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)

Disease

Average Age at Onset

Average Age at Onset from Cox regression

Cancer

783

22

600.5

238

Cardiovascular

831

181

770.3

226

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

(b)

Disease

No cancer

Cancer

Total

Octogenarians

58

22 (28%)

80

Centenarians

171

73 (30%)

244

Total

229

95 (29%)

324

A Fisher’s exact test [14] is not significant at , nor is a -test, significant, with on the proportions, 0.28 and 0.30.

(c)

Disease

No Cardiovascular

Cardiovascular

Total

Octogenarians

19

61 (76%)

80

Centenarians

48

196 (80%)

244

Total

67

257 (79%)

324

A Fisher’s exact test [14] is not significant at , nor is a -test, significant, with on the proportions, 0.76 and 0.80.