‘Add-on’ tests: a national audit
of current practice
John Monaghan
Royal Derby Hospital & Chesterfield
Royal Hospital
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Reflective testing
• Adding on tests to help
–
–
–
–
Establish diagnosis
Assist patient management
Reduce time to diagnosis
Reduce cost in repeating sampling
• Based on Clinical judgement
• Ethics
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Guidance – General medical
council
GMC. Consent: Patients and Doctors Making Decisions
Together, 2008 statement
* Note for pathologists and radiologists: there may be times
when uncertainty about a diagnosis can only be resolved by
investigations which were not specifically ordered as part of
the original request for testing. If these investigations
appear to fall outside the scope of the original consent
given by the patient, or there are particular sensitivities
around the condition for which the pathologist or radiologist
wishes to test, they must contact the treating doctor and
establish whether further discussion with,and consent from,
the patient is necessary before proceeding.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Guidance – Royal Collage of
Pathologist
Guidance on consent for the processing and analysis of clinical
samples following an initial consultation November 2008
4.2 If the investigation is to be extended beyond the list of tests that have
been specifically discussed, then those responsible must satisfy
themselves that either:
• the course of action lies within the overall nature of the problem, or
• the information revealed by the results available requires immediate
further investigation because of the clinical importance of the
situation and obtaining further explicit consent from the patient is
impractical, and
• the investigation is in the best interests of the patient.
4.3 Patients have the right to exclude the performance of specific tests.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Published Evidence
• Paterson JR et al (2004) – Clinical
effectiveness
• Srivastava R et al (2010) - Clinical
effectiveness
• Darby D et al (2006) – User questionaire
• Menlowe M et al (2010) - Guidance
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Trent audit group
• Audited with questions based on work
published by Darby et al
• Audit 2008, re-audited Jan 2010
Tests added at
authorising
Hormone
General Chemistry
Troponin
National Audit Meeting – Add-on tests 24/09/10
Results commented
with suggested test
Tumour markers
Genetic test
Pregnancy test
Derby Hospitals
NHS Foundation Trust
Audit Responses
In which field is your main area of work
conducted in?
100
Clinical
Biochemistry
344 responses
80
%
60
40
Clinical
Immunology
20
Clinical
Microbiology
Other (please
specify)
0
To which emplyment category do you feel you fall
in to?
100
Clinical Biochemistry &
Immunology
%
80
60
40
20
0
Medics
Scientists
Technical staff
Other (please
specify)
National Audit Meeting – Add-on tests 24/09/10
77 medical staff
217 Scientist
2 Technical
Derby Hospitals
NHS Foundation Trust
Answers
• A – Add-on Test
• B – Discuss with requesting clinician before adding on
the test
• C – Add a comment about suggesting the test
• D – Comment on results without suggesting further
testing
• E – Take no further action
• F – Other (please specify). This includes automated or
reflex testing.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 1
35-year-old female with fatigue. No previous
results.
• Free T4 – 26.0 pmol/L (RR 10-24 pmol/L)
• TSH - <0.05 miu/L (RR 0.35-5.5 miu/L)
When considering hyperthyroidism would you
add on a Free T3?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 1 - Responses
Other comments : Reflex tested, add on Total T3, local
audit showed no extra information
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 2
23-year-old female with Amenorrhoea.
Gonadotrophins and hormones were normal over the
previous 12 months but no clinical details.
No urine or serum pregnancy test had been carried out.
• LH - <0.5 IU/L
• FSH - <0.5 IU/L
Would you add on serum HCG?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 2 - Responses
Other comments : Add on TFTs, E2, Prolactin.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 3
21-year-old male. Request form gives the
clinical details as erectile dysfunction. No
previous results.
Testosterone – 7 nmol/L (RR 10-34 nmol/L)
Would you add on LH/FSH to determine if this
Is primary or secondary hypogonadism?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 3 responses
Other comments : Add SHBG, TFTs, Prolactin, repeat in
am. Suggest endocrine referral.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 4
84-year-old female. Request form gives Clinical details
as “TATT”.
Thyroid function tests had been measured 12 months
before and TSH was within the reference range. No other
tests were done.
Free T4 – 8.0 pmol/L (RR 10-24 pmol/L)
TSH – 0.35 miu/L (RR 0.35-5.5 miu/L)
Would you add on further pituitary hormones to
confirm hypopituitarism?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 4 - Responses
Other comments : Discussion of poor fT4 assays. Discuss
?clinically hypopit. Add T3 to check for T3-treatment.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 5
54-year-old male with no clinical details
on the form nor any previous results.
Request was for a U&E but the sample
was noted to be lipaemic.
Would you add on triglycerides/lipids?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 5 - Responses
Other comments : Several laboratories reflex this test. One
lab used to reflex but had a complaint from a patient.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 6
68-year-old male with clinical details on the form as
“anaemia”. No previous results for several years.
Bilirubin – 19 μmol/L (RR range <20 μmol/L)
Alkaline phosphatase – 158 IU/L (RR 56 – 119 IU/L)
ALT – 40 IU/L (RR <40 IU/L)
Total protein – 106 g/L (RR 60 – 80 g/L)
Albumin – 40 g/L (RR 35 – 50 g/L)
Globulin – 66 g/L
Would you add on electrophoresis and/or immunoglobulins?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 6 - Responses
Other comments : Not all labs do total protein/Globulins on
profiles. Some would use CRP before deciding on adding
on globs.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 7
56-year-old female with no clinical details. Previous results showed
a steadily increasing ALP.
Bilirubin – 18 μmol/L (RR <20 μmol/L)
Alkaline phosphatase – 203 IU/L (RR 53 – 141 IU/L)
ALT – 32 IU/L (RR <40 IU/L)
Total protein – 78 g/L (RR 60 – 80 g/L)
Albumin – 42 g/L (RR 35 – 50 g/L)
Globulin – 26 g/L
If this is not on your routine profile of requests would you add on
serum gamma glutamyl-transferase to help determine origin of
raised ALP?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 7 - Responses
Others comments: GGT part of profile, some prefer to do
ALP-isoenzyme electrophoresis as next line of
investigation.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 8
78-year-old male, clinical details “Bone pain”. Previous results
showed a steadily increasing ALP but with glutamyltransferase
within the reference range.
25-OH Vitamin D had been analysed recently and
suggested adequate intake.
Bilirubin – 20 μmol/L (RR <20 μmol/L)
Alkaline phosphatase – 548 IU/L (RR 56 – 119 IU/L)
ALT – 32 IU/L (RR <40 IU/L)
Total protein – 79 g/L (RR 60 – 80 g/L)
Albumin – 40 g/L (RR 35 – 50 g/L)
Globulin – 39 g/L
Would you add on PSA to check for prostate cancer?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 8 - Responses
Other comments : Several would check calcium & PTH,
many would want to discuss to exclude Pagets. One
respondent suggested other malignancies.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 9
GP patient, 42-year-old male has clinical details
“Chest Pain”. No previous results. Sample
arrived in the lab the same day as being taken.
Request form asked for CK.
Creatinine Kinase – 560 IU/L (RR 10-200 IU/L)
Would you add on troponin?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 9 - Responses
Other comments (Medics): Phone GP to discuss.
Other comments (Scientist): Phone GP. Add AST/LDH,
some sites do not offer to primary care, Troponin carried
out before CK with those clinical details.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 10
45-year-old female with clinical details
Borderline TFTs”. Previous results 6 and 12
months earlier were similar to those shown
below.
Free T4 – 12.0 pmol/L (RR 10-24 pmol/L)
TSH – 9.0 miu/L (RR 0.35-5.5 miu/L)
Would you add on anti-thyroid peroxisomal antibodies?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 10 - Responses
Other comments : Refer to regional guidelines. Contrasting
views on use/misuse of TPO antibodies
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 11
50-year-old male with previously
deranged LFTs. U&E and full blood
count gave all results within reference
ranges. Ferritin was requested.
Ferritin – 981 μg/L (RR 10 – 290)
Would you add on a transferrin saturation or
TIBC (form indicates this is a fasting sample)?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 11 - Responses
Other comments : Ferritin authorised by Haematology
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 12
The GP sends a further fasting sample two
weeks later with the following results:
Iron – 37 μmol/L (RR 12-25)
Transferrin – 24.4 μmol/L
Transferrin Saturation - 76% (RR 20-45)
If the appropriate sample type was available
would you add on HFE genotyping?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 12 - Responses
Other comments : Refer to Haemochromatosis specialist,
need to obtain consent.
Tests not carried out in Biochemistry.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 13
40-year-old male with clinical details “Liver disease”.
Electrophoresis showed significantly decreased
alpha-1 proteins.
Would you add on alpha-1-antitrypsin/phenotyping?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 13 - Responses
Other comments : Many comments would add-on A1AT to
determine activity as first line.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 14
18 year old female with clinical details “Diarrhoea”. No previous
results.
Alkaline phosphatase – 65 IU/L (RR 35 – 104 IU/L)
Calcium – 2.01 mmol/L (RR 2.20-2.60 mmol/L)
Adjusted calcium - 2.07 mmol/L (RR 2.20-2.60 mmol/L)
Phosphate – 0.80 mmol/L (RR 0.70 – 1.40 mmol/L)
Total protein – 70 g/L (RR 60 – 80 g/L)
Albumin – 37 g/L (RR 35 – 50 g/L)
Globulin – 33 g/L
Would you add on magnesium?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 14 - Responses
Other comments : Add potassium, reflex testing for
magnesium. Add PTH.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 15
50 year old male with clinical details “Anaemia”.
Full blood count results showed patient has a
macrocytic anaemia.
Vitamin B12 – 167 ng/L (RR >190 ng/L)
Serum Folate – 12 ng/ml (RR >2.5 ng/ml)
Ferritin – 78 μg/L (RR 20 to 320 μg/L)
Would you add on intrinsic factor antibodies?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 15 - Responses
Other comments : Suggest anti-TTG, parietal cell
antibodies, Methylmalonic acid investigation. Results
authorised by haematology.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 16
18 year old male with clinical details “New
diabetic”.
HbA1c analysis shows patient has a
haemoglobin variant.
Would you add on haemoglobin variant
electrophoresis?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Question 16 - Responses
Other comments : Lots of comments.
Depends if variant interferes with HbA1c peak. Sample
referred for assay which gives accurate result. Refer to
Haematology consultant. Carry out fructosamine.
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Choices affected by additional cost
to requestor
Choices affected by additional cost to requestor
120
100
%
80
No
60
Yes
40
20
0
Medic
Scientist
Trent
Comments : Most responses state GP on block contract.
Cost not seen by requestor. Genetic tests considered very
expensive so these limited
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Are any of the above scenarios
formally covered in a written SOP or
authorising guidelines?
Scenarios covered in written SOPs
70
60
%
50
40
No
30
Yes
20
10
0
Medic
Scientist
Trent
Most laboratories had 3-4 protocols. One had 8 protocols
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Summary
• Hormone and general chemistry testing added on if
useful to answer question
• Tumour marker PSA is not added on but commented,
myeloma screening is added on
• Genetic testing HFE, Hb variant is not generally
added on but alpha-1 anti-trypsin is
• Difficult to determine processes in cross-discipline
tests e.g. IFA, Ferritin, TIBC
• Most respondents comment if test is not added on
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
No responses
Those in clinical biochemistry field that didn’t comment were
consistent.
15% medics and 25% of scientist. Why?
•
•
•
•
No enough time to fill out audit?
Not normal practice to comment?
Test not authorised by individual?
Inexperience?
• ‘E’ responders were not consistent
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
What next?
•
•
•
•
Publish
Raise awareness
Ask GPs what they want
Should there be a box for GP to stop
reflex of any test?
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
Acknowledgements
• Dr Adam Gerrard, Birmingham Children’s
Hospital
• Dr Paul Masters, Chesterfield Royal
Hospital
• Professor Eric Kilpatrick, Hull Royal
Infirmary
• National audit group
• Trent Health Chemical Pathology Panel
and Audit Group
• Mr Mike Lester, ACB
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust
References
• Paterson JR et al. Reflective testing: how useful is the practice
of adding on tests by laboratory clinicians. J Clin Pathol. 2004,
57 : 273-275
• Darby D et al. Reflective testsing – what do our service users
think? Ann Clin Biochem 2006, 43, 361-368
• GMC Consent: patients and doctors making decisions together.
2008
• RCPath Guidance on consent for the processing and analysis of
clinical samples following an initial consultation. 2nd edn. 2008
• Menlowe M. Guidance on consent for the processing and
analysis of clinical samples following an initial consultation.
Buttetin of the royal college of pathologist 2010, 149, 57-58
• Srivastava R et al Reflex and reflective testing: efficiency and
effectiveness of adding on laboratory tests Ann Clin Biochem
2010,47,223-227
National Audit Meeting – Add-on tests 24/09/10
Derby Hospitals
NHS Foundation Trust