Diabetic Retinopathy Screening in Scotland

Roderick Harvey

DRS Lead Clinician

Population 5,144,200

The national programme

White paper 2000

Commitment to develop a Scottish Diabetes Framework

“The framework will include plans to establish a national screening strategy for diabetic retinopathy”

HTBS Report 2002

Aim – detection of sight threatening diabetic retinopathy

Screening modalities Primary - digital retinal

photography Secondary - slit lamp

biomicroscopy

Benefits of photographic screening

High sensitivity and specificity for sight threatening disease

Ease of image acquisition, storage and transmission

The opportunity for quality assurance through double reading

Cost effectiveness

Publications

NHS QIS DRS Standards

Screening delivered to a defined specification

80% of eligible people screened per year

100% of eligible people invited per year

Call & recall in place using national software

Arrangements for hard to reach groups

Staff trained and qualified (or under supervision)

Quality assurance is in place

Special features

Single field macular centred image

Mydriasis only if initial image of inadequate quality

Grading

Feature based

Software calculates final grade according to grading algorithm

Outcome determined automatically

All graders perform full grading Level 1 final grade normals only Level 2 final grade non referrable Level 3 final grade all referrable

Outcomes

Re screen 12 months R0 or R1

M0

Re screen 6 months R2 or M1

Refer ophthalmology R3 or above, or M2

Non diabetic lesions

Technical failure R6 – inadequate image

Quality assurance

All L1 & L2 graders have 500 image pairs per year regraded randomly by L3 grader

External QA of images under development 1st round of pilot completed 2008

External QA of programmes Standardised annual report template National Key Performance Indicators

Training & Accreditation

City & guilds Level 3 Certificate in Diabetic Retinopathy Screening

140 people in Scotland registered

110 modules passed

Slit lamp examiner standards and accreditation process defined

The Scottish National DRS Programme

Responsibility for screening lies with the fourteen individual Health Boards

Within each Board the programme is delivered to common standards defined by

NHS QIS standards on DRS Policies developed by the DRS Collaborative Constraints embedded in the national DRS software

National software for photography, administration and grading

SGHD

SDG

NSD

ExecutiveGroup

DRS IT BoardPFIG

ClinicalGroup

ServiceManagement

As required

BoardCo-ordinators

IT UsersGroup

Short-life groups

SCI-DC

NSD IT Board

The Board Programmes are all members of a formal DRS Collaborative

Implications of franchise model

Adherence to national standards

Sharing of a national database of eligible patients

Ability to tailor the details of the delivery of the screening programme to suit local needs Fixed site photography Mobile units Image capture through optometrists

Eligible population

All people resident in Scotland with confirmed diabetes

Aged 12 years or older

Not under the care of an ophthalmologist for treatment of diabetic retinopathy

Not suspended for a valid clinical or organisational reason (excludes temporarily unavailable)

SuspensionsSuspension Reason Suspension

TypeWho suspends and can unsuspend

Informed choice to opt out Temporary GP

Under Age Temporary System

Total Loss of Vision Permanent GP as advised by Ophthalmologist

Terminal Illness Temporary GP

Disabilities:Learning, Mental or Physical

Temporary orPermanent

GP

Under the care of an Ophthalmologist Temporary Retinal Screening Administrator as advised by Ophthalmologist

Temporarily Unavailable Temporary GP or Retinal Screening Administrator

Deceased TemporaryPermanent

GPSystem

Not Diabetic Permanent GP or other HCP

Not Permanently Resident in Scotland Permanent System

How is it all put together

Maintenace of the eligible population

Recording of diabetes in a primary care system automatically registers the patient for DRS

Dynamic link with SCI-DC and the CHI ensures that the population is accurately maintained

Registration can also be done directly through SCI-DC or Soarian

Suspensions are managed through SCI-DC and Soarian

Consortia server

CHI

SCI-DCGPASSVision

EMISXML Messages

Staging Server

Soarian

Mobile Admin Fixed

SCI-DC

Soarian

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How are we doing

DRS Population Scotland Over 12 years

0

10000

20000

30000

40000

50000

60000

70000

12 to 14 15 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 to 74 75 to 84 85 plus

Age

Nu

mb

er TS

PS

EP

Total living diabetic population 239,495

Eligible population 204,817

Annual DRS Screening Uptake Scotland

0

20

40

60

80

100

12 to 14 15 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 to 74 75 to 84 85 plus

Age

Pe

rce

nt Invited %

Attended %

Screened %

Invitation rate 93.2%

Attendance rate 77.0%

Successful screening rate 73.7%

Overall Referable 3.5%

Observable 1.9%

Tech failure 7.6%

DRS Scotland Screening Outcome

0

5

10

15

20

25

30

12 to 14 15 to 24 25 to 34 35 to 44 45 to 54 55 to 64 65 to 74 75 to 84 85 plus

Age

Pe

rce

nt % Referrable

% Observable

% Tech failure

Challenges

Slit lamp examination

About 8% of patients require slit lamp examination

Training & accreditation requirements defined

Difficulty for small and dispersed boards in meeting the requirements

Optometry

Most optometrists now have digital retinal cameras

Photography is part of GOS contract for over 60s

Opportunities for synergy and image capture by optometrists

Challenges of integration with board wide screening programmes without compromise of quality standards on grading

Framework for optometry image capture is being piloted in two health board regions

Ophthalmlogy

Closing the loop

Capturing outcome of ophthalmology consultations

Ensuring appropriate suspension of patients under the care of ophthalmology

Failsafe to track ophthalmology referrals

Capacity

Quality assurance

Need for more robust analysis of internal QA performance across all health boards

Need to establish regular external QA image sets and define reporting formats

FutureAutomated Grading

Start

Image of adequate quality?

Microaneurysms present?

Final Grade R0 M0

Refer to Level 2 Manual Grader

Yes

Yes

No

No

Automated Grading

6732 patients using gold standard grading for actionable retinopathy Automated grading 97.9% Routine manual 99.1%

33,535 patients from the Scottish DRS service the performance of automated grading for actionable retinopathy was Sensitivity 99.1% Specificity 59%

Automated grading DRS Collaborative commissioned an

independent review of the performance of automated lesion detection software

Four patients from 33535 (0.012%) may have missed clinically relevant maculopathy

Cost to detect these patients in Scotland £275,000 pa

Conclusion that it should be used for DRS programme in Scotland

Thank you for you attention