Contents
Foreword
Preface
Reducing unwarranted variation in diagnostics services
Why does unwarranted variation matter?
Does unwarranted variation matter to patients?
What can we do about unwarranted variation?
Where can we find data on variation in the provision of diagnostic services?
Imaging services
Endoscopy services
Physiological diagnostic services
Pathology services
Genetic testing
Map and chart presentation
Selection of indicators
Order of appearance
Data sources
Classification
Standardisation
Confidence intervals
Statistical dispersion and the interquartile range
The use of estimated data for local areas
The use of categorical data
Exclusions
Domains in the NHS Outcomes Framework
Table S.1: Summary of indicators in the Diagnostic Services Atlas
Imaging services
1

Map 1: Rate of magnetic resonance imaging (MRI) activity per weighted population by PCT 2012/13
Map 2: Rate of computed axial tomography (CT) activity per weighted population by PCT 2012/13
Map 3: Rate of non-obstetric ultrasound activity per weighted population by PCT 2012/13
Map 4: Rate of positron emission tomography computed tomography (PET CT) activity from independent sector treatment centres per population by PCT 2011/12
Map 5: Rate of dual-energy X-ray absorptiometry (DEXA) activity per weighted population by PCT
2012/13
Map 6: Median time (minutes) from arrival at hospital to brain imaging for stroke patients by hospital Trust October-December 2012
Map 7: Proportion (%) of stroke patients undergoing brain imaging within 1 hour of arrival at hospital by hospital Trust October-December 2012
Map 8: Proportion (%) of stroke patients undergoing brain imaging within 24 hours of arrival at hospital by hospital Trust October-December 2012
Map 9: Median time (hours) to head computed axial tomography (CT) for patients admitted directly to hospital meeting NICE head injury guidelines by hospital 2012/13
Map 10: Median time (hours) to pelvic computed axial tomography (CT) for patients admitted directly to hospital with pelvic injury 2012/13
Map 11: Provision of endovascular aneurysm repair (EVAR) offered by interventional radiology services “within hours” by hospital Trust November 2012
Map 12A: Rate of endovascular aneurysm repair (EVAR) procedures for abdominal aortic aneurysm
(AAA) per population by PCT 2009/10-2011/12
Map 12B: Rate of endovascular aneurysm repair (EVAR) procedures for abdominal aortic aneurysm
(AAA) per population by CCG 2009/10-2011/12
Map 13A: Proportion of elective procedures for abdominal aortic aneurysm (AAA) that were EVAR by
PCT 2009/10-2011/12
Map 13B: Proportion of elective procedures for abdominal aortic aneurysm (AAA) that were EVAR by
CCG 2009/10-2011/12
Map 14: Provision of uterine fibroid embolisation procedures offered by interventional radiology services “within hours” by hospital Trust November 2012
Endoscopy services
Map 15A: Rate of colonoscopy procedures and flexible sigmoidoscopy procedures per population by
PCT 2011/12
2

Map 15B: Rate of colonoscopy procedures and flexible sigmoidoscopy procedures per population by
CCG 2011/12
Map 16: Rate of computed tomography (CT) colonoscopy procedures per population by PCT April-
November 2012
Map 17: Rate of activity for barium enema per weighted population by PCT April-November 2012
Map 18A: Rate of activity for gastroscopy (upper gastro-intestinal endoscopy) per population by PCT
2011/12
Map 18B: Rate of activity for gastroscopy (upper gastro-intestinal endoscopy) per population by CCG
2011/12
Map 19A: Proportion (%) of patients undergoing gastroscopy (upper gastro-intestinal endoscopy) procedures who are aged under 55 years by PCT 2011/12
Map 19B: Proportion (%) of patients undergoing gastroscopy (upper gastro-intestinal endoscopy) procedures who are aged under 55 years by CCG 2011/12
Map 20A: Rate of capsule endoscopy procedures per population by PCT 2011/12
Map 20B: Rate of capsule endoscopy procedures per population by CCG 2011/12
Map 21A: Rate of endoscopic ultrasound procedures per population by PCT 2011/12
Map 21B: Rate of endoscopic ultrasound procedures per population by CCG 2011/12
Map 22A: Admission rate for children for upper and/or lower gastro-intestinal endoscopy per population aged 0-17 years by PCT 2009/10-2011/12
Map 22B: Admission rate for children for upper and/or lower gastro-intestinal endoscopy per population aged 0-17 years by CCG 2009/10-2011/12
Physiological diagnostic services
Map 23: Rate of audiology assessments undertaken per weighted population by PCT 2012/13
Map 24: Mean time (days) from referral to assessment for hearing tests in newborns by PCT 2012
Map 25: Rate of sleep studies undertaken per weighted population by PCT 2012/13
Map 26: Percentage of patients with COPD with a record of FEV1 in the previous 15 months by PCT
(QOF COPD with exception-reported patients included) 2011/12
Map 27: Rate of urodynamic (pressures and flows) tests undertaken per weighted population by PCT
2012/13
Map 28: Rate of echocardiography activity undertaken per weighted population by PCT 2012/13
Map 29: Rate of invasive electrophysiology activity undertaken per weighted population by PCT
2012/13
3

Map 30: Rate of peripheral neurophysiology tests undertaken per weighted population by PCT
2012/13
Pathology services
Thyroid function tests
Map 31: Estimated annual rate of use for thyroid stimulating hormone (TSH) tests ordered by GPs per practice population by PCT 2012
Map 32: Estimated annual rate of use for free thyroxine [T4 (free); fT4] tests ordered by GPs per practice population by PCT 2012
Map 33: Estimated annual rate of use for free tri-iodothyronine [T3 (free); fT3] tests ordered by GPs per practice population by PCT 2012
Map 34: Estimated annual rate of use for free thyroid peroxisomal antibody (TPO Ab) tests ordered by GPs per practice population by PCT 2012
Tumour markers
Map 35: Estimated annual rate of use for carbohydrate antigen 125 (CA 125) tests ordered by GPs per practice population by PCT 2012
Map 36: Estimated annual rate of use for prostate-specific antigen (PSA) tests ordered by GPs per practice population by PCT 2012
Therapeutic drug monitoring
Map 37: Estimated annual rate of use for lithium tests ordered by GPs per practice population by
PCT 2012
Map 38: Estimated annual rate of use for carbamazepine tests ordered by GPs per practice population by PCT 2012
Map 39: Estimated annual rate of use for valproate tests ordered by GPs per practice population by
PCT 2012
Map 40: Estimated annual rate of use for digoxin tests ordered by GPs per practice population by
PCT 2012
Map 41: Estimated annual rate of use for phenytoin tests ordered by GPs per practice population by
PCT 2012
Diabetes
Map 42: Estimated annual rate of use for blood glucose (fasting) tests ordered by GPs per practice population by PCT 2012
Map 43: Estimated annual rate of use for blood glucose (2 hours post) tests ordered by GPs per practice population by PCT 2012
4

Map 44: Estimated annual rate of use for glycated haemoglobin (HbA1c) tests (IFCC) ordered by GPs per practice population by PCT 2012
Immunology
Map 45: Estimated annual rate of use for serum rheumatoid factor tests ordered by GPs per practice population by PCT 2012
Radio-allergosorbent test (RAST)
Map 46: Estimated annual rate of use for allergen-specific immunoglobulin E (IgE) assays (known as
RAST) ordered by GPs per practice population by PCT 2012
Cardiac disease
Map 47: Estimated annual rate of use for serum total cholesterol tests ordered by GPs per practice population by PCT 2012
Map 48: Estimated annual rate of use for triglyceride tests ordered by GPs per practice population by PCT 2012
Map 49: Estimated annual rate of use for high-density lipoprotein cholesterol (HDLC) tests ordered by GPs per practice population by PCT 2012
Map 50: Estimated annual rate of use for troponin tests ordered by GPs per practice population by
PCT 2012
Map 51: Estimated annual rate of use for brain natriuretic peptide (BNP or NTproBNP) tests ordered by GPs per practice population by PCT 2012
Haematological tests
Map 52: Estimated annual rate of use for haemoglobin tests ordered by GPs per practice population by PCT 2012
Map 53: Estimated annual rate of use for vitamin B12 tests ordered by GPs per practice population by PCT 2012
Map 54: Estimated annual rate of use for serum folate tests ordered by GPs per practice population by PCT 2012
Map 55: Estimated annual rate of use for red cell folate tests ordered by GPs per practice population by PCT 2012
Map 56: Estimated annual rate of use for ferritin tests ordered by GPs per practice population by
PCT 2012
Bone-related analyses
Map 57: Estimated annual rate of use for serum calcium tests ordered by GPs per practice population by PCT 2012
5

Map 58: Estimated annual rate of use for vitamin D tests ordered by GPs per practice population by
PCT 2012
Map 59: Estimated annual rate of use for parathyroid hormone (PTH) tests ordered by GPs per practice population by PCT 2012
Kidney disease
Map 60: Estimated annual rate of use of creatinine tests ordered by GPs per practice population by
PCT 2012
Map 61: Estimated annual rate of use of eGFR tests ordered by GPs per practice population by PCT
2012
Map 62: Estimated annual rate of use of urine protein-creatinine tests ordered by GPs per practice population by PCT 2012
Liver disease
Map 63: Estimated annual rate of use of alanine transferase (ALT) tests ordered by GPs per practice population by PCT 2012
Muscle disease
Map 64: Estimated annual rate of use of creatine kinase tests ordered by GPs per practice population by PCT 2012
Urate
Map 65: Estimated annual rate of use of urate tests ordered by GPs per practice population by PCT
2012
Proteinuria
Map 66: Estimated annual rate of use of albumin:creatinine ratio (ACR) tests ordered by GPs per practice population by PCT 2012
Inflammatory bowel disease
Map 67: Estimated annual rate of use of calprotectin tests ordered by GPs per practice population by
PCT 2012
Genetic testing
Map 68: Rate of overall genetic test reporting undertaken per population by NHS area team 2011/12
Map 69: Rate of breast cancer test reporting undertaken in women aged 15 years and over per population by NHS area team 2011/12
Glossary of Technical Terms relating to Diagnostic Services
Glossary of Essential Terms
6

Glossary of Organisations
Acknowledgements
7