Table 3.
Association of social class at phase 1 with Day 1 cortisol measures in participants of the of the Speedwell study at phase 5.
| Pre-stress baseline (n = 809) | Response to cognitive test (n = 789) | Response to venepuncture (n = 778) | Post-stress recovery (n = 773) | Post-cognitive test recovery (n = 752) | Post-venepuncture recovery (n = 752) | ||
|---|---|---|---|---|---|---|---|
| Model 1a | |||||||
| Manual-AM | β coeff. (95% CI) | 0.02 (−0.15, 0.10) | 0.03 (−0.08, 0.13) | -0.05 (−0.16, 0.05) | 0.18 (0.03, 0.32) | 0.16 (0.01, 0.31) | 0.21 (0.07, 0.36) |
| P-value | 0.70 | 0.60 | 0.33 | 0.02 | 0.03 | 0.003 | |
| Model 2b | |||||||
| Manual-AM | β coeff. (95% CI) | 0.05 (−0.10, 0.21) | -0.02 (−0.15, 0.11) | -0.03 (−0.16, 0.01) | 0.25 (0.07, 0.43) | 0.19 (−0.002, 0.38) | 0.20 (0.02, 0.39) |
| P-value | 0.50 | 0.80 | 0.69 | 0.008 | 0.05 | 0.03 | |
| Manual-PM | β coeff. (95% CI) | -0.13 (−0.33, 0.07) | 0.10 (−0.07, 0.23) | -0.07 (−0.25, 0.09) | 0.08 (−0.15, 0.32) | 0.12 (−0.12, 0.37) | 0.23 (−0.01, 0.47) |
| P-value | 0.21 | 0.26 | 0.39 | 0.50 | 0.33 | 0.06 | |
| Interaction P-value | 0.16 | 0.29 | 0.66 | 0.27 | 0.67 | 0.86 |
β coefficient and P-values are from:
Model 1: unadjusted linear regression of log-transformed cortisol measures (ng/ml);
Model 2: model 1 adjusted for age at phase 5, time of sample(s), cortisol assay batch, venepuncture results (for response to venepuncture and post-stress recovery cortisol measures) and completion of cognitive test (response to cognitive test, response to venepuncture and post-stress recovery cortisol measures). Model 2 also included an interaction term to test for interaction between social class and time of clinic visit. β coefficient and P-values for cortisol measures in Manual-PM group were derived from the interaction term. Coeff.: coefficient; CI: confidence interval.