Table 2.
Association between the number of comorbidities and PSQI score among PwMS (N = 1597).
| Number of comorbidities | PSQI score (0-21) | |
|---|---|---|
| Predicted PSQI mean (95% CI) | Adjusted coefficients (β, 95% CI) a | |
| Any comorbidities b | ||
| 0 | 5.61 (4.84,6.38) | 0.00 (Reference) |
| 1 | 6.36 (5.80,6.93) | 0.86 (-0.09,1.82) |
| 2-3 | 7.45 (7.12,7.78) | 2.05 (1.22,2.89) |
| ⩾4 | 9.23 (8.94,9.51) | 3.86 (3.03,4.68) |
| Test for trend | p < 0.001 | |
| Doctor-diagnosed comorbidities c | ||
| 0 | 5.99 (5.38,6.59) | 0.00 (Reference) |
| 1 | 6.88 (6.39,7.38) | 1.07 (0.29,1.84) |
| 2-3 | 7.73 (7.40,8.06) | 2.01 (1.32,2.69) |
| ⩾4 | 9.39 (9.04,9.68) | 3.72 (3.03,4.41) |
| Test for trend | p < 0.001 | |
PSQI score: Pittsburgh Sleep Quality Index to measure sleep quality.
Bold font portrays statistical significance at a 95% confidence interval. The coefficients were obtained from the linear regression analysis and the predicted PSQI mean was obtained from the margins command (adjusted result). The coefficient of determination (R2) was 11.4% for the adjusted model.
a
The values were adjusted for age, sex and educational attainment.
b
Total comorbidities refer to any self-reported comorbidity.
c
Doctor-diagnosed comorbidities refer to any comorbidity the patient reported as diagnosed by a doctor.