title: Childbearing history and late-life mortality: the Dubbo study of Australian elderly.
abstract: OBJECTIVE
  to examine the association of parity with mortality in later life.
  
  
  METHODS
  a longitudinal, community-based study.
  
  
  METHODS
  semi-rural town of Dubbo, NSW, Australia.
  
  
  METHODS
  a total of 1,571 women and 1,233 men 60 years and older first examined in 1988-89.
  
  
  METHODS
  all-cause and cause-specific mortality rates analysed over 16-year follow-up. Hazard ratios obtained from proportional hazards models employing conventional predictors, potential confounders and measure of parity.
  
  
  RESULTS
  increasing parity in women was weakly associated with overweight, diabetes and hypertension. All-cause mortality fell progressively with increasing parity in women (hazard ratio and 95% confidence intervals): childless, 1.00; 1 child, 1.03 (0.75-1.43); 2 children, 0.83 (0.61-1.11); 3 children, 0.80 (0.60-1.08); 4 children, 0.91 (0.66-1.25); 5 children, 0.70 (0.49-1.01); 6+ children, 0.60 (0.43-0.85) (trend for parity P<0.002). This result was similar whether or not hypertension, diabetes and overweight were included in multivariate models adjusting for social variables and other confounders. The reduction in all-cause mortality was accompanied by a parallel reduction in deaths from cancer and respiratory conditions, while coronary heart disease mortality increased 60-111% in all parous women.
  
  
  CONCLUSIONS
  there was increased all-cause mortality in later life in childless women, accompanied by reduced mortality as parity increased. Underlying mechanisms are unclear but findings may have public health importance.
authors.affiliation: Lipid Department, St Vincent's Hospital, University of NSW, Sydney, New South Wales, Australia. l.simons@unsw.edu.au
authors.forename: Leon A
authors.initials: LA
authors.lastname: Simons
authors.forename: Judith
authors.initials: J
authors.lastname: Simons
authors.forename: Yechiel
authors.initials: Y
authors.lastname: Friedlander
authors.forename: John
authors.initials: J
authors.lastname: McCallum
mesh_terms: D000367:Age Factors; D000375:Aging; D002423:Cause of Death; D015897:Comorbidity; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009517:New South Wales / Q000453:epidemiology; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D016016:Proportional Hazards Models; D011446:Prospective Studies; D043762:Reproductive Behavior; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors