Table 1

Sample characteristics

CovariateClassificationPresence of serum folate deficiencyAbsence of serum folate deficiency
n 341823 770
N/mean (%/SD)N/mean (%/SD)
Birth year1945.89 (4.3)1945.34 (4.2)
SexMale1874 (54.8%)10 233 (43.1%)
Female1544 (45.2%)13 537 (56.9%)
Smoking statusNon-smoker2634 (77.1%)20 940 (88.1%)
Smoker784 (22.9%)2830 (11.9%)
Vitamin B12 deficiencyAbsent15 (0.4%)65 (0.3%)
Present*3403 (99.6%)23 705 (99.7%)
Folic acid supplementsAbsent2449 (71.7%)20 176 (84.9%)
Present*969 (28.3%)3594 (15.1%)
Type 2 diabetesAbsent2155 (63.0%)15 532 (65.3%)
Present*1263 (37.0%)8238 (34.7%)
DepressionAbsent3173 (92.8%)22 320 (93.9%)
Present*245 (7.2%)1450 (6.1%)
Cognitive declineAbsent3050 (89.2%)21 243 (89.4%)
Present*368 (10.8%)2527 (10.6%)
OutcomeAll-cause mortality268 (7.8%)913 (3.8%)
Dementia115 (3.4%)750 (3.2%)
Censored3035 (88.9%)22 107 (93.0%)
  • *Presence at any time point during the follow-up.