Open access
Protocol
Compliance with pathology testing
guidelines in Australian general
practice: protocol for a secondary
analysis of electronic health record data
Gorkem Sezgin,1 Andrew Georgiou,1 Rae-Anne Hardie,1 Ling Li,1 Lisa G Pont,1,2
Tony Badrick,3 Guilherme S Franco,1 Johanna I Westbrook,1 Natalie Rinehart,4
Adam McLeod,4 Christopher Pearce,4 Marianne Shearer,5 Robin Whyte,6
Elizabeth Deveny7
To cite: Sezgin G, Georgiou A,
Hardie R-A, et al. Compliance
with pathology testing
guidelines in Australian
general practice: protocol for a
secondary analysis of electronic
health record data. BMJ Open
2018;8:e024223. doi:10.1136/
bmjopen-2018-024223
► Prepublication history for
this paper is available online.
To view these files, please visit
the journal online (http://dx.doi.
org/10.1136/bmjopen-2018024223).
Received 15 May 2018
Revised 26 July 2018
Accepted 20 September 2018
© Author(s) (or their
employer(s)) 2018. Re-use
permitted under CC BY-NC. No
commercial re-use. See rights
and permissions. Published by
BMJ.
For numbered affiliations see
end of article.
Correspondence to
Gorkem Sezgin;
gorkem.sezgin@mq.edu.au
AbstrACt
Introduction In Australia, general practitioners usually
are the first point of contact for patients with non-urgent
medical conditions. Appropriate and efficient utilisation of
pathology tests by general practitioners forms a key part
of diagnosis and monitoring. However overutilisationand
underutilisation of pathology tests have been reported
across several tests and conditions, despite evidencebased guidelines outlining best practice in pathology
testing. There are a limited number of studies evaluating
the impact of these guidelines on pathology testing in
general practice. The aim of our quantitative observational
study is to define how pathology tests are used in general
practice and investigate how test ordering practices align
with evidence-based pathology guidelines.
Methods and analysis Access to non-identifiable
patient data will be obtained through electronic health
records from general practices across three primary
health networks in Victoria, Australia. Numbers and
characteristics of patients, general practices, encounters,
pathology tests and problems managed over time will be
described. Overall rates of encounters and tests, alongside
more detailed investigation between subcategories
(encounter year, patient’s age, gender, and location and
general practice size), will also be undertaken. To evaluate
how general practitioner test ordering coincides with
evidence-based guidelines, five key candidate indicators
will be investigated: full blood counts for patients on
clozapine medication; international normalised ratio
measurements for patients on warfarin medication;
glycated haemoglobin testing for monitoring patients with
diabetes; vitamin D testing; and thyroid function testing.
Ethics and dissemination Ethics clearance to collect
data from general practice facilities has been obtained by
the data provider from the RACGP National Research and
Evaluation Ethics Committee (NREEC 17–008). Approval for
the research group to use these data has been obtained
from Macquarie University (5201700872). This study
is funded by the Australian Government Department of
Health Quality Use of Pathology Program (Agreement ID:
4-2QFVW4M). Findings will be reported to the Department
of Health and disseminated in peer-reviewed academic
journals and presentations (national and international
conferences, industry forums).
strengths and limitations of this study
► The study population will be drawn from a large re-
gion in Victoria, Australia, and is expected to contain
a large sample population (data from approximately
350 general practices), along with a large number
of demographic variables (eg, region, gender, age).
► Electronic health records contain a vast amount of
information on patients, allowing us to control for
potential interacting or predictive variables on patient outcomes using statistical modelling.
► Some electronic health record fields may not be
completely standardised across practices and could
contain inconsistencies and missing information,
which may limit the volume of data that can be extracted and analysed.
► Some medications being investigated in this study
may be prescribed and/or monitored by specialists,
which may result in cases being missed.
IntroduCtIon
In Australia, general practitioners (GPs) are
usually the first point of contact for patients
with non-emergency health problems. They
play an important role in the early detection, prevention (including shared-care
arrangements) and treatment of disease.1
Pathology tests are a key part of general practice assisting GPs in diagnosing, screening,
treating and monitoring diseases. The past
decade has seen an increase in both visits to
and problems managed by GPs in Australia,
resulting in an estimated 24.2 million additional pathology tests being ordered in 2015–
2016 compared with 2006–2007.2
Appropriate and timely utilisation of
pathology tests can improve the quality and
outcome of patient care. However, both overutilisation and underutilisation of pathology
tests have been frequently observed in a
Sezgin G, et al. BMJ Open 2018;8:e024223. doi:10.1136/bmjopen-2018-024223
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range of clinical scenarios.3 4 Several guidelines have been
established to encourage better utilisation of pathology
tests among GPs across Australia, USA, Canada and the
UK. These include initiatives such as Choosing Wisely5,
National Institute for Health and Clinical Excellence (NICE)6
and Royal Australian College of General Practitioners (RACGP)
Guidelines for preventative activities in general practice.7
Currently, there is little evidence on how test ordering
practices by GPs align with these recommendations and
guidelines in Australia, and elsewhere. A survey of 600 US
doctors revealed only 21% of doctors were familiar with
the Choosing Wisely campaign. However, doctors aware
of the campaign had a lower proportion of unnecessary
pathology testing.8 In Australia, increased awareness of
best-practice in vitamin D test ordering is reported to
have contributed to a reduction in healthcare costs and
potentially unnecessary tests.9 Considering the importance of pathology testing for managing diseases, a better
understanding of how pathology testing by GPs coincides
with evidence-based guidelines will be invaluable for the
success of management and disease-prevention strategies.
Until recently, the survey-based Bettering the Evaluation
and Care of Health (BEACH) study provided the most
comprehensive data on Australian GP activity.2 However,
its cross-sectional design prevented it from reporting
longitudinal patient level changes and outcomes. The
BEACH study was discontinued in 2016 and has since
left a gap in our understanding of GP activity, particularly in relation to pathology test ordering. The extensive use of computers by Australian GPs has prompted
interest in the use of electronic health record (EHR)
data as a research source for monitoring the quality of GP
services, and has led to research and publications based
on EHR data.10 The Australian Department of Health
funded NPS Medicinewise MedicinesInsight data set
contains a national collection of EHRs from 650 practices covering over 3300 GPs and nearly 3.6 million active
patients.11This data set has been used in several population health research projects and has demonstrated the
value of EHR data in research.12 This study will use EHR
data from the POLAR Data Space, containing de-identified data from consenting general practices collected
on behalf of Australian primary health networks (PHNs)
from approximately 350 practices. POLAR Data Space
has added measures to ensure robust and accurate data,
and implements standardised terminologies to make the
data more approachable for research use. This study,
undertaken in collaboration with POLAR Data Space
Research Consortia and its associated PHNs, will facilitate
a comprehensive analysis of general practice activity and
its relationship to pathology testing in Australia through
EHR data.
objectives
The objectives of this study are to:
1. Describe general practice activity and characteristics
of pathology test ordering based on electronic health
record data.
2
2. Investigate compliance with evidence-based guidelines
to determine the appropriateness and quality use of
pathology in general practice.
MEthods And AnAlysEs
study design
A retrospective observational study of Australian general
practice health records and pathology testing data. The
study will run for a period of approximately 2 years spanning from early 2018 to late 2019.
data source
Data to be used in this study will be provided by the
POLAR Data Space.10 POLAR Data Space collects
de-identified data from consenting general practices on
behalf of Australian PHNs including Gippsland, Eastern
Melbourne and South Eastern Melbourne PHNs. Data
are extracted from approximately 350 practices in urban
and rural regions in Victoria, Australia. The primary
purpose of the data collection is to provide information
to improve patient care at the practice level and population health initiatives at the PHN level. POLAR Data
Space has ethics approval for the collection, storage and
de-identification of the data, which it makes available for
approved research governed by the involved PHNs.
The data source will include pooled general practice patient data extracted from Best Practice, Medical
Director and Zedmed EHRs. Data will include de-identified demographic information about patients and general
practices, as well as visit records (diagnosis, past history,
medications) and pathology test records (test name and
result). Both historical and current information about
patients will be acquired, providing a longitudinal record.
It is expected that the data will span a period of over a
decade, from early 2000s to early 2018.
study population
The study population will consist of all patients who visited
any of the general practices included in the study and had
their visit recorded in the practices’ EHR software.
Variables
The following criteria will be adopted to accurately
describe general practice activity and ensure data quality:
(i) a patient will be distinguished by a unique (non-identifiable) patient code recorded within a general practice
and included if determined to be an active patient (ie,
has visited the GP three or more times in the past 2 years,
not deceased); (ii) an encounter (ie, consultation, visit)
will be defined as a patient visit recorded by a doctor or
nurse during which an action (eg, consultation, prescription) is performed, and will be identified through a variable indicating the visit type (eg, surgery, administrative,
phone call); (iii) a pathology test will be defined as either
a panel of interrelated tests (eg, full blood count) or an
individual test (eg, troponin test); (iv) where possible,
standardised records such as Logical Observation Identifiers Names and Codes (LOINC) and Systematised
Sezgin G, et al. BMJ Open 2018;8:e024223. doi:10.1136/bmjopen-2018-024223
Open access
Nomenclature of Medicine (SNOMED) terminologies
will be prioritised to identify variables; otherwise, free-text
data will be searched for terms of interest (eg, ‘diabetes’
or its abbreviated forms in the diagnosis field, excluding
‘not diabetes’).
Analyses
Data examination and analysis will be performed using
Stata/MP V.15.1 (StataCorp). The methods outlined in
this protocol are structured according to the Strengthening the Reporting of Observational Studies in Epidemiology checklist of items to be included in observational
studies.13
Characteristics of general practice activity and pathology testing
In line with objective 1 of this study, we will analyse and
describe Australian general practice characteristics
and activity. These characteristics can subsequently be
compared with reports on national demographics and
healthcare statistics, such as Australian Institute of Health
and Welfare’s annual reports.
Sample population characteristics will be reported.
This will include describing the characteristics of patients,
general practices, encounters, tests and problems
managed across time. Subsequent analyses will describe
overall median rates of encounters and tests, alongside more detailed investigation between subcategories
(encounter year, patient’s age, gender and postcode and
number of active general practitioners in practice) using
the following indicators: encounters per patient per year
and tests per encounter.
The differences between subcategories will be further
described as incidence rate ratios by generalised linear
modelling (Poisson or negative binomial, whichever is
appropriate).
Best practice guidelines-based analyses
In line with objective 2 of this study, we will describe the
extent to which pathology ordering practices among
Australian GPs aligns with evidence-based pathology
testing guidelines. Five initial candidate indicators have
been identified for analyses.
Monitoring patients on clozapine medication
Rationale
Clozapine is a highly effective antipsychotic drug that
is used for managing chronic schizophrenia. However,
clozapine use can result in neutropenia in nearly 2%
of patients, and agranulocytosis in 1%14, warranting
close monitoring of patients taking clozapine. Although
clozapine is prescribed by specialists, monitoring is more
frequently managed by GPs through shared-care arrangements.15 After 18 weeks of initiation and monitoring
under a specialist, GPs can also prescribe clozapine.
Australian guidelines recommend patients on clozapine
medication have blood tests for white blood cell and
neutrophil counts weekly for the first 18 weeks of initiation, and monthly thereafter.16 17 Furthermore, a patient
Sezgin G, et al. BMJ Open 2018;8:e024223. doi:10.1136/bmjopen-2018-024223
cannot obtain clozapine from the pharmacist without a
recent blood test. Currently, the state of monitoring for
patients on clozapine medication is not known.
Analysis
The study population will be patients who are being
prescribed clozapine by the GP (and therefore also need
to be monitored). The time frame will include records
after the first entry of the prescription into the EHR software, and before medication is discontinued (or patient
is deceased or is no longer an active patient). The demographic characteristics of patients on clozapine medication as well as number of full blood counts for these
patients will be described overall, by patient gender, age
and location, general practice size and year of test. The
number of full blood counts per patient per year will
also be described overall and by the demographic characteristics, by counting the number of full blood count
tests conducted for each patient on clozapine medication for each available year. Subsequently, the median
number of full blood count tests per patient per year will
be calculated, with the inter-quartile range. For patients
who undergo more than one test, the time between tests
will be determined. Subsequently, median time between
tests will be calculated, with the inter-quartile range. As
clozapine may also be prescribed by specialists, it may not
be possible to determine when the medication was initiated through the EHR software. Consequently, it may not
be possible to differentiate patients who require weekly
tests from patients who require monthly tests. Nonetheless, it is expected patients on clozapine medication will
have at least one full blood count test within approximately 4 to 6 weeks of a prior test; which will indicate
compliance with guidelines.
Measuring international normalised ratio levels for patients on
warfarin medication
Rationale
Warfarin is a highly effective and widely used anticoagulant in Australia. However, it is also one of the most
common causes of prescribed medication-related
mortality, due to its risk of causing bleeding.18 Best practice guidelines recommend that the initiation of warfarin
medication should be accompanied by frequent International Normalised Ratio (INR) measurements until
a stable therapeutic range is reached. After INR levels
are stable, testing frequency should be once every 4 to
6 weeks unless a change (eg, initiation of another medication) that can affect INR levels occurs.19 20 Failure to
correct INR levels is associated with increased mortality.21
Analysis
The sample population will be patients with a warfarin
prescription. Only data entered after the first instance
the prescription is recorded in the GP’s computer and
before the patient permanently stops the medication (or
death) will be considered for analysis. As the pathology
test frequency and repeat interval requirements for
3
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patients treated with warfarin are similar to the requirements for clozapine, similar reporting standards will be
used. As with clozapine medication, it may not be possible
to differentiate patients who are initiating warfarin medication from those who have reached stable INR levels.
Despite this, based on best practice guidelines, it is
expected that patients on warfarin medication will have at
least one INR measurement approximately within 4 weeks
of a prior measurement, which will be the criteria used to
determine compliance with guidelines.
Glycated haemoglobin testing for management of patients with
diabetes
Rationale
It is estimated that over one million Australians are
diagnosed with diabetes, 85% of whom have type 2
diabetes.22 Poor management of diabetes can lead to a
range of complications, including cardiovascular and
renal diseases and retinopathy.23 Best practice guidelines
recommend recurrent glycated haemoglobin (HbA1c)
testing in at least half-yearly intervals for patients with
diabetes.24 HbA1c levels are a good indicator of longterm blood glucose control over the previous 8–12 weeks.
Uncontrolled glucose leading to high HbA1c levels may
indicate increased risk of diabetes-related complications.
As such, undertesting may be associated with failure to
identify complications.
Analysis
The sample population will be patients diagnosed with
type 2 diabetes. Only data after the diagnosis being
recorded and before death will be included. The analyses will be conducted and reported in a similar structure
as outlined previously for clozapine and warfarin medication pathology testing guidelines. Based on the best
practice guidelines, it is expected that a minimum of two
HbA1c tests will be conducted in a year for patients diagnosed with diabetes.
Frequency of vitamin D testing
Rationale
A study on vitamin D testing found a considerable
number of potentially unnecessary vitamin D tests
ordered by Australian GPs.25 This has led to changes in
funding programmes and the establishment of guidelines, suggesting only patients at risk of complications
that may arise due to low vitamin D levels (eg, pregnant
women, older patients at risk of falls, patients with osteoporosis) should be tested.26 Ultimately, an overall reduction of vitamin D tests was observed9; however, studies
on whether the tests are being ordered according to the
guidelines are limited.27
Analysis
To understand if vitamin D tests are being ordered
according to guidelines, population and demographic
characteristics associated with higher vitamin D testing
4
will be investigated. The sample population will be all
patients from which patients who had a vitamin D test
will be identified and flagged (as the outcome variable).
Univariate and multivariate logistic regression models
will be fitted to identify any variation in vitamin D testing
by the demographic characteristics of patients, diagnoses
and general practices. Differences will be reported as ORs
and their 95% confidence intervals. Descriptive characteristics (patient’s gender, age, and location, general
practice’s size and year of test) of the sample population will also be described. To obtain an understanding
of the reasons for vitamin D testing, other tests ordered
simultaneously will be identified and examined, as well as
preceding medication prescriptions and diagnoses.
Thyroid function tests
Rationale
Thyroid dysfunction can occur due to overutlisation
or underfunction of the thyroid gland, and can lead to
cardiovascular diseases or subclinical hypothyroidism
(remains asymptomatic).28 Guidelines recommend
assessing thyroid dysfunction by initial thyroid-stimulating hormone (TSH) tests, which may be followed up
by free triiodothyronine (fT3) and free thyroxine (fT4)
tests to assist with diagnosis if an abnormal TSH result is
observed.29 Otherwise, fT3 and fT4 tests are not recommended without a prior TSH test. In Australia, there
are currently no screening guidelines for when and how
frequently TSH tests should be conducted among adults.
The benefit of screening for thyroid disease, or even
treating subclinical hypothyroidism, remains uncertain.30
It would be valuable to understand the demographics for
and frequency of TSH test ordering by Australian GPs.
Analysis
To describe thyroid function test use by Australian GPs,
patients with TSH, fT3 and fT4 tests will be identified
from the data. The associations with population characteristics and diagnoses in TSH, fT3 and fT4 testing will
be investigated and reported by univariate and multivariate logistic regression models, similar to the reporting
of vitamin D testing outlined previously. In addition to
the population and general practice demographics, the
odds of fT3 and fT4 testing by prior TSH test result and
normal/abnormal TSH test will also be analysed.
The descriptive characteristics for TSH, fT3 and fT4
tests will be described overall, and by patient's gender,
age and location, general practice size and year of test.
The number of fT3 and fT4 tests will be further described
by TSH testing status: without a prior TSH test, simultaneously ordered with a TSH test and following a reported
TSH test. Where TSH test results are available, fT3 and
fT4 tests following TSH testing will be further described
by whether the initial TSH test was normal or abnormal.
sample size considerations
The study will be based on a dynamic cohort, with the
number of practices, GPs and patients expected to rise.
Sezgin G, et al. BMJ Open 2018;8:e024223. doi:10.1136/bmjopen-2018-024223
Open access
Current estimates suggest that the study will have data
from 350 general practices. Therefore, it is expected that
there will be ample scope to detect significant variation
in practices across patient and general practice demographic domains.
Patient and public involvement
There was no involvement of patients or the public in this
study.
dIsCussIon
Pathology tests play an important role in general practice.
There are guidelines outlining best practice for utilising
tests, although the role of these guidelines in decision
making is not well established.
A limitation of using EHRs is that recording of clinical
data is not always well-standardised, resulting in variation and inconsistencies in the information available.31
Issues may arise due to free-text data with no standard
formatting and absence of recorded comorbidities and
diagnoses or missing data,32 which are addressed by prioritising standardised terms and adopting stringent criteria
to define variables. The POLAR program already codes
and organises significant amounts of extracted data,
and LOINC and SNOMED, both of which are available,
provide standardised pathology tests and diagnoses.
Another limitation of this study is that the study population will be drawn from only one region of Australia
(Victoria), and the results may not be nationally representative. One other limitation is related to the indicators being measured. Medications, such as clozapine and
warfarin, are generally prescribed by specialists who might
also continually monitor the patient’s status. In such
cases, observed compliance with guidelines in general
practice may be low. Furthermore, a patient monitored by
a general practitioner may have occasional visits to their
specialist, who may order the tests, rather than the GP.
This research will help define the extent to which
evidence-based best practice guidelines influence decision making in general practices. To date, difficulties in
obtaining patient data from EHR software have hindered
studying pathology test ordering in general practice. This
study will be one of the first in Australia to extensively
investigate the impact of best practice guidelines on GP
testing patterns. The study can ultimately lead to better
efficiency in pathology testing and improvements in
patient outcomes by providing much needed information
on the adherence of GPs to pathology testing guidelines.
Ethics and dissemination
The data will be de-identified and reported at an aggregate level, and the results will neither identify GPs nor
patients.
The results of this study will be reported to the Australian Government’s Department of Health, disseminated
in peer-reviewed academic journals and presented in
national and international conferences and industry
Sezgin G, et al. BMJ Open 2018;8:e024223. doi:10.1136/bmjopen-2018-024223
forums. The involvement of the PHNs in the research
process also allows for the research findings to inform
their activities at an early stage, reducing the usual
‘research into practice’ delay.
Author affiliations
1
Centre for Health Systems and Safety Research, Australian Institute of Health
Innovation, Macquarie University, Sydney, New South Wales, Australia
2
Graduate School of Health, University of Technology Sydney, Sydney, New South
Wales, Australia
3
The Royal College of Pathologists of Australasia Quality Assurance Program, St
Leonards, New South Wales, Australia
4
Outcome Health, Burwood, Victoria, Australia
5
Gippsland Primary Health Network, Moe, Victoria, Australia
6
Eastern Melbourne Primary Health Network, Box Hill, Victoria, Australia
7
South Eastern Melbourne Primary Health Network, Heatherton, Victoria, Australia
Contributors This study is jointly undertaken through a collaboration between
Centre for Health Systems and Safety Research at Macquarie University, the
Royal College of Pathologists of Australasia Quality Assurance Programs, POLAR
Data Space (Outcome Health, Eastern Melbourne PHN, Gippsland PHN and South
Eastern Melbourne PHN). AG initiated the project and led the development of the
Quality Use of Pathology Program (QUPP) grant proposal. AG, JIW, LL, LGP, TB, CP
and NR are chief investigators on the project and have contributed to the grant
proposal and protocol in their area of expertise. From the PHNs, MS, RW and ED
contributed their expertise in general practice to the protocol. AM, from Outcome
Health, has contributed his expertise in EHR data to the protocol. R-AH, GS and
GSF are members of the project team and contributed to the protocol in relation to
describing the procedures of data collection, validation, and analyses procedures.
R-AH and GS prepared the first draft of this protocol based on the grant proposal.
All authors have reviewed and approved the final version of this protocol.
Funding This study is independently executed through funding by a grant from
the Australian Government Department of Health, Quality Use of Pathology Program
(Agreement ID: 4-2QFVW4M). This Australian national grants programme aims to
improve health and economic outcomes from pathology tests.
Competing interests None declared.
Patient consent Not required.
Ethics approval Ethics clearance to collect data from general practice facilities
has been obtained by the data provider from the RACGP National Research and
Evaluation Ethics Committee (NREEC 17–008). Approval for the research group to
use these data has been obtained from Macquarie University (5201700872).
Provenance and peer review Not commissioned; externally peer reviewed.
open access This is an open access article distributed in accordance with the
Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which
permits others to distribute, remix, adapt, build upon this work non-commercially,
and license their derivative works on different terms, provided the original work is
properly cited, appropriate credit is given, any changes made indicated, and the use
is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
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