Table 3. Multiplicative factors and P values from univariate regression of apoptosis percent regressed on age or semen characteristics of ejaculated sperm (n = 23)^*

Characteristic   Percentage Increase (Decrease) per Unit Change   P   Age (y)   (0.95)   .78   Volume (mL)   (0.61)   .97   Viscosity (1–5)   1.19   .94   pH   (9.74)   .90   Concentration (106/mL)   (0.10)   .65   Motile sperm concentration (106/mL)   (0.36)   .21   Motility (%)   (2.38)   .0025   Progressive motile sperm concentration (106/mL)   (0.63)   .20   Progressive motility (%)   (3.26)   .0051   Total progressive motile sperm (106)   (0.22)   .25   Morphology normal (%)   (10.44)   .0045   Head defects (%)   1.97   .57   Mid-piece defects (%)   (7.79)   .09   Tail defects (%)   8.83   .0053   Endtz test (106/mL)   100.81   .53   *Multiplicative factor represents the change in apoptosis percent per one unit change in age (y) or semen characteristic. For instance, for sperm motility, the multiplicative factor represents a 2.38% multiplicative change in apoptosis percent per unit change in sperm motility   P < .05