Study Design — Flashcards

Flashcard 221: What selection bias occurs when specifically selecting healthy people? _____

Answer: Healthy worker effect

Flashcard 222: If the confidence interval does not include the null value, the result is statistically _____

Answer: significant

Flashcard 223: What is the equation for standard error?

Answer: SE = SD / √n

Extra: Standard Error (SE) = Standard Deviation (SD) / Square root of the sample size (n). SE measures how far the sample mean of the data is likely to be from the true population mean. It decreases as sample size increases.

Flashcard 224: _____ surveys are observational studies that compare a frequency of disease and frequency of risk related factors at one time point

Answer: Cross-sectional

Flashcard 225: The power of a study is increased with _____ sample size

Answer: increased

Flashcard 226: Patients typically get exposed to _____ radiation via exposure to the sunlight

Answer: Non-Ionizing

Flashcard 227: In a Ratio of A/B, is A part of B? _____

Answer: No

Flashcard 228: What type of bias is caused by increased detection of diseases (e.g. cancer) with a more benign course? _____

Answer: Length-time bias

Flashcard 229: A _____ is similar to a Chi-square test in that it is used to compare categorical outcomes but in small populations.

Answer: fisher's exact test

Flashcard 230: For a short duration disease, how are prevalence and incidence related? _____

Answer: Prevalence ~ Incidence