Homework3_2014.docx - HOMEWORK 3 Due Tuesday April 15 at 10:30 AM IMPORTANT INSTRUCTIONS Please read BEFORE starting your work 1 Please provide your

Homework3_2014.docx - HOMEWORK 3 Due Tuesday April 15 at...

This preview shows page 1 - 3 out of 8 pages.

HOMEWORK 3 – Due Tuesday, April 15 at 10:30 AM Table. List of variables used for this homework assignment Variable Name Description death death during follow-up (1=yes, 0=no) ageyrs age (years) sex sex (1=men, 2=women) race race (1=white, 2=black, 3=other) height height in centimeters (cm) wt weight (kilograms) smokever smoking status (0=never smoker, 1=ever smoker) booze alcohol consumption (number of drinks per week, continuous) Part I Logistic Regression 1. Create a new dataset named “hw3” by restricting the NHANES II dataset (nh2fs2014.sas7bdat, available from the course website under the Homework 3 directory) to subjects with complete data on the covariates listed in the above Table. Then create the following variables: - BMI (continuous): calculated by [weight (kg)/ (height(m)) 2 ] - Create a three-level variable “BMICAT” using the following categories: normal (BMI<25), overweight (25≤BMI<30) and obese (BMI≥30). Code this variable as 0, 1, 2 for future questions. - Male: 0 for female, 1 for male How many subjects are included in the “hw3” dataset? Please also provide SAS code as part of your answer to this question. This restricted data set contains 9196 subjects. See appendix for SAS code. 1 IMPORTANT INSTRUCTIONS: Please read BEFORE starting your work!!! 1. Please provide your answers along with supporting graphs, if needed, in your main document. 2. Do not include SAS code in the answer unless explicitly asked for as part of the question. Attach your SAS code and relevant output only in an Appendix. 3. Please follow the variable coding specified in the questions. 4. Use α =0.05 to decide on the statistical significance throughout this homework.
Image of page 1
2. Create a three-level variable ‘alc’ for alcohol consumption using the following categories: light (<0.5 drinks/week), moderate (≥0.5 and <2 drinks/week) and heavy (≥2 drinks/week). Code each category as 0, 1 and 2, respectively for future questions. How many participants are in each category? Alc Number 0 4052 1 2244 2 2900 3.In each level of alcohol consumption (ie, “ALC” variable), what percentage of participants dies over the follow-up period? 4. Run a univariate logistic regression model with death as the outcome and “ALC” as the predictor. Use ALC=0 as the reference group. Interpret the odds ratios for the “ALC” variables. An individual consuming ≥0.5 and <2 drinks/week has 0.693 the odds of death compared to an individual consuming <0.5 drinks/week, over the study period. An individual consuming ≥2 drinks/week has 0.744 the odds of death compared to an individual consuming <0.5 drinks/week, over the study period.
Image of page 2
Image of page 3

You've reached the end of your free preview.

Want to read all 8 pages?

  • Spring '14
  • Hernandez-Diaz
  • Logit

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes