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Table 1 Baseline characteristics of subjects in the 40–49 year age range by contraceptive method use

From: Bone mineral density in midlife long-term users of hormonal contraception in South Africa: relationship with obesity and menopausal status

Characteristics DMPA (n = 127) NET-EN (n = 102) COC (n = 106) Non-user Controls (n = 161) P-value
Mean age, years (SD) 43.6 (2.7) 43.0 (2.2) 43.7 (2.5) 45.4 (2.5) < 0.001
Ethnicity %
 African 98.4 95.2 67.0 94.4 0.007
 Coloured 1.6 1.0 7.5 2.5  
 Indian 0 3.8 25.5 3.1  
Exercise
 No regular exercise (%) 96.9 96.0 94.3 93 0.48
Dieted in last 6 months (%) 0 0 4.7 < 1 0.003
Current smoker (%) 4.7 5.6 5.7 9.9 0.23
Parity (median) 4 3 3 3 0.04
Ever lactated % 88.2 91.3 87.7 83.2 0.34
Mean age at menarche, years(SD) 15.2±  1.7 15.5 ± 1.7 14.8 ± 1.7 14.8 ± 1.6 0.014
Lactation (yrs) median 3.5 3.2 3.0 3.2 0.06
FSH
  < 25.8 mIU/mL, % 72 94 90 68 < 0.0001
  ≥ 25.8 mIU/mL, % 28 6 10 32  
Use of group method*
 Median use last 5 yrs. (months) 53 45 52 NA  
 Median lifetime use (months) 84 49 89 NA  
 Median age at first use 36 37 36 NA  
Radius BMD g/cm2 0.514 0.514 0.500 0.518 0.26
  1. *Only group method shown i.e. group to which women using that method at the time of recruitment were allocated