Question

 

A researcher was interested in assessing the prevalence of internet addiction risk (IAR) on a college campus in California. Data was gathered by having students complete a questionnaire on orientation day at the beginning of the school year. 1. What study design was used in this scenario?

Coding for study variables:

IAR – internet addiction risk; 1 = low; 2 = medium; 3 = high

SEX – 1 = male; 2 = female

YEAR – 1 = freshman; 2 = sophomore; 3 = junior; 4 = senior

Researchers were interested in determining whether a new drug could be used to ease post-traumatic stress disorder (PTSD) symptoms among veterans. Three hundred patients were recruited from 10 Veterans Affairs hospitals; half were given the new drug while the other half were given a placebo. The results indicated statistically significant improvements in sleep quality index (SQI) scores for patients taking the new drug as opposed to patients taking the placebo. However, side effects like dizziness (DIZZ) were also greater among patients taking the new drug.

Coding for study variables:

MED— 1 = medication; 2 = placebo

SQI— sleep quality index; overall score 0-21

DIZZ – 0 = no dizziness; 1 = dizziness

A study was conducted to determine the source of an outbreak of influenza A (H5N1) in Hong Kong. A total of 45 cases with fever plus cough or sore throat and 90 matched controls without symptoms were interviewed with a standardized questionnaire. Exposure to live poultry (EXP) in the week before illness was significantly associated with H5N1 infection.  What study design was used in this scenario?

Coding for study variables:

EXP—live poultry exposure; 1 = yes; 2 = no

·          H5N1—Influenza A (H5N1) infection; 1 = yes; 2 = no

The Nurses’ Health Study is one of the largest prospective investigations of risk factors for major chronic diseases in women. Using data from food frequency questionnaires and mortality records collected between 1986-2010, researchers examined the association between long term gluten intake (GLUT) and development of coronary heart disease (CHD). The results indicated that consumption of foods containing gluten was not significantly associated with risk of CHD, even after adjusting for race, body mass index (BMI), and other known risk factors. What study design was used in this scenario?

Coding for study variables:

GLUT—gluten intake; 1 = lowest; 2 = low; 3 = medium; 4 = high; 5 = highest

RACE – 1 = White; 2 = Black; 3 = other

BMI – body mass index (kg/m²)

CHD —coronary heart disease; 1 = yes; 2 = no

Answer 1

A researcher was interested in assessing the prevalence of internet addiction risk (IAR) on a college campus in California. Data was gathered by having students complete a questionnaire on orientation day at the beginning of the school year. 1. What study design was used in this scenario?

Coding for study variables:

IAR – internet addiction risk; 1 = low; 2 = medium; 3 = high

SEX – 1 = male; 2 = female

YEAR – 1 = freshman; 2 = sophomore; 3 = junior; 4 = senior

This study is descriptive and observational. As the researcher are only trying to get the information about students with regards to internet additction and also no experiment is being performed so it observational.

Variables IAR & Year are ordinal and SEX is nominal.

Researchers were interested in determining whether a new drug could be used to ease post-traumatic stress disorder (PTSD) symptoms among veterans. Three hundred patients were recruited from 10 Veterans Affairs hospitals; half were given the new drug while the other half were given a placebo. The results indicated statistically significant improvements in sleep quality index (SQI) scores for patients taking the new drug as opposed to patients taking the placebo. However, side effects like dizziness (DIZZ) were also greater among patients taking the new drug.

Coding for study variables:

MED— 1 = medication; 2 = placebo

SQI— sleep quality index; overall score 0-21

DIZZ – 0 = no dizziness; 1 = dizziness

This is an experimental study. There is one control group and other is treatment group. The study is comparing the effect of taking the drug and not taking it.

MED 1,2 ---> Can be termed as Index and it is a categorical variable

SQI --> Scale, dependent variable

DIZZINESS --> Index, Categorical and dependent variable

A study was conducted to determine the source of an outbreak of influenza A (H5N1) in Hong Kong. A total of 45 cases with fever plus a cough or a sore throat and 90 matched controls without symptoms were interviewed with a standardized questionnaire. Exposure to live poultry (EXP) in the week before illness was significantly associated with H5N1 infection.  What study design was used in this scenario?

Coding for study variables:

EXP—live poultry exposure; 1 = yes; 2 = no

H5N1—Influenza A (H5N1) infection; 1 = yes; 2 = no

This is an explanatory and observational study. The researcher was trying to find the source behind H5N1 and they didn't perform any experiment.

EXP Categorical variable

H5N1 Categorical variable

The Nurses’ Health Study is one of the largest prospective investigations of risk factors for major chronic diseases in women. Using data from food frequency questionnaires and mortality records collected between 1986-2010, researchers examined the association between long-term gluten intake (GLUT) and development of coronary heart disease (CHD). The results indicated that consumption of foods containing gluten was not significantly associated with risk of CHD, even after adjusting for race, body mass index (BMI), and other known risk factors. What study design was used in this scenario?

Coding for study variables:

GLUT—gluten intake; 1 = lowest; 2 = low; 3 = medium; 4 = high; 5 = highest . ---> Ordinal

RACE – 1 = White; 2 = Black; 3 = other --> Categorical

BMI – body mass index (kg/m2) . ---> Scale

CHD —coronary heart disease; 1 = yes; 2 = no --> Categorical

This is an exploratory and observational study.