BIOEPI “ACCURACY”

Accuracy

refers to the closeness of a measurement or an estimate to the true value. 

Validity

The extent to which a test or measurement accurately represents what it intends to measure.

Construct Validity

Evaluates how well a test or measurement reflects the theoretical concept it is intended to measure.

Internal Validity

Assesses whether the observed effects in a study are truly due to the independent variable and not due to other confounding factors.

External Validity

Determines the extent to which study results can be generalized to other populations, settings, or times.

Bias

Any systematic error in the design, conduct, or analysis of a study that results in a mistaken estimate of an exposure’s effect on the risk of disease.

Differential Bias

Occurs when measurement errors differ between study groups, leading to systematic misclassification and distorted results.

Nondifferential Bias

Affects all study groups equally and generally biases results toward the null hypothesis, making it harder to detect a true association.

Selection Bias

Occurs when study participants are not representative of the target population, leading to incorrect associations between exposure and outcomes; arising from how participants are chosen

Information Bias

Arises from errors in data collection, measurement, or recall; from errors in measurement or reporting

Recall Bias

Differences in memory accuracy between study groups.

Interviewer Bias

When researchers unintentionally influence responses.

Minimizing bias

Essential for maintaining the validity of a study.

Confounding Bias

From unaccounted third variables affecting the relationship between exposure and outcome.

Restriction

Excluding participants with a known confounder.

Matching

Pairing study participants with similar characteristics.

Randomization

Randomly assigning participants to different groups to distribute confounders equally.

Multivariate Analysis

Using statistical models (e.g., regression) to adjust for confounding effects.

Stratification

Involves dividing a study population into subgroups (strata) based on a potential confounder.

Adjustment

A statistical technique used to control for confounding.

Standardization

Adjusting rates to a standard population.

Multivariable regression models

Using statistical methods (e.g., logistic regression) to control for multiple confounders simultaneously.

Precision

Refers to the consistency and reproducibility of a measurement.

Reliability

The extent to which a measurement tool consistently produces the same results under the same conditions.

Test-retest reliability

Measures consistency over time.

Inter-rater reliability

Assesses consistency between different observers.

Internal consistency

Examines how well different parts of a test measure the same concept.

Statistical significance

Determines whether an observed effect is likely due to chance.

P-values

Quantifies the probability that the observed data (or more extreme results) would occur under the null hypothesis.

Sample size

Refers to the number of subjects in a study.