Table 11Parameters used in Mein (2004) analysis and in the UK adaptation

ParameterMein (2004) basecase, (range)UK basecaseUK range for sensitivity analysis
Age35 (20–60)3520–60
Life-expectancy (IBS or diagnosed coeliac disease)42.8LYs45.7LYsN/A
Prevalence of coeliac disease3% (1–5%)3.3%, Saunders (2003)1%, general population prevalence, Saunders (2003)
IBS utility0.689 (0.6–0.9)0.675, Akehurst (2002)0.636, lower CI from Akehurst (2002)
Utility gain resulting from correct diagnosis of coeliac disease0.024 (0.01–0.04)None (conservative)Threshold analysis at £20,000 per QALY assuming no survival gain
Sensitivity of antibody test94% (87–97%) IgA TTG98% IgA EMA, Dretzke (2004)92%, lower 95% CI, Dretzke (2004)
Specificity of antibody test95% (87–98%) IgA TTG98% IgA EMA, Dretzke (2004)92%, lower 95%CI, Dretzke (2004)
Probability of EGD biopsy complication0.2% (0.05 – 0.5%)As for US modelN/A
Probability of death if complication5% (2–10%)As for US modelN/A
Cost of IBS care and coeliac care excluding GFD$450 ($225–$675)
(£196)*
£123, Akehurst (2002)
(£172)*
£221, upper 95%CI, Akehurst (2002)
(£307)*
Cost of antibody test$68 ($22–$136) IgA TTG (£30)**£10 IgA EMA, Dretzke (2004)
(£12)*
£11, upper 95% CI, Dretzke (2004)
(£14)*
Cost EGD with biopsy$800 ($300–$1800)
(£348)**
£463, Department of Health (2006)£767 upper limit, Department of Health (2006)
Cost of EGD with complication$5,700 ($2850–$11400), (£2482)**£597, Department of Health (2006)£1010 upper limit, Department of Health (2006)
Discount rate for costs and QALYs3%3.5%, NICE (2007)0% (undiscounted)
Survival difference between diagnosed and undiagnosedN/A0.54 (discounted) Calculated using lifetables and survival ratio from Corrao (2001)0.31 (discounted) Using upper limit of survival ratio from Corrao (2001)
Cost per annum of gluten-free foods on prescriptionN/A£162 Calculated from prescription data and lower estimate of pop prevalenceThreshold analysis at £20K per QALY
*

Uplifted to 05/06 prices using Hospital and Community Health Services Pay and Prices Index, Netten (2006)

**

Equivalent cost in UK£ converted from US$ using Health Care Purchasing Power Parity rates and uplifted to 05/06, OECD (2006)

From: 6, Diagnosis

Cover of Irritable Bowel Syndrome in Adults
Irritable Bowel Syndrome in Adults: Diagnosis and Management of Irritable Bowel Syndrome in Primary Care [Internet].
NICE Clinical Guidelines, No. 61.
National Collaborating Centre for Nursing and Supportive Care (UK).
Copyright © 2008, Royal College of Nursing.

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