Table 4.
Adjusted relationship of pain (mean NRS) and functional disability (ODI) with HRQoL paramenters (EQ-utility, EQ-VAS, SF-PCS, SF-MCS) during follow-up
| EQ-Utility | EQ-VAS | SF-PCS | SF-MCS | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Independent variables | Regr. Coef. | 95% CI | P | Regr. Coef. | 95% CI | P | Regr. Coef. | 95% CI | P | Regr. Coef. | 95% CI | P |
| Mean NRS | −0.018 | −0.027,-0.009 | < 0.001 | −3.187 | −4.095,-1.985 | < 0.001 | −0.745 | −1.108,-0.382 | < 0.001 | −1.371 | −1.938,-0.805 | < 0.001 |
| ODI | −0.009 | −0.010,-0.008 | < 0.001 | − 0.253 | − 0.402,-0.112 | 0.001 | − 0.228 | −0.275,-0.181 | < 0.001 | − 0.083 | −0.159,-0.007 | 0.031 |
| Baseline HRQoL score | 0.217 | 0.143,0.291 | < 0.001 | 0.121 | 0.016,0.246 | 0.038 | 0.467 | 0.298,0.636 | < 0.001 | 0.453 | 0.306,0.600 | < 0.001 |
| Age (years) | 0.001 | −0.002,0.002 | 0.930 | −0.066 | − 0.226,0.097 | 0.432 | − 0.012 | −0.092,0.067 | 0.761 | −0.018 | − 0.135,0.099 | 0.767 |
| Sex | ||||||||||||
| Female – reference | – | – | – | – | – | – | – | – | – | – | – | – |
| Male | 0.001 | −0.044,0.045 | 0.974 | −3.341 | −8.314,0.941 | 0.159 | −0.652 | −2.727,1.424 | 0.538 | −1.088 | −4.045,1.869 | 0.471 |
| Education | ||||||||||||
| None - reference | – | – | – | – | – | – | – | – | – | – | – | – |
| Lower secondary school | −0.014 | −0.079,0.050 | 0.661 | 1.554 | −5.639,6.915 | 0.642 | −1.475 | −4.466,1.516 | 0.334 | −0.085 | −4.395,4.224 | 0.969 |
| Upper secondary school/university | −0.039 | −0.087,0.010 | 0.124 | −1.456 | −6.014,3.982 | 0.558 | 0.951 | −1.291,3.193 | 0.406 | −0.175 | −3.343,2.993 | 0.914 |
| Previous surgery | ||||||||||||
| None or 1 - reference | – | – | – | – | – | – | – | – | – | – | – | – |
| More than 1 | 0.004 | −0.044,0.052 | 0.861 | −1.254 | −6.014,3.982 | 0.628 | 0.621 | −1.291,3.193 | 0.587 | −2.326 | −5.579,0.926 | 0.161 |
| Visit (time) | 0 .003 | −0.009,0.014 | 0.642 | 1.945 | 0.440,3.415 | 0.011 | −0.339 | −0.714,0.097 | 0.077 | −0.331 | − 0.962,0.300 | 0.303 |
| Intercept | 1.039 | 0.904,1.174 | < 0.001 | 80.165 | 65.235,93.185 | < 0.001 | 35.095 | 27.878,42.313 | < 0.001 | 35.753 | 26.383,45.123 | < 0.001 |
| Random intercept (SD) | 0.061 | 0.042,0.088 | < 0.0001 | 3.714 | 1.485,9.284 | 0.117 | 3.713 | 2.982,4.624 | < 0.0001 | 4.995 | 3.887,6.418 | < 0.0001 |
| Random residuals (SD) | 0.140 | 0.129,0.153 | 15.116 | 13.717,16.657 | 4.706 | 4.338,5.106 | 7.966 | 7.344,8.641 | ||||
The column on the left lists the independent variables introduced in the regression models, and the intercept and the random component of the model. The other columns show the regression coefficients and the standard deviations of the random intercept and random residuals, the 95% confidence intervals and the p values estimated for each independent variable analysed with the dependent variables EQ-utility index, EQ-VAS, SF-PCS and SF-MCS. Positive regression coefficients indicate a direct association, and negative regression coefficients indicate an inverse association between the dependent variables and the independent variables. Confidence intervals and p values indicate the level of significance of the regression coefficients