds ratio (95% confidence intervals) (n=2022)
| Total number of cases | Non-success in neck disability (12-mo NDI ≥26) * | Odds Ratio (95% CI) | Total number of cases | Non-success in arm pain (12-mo arm pain ≥3) ** | Odds Ratio (95% CI) | |
|---|---|---|---|---|---|---|
| n=2020 | n=768 (38%) | n=1980 | n=698 (35.3%) | |||
| Socio-demographic | ||||||
| Female gender | 2020 | 408 | 1.25 (1.04, 1.49) | 1980 | 366 | 1.18 (0.98, 1.42) |
| Age, years | 2019 | 1979 | ||||
| Age <40 | 69 | Ref | 59 | Ref | ||
| Age 40-60 | 593 | 1.09 (0.79, 1.49) | 549 | 1.23 (0.89, 1.70) | ||
| Age >60 | 105 | 0.94 (0.65, 1.38) | 89 | 0.99 (0.67, 1.49) | ||
| Work status | 2009 | 1969 | ||||
| Student, in work or stay-at-home | 61 | Ref | 62 | Ref | ||
| Retired or disability pension | 173 | 2.25 (1.55, 3.27) | 134 | 1.41 (0.96, 2.05) | ||
| Rehabilitation pension | 113 |
5.31 (3.31, 8.43) |
95 |
3.20 (2.04, 5.00) |
||
| Sick leave | 415 |
0.93 (0.67,1.30) |
403 |
0.86 (0.62, 1.20) |
||
| Physical demands in work | 1712 | 1683 | ||||
| Computers/ sitting | 187 | Ref | 174 | Ref | ||
| Light physical work | 103 |
1.34 (1.00, 1.79) |
99 |
1.41 (1.05, 1.89) |
||
| Hard physical work | 296 |
2.16 (1.72, 2.70) |
286 | 2.28 (1.81, 2.87) | ||
| Educational level | 1974 | 1935 | ||||
| High school or less | 528 | Ref | 486 | Ref | ||
| Less than 4 years of university | 143 |
0.73 (0.58, 0.92) |
129 |
0.7 (0.55, 0.89) |
||
| 4 or more years of university | 78 |
0.40 (0.30, 0.52) |
61 |
0.33 (0.25, 0.45) |
||
| Non-native speaker | 2018 | 70 |
1.08 (1.03, 1.13) |
1978 | 72 |
1.11 (1.06, 1.16) |
| Pending litigation1 | 1996 | 1957 | ||||
| None | 565 | Ref | 537 | Ref | ||
| Yes | 119 | 3.06 (2.26, 4.15) | 95 | 2.01 (1.49, 2.72) | ||
| Already approved | 71 | 3.13 (2.12, 4.60) | 59 | 2.27 (1.55, 3.33) | ||
| Physical/ somatic | ||||||
| Obesity (Body Mass Index ≥ 30) | 1972 | 169 |
1.14 (0.92, 1.42) |
1932 | 141 |
0.98 (0.78, 1.24) |
| Smoking | 1980 | 273 |
1.71 (1.40, 2.08) |
1941 | 263 |
1.93 (1.58, 2.36) |
| Comorbidities | 2020 | 378 |
1.66 (1.38, 1.99) |
1980 | 323 |
1.55 (1.12, 1.63) |
| Previous neck surgery | 1980 | 89 |
1.09 (1.05, 1.15) |
1940 | 84 |
1.10 (1.06, 1.14) |
| Number of surgical levels | 1998 | 1958 | ||||
| One level | 550 | Ref | 512 | Ref | ||
| Two or more levels | 209 |
1.18 (0.96, 1.45) |
177 |
0.91 (0.82, 1.25) |
||
| Pain and symptoms | ||||||
| Duration of arm pain | 1971 | 1933 | ||||
| < 3 months | 65 | Ref | 57 | Ref | ||
| 3-12 months | 237 |
1.66 (1.21, 2.29) |
214 |
1.67 (1.20, 2.33) |
||
| > 1 year | 444 |
2.81 (2.07, 3.81) |
406 |
2.83 (2.06, 3.90) |
||
| Duration of pre-operative paresis | 1828 | 1860 | ||||
| No paresis | 124 | Ref | 107 | Ref | ||
| < 3 months | 110 |
1.08 (0.80, 1.47) |
96 |
1.08 (0.78, 1.49) |
||
| 3 months or more | 467 |
1.75 (1.38, 2.23) |
441 |
1.91 (1.49, 2.46) |
||
| Daily use of Analgetic drugs | 1985 | 268 |
0.45 (0.37, 0.54) |
1946 | 269 |
0.58 (0.48, 0.71) |
| ASA level 3 or more2 | 1944 | 47 |
1.50 (1.00, 2.24) |
44 | 44 |
1.57 (1.05, 2.37) |
| Neck pain worse than arm pain | 1895 | 270 |
1.13 (1.08, 1.17) |
1951 | 195 |
0.88 (0.72, 1.08) |
| Baseline NDI score (0-100)3 | 2013 | 1973 | ||||
| Low (0-40) | 173 | Ref | 225 | Ref | ||
| Medium (41-60) | 448 |
4.84 (3.92, 5.99) |
358 |
2.29 (1.87, 2.28) |
||
| High (> 60) | 144 |
10.74 (7.62, 15.14) |
113 |
4.21 (3.06, 5.80) |
||
| Baseline NRS arm pain (0-10)4 | 1982 | 1944 | ||||
| Low (0-5) | 117 | Ref | 86 | Ref | ||
| Medium (6-7) | 300 |
1.45 (1.12, 1.87) |
273 |
1.87 (1.42, 2.48) |
||
| High (> 8) | 334 |
2.06 (1.59, 2.67) |
330 |
3.01 (2.28, 3.40) |
||
| Psychological | ||||||
| Anxiety or depression5 | 1989 | 422 |
2.62 (2.18, 3.16) |
1950 |
1.75 (1.45, 2.11) |
|
*38% did not achieve a substantial improvement in disability. **35.3% did not achieve a substantial improvement in arm pain.1Pending medical claim/litigation against the Norwegian public welfare agency fund concerning disability pension or pending medical compensation claim/litigation against private insurance companies or the public Norwegian System of Compensation to Patients.2American Society of Anesthesiologists grade. 3Neck Disability Index, 0-100 (no-maximal disability). 4Numeric Rating Scale (0-10). 5Based on scoring “moderate” to “extremely” anxious or depressed in the item in EQ-5D-3L questionnaire