FIGURE 1-2. Hypothetical changes in level and slope of a time–series.

FIGURE 1-2Hypothetical changes in level and slope of a time–series

Assumption: the (counterfactual) experience of patients, had the policy not been implemented, is correctly reflected by the extrapolation of the pre-policy trend.

From: 1, Hints of a Different Way—Case Studies in Practice-Based Evidence

Cover of The Learning Healthcare System
The Learning Healthcare System: Workshop Summary.
Institute of Medicine (US) Roundtable on Evidence-Based Medicine; Olsen LA, Aisner D, McGinnis JM, editors.
Washington (DC): National Academies Press (US); 2007.
Copyright © 2007, National Academy of Sciences.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.