Point of Care Testing in the Community
Maurice O’Kane Altnagelvin Hospital
Londonderry Western Health and Social Care Trust
The broadening scope of POCT
The broadening scope of POCT
• Primary care – non-acute • Primary care - acute • Community pharmacies • Patient charities • Ambulance service • Outreach projects • Patient self management • Private sector
Time
Ad
optio
n Adoption Process
Policy makers, funders
Professional body endorsement
Early adopters, opinion leaders
Scottish MDN Survey 2015
• Responses from 1031 POCT services, [615 in primary care]
• Estimated that ~ 2 million tests per year in primary care
Tests undertaken in primary care locations: glucose, urinalysis, INR urine h CG, blood gas, Drugs of abuse screening, D-dimer, Hb, Tn, urine mAlb, electrolytes, FBC
Survey of 1109 GPs For which conditions might POCT be most useful? • UTI for diagnosis • Pulmonary embolism for referral
reduction • INR for monitoring
More than half respondents use > 15 POCT tests weekly The top ten: • Glucose
• HbA1c • Urine pregnancy test • Urine dipstick • INR • Lipids • FBP • U&Es • Creatinine • FOB
J Am Board Fam Med 2016;29;371-376
This be the verse
‘They fill you with the faults they had
And add some extra just for you’ Philip Larkin 1922-1985 [with reference to parents and children Or Central lab testing and POCT…..]
Patient safety
‘To err is human: Building a Safer Health System’
Institute of Medicine 1999
Medical error – 98 000 deaths per year in US • Laboratory tests? • POCT?
• Home blood glucose testing devices > 3200 complaints filed with FDA ; 16 deaths
Plebani Clin Chim Acta 2009;404:59
• 15 outbreaks of HBV associated with improper use of blood glucose testing equipment 147 patients [6 deaths]
Thompson ND, Perz JF J Diab Sci Tech 2009;3: 283
Frequency of POCT error
• Little information available – difficult to investigate
• Central lab error rate 0.085 - 0.6%
• POCT error rate: 0 – 0.65%
Sources of Error
POCT 1 Central Lab 2
Pre-analytical 32 % 87.6%
Analytical 65.3% 11.1%
Post - analytical 2.7% 1.3%
1 Clin Chem 2011; 57:1267-71 2 Ann Clin Biochem 2008;45:129-134
Key questions in community POCT
• What is the clinical problem? [Testing must have clinical utility] • Is POCT the best option?
• How?
• Governance
CRP < 20mg/L: NPV 97.4% CRP >100mg/L: PPV 35.4% Specificity 90% If CRP : < 20mg/L - no antibiotic 20 – 100mg/L - defer antibiotic > 100mg/L - antibiotic
Anticoagulant monitoring
• 5%-10% of over 65y on anticoagulant
• Narrow therapeutic range
• Potential for patient self testing and dosing
How does this compare with usual care?
22 trials, 8413 patients of patient self testing [PST] alone or in conjunction with self–dose adjustment.
• ‘Compared with usual care, PST with or without PSM is associated with significantly fewer deaths and thromboembolic events ….. without increased risk for a serious bleeding event, for a highly selected group of motivated adult patients …’
Assessment of CVD risk [BP, lipids, glucose, weight, waist circumference] Mean Framingham CVD risk score fell from 13.1% to 12.3% at one year [p=0.01]
• Community NHS Health check • POCT allows for immediate feedback • CVD risk assessment by POCT [Cholestech LDX] v. central
lab testing
Barriers to community POCT uptake Huddy JR, et al. BMJ Open 2016;6:e009959. doi:10.1136/bmjopen-2015-009
Point-of-care C reactive protein for the diagnosis of lower respiratory tract infection in NHS primary care: a qualitative study of barriers and facilitators to adoption • Reimbursement model • Quality control and training • Laboratory support • Practitioner attitude
The challenges • Difficult testing environments • Governance • Patient pathway - whose responsibility? • Instrument selection • Training, competency assessment • Quality control , assurance • Connectivity with patient record
• ISO 22870:2016
Point-of-care testing (POCT) -- Requirements for quality and competence
• ISO 15189:2012 Medical laboratories – Requirements for quality and competence
• Laboratory support is essential in planning and delivering a safe and effective standard
Laboratory has a central role
• Laboratory must play a lead role in generating the evidence for clinical utility of POCT
Commissioning POCT services
• Planning the service • Instrument selection, verification • Staff training, competency assessment • Quality control / assurance • Trouble shooting • Service supervision • Evaluation of clinical utility Expensive
Analytical Performance
• POCT analytical performance should be appropriate to the clinical purpose
• The relevant comparator may be ‘no testing’
Better engineering
Individualised Quality Control Plan CLSI Paradigm
Of particular relevance to POCT: • Risk assessment –may differ between testing
environments
• Quality Control plan
• Quality assessment
37
Incorrect Test Result
1 Samples
2 Operator
3 Reagents
5Measuring
System
4Laboratory Environment
Sample Integrity
Sample Presentation
- Lipemia- Hemolysis- Interfering subtances- Clotting- Incorrect tube
- Bubbles- Inadequate volume
Operator Capacity
Operator staffing
Atmospheric Environment
Utility Environment
- Training- Competency
- Short staffing- Correct staffing
- Dust- Temperature- Humidity
- Electrical- Water quality- Pressure
Reagent Degradation- Shipping- Storage- Used past expiration- Preparation
Quality Control Material Degradation- Shipping- Storage- Used past expiration- Preparation
Calibrator Degradation- Shipping- Storage- Used past expiration- Preparation
Instrument Failure
Inadequate Instrument Maintenance
- Software failure- Optics drift- Electronic instability
- Dirty optics- Contamination- Scratches
Identify Potential Hazards
• Instrument evaluation • Training • EQA • Site visits • Case reports etc • Research programme
‘Noklus' quality policy Noklus endeavours to ensure that all laboratory analyses that are ordered, carried out and interpreted outside of hospital will safeguard the patients' needs for investigation, treatment and follow-up’