Table 2.
Correlation between ISI score and other variables*
| ISI score | Daily dairy Ca intake (mg/d) | HADS-anxiety score | HADS-depression score | MSP intensity during the previous month (0–10) | Number of painful body sites (1–12) | |
|---|---|---|---|---|---|---|
| Age (years) | r = 0·01; P = 0·74 | r = 0·09; P < 0·01 | r = −0·11; P < 0·001 | r = −0·04; P = 0·20 | r = −0·04; P = 0·17 | r = −0·08; P = 0·02 |
| BMI (kg/m2) | r = −0·01; P = 0·78 | r = 0·04; P = 0·28 | r = −0·02; P = 0·65 | r = −0·02; P = 0·52 | r = 0·06; P = 0·04 | r = 0·03; P = 0·44 |
| Number of family members | r = 0·05; P = 0·12 | r = −0·09; P < 0·01 | r = 0·02; P = 0·46 | r = 0·07; P = 0·02 | r = 0·01; P = 0·77 | r = −0·02; P = 0·55 |
| ISI score | – | r = −0·10; P < 0·01 | r = 0·43; P < 0·001 | r = 0·27; P < 0·001 | r = 0·24; P < 0·001 | r = 0·24; P < 0·001 |
| Daily dairy Ca intake (mg/d) | – | – | r = −0·06; P = 0·06 | r = −0·12; P < 0·001 | r = −0·01; P = 0·73 | r = −0·06; P = 0·05 |
| HADS-anxiety score | – | – | – | r = 0·52; P < 0·001 | r = 0·35; P < 0·001 | r = 0·34; P < 0·001 |
| HADS-depression score | – | – | – | – | r = 0·24; P < 0·001 | r = 0·23; P < 0·001 |
| MSP intensity during the previous month (0–10) | – | – | – | – | – | r = 0·66; P < 0·001 |
ISI, Insomnia Severity Index; HADS, Hospital Anxiety and Depression Scale; MSP, musculoskeletal pain.
*
Pearson’s or Spearman’s correlation test was used as appropriate (P-values were two-tailed and considered statistically significant at < 0·05).