Table 3.
Adjusted Relative Risk of Clinically Relevant Depression Symptomsa According to Baseline Restless Legs Syndrome Status, Nurses' Health Study, 2002–2008
|
No RLS |
RLS |
|||||||
|---|---|---|---|---|---|---|---|---|
| No. | Score | RR | 95% CI | No. | Score | RR | 95% CI | |
| Clinically relevant depression symptoms (CESD-10 score ≥10 or GDS-15 score ≥5) | ||||||||
| No. of cases | 7,292 | 212 | ||||||
| Person-years of follow-up | 299,386 | 4,791 | ||||||
| Crude incidence (per 100,000 person-years) | 2,436 | 4,425 | ||||||
| Age-adjusted RR | 1 | Reference | 1.71* | 1.49, 1.96 | ||||
| Multivariate RRb | 1 | Reference | 1.53* | 1.33, 1.76 | ||||
| CESD-10 score | ||||||||
| Age-adjusted mean score | 4.97 | 4.94, 5.00 | 6.21* | 5.98, 6.44 | ||||
| No. of cases with CESD-10 score ≥10 | 5,775 | 172 | ||||||
| Age-adjusted RR | 1 | Reference | 1.73* | 1.49, 2.02 | ||||
| Multivariate RRb | 1 | Reference | 1.52* | 1.30, 1.77 | ||||
| GDS-15 score | ||||||||
| Age-adjusted mean score | 1.36 | 1.34, 1.38 | 1.91 | 1.78, 2.04 | ||||
| No. of cases with GDS-15 score ≥5 | 2,323 | 71 | ||||||
| Age-adjusted RR | 1 | Reference | 1.82* | 1.44, 2.30 | ||||
| Multivariate RRb | 1 | Reference | 1.70* | 1.34, 2.15 | ||||
Abbreviations: CESD-10, 10-item version of the Center for Epidemiologic Studies Depression Scale; CI, confidence interval; GDS-15, 15-item version of the Geriatric Depression Scale; RLS, restless legs syndrome; RR, relative risk.
* P < 0.0001.
a Depression symptoms were evaluated with the CESD-10 in 2004 and the GDS-15 in 2008. Clinically relevant depression symptoms were defined as CESD-10 score ≥10 or GDS-15 score ≥5.
b Adjusted for age (years), body mass index (weight (kg)/height (m)2; continuous), ethnicity (Caucasian or other), smoking status (never, past, or current smoker), marital status (married/in a partnership, widowed, or separated/divorced/single), solitary living status (yes/no; binary), regular involvement in a social or community group (yes/no; binary), menopausal status (premenopausal or postmenopausal), menopausal hormone use (never, past, or current user), alcohol intake (0, 0.1–4.9, 5.0–9.9, 10.0–14.9, or ≥15 g/day), physical activity (quintiles), the presence of diabetes, arthritis, stroke, myocardial infarction, angina, cancer, hypertension, high cholesterol level, or Parkinson's disease (yes/no), use of iron-specific supplements, sleep duration (≤5, 6, 7, 8, or ≥9 hours per 24-hour period), and snoring frequency (every night, most nights, a few nights per week, occasionally, or almost never).