Chapter 1

Patient Centered Outcomes (the 5 Ds)



How often does a disesase occur?


Is the patient sick or well?


How accurate are tests used to diagnose disease?


What factors are associated with an increased risk of disease?


What are the consequences of having a disease?


How does treatment change the course of disease?


Does an intervention on well people keep disease from arising? Does early detection and treatment improve the course of disease?


What conditions lead to disease? What are the origins of disease?

Clinical Epidemiology

The science of making predictions about individual patients by counting clinical events in groups of similar patients and using strong scientific methods to ensure the predictions are accurate

Clinical Sciences

Provide the questions and the approach that can be used to care for individual patients


The study of disease occurrence in human populations

Evidence-based Medicine

Modern term for the application of clinical epidemiology to the care of patients

Health Services Research

The study of how non-biologic factors (e.g. clinical workforce, facilities, costs) affect patients' health


Things that vary and can be measured

Independent Variable

Purported cause or predictor variable

Dependent Variable

Possible effect or outcome variable

Extraneous Variable

Covariate; part of the system under study and may affect the relationship between the independent and dependent variables


All people in a define setting or with certain defined characteristics


A reasoned judgement based on data


A process at any stage of inference tending to produce results that depart systematically from the true values

Selection Bias

Occurs when comparisons are made between groups of patients that differ in determinates of outcome other than the one under study

Measurement Bias

Occurs when the methods of measurement are dissimilar among groups of patients


Occurs when two factors are associated (travel together) and the effect of one is confused with or distorted by the effect of the other

Recall Bias

A type of measurement bias that refers to differential recall in people with an adverse outcome compared to those with a normal outcome

Random Variation

The divergence of an observation on a sample from the true population value, due to chance alone