Table 1 Estimated age at menarche among women born in Navarre from 1925 to 1962, and percentage change over 5 years in cities or towns of over 10000 inhabitants compared to those of under 10000 inhabitants (n = 79396)
From: Decline in age at menarche among Spanish women born from 1925 to 1962
Age at menarche first 5-year birth cohort (1925-1929) | Age at menarche last 5-year birth cohort (1958-1962) | 5-year change | ||||||
|---|---|---|---|---|---|---|---|---|
Size of city of birth | N | Mean | 95%CI | Mean | 95%CI | Years | 95%CI | p |
<10000 (reference) | 55085 | 13.73 | 13.70, 13.77 | 12.95 | 12.91, 12.99 | -0.136 | -0.143, -0.131 | <0.001 |
>10000 | 24311 | 13.64 | 13.54, 13.74 | 12.82* | 12.79, 12.86 | -0.120* | -0.130, -0.111 | <0.001 |