Table 2.
Outcome measures at baseline and 6 months after surgery of patients receiving standard medical care (SMC), Supportive Intervention (SUPPORT) or Expectation Manipulation Intervention (EXPECT) (observed means)
| (A) SMC | (B) SUPPORT | (C) EXPECT | Test statistic (F scores indicate interaction terms) | Significant pre–post comparisons | |
|---|---|---|---|---|---|
| Disability (PDI) | |||||
| Baseline | 22.78 (18.36–27.19) | 22.14 (17.04–27.23) | 25.89 (20.81–30.97) | F(2, 102.542) = 4.762; | B, C |
| Follow-up | 20.79 (15.35–26.23) | 15.23 (10.82–19.65) | 12.19 (8.50–15.89) | P = 0.011 | |
| Mental quality of life (SF-12) | |||||
| Baseline | 48.96 (45.71–52.20) | 51.60 (48.56–54.63) | 47.98 (43.66–52.31) | F(2, 94.803) = 4.627; | C |
| Follow-up | 50.58 (47.02–54.14) | 52.40 (48.83–55.97) | 56.74 (54.29–59.19) | P = 0.012 | |
| Physical quality of life (SF-12) | |||||
| Baseline | 40.26 (36.80–43.73) | 39.55 (35.82–43.29) | 37.15 (34.04–40.26) | F(2, 103.928) = 3.186; | B, C |
| Follow-up | 40.28 (36.58–43.98) | 45.21 (41.23–49.19) | 44.77 (41.13–48.41) | P = 0.045 | |
| Patient subjective working ability in hours per week follow-up | 15.97 (10.50–21.43) | 17.14 (10.45–23.80) | 25.40 (19.90–30.90) | F(2, 74) = 3.325; P = 0.041a | ACa, BCa |
| Physical activity levels (IPAQ) | |||||
| Baseline | 2668.40 (1919.56–3417.24) | 2635.54 (1547.50–3723.57) | 2433.63 (1249.51–3617.75) | F(2, 72.915) = 4.776; | B, C |
| Follow-up | 2957.64 (2128.50–3786.78) | 5388.21 (3618.71–7157.71) | 4700.60 (3470.76–5930.45) | P = 0.011 | |
| Cardiac anxiety (CAQ) | |||||
| Baseline (pre-intervention) | 2.48 (2.29–2.67) | 2.68 (2.47–2.90) | 2.67 (2.44–2.89) | F(2, 107.021) = 3.980; | B, C |
| Follow-up (after 6 months) | 2.50 (2.31–2.69) | 2.34 (2.11–2.57) | 2.29 (2.11–2.47) | P = 0.022 | |
| Anxiety (HADS) | |||||
| Baseline (pre-intervention) | 4.03 (3.07–4.98) | 4.55 (3.42–5.67) | 5.17 (3.47–6.86) | F(2,102.409) = 1.325; | |
| Follow-up (after 6 months) | 3.24 (2.42–4.05) | 2.52 (1.52–3.51) | 3.61 (2.22–4.99) | P = 0.270 | |
| Depression (HADS) | |||||
| Baseline (pre-intervention) | 4.59 (3.60–5.58) | 4.00 (2.89–5.11) | 5.11 (3.75–6.47) | F(2, 99.211) = 2.604; | |
| Follow-up (after 6 months) | 3.68 (2.62–4.75) | 1.88 (1.20–2.57) | 2.58 (1.60–3.56) | P = 0.079 | |
| Outcome expectations (IPQ-E) | |||||
| Baseline (pre-intervention) | 12.05 (11.49–12.62) | 12.61 (12.10–13.12) | 12.37 (11.90–12.83) | F(2, 98.882) = 0.084; P = 0.919 | |
| Post psychological intervention | 11.94 (11.32–12.56) | 12.29 (11.97–12.60) | 12.09 (11.52–12.66) | ||
| Expected personal control (IPQ-E) | |||||
| Baseline (pre-intervention) | 15.28 (14.74–15.81) | 15.24 (14.55–15.92) | 14.03 (12.90–15.16) | F(2, 103.971) = 8.748; P < 0.001 | C |
| Post psychological intervention | 15.16 (14.43–15.88) | 14.91 (14.13–15.68) | 16.06 (15.40–16.73) | ||
| Patients rehospitalized after CABG, n (%)a | |||||
| Follow-up | 9 (26.47) | 7 (23.33) | 3 (9.38) | χ 2 (2) = 3.380; P = 0.185 | |
| LVEF, n (%) at follow-up | |||||
| ≥ 50 | 25 (80.6) | 23 (88.5) | 24 (100) | χ 2 (2) = 5.138; P = 0.077 | |
| 49–30 | 6 (19.4) | 3 (11.5) | 0 (0) | ||
| < 30 | 0 (0) | 0 (0) | 0 (0) | ||
| Interleukin-6 (pg/mL)a | |||||
| Baseline (pre-intervention) | 3.71 (2.14–5.27) | 2.10 (1.34–2.86) | 3.58 (1.91–5.25) | F = (6, 216.924) =2.523; P = 0.022 | Follow-up: AC |
| Post psychological intervention | 3.06 (2.03–4.10) | 1.83 (1.44–2.22) | 3.44 (2.07–4.82) | ||
| After surgery | 24.75 (18.61–30.89) | 19.56 (13.63–25.49) | 19.90 (15.63–24.18) | ||
| Follow-up (after 6 months) | 4.83 (2.99–6.68) | 3.66 (2.16–5.16) | 2.39 (1.38–3.41) | ||
| Interleukin-8 (pg/mL) | |||||
| Baseline (pre-intervention) | 5.48 (4.05–6.90) | 5.56 (4.33–6.79) | 5.78 (4.18–7.38) | F = (6, 206.632) = 4.186; P = 0.001 | Post-surgery: AB, AC |
| Post psychological intervention | 4.76 (3.86–5.66) | 5.13 (3.89–6.38) | 5.52 (3.73–7.30) | ||
| After surgery | 13.71 (11.44–15.97) | 10.31 (8.14–12.48) | 11.02 (8.64–13.40) | ||
| Follow-up (after 6 months) | 5.08 (3.63–6.52) | 4.83 (4.22–5.45) | 6.07 (4.76–7.37) | ||
| Tumor necrosis factor alpha (pg/mL)a | |||||
| Baseline (pre-intervention) | 2.01 (1.60–2.42) | 1.48 (1.19–1.76) | 1.61 (1.39–1.83) | F(6, 174.813) = 1.404; P = 0.216 | |
| Post psychological intervention | 2.20 (1.78–2.62) | 1.54 (1.32–1.76) | 1.72 (1.43–2.01) | ||
| After surgery | 3.63 (2.72–4.54) | 2.17 (1.81–2.52) | 3.12 (2.51–3.72) | ||
| Follow-up (after 6 months) | 2.66 (2.00–3.32) | 1.72 (1.48–1.96) | 2.09 (1.70–2.49) | ||
| C-reactive protein (μg/mL)a | |||||
| Baseline (pre-intervention) | 2.49 (1.84–3.15) | 2.23 (1.32–3.15) | 2.96 (2.00–3.92) | F(6, 209.520) = 1.410; P = 0.212 | |
| Post psychological intervention | 2.22 (1.62–2.81) | 2.19 (1.52–2.86) | 3.42 (2.07–4.76) | ||
| After surgery | 123.93 (94.24–153.62) | 101.71 (77.65–125.76) | 96.14 (76.91–115.38) | ||
| Follow-up (after 6 months) | 4.23 (2.05–6.42) | 4.17 (1.96–6.38) | 2.33 (1.54–3.12) | ||
For significant group × time interactions follow-up tests were calculated. ‘Significant pre–post comparisons’ (last column) means that the baseline value was significantly different from the post value for the groups stated in this column (e.g., ‘B, C’ would indicate that for SUPPORT and EXPECT the baseline values were significantly different from the post values within both groups, but for SMC baseline and post values did not differ significantly). For variables only reported at follow-up (e.g., working ability) and for biological variables (four assessment points), the letters indicate significant group differences at the indicated time point. (e.g. ‘Follow-up: AC’ would indicate that groups SMC and EXPECT have significantly different scores at follow-up)
aBecause this variable was only assessed at follow-up, the column “test statistics” includes group comparison (three groups), while the column “pre–post comparison” includes pairwise comparisons
PDI Pain Disability Index, SF-12 Short-Form Health Survey, IPAQ International Physical Activity Questionnaire, CAQ Cardiac Anxiety Questionnaire, HADS Hamilton Anxiety and Depression Scale, IPQ-E Expected Illness Perception Questionnaire, CABG coronary artery bypass graft, LVEF left ventricular ejection fraction