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Visit Entropy: comparing a novel method to existing continuity of care measures

Gregory M Garrison, Buck Bania


Introduction: Continuity of care is a key characteristic of primary care yet there is little agreement on an accepted measure of continuity.  Density (Usual Provider Continuity, Primary Provider Continuity), dispersion (Continuity of Care Index), and sequence (Sequence of Care Index) are often used measures, but they each have specific drawbacks when applied to patients with multi-comorbidity who are cared for within a patient-centered medical home practice.

Methods: A new measure of continuity called Visit Entropy was developed using mathematical constructs from information theory and physics.  This was compared to four existing measures of continuity in a dataset of 811 hospitalized primary care patients.

Results: Visit Entropy is inversely related to other measures of continuity of care.  It has a less skewed distribution and it helps differentiate the substantial number of patients at the extremes of other measures of continuity of care.  Visit Entropy also eliminates the problem of undefined values caused by division by zero seen in other continuity measures.

Conclusions: Visit Entropy solves many of the shortcomings of existing continuity measures when applied to a dataset of primary care patients cared for within a medical home practice.  Further study is indicated to determine if Visit Entropy is associated with the benefits commonly ascribed to continuity of care and if it matches patient and physician perceptions of continuity of care.


Continuity of patient care, entropy, informatics, information, theory, person-centered healthcare, primary healthcare

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