Reference no: EM133704935
Assignment: Worksheet: Study Designs, Variables, and Levels of Measurement
Instructions
Read the research scenario and identify the study design, variables, and levels of measurement. Click on the answer box and select the correct answer for each question.
These are the answer choices:
Study designs: case-control, cohort, cross-sectional, experimental
Variables: dependent, independent
Levels of measurement: categorical*, ordinal, quantitative*
*Note: In this course, levels of measurement will be classified according to terms used in the Gerstman textbook. Nominal is a synonym for categorical. Continuous, scale, interval, and ratio are synonyms for quantitative.
Scenario I:
Researchers tested whether a new drug called AMP50 (DRUG) could shrink cancer cells. Two hundred patients were recruited from a large university hospital; half were given the new drug while the other half were given a placebo. The results indicated a statistically significant reduction in tumor volume (TUM) for patients taking the new drug as opposed to patients taking the placebo.
Coding for study variables:
1) DRUG- 1 = AMP50 drug; 2 = placebo
2) TUM- tumor volume (V = (L x W2)/2); 0-300 cm2
Task
A. What study design was used in this scenario?
B. What was the independent variable?
C. What was the dependent variable?
D. What is the level of measurement for DRUG?
E. What is the level of measurement for TUM?
Scenario II:
A study was conducted to determine the source of an outbreak of Middle East Respiratory Syndrome (MERS) in United Arab Emirates. A total of 27 cases with fever, cough, and shortness of breath and 54 matched controls without symptoms were interviewed with a standardized questionnaire. Exposure to dromedary camels at a farm in Abu Dhabi (EXP) in the week before illness was significantly associated with MERS infection.
Coding for study variables:
1) EXP - dromedary camel exposure; 0 = no; 1 = yes
2) MERS - Middle East Syndrome infection; 0 = no; 1 = yes
Task
A. What study design was used in this scenario?
B. What was the independent variable?
C. What was the dependent variable?
D. What is the level of measurement for EXP?
E. What is the level of measurement for MERS?
Scenario III:
A team of researchers was interested in assessing whether chlamydia infection (CLMD) was associated with alcohol use (ALC) on a college campus in Illinois. Participants included 350 students who attended a sexually transmitted disease screening event in April 2019. Urine samples were tested in a laboratory for presence of chlamydia and alcohol use was assessed by self-reported questionnaire.
Coding for study variables:
1) CLMD - 0 = no; 1 = yes
2) ALC - Average # drinks per week (0-85)
Task
A. What study was used in this scenario?
B. What was the independent variable?
C. What was the dependent variable?
D. What is the level of measurement for CLMD?
E. What is the level of measurement for ALC?
Scenario IV:
The DANLIFE Study is a large prospective investigation of psychosocial predictors of health in Denmark. All children born after 1980 are given a personal registration number that can be linked to databases that collect information on drug prescriptions, hospitalizations, income, and employment over the lifecourse. Researchers used linked data to examine the association between childhood adversities and development of type 1 diabetes (DIA). The results indicated that parental separation (SEP, the most common childhood adversity) was significantly associated with diagnosis of type 1 diabetes, even after adjusting for maternal education (EDUC).
Coding for study variables:
1) EDUC- maternal education; 1 = low; 2 = middle; 3 = high
2) SEP - parental separation; 0 = no; 1 = yes
3) DIA - type 1 diabetes; 0 = no; 1 = yes
Task
A. What study design was used in this scenario?
B. What was the independent variable?
C. What was the dependent variable?
D. What is the level of measurement for EDUC?
E. What is the level of measurement for SEP?