Research Article

Season of Birth and Exceptional Longevity: Comparative Study of American Centenarians, Their Siblings, and Spouses

Table 6

Odds ratios ( values) to become a centenarian as predicted by conditional logistic regression (fixed effects), by different birth cohort subgroups for siblings survived to age 50. Effects of month of birtha.

VariableBorn before 1889Born in 1889 or later

Month of birth:
 January1.42 (0.109)0.90 (0.628)
 February1.41 (0.118)1.02 (0.911)
 MarchReferenceReference
 April1.09 (0.717)1.18 (0.467)
 May1.27 (0.312)0.86 (0.500)
 June1.30 (0.289)1.35 (0.192)
 July1.14 (0.579)1.00 (0.984)
 August1.19 (0.446)1.23 (0.360)
 September1.31 (0.209)1.55 (0.042)
 October1.61 (0.027)1.13 (0.578)
 November1.78 (0.008) b1.23 (0.357)
 December1.33 (0.185)0.94 (0.772)

Female sex3.32 (<0.001)4.74 (<0.001)

Pseudo 0.08420.1249
Number of observations3,2793,441

aStatistically significant effects ( ) are highlighted in bold.
bStatistically significant after Benjamini-Hochberg procedure.