Diagnosis of Helicobacter pylori after triple therapy in uncomplicated duodenal ulcers--a cost-effectiveness analysis

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

ACG Clinical Guideline: Treatment of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) infection is a common worldwide infection that is an important cause of peptic ulcer disease and gastric cancer. H. pylori may also have a role in uninvestigated and functional dyspepsia, ulcer risk in patients taking low-dose aspirin or starting therapy with a non-steroidal anti-inflammatory medication, unexplained iron deficiency anemia, and idiopathic thrombocytopenic purpura. While choosing a treatment regimen for H. pylori, patients should be asked about previous antibiotic exposure and this information should be incorporated into the decision-making process. For first-line treatment, clarithromycin triple therapy should be confined to patients with no previous history of macrolide exposure who reside in areas where clarithromycin resistance amongst H. pylori isolates is known to be low. Most patients will be better served by first-line treatment with bismuth quadruple therapy or concomitant therapy consisting of a PPI, clarithromycin, amoxicillin, and metronidazole. When first-line therapy fails, a salvage regimen should avoid antibiotics that were previously used. If a patient received a first-line treatment containing clarithromycin, bismuth quadruple therapy or levofloxacin salvage regimens are the preferred treatment options. If a patient received first-line bismuth quadruple therapy, clarithromycin or levofloxacin-containing salvage regimens are the preferred treatment options. Details regarding the drugs, doses and durations of the recommended and suggested first-line and salvage regimens can be found in the guideline.

Long-term follow-up of 1,000 patients cured of Helicobacter pylori infection following an episode of peptic ulcer bleeding

OBJECTIVES

To evaluate the effect of Helicobacter pylori (H. pylori) eradication on ulcer bleeding recurrence in a prospective, long-term study including 1,000 patients.

METHODS

Patients with peptic ulcer bleeding were prospectively included. Prior non-steroidal anti-inflammatory drug (NSAID) use was not considered exclusion criteria. H. pylori infection was confirmed by rapid urease test, histology, or (13)C-urea breath test. Several eradication therapies were used. Subsequently, ranitidine 150 mg o.d. was administered until eradication was confirmed by (13)C-urea breath test 8 weeks after completing therapy. Patients with therapy failure received a second, third, or fourth course of eradication therapy. Patients with eradication success did not receive maintenance anti-ulcer therapy and were controlled yearly with a repeat breath test. NSAID use was not permitted during follow-up.

RESULTS

Thousand patients were followed up for at least 12 months, with a total of 3,253 patient-years of follow-up. Mean age 56 years, 75% males, 41% previous NSAID users. In all, 69% had duodenal ulcer, 27% gastric ulcer, and 4% pyloric ulcer. Recurrence of bleeding was demonstrated in three patients at 1 year (which occurred after NSAID use in two cases, and after H. pylori reinfection in another one), and in two more patients at 2 years (one after NSAID use and another after H. pylori reinfection). The cumulative incidence of rebleeding was 0.5% (95% confidence interval, 0.16-1.16%), and the incidence rate of rebleeding was 0.15% (0.05-0.36%) per patient-year of follow up.

CONCLUSION

Peptic ulcer rebleeding virtually does not occur in patients with complicated ulcers after H. pylori eradication. Maintenance anti-ulcer (antisecretory) therapy is not necessary if eradication is achieved. However, NSAID intake or H. pylori reinfection may exceptionally cause rebleeding in H. pylori-eradicated patients.

Transferability indices for health economic evaluations: methods and applications

In this paper, we have elaborated an index in two phases to measure the degree of transferability of the results of the economic evaluation of health technologies. In the first phase, we have considered the objective factors (critical and non-critical) to derive a general transferability index, which can be used to measure this internal property of the studies of economic evaluation applied to health technologies. In the second phase, with a more specific index, we have measured the degree of applicability of the results of a given study to a different setting. Both indices have been combined (arithmetic and geometric mean) to obtain a global transferability index. We have applied the global index to a sample of 27 Spanish studies on infectious diseases. We have obtained an average value for the index of 0.54, quite far from the maximum theoretical value of 1. We also found that 11 studies lacked some critical factor and were directly deemed as not transferable.

Comparison of two management strategies for Helicobacter pylori treatment: clinical study and cost-effectiveness analysis

BACKGROUND

First-line proton pump inhibitor-based triple and quadruple therapies for Helicobacter pylori eradication present similar levels of efficacy. Cross-over treatment (quadruple following triple failure, and triple following quadruple failure) seems the most sensible approach to treatment failures, but the two strategies -'quadruple first' versus 'triple first'- have not been previously compared. The aims of our study were to assess the usefulness and the cost-effectiveness of the two treatment strategies.

MATERIAL AND METHODS

Forty-nine out of 344 patients included in a previous study comparing triple therapy - 7 days of omeprazole, amoxicillin and clarithromycin twice a day - with quadruple therapy - 7 days of omeprazole twice a day, plus tetracycline, metronidazole and bismuth subcitrate three times a day - failed initial treatment and were assigned to cross-over therapy. Cure was determined by urea breath test. A decision analysis was performed to compare the two eradication strategies.

RESULTS

Intention to treat cure rates were 46% (10/22 patients; 95% CI 24-68%) for second-line triple therapy and 63% (17/27 patients; 95% CI 42-81%) for second-line quadruple therapy. Per protocol cure rates were 71% and 85%, respectively. Intention to treat cure rates were 87% (95% CI 81-92%) for the 'triple first' versus 86% (95% CI 80-91%) for the 'quadruple first' strategy (p = .87). The 'quadruple first' strategy was more cost-effective. The incremental cost of 'triple first' strategy per person was 19 in the low-cost area and 65 US dollars in the high-cost area.

CONCLUSIONS

The effectiveness of 'triple first' and 'quadruple first' strategies is similar, although the latter seems slightly more cost-effective.

[Management of dyspepsia, gastroduodenal ulcer and Helicobacter pylori infection in primary care]

OBJECTIVE

To evaluate management of dyspepsia, gastroduodenal ulcer and Helicobacter pylori infection in the setting of family practice.

DESIGN

An observational transversal study was performed. An anonymous questionnaire was send by mail between January and October 2000.

SETTING

Primary care.

PARTICIPANTS

Physicians of 17 Primary Care centers.

RESULTS

Sixty-four per cent of the physicians returned the answered questionnaire (107/165). Primary care doctors reported they had indicated eradication therapy at least once during last year in 94.3%; 89.7% usually indicate H. pylori eradication for duodenal ulcer and 70.1% for gastric ulcer. The main method for the study of dyspepsia was endoscopy associated with antral histology or rapid urease test for determination of H. pylori status. Omeprazole, clarithromycin and amoxicillin twice daily for seven days was the preferred eradication therapy (77.6%). Forty-five percent of physicians systematically tested patients to confirm cure of the infection; 36.4% tested patients only if symptoms relapsed. Breath test (72.7%) was the preferred method to confirm eradication. Physicians with postgraduate specialty in Family Care and Community Medicine (MFyC) demand less often gastroenterologist evaluation, indicate less frequently upper tract radiology, use more often C13 urea breath test for diagnosis and indicate more often eradication treatment for erosive duodenitis than unspecialised family doctors.

CONCLUSIONS

Management of dyspepsia and H. pylori infection in Primary Care in our area is reasonably adapted to current consensus recommendations. Many differences in management were observed between MFyC and non-specialised primary care physicians.

What is the optimal length of proton pump inhibitor-based triple therapies for H. pylori? A cost-effectiveness analysis

BACKGROUND

Triple therapy with a proton pump inhibitor, clarithromycin and amoxicillin is widely used for H. pylori infection. The appropriate length of treatment remains controversial.

AIM

To determine whether length of treatment has an impact on the cost-effectiveness of triple therapy.

METHODS

The study took the form of a cost-effectiveness analysis spanning 2 years. The perspective was societal and the setting, ambulatory care. Subjects were Helicobacter pylori-positive patients with a duodenal ulcer. The triple therapy trials spanned 7, 10 or 14 days and the main outcome measures were cost per patient and marginal cost for additional cured patient calculated for a low cost-of-care setting (Spain), for a high-cost setting (USA), and for two follow-up strategies: (i) systematic 13C-urea breath test after eradication; (ii) clinical follow-up, breath-test if symptoms recurred.

RESULTS

Base-case analysis showed that for both the 13C-UBT and the clinical follow-up branches, lowest costs were obtained with 7-day schedules both in Spain and the USA. Sensitivity analysis showed that in Spain, 10-day therapies would have to increase 7-day cure rates by 10-12% to become cost-effective. In contrast, in the USA only a 3-5% increase was needed. The corresponding figures for 14-day therapy were 25-35% and 8-11%, respectively.

CONCLUSIONS

Seven-day therapies seem the most cost-effective strategy. However, in high-cost areas the differences were less evident.