Table 4: Age at onset of chronic disease and lifetime prevalence in control group of 80 octogenarians versus 244 centenarians. To correct for right censoring due to GCS study termination a stepwise Cox Regression [17] from survival analysis was performed to estimate average age at onset in centenarians. The average age at onset from the Cox regression [17] was computed at the mean of the covariates.
(a)

DiseaseAverage Age at Onset 𝑛 Average Age at Onset from Cox regression 𝑛

Cancer 78 ± 32260 ± 0.5238
Cardiovascular83 ± 118177 ± 0.3226

Many cancers are absent, and skin cancers were excluded because of their later onset. The 𝑛 above differs from the totals in (b) due to missing data.
(b)

DiseaseNo cancerCancerTotal

Octogenarians5822 (28%)80
Centenarians17173 (30%)244
Total22995 (29%)324

A Fisher’s exact test [14] is not significant at 𝛼 = 0 . 0 5 , nor is a 𝑧 -test, significant, with 𝑧 = 0 . 9 0 on the proportions, 0.28 and 0.30.
(c)

DiseaseNo CardiovascularCardiovascularTotal

Octogenarians19 61 (76%)80
Centenarians48196 (80%)244
Total67257 (79%)324

A Fisher’s exact test [14] is not significant at 𝛼 = 0 . 0 5 , nor is a 𝑧 -test, significant, with 𝑧 = 1 . 8 0 on the proportions, 0.76 and 0.80.