Reference no: EM132372802

An investigator reviewed 700 singleton birth records from the past 5 years at St. Catharines General Hospital. A total of 56 records were identified as low birth weight infants (birth weight less than 2500 grams). She also identified another 56 infants whose birth weight were higher than 2500 grams, but who were born the same day and matched with the same gender as in the low birth weight group. Each infant's mother was interviewed to determine whether cigarette smoking exposure was associated with fetal birth weight.

a) What type of study is this? This is a retrospective study.

b) How many factors (variables) are involved in this study? What are they? (Not sure how to determine an answer for this kind of question, explanation would be very helpful)

c) What are the measurement scales for these factors (variables)? (Once again, not too sure how to identify whether variable are nominal, ordinal, interval, or ratio)