Table 1 Demographic characteristics and sleep outcomes according to urinary fluoride and water fluoride samples (unweighted data showna)
From: Fluoride exposure and duration and quality of sleep in a Canadian population-based sample
|  | Urinary fluoride sample (n = 1303) | Water fluoride sample (n = 1016) |
|---|---|---|
Demographic characteristics | ||
 Age (years); mean (SD) | 42.4 (19.0) | 43.3 (18.6) |
 Total household income (Canadian dollars); Mean (SD) | 83,868 (65,489) | 87,293 (66,421) |
 Ethnicity; n (%) | ||
  White | 1052 (80.7) | 812 (79.9) |
  Non-white | 251 (19.3) | 204 (20.1) |
 Sex; n (%) | ||
  Female | 669 (51.3) | 515 (50.7) |
  Male | 634 (48.7) | 501 (49.3) |
 BMI category; n (%) | ||
  Underweight | 39 (3.0) | 30 (3)b |
  Normal weight | 507 (38.9) | 417 (41)b |
  Overweight | 434 (33.3) | 345 (34)b |
  Obese | 323 (24.8) | 224 (22)b |
 Water fluoridation status; n (%) | ||
  Not fluoridated | 387 (29.7) | 309 (30.4) |
  Fluoridated | 415 (31.9) | 342 (33.7) |
  Missing or mixed fluoridation | 501 (38.5) | 365 (35.9) |
Sleep outcomes | ||
 Sleep duration; n (%) | ||
  Lower than recommended | 377 (28.9) | 290 (28.5) |
  Within recommendedc | 858 (65.9) | 677 (66.6) |
  Higher than recommended | 68 (5.2) | 49 (4.8) |
 Trouble sleeping; n (%) | ||
  Never | 389 (29.9) | 317 (31.2) |
  Rarely | 300 (23.0) | 246 (24.2) |
  Sometimes | 306 (23.5) | 217 (21.4) |
  Most of the time | 187 (14.4) | 143 (14.1) |
  All of the time | 121 (9.3) | 93 (9.2) |
 Trouble staying awake; n (%) | ||
  Never | 439 (33.7) | 344 (33.9) |
  Rarely | 383 (29.4) | 313 (30.8) |
  Sometimes | 388 (29.8) | 291 (28.6) |
  Most of the time | 73 (5.6) | 68 (6.7)d |
  All of the time | 20 (1.5) | d |