Table 4.
Mean (95% CI) measures by group and decrement in quality of life measures, controlling for age, sex, age × sex interaction, and sampling
| Measure | Cohort
|
Decrement* | P-value | |
|---|---|---|---|---|
| NHMS | SIJ | |||
| SF-36 PCS | 49.23 (48.74–49.70) | 31.80 (31.06–32.54) | 17.82 (16.89–18.74) | <0.0001 |
| SF-36 MCS | 53.78 (53.35–54.20) | 39.24 (37.67–40.82) | 14.25 (12.61–15.89) | <0.0001 |
| SF-6D utility | 0.789 (0.782–0.796) | 0.512 (0.502–0.522) | 0.277 (0.264–0.290) | <0.0001 |
| EQ-5D index | 0.868 (0.861–0.876) | 0.442 (0.416–0.468) | 0.427 (0.399–0.454) | <0.0001 |
Notes:
*
Mean (95% CI). Values show the age- and sex-adjusted decrement associated with membership in the SIJ cohort; calculations were performed using SAS PROC SURVEYREG (SAS Institute Inc., Cary, NC, USA).
Abbreviations: CI, confidence interval; NHMS, National Health Measurement Study; SIJ, sacroiliac joint; SF-36, Short Form-36; PCS, physical component summary; MCS, mental component summary; EQ-5D, EuroQol-5D.