Biostats and Data in Public Health

What is the prevalence of age-related macular degeneration based on studies?

range from 1.1% to 40.5%

What is the prevalence of diabetic retinopahty based on studies?

1.2% to 48%

NHANES showed that prevalence of age-related macular degeneration varied by what?

Age and race/ethnicity

What is the prevalence of open-angle glaucoma based on studies?

1-9% to 13.8%

What is the prevalence of uncorrected refractive error based on studies?

1.8 to 15.1%

What is the prevalence of cataracts based on studies?

2.8% to 29.5%

What is the prevalence of vision impairment overall based on studies?

0.7 to 7.5%

What is a type I error?

False positive; declared to be statistically significant difference when no difference exists. Rejecting the null hypothesis when the null hypothesis should not have been rejected. Alpha error.

What is type II error?

False negative; declared to be no statistically significant difference when a difference exists. Accepting the null hypothesis when the null hypothesis should have been rejected. Beta error.

What are the 2 competing hypotheses that are considered when quantifying research questions?

• Null hypothesis: H₀

• Alternative hypothesis: H₁

What is the null hypothesis?

Hypothesis of no relationship between the dependent and independent variables. This is what we are actually testing in order to determine if we accept the results of a study.

What is the alternative hypothesis?

Hypothesis that there is a relationship between the dependent and independent variables. Typically, by rejecting the null hypothesis, we are accepting the alternative hypothesis.

How is either null or alternative hypothesis decided to be true?

Evaluation of statistical significance on data. Such as p-value.

What is internal validity?

Measurements accurately reflect the sample

What is external validity?

Measurements accurately reflect the sample population

What is generalizability?

The extent to which result or findings obtained from a sample are applicable to a broader population

What is selection bias?

Results from the way subjects are entered into a sample/subjects in a study may not be representative of the target population.

What is information bias?

Results from misclassification or measurement bias.

What is interviewer bias?

The way questions are presented may influence response.

What is confounding bias?

Groups being tested for differences have some underlying difference which is not controlled.

What is big data?

Data that is so large and complex that it exceeds the storage or computing capacity of most systems ability to perform timely

What is systemic review?

Summarizes the results of available carefully designed healthcare studies and provides a high level of evidence on the effectiveness of healthcare interventions.

What is meta-analysis?

The statistical analysis of large collection of analysis results from individuals studies for the purpose of integrating the findings.