Table 2.

Risk factors for Z-score <−2 at any site as assessed by PPR in 442 women with POI

Risk factors	PPR	95% CI	P
Factors related to POI
Onset of menstrual irregularity before age 20 yr	2.72	1.74, 4.33	<0.0001
Delay in diagnosis >1 yr	1.96	1.14, 3.35	0.018
Modifiable risk factors (proportion of women with risk factor)
Serum 25(OH)D <32 ng/ml (80 nmol/liter) (58%)	2.89	1.47, 5.69	0.002
No regular exercise (23%)	1.93	1.22, 3.06	0.005
Weight <55 kg (18%)	2.8	1.47, 5.36	0.002
Daily calcium intake <1000 mg (49%)	2.8	1.37, 5.75	0.005
Smoking >2 cigarettes/day (10%)	0.91	0.25, 3.39	0.84

PPR of 2.72 in the first row means that if a woman with POI had onset of menstrual irregularity before age 20, her chance of having Z-score below −2 is 2.72 times higher than a woman with POI with onset of menstrual irregularity after age 20.