Implementation of National Institute for Health and Care Excellence (NICE) guidance to measure immunoglobulin A with all coeliac screens: can an affordable solution be devised?

There has been a dramatic increase in requests for coeliac disease (CD) serological screening using immunoglobulin (Ig)A tissue transglutaminase antibodies (IgA-tTG). Recently, the UK National Institute for Health and Care Excellence has revised its guidance, recommending that total IgA should also be measured in all samples. This is justified, as false-negative results may occur with IgA deficiency. However, implementation of this guidance will incur considerable expense. Tests that measure IgA-tTG antibodies can detect IgA deficiency, indicated by low background signal. This provides an opportunity to identify samples containing IgA ≤ 0·2g/l, obviating the need for unselected IgA measurement. We investigated the feasibility of this approach in two centres that use the EliA™ Celikey™ assay or QUANTA Lite® enzyme-linked immunosorbent assay to quantify IgA-tTG antibodies. In both cases, total IgA correlated strongly with background IgA-tTG assay signal. Using the Celikey™ assay, a threshold of < 17·5 response units achieved 100% sensitivity (95% confidence intervals 79·4-100%) for detection of IgA ≤ 0·2g/l, circumventing the need for IgA testing in > 99% of sera. A similar principle was demonstrated for the QUANTA Lite® assay, whereby a threshold optical density of < 0·0265 also achieved 100% sensitivity (95% confidence intervals 78·2-100%) for IgA ≤ 0·2 g/l, avoiding unnecessary IgA testing in 67% of cases. These data suggest that CD screening tests can identify samples reliably containing low IgA in a real-life setting, obviating the need for blanket testing. However, this approach requires careful individualized validation, given the divergent efficiency with which assays identify samples containing low IgA.

Use of health care services and pharmaceutical agents in coeliac disease: a prospective nationwide study.

BACKGROUND: Approximately 1% of the population suffer from coeliac disease. However, the disease is heavily underdiagnosed. Unexplained symptoms may lead to incremented medical consultations and productivity losses. The aim here was to estimate the possible concealed burden of untreated coeliac disease and the effects of a gluten-free diet. METHODS: A nationwide cohort of 700 newly detected adult coeliac patients were prospectively evaluated. Health care service use and sickness absence from work during the year before diagnosis were compared with those in the general population; the data obtained from an earlier study. Additionally, the effect of one year on dietary treatment on the aforementioned parameters and on consumption of pharmaceutical agents was assessed. RESULTS: Untreated coeliac patients used primary health care services more frequently than the general population. On a gluten-free diet, visits to primary care decreased significantly from a mean 3.6 to 2.3. The consumption of medicines for dyspepsia (from 3.7 to 2.4 pills/month) and painkillers (6.8-5.5 pills/month) and the number of antibiotic courses (0.6-0.5 prescriptions/year) was reduced. There were no changes in hospitalizations, outpatient visits to secondary and tertiary care, use of other medical services, or sickness absence, but the consumption of nutritional supplements increased on treatment. CONCLUSIONS: Coeliac disease was associated with excessive health care service use and consumption of drugs before diagnosis. Dietary treatment resulted in a diminished burden to the health care system and lower use of on-demand medicines and antibiotic treatment. The results support an augmented diagnostic approach to reduce underdiagnosis of coeliac disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT01145287.

Cost effectiveness of mass screening for coeliac disease is determined by time-delay to diagnosis and quality of life on a gluten-free diet.

BACKGROUND: Coeliac disease is frequently diagnosed after a long delay resulting in increased morbidity and mortality. AIMS: To define the parameters which have the highest impact on the cost-effectiveness of mass screening for coeliac disease. METHODS: A Markov model examined a coeliac disease screening programme of the healthy young-adult general population compared with a no-screening strategy. The main outcome measures were quality adjusted life-years (QALYs) and incremental cost-effectiveness ratio (ICER). Effects of variables were examined using sensitivity analyses. RESULTS: The screening strategy resulted in a gain of 0.0027 QALYs. The ICER of screening vs. no-screening strategy was US$48,960/QALYs. The variables with the largest impact on cost effectiveness were: the time delay from symptom onset to diagnosis, the utility of adherence to a gluten-free diet (GFD) and the prevalence of coeliac disease. Screening would be cost-effective if the time delay to diagnosis is longer than 6 years and utility of GFD adherence is greater than 0.978. CONCLUSIONS: Our model suggests that mass screening for coeliac disease of the young-adult general population is associated with improved QALYs and is a cost effectiveness strategy. Shortening of the time-delay to diagnosis by heightened awareness of health-care professionals may be a valid alternative to screening.