Automated imaging technologies for the diagnosis of glaucoma: a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study)

Augusto Azuara-Blanco, Katie Banister, Charles Boachie, Peter McMeekin, Joanne Gray, Jennifer Burr, Rupert Bourne, David Garway-Heath, Mark Batterbury, Rodolfo Hernandez, Gladys McPherson, Craig Ramsay, Jonathan Cook

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Abstract

Background

Many glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population.

Objectives

To assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma.

Design

Within-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care.

Setting

Secondary care.

Participants

Adults referred from the community to hospital eye services for possible glaucoma.

Interventions

Heidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement.

Main outcome measures

(1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is ‘discharge’ or ‘do not discharge’. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY).

Results

Data from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1% were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8% of participants; 37.9% of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0%, 95% confidence interval (CI) 80.2% to 92.1%] but the lowest specificity (63.9%, 95% CI 60.2% to 67.4%) and GDx had the lowest sensitivity (35.1%, 95% CI 27.0% to 43.8%) but the highest specificity (97.2%, 95% CI 95.6% to 98.3%). HRT-GPS had sensitivity of 81.5% (95% CI 73.9% to 87.6%) and specificity of 67.7% (95% CI 64.2% to 71.2%) and OCT had sensitivity of 76.9% (95% CI 69.2% to 83.4%) and specificity of 78.5% (95% CI 75.4% to 81.4%). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0%, 95% CI 82.8% to 88.7%) but the lowest specificity (39.1%, 95% CI 34.0% to 44.5%), GDx had the lowest sensitivity (64.7%, 95% CI 60.7% to 68.7%) but the highest specificity (53.6%, 95% CI 48.2% to 58.9%). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs.

Conclusions

Automated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective.

Future work

There are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored.

Funding

The National Institute for Health Research Health Technology Assessment programme.
Original languageEnglish
Number of pages202
JournalHealth Technology Assessment
Volume20
Issue number8
DOIs
Publication statusPublished - Jan 2016

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Triage
Glaucoma
Cost-Benefit Analysis
Confidence Intervals
Technology
Costs and Cost Analysis
Regression Analysis
Quality-Adjusted Life Years
Community Hospital
Optical Coherence Tomography
Referral and Consultation
Consultants
Intraocular Pressure
Health Care Costs
Scanning Laser Polarimetry
Outcome Assessment (Health Care)
Economic Models
Biomedical Technology Assessment
National Institutes of Health (U.S.)
Diagnostic Imaging

Cite this

Automated imaging technologies for the diagnosis of glaucoma : a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study). / Azuara-Blanco, Augusto; Banister, Katie; Boachie, Charles; McMeekin, Peter; Gray, Joanne; Burr, Jennifer; Bourne, Rupert; Garway-Heath, David; Batterbury, Mark; Hernandez, Rodolfo; McPherson, Gladys; Ramsay, Craig; Cook, Jonathan.

In: Health Technology Assessment, Vol. 20, No. 8, 01.2016.

Research output: Contribution to journalArticle

Azuara-Blanco, Augusto ; Banister, Katie ; Boachie, Charles ; McMeekin, Peter ; Gray, Joanne ; Burr, Jennifer ; Bourne, Rupert ; Garway-Heath, David ; Batterbury, Mark ; Hernandez, Rodolfo ; McPherson, Gladys ; Ramsay, Craig ; Cook, Jonathan. / Automated imaging technologies for the diagnosis of glaucoma : a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study). In: Health Technology Assessment. 2016 ; Vol. 20, No. 8.
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title = "Automated imaging technologies for the diagnosis of glaucoma: a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study)",
abstract = "BackgroundMany glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population.ObjectivesTo assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma.DesignWithin-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care.SettingSecondary care.ParticipantsAdults referred from the community to hospital eye services for possible glaucoma.InterventionsHeidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement.Main outcome measures(1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is ‘discharge’ or ‘do not discharge’. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY).ResultsData from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1{\%} were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8{\%} of participants; 37.9{\%} of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0{\%}, 95{\%} confidence interval (CI) 80.2{\%} to 92.1{\%}] but the lowest specificity (63.9{\%}, 95{\%} CI 60.2{\%} to 67.4{\%}) and GDx had the lowest sensitivity (35.1{\%}, 95{\%} CI 27.0{\%} to 43.8{\%}) but the highest specificity (97.2{\%}, 95{\%} CI 95.6{\%} to 98.3{\%}). HRT-GPS had sensitivity of 81.5{\%} (95{\%} CI 73.9{\%} to 87.6{\%}) and specificity of 67.7{\%} (95{\%} CI 64.2{\%} to 71.2{\%}) and OCT had sensitivity of 76.9{\%} (95{\%} CI 69.2{\%} to 83.4{\%}) and specificity of 78.5{\%} (95{\%} CI 75.4{\%} to 81.4{\%}). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0{\%}, 95{\%} CI 82.8{\%} to 88.7{\%}) but the lowest specificity (39.1{\%}, 95{\%} CI 34.0{\%} to 44.5{\%}), GDx had the lowest sensitivity (64.7{\%}, 95{\%} CI 60.7{\%} to 68.7{\%}) but the highest specificity (53.6{\%}, 95{\%} CI 48.2{\%} to 58.9{\%}). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs.ConclusionsAutomated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective.Future workThere are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored.FundingThe National Institute for Health Research Health Technology Assessment programme.",
author = "Augusto Azuara-Blanco and Katie Banister and Charles Boachie and Peter McMeekin and Joanne Gray and Jennifer Burr and Rupert Bourne and David Garway-Heath and Mark Batterbury and Rodolfo Hernandez and Gladys McPherson and Craig Ramsay and Jonathan Cook",
note = "Funding The National Institute for Health Research Health Technology Assessment programme. Acknowledgements The authors would like to thank: Pauline Garden for her data management and secretarial support; Lara Kemp for secretarial support in producing the final report; Cynthia Fraser for literature searches and referencing the final report; Kirsty McCormack for support in setting up and initiating the study; Gladys McPherson and the programming team at the Centre for Healthcare Randomised Trials for providing and maintaining the study website; Luke Vale for invaluable advice and assistance in the development of the economic model; Ian Russell (user) and Russell Young (IGA representative) for reviewing the executive summary and lay summary; independent members of the steering committee, and research and development departments at each research centre. Particular thanks go to all the GATE study participants who gave of their time to take part in the study and staff who facilitated recruitment and data collection at Aberdeen Royal Infirmary, Bedford Hospital, Hinchingbrooke Hospital, Moorfields Eye Hospital and Royal Liverpool University Hospital.",
year = "2016",
month = "1",
doi = "10.3310/hta20080",
language = "English",
volume = "20",
journal = "Health Technology Assessment",
issn = "1366-5278",
publisher = "National Co-ordinating Centre for HTA",
number = "8",

}

TY - JOUR

T1 - Automated imaging technologies for the diagnosis of glaucoma

T2 - a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study)

AU - Azuara-Blanco, Augusto

AU - Banister, Katie

AU - Boachie, Charles

AU - McMeekin, Peter

AU - Gray, Joanne

AU - Burr, Jennifer

AU - Bourne, Rupert

AU - Garway-Heath, David

AU - Batterbury, Mark

AU - Hernandez, Rodolfo

AU - McPherson, Gladys

AU - Ramsay, Craig

AU - Cook, Jonathan

N1 - Funding The National Institute for Health Research Health Technology Assessment programme. Acknowledgements The authors would like to thank: Pauline Garden for her data management and secretarial support; Lara Kemp for secretarial support in producing the final report; Cynthia Fraser for literature searches and referencing the final report; Kirsty McCormack for support in setting up and initiating the study; Gladys McPherson and the programming team at the Centre for Healthcare Randomised Trials for providing and maintaining the study website; Luke Vale for invaluable advice and assistance in the development of the economic model; Ian Russell (user) and Russell Young (IGA representative) for reviewing the executive summary and lay summary; independent members of the steering committee, and research and development departments at each research centre. Particular thanks go to all the GATE study participants who gave of their time to take part in the study and staff who facilitated recruitment and data collection at Aberdeen Royal Infirmary, Bedford Hospital, Hinchingbrooke Hospital, Moorfields Eye Hospital and Royal Liverpool University Hospital.

PY - 2016/1

Y1 - 2016/1

N2 - BackgroundMany glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population.ObjectivesTo assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma.DesignWithin-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care.SettingSecondary care.ParticipantsAdults referred from the community to hospital eye services for possible glaucoma.InterventionsHeidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement.Main outcome measures(1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is ‘discharge’ or ‘do not discharge’. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY).ResultsData from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1% were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8% of participants; 37.9% of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0%, 95% confidence interval (CI) 80.2% to 92.1%] but the lowest specificity (63.9%, 95% CI 60.2% to 67.4%) and GDx had the lowest sensitivity (35.1%, 95% CI 27.0% to 43.8%) but the highest specificity (97.2%, 95% CI 95.6% to 98.3%). HRT-GPS had sensitivity of 81.5% (95% CI 73.9% to 87.6%) and specificity of 67.7% (95% CI 64.2% to 71.2%) and OCT had sensitivity of 76.9% (95% CI 69.2% to 83.4%) and specificity of 78.5% (95% CI 75.4% to 81.4%). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0%, 95% CI 82.8% to 88.7%) but the lowest specificity (39.1%, 95% CI 34.0% to 44.5%), GDx had the lowest sensitivity (64.7%, 95% CI 60.7% to 68.7%) but the highest specificity (53.6%, 95% CI 48.2% to 58.9%). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs.ConclusionsAutomated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective.Future workThere are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored.FundingThe National Institute for Health Research Health Technology Assessment programme.

AB - BackgroundMany glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population.ObjectivesTo assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma.DesignWithin-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care.SettingSecondary care.ParticipantsAdults referred from the community to hospital eye services for possible glaucoma.InterventionsHeidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement.Main outcome measures(1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is ‘discharge’ or ‘do not discharge’. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY).ResultsData from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1% were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8% of participants; 37.9% of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0%, 95% confidence interval (CI) 80.2% to 92.1%] but the lowest specificity (63.9%, 95% CI 60.2% to 67.4%) and GDx had the lowest sensitivity (35.1%, 95% CI 27.0% to 43.8%) but the highest specificity (97.2%, 95% CI 95.6% to 98.3%). HRT-GPS had sensitivity of 81.5% (95% CI 73.9% to 87.6%) and specificity of 67.7% (95% CI 64.2% to 71.2%) and OCT had sensitivity of 76.9% (95% CI 69.2% to 83.4%) and specificity of 78.5% (95% CI 75.4% to 81.4%). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0%, 95% CI 82.8% to 88.7%) but the lowest specificity (39.1%, 95% CI 34.0% to 44.5%), GDx had the lowest sensitivity (64.7%, 95% CI 60.7% to 68.7%) but the highest specificity (53.6%, 95% CI 48.2% to 58.9%). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs.ConclusionsAutomated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective.Future workThere are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored.FundingThe National Institute for Health Research Health Technology Assessment programme.

U2 - 10.3310/hta20080

DO - 10.3310/hta20080

M3 - Article

VL - 20

JO - Health Technology Assessment

JF - Health Technology Assessment

SN - 1366-5278

IS - 8

ER -