Methods to Describe Referral Patterns in a Canadian Primary Care Electronic Medical Record Database: Modelling Multilevel Count Data

Authors

Bridget L Ryan
Joshua Shadd
Heather Maddocks
Moira Stewart

Document Type

Article

Publication Date

2017

Journal

Journal of Innovation in Health Informatics

Volume

31

Issue

1

URL with Digital Object Identifier

10.14236/jhi.v24i4.888

Abstract

Background: A referral from a family physician (FP) to a specialist is an inflection point in the patient journey, with potential implications for clinical outcomes and health policy. Primary care electronic medical record (EMR) databases offer opportunities to examine referral patterns. Until recently, software techniques were not available to model these kinds of multi-level count data. Objective: To establish methodology for determining referral rates from FPs to medical specialists using the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) EMR database. Method: Retrospective cohort study, mixed effects and multi-level negative binomial regression modelling with 87,258 eligible patients between 2007 and 2012. Mean referrals compared by patient sex, age, chronic conditions, FP visits, and urban/rural practice location. Proportion of variance in referral rates attributable to the patient and practice levels. Results: On average, males had 0.26, and females 0.31 referrals in a 12-month period. Referrals were significantly higher for females, increased with age, FP visits, and number of chronic conditions (p<.0001). Overall, 14% of the variance in referrals could be attributed to the practice level, and 86% to patient level characteristics. Conclusions: Both patient and practice characteristics influenced referral patterns. The methodologic insights gained from this study have relevance to future studies on many research questions that utilize count data, both within primary care and broader health services research. The utility of the CPCSSN database will continue to increase in tandem with data quality improvements, providing a valuable resource to study Canadian referral patterns over time.

Notes

Copyright © 2017 The Author(s). Published by BCS, The Chartered Institute for IT under Creative Commons license http://creativecommons.org/licenses/by/4.0/ Ryan BL, Shadd J, Maddocks H, Stewart M, Thind A, Terry AL. Methods to describe referral patterns in a Canadian primary care electronic medical record database: modelling multi-level count data. J Innov Health Inform.2017;24(4):311–31

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