Based on data presented in Table 1 a ratio measure for the association of cigarette smoking during this pregnancy (yes versus no) and less-tight control (versus tight control) could be calculated. Name, calculate, and interpret the measure showing your calculations. Please show calculations.

Table 1. Baseline Characteristics at Enrollment. * Less-Tight Control Tight Control Characteristic (N =497) (N=490) Maternal age at expected date of delivery - yr 34.015.7 33.7+5.8 Body.mass index - no./total no. (96)