Table 2.
Association between age at hair product use prior to age 13 and age at menarche before <=12 years in the Greater New York Hair Products Study, 2004-2005
| Childhood Hair Product Use |
N% | Unadjusted RR (95% CI) |
Adjusted Multivariable RR a (95% CI) |
Adjusted Multivariable RRb (95% CI) |
|---|---|---|---|---|
| Ever | 209 (69.7) | 1.2 (0.9-1.5) | 1.2 (1.0-1.5) | 1.0 (0.8-1.4) |
| Never | 91 (30.3) | Ref. | Ref. | Ref. |
| Hair oils | ||||
| Yes | 165 (55.0) | 1.4 (1.1-1.7) | 1.5 (1.2-1.8) | 1.4 (1.1-1.9) |
| No | 135 (45.0) | Ref. | Ref. | Ref. |
| Hair lotions | ||||
| Yes | 34 (11.3) | 1.2 (0.9-1.6) | 1.2 (0.9-1.5) | 1.1 (0.8-1.4) |
| No | 266 (88.7) | Ref. | Ref. | Ref. |
|
Leave-in
conditioners |
||||
| Yes | 45 (15.0) | 1.2 (1.0-1.5) | 1.3 (1.0-1.6) | 1.3 (1.0-1.6) |
| No | 255 (85.0) | Ref. | Ref. | Ref. |
| Perms/Relaxers | ||||
| Yes | 50 (16.7) | 1.4 (1.2-1.7) | 1.5 (1.1-1.8) | 1.4 (1.1-1.8) |
| No | 250 (83.3) | Ref. | Ref. | Ref. |
| Other | ||||
| Yes | 38 (12.7) | 0.8 (0.5-1.1) | 0.8 (0.5-1.2) | 0.7 (0.6-1.2) |
| No | 262 (87.3) | Ref. | Ref. | Ref. |
a
Adjusted for year of birth
b
Adjusted for year of birth and race/ethnicity