DISEASE BURDEN

Epidemiology

H. pylori is also believed to play a role in peptic ulcer disease. This speculation came about after the organism was found to be present more frequently in idiopathic peptic ulcer disease than in age-matched controls. Furthermore, H. pylori has been associated with duodenal ulcers. Chronic superficial gastritis may progress to chronic gastric atrophy with the possible risk of gastric adenocarcinoma. Therefore, H. pylori can be considered a risk factor for gastric cancer.

For the purposes of the calculations in this report, the committee estimated that there are approximately 1,240,000 new infections of Helicobacter pylori (H. pylori) each year in the United States. The incidence rate is highest in people between the ages of 1 and 24 years of age; it was assumed that there are no new infections after 44 years of age. It was assumed that there are approximately 14,500 deaths annually due to H. pylori infection. Most of these deaths occur in people 65 years of age or older. See Table A7–1.

Table A7–1

Incidence and Mortality Rates of H. pylori Infection.

Disease Scenarios

For the purposes of the calculation in this report, the committee assumed that there are acute and chronic manifestations of H. pylori infection (see Table A7–2). Some of the chronic manifestations last for decades; others manifest for much shorter periods of time. It was assumed that 30% of people infected with H. pylori experience a week of acute gastritis. Half of those people go on to experience recurrent attacks of gastritis (approximately 2 days per month) for the lifetime of the person with no other complications. The health utility index (HUI) associated with gastritis was estimated to be .74. It was assumed that approximately 10% of infections are associated with approximately 30 years of recurrent gastritis, followed by peptic ulcer disease.

Table A7–2

Disease Scenarios for H. pylori Infection.

It was assumed that there is a 30-year latency between time of infection and acute peptic ulcer disease; half of the people with acute peptic ulcer disease experience chronic peptic ulcer disease for the duration of their lives.

It was further assumed that a small proportion (1.5%) of infected people develop cancer secondary to the H. pylori infection and that the cancers are diagnosed around age 70 and that these people die within a year. HUI states associated with these latent conditions range from .40 for acute complications of peptic ulcer disease to .74 for recurrences of chronic, mild peptic ulcer disease, to .82 for the average state during the year of life from diagnosis of cancers to death.

COST INCURRED BY DISEASE

Table A7–3 summarizes the health care costs incurred by H. pylori infections. For the purposes of the calculations in this report, it was assumed that 100% of people experiencing gastritis incur costs for inexpensive over-the-counter medication, but that only 10% incur costs for a limited visit to a physician. It was assumed that 5% of patients with gastritis visit a specialist. For recurrent disease, it was assumed that costs incurred include 1 visit to a physician per year and 6 purchases of over-the-counter medication per year for lifetime or until a diagnosis of peptic ulcer disease is made.

Table A7–3

Health Care Costs Associated with H. pylori Infections.

It was assumed that all patients with acute peptic ulcer disease (PUD) incur costs associated with over-the-counter medications, a limited visit to a physician, and two visits to a specialist. It was assumed that half these patients receive a relatively expensive diagnostic procedure. It was assumed that 25% of patients receive ambulatory surgery for these symptoms, and that 75% of acute PUD patients receive expensive prescription medications. Similar patterns and costs of care were assumed for the patients with chronic, mild peptic ulcer disease (each year for the remainder of life). The patients who experience serious complications of PUD incur costs for hospitalization and follow-up.

It was assumed that all patients with gastric adenocarcinomas and lymphomas receive extensive care during the year of life from diagnosis to death. Costs included in the analysis are multiple visits to a general physician and a specialist, expensive diagnostics, and one hospitalization.

The annualized present value of the cost of care averted by a vaccine strategy (with the program assumptions described below) is approximately $70,000,000.

VACCINE DEVELOPMENT

The committee assumed that will take 7 years until licensure and that $240 million needs to be invested. Table 4–1 summarized vaccine development estimates for all candidates considered in this report.

VACCINE PROGRAM CONSIDERATIONS

RESULTS

If a vaccine program for H. pylori were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the QALYs gained would be 90,000. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the QALYs gained would be 14,000. The majority of these lost QALYs are associated with gastritis, because of the large number of cases.

If a vaccine program for H. pylori were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the health care costs saved would be $430 million. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the health care costs saved would be $67.3 million.

If a vaccine program for H. pylori were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the program cost would be $720 million. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the program cost would be $150 million.

Using committee assumptions of time and costs until licensure, the fixed cost of vaccine development has been amortized and is $7.2 million for a H. pylori vaccine.

If a vaccine program were implemented today and the vaccine were 100% efficacious and utilized by 100% of the target population, the annualized present value of the cost per QALY gained is $3,300, Using committee assumptions of less-than-ideal utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the cost per QALY gained is $6,500.

See Chapters 4 and 5 for details on the methods and assumptions used by the committee for the results reported.

READING LIST

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• Dubois A. Spiral Bacteria in the Human Stomach: The Gastric Helicobacters. Emerging Infectious Diseases 1995; (1)3:79–83. [PMC free article: PMC2626874] [PubMed: 8903168]
• Fendrick AM, Chernew ME, Hirth RA, et al. Alternative Management Strategies for Patients with Suspected Peptic Ulcer Disease. Annals of Internal Medicine 1995; 123:260–268. [PubMed: 7611591]
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• Ruiz-Palacios G, Pickering LK. Campylobacter and Helicobacter Infections. In: Textbook of Pediatric Infectious Diseases. RD Feigin, editor; and JD Cherry, editor. eds. Philadelphia, PA: WB Saunder Company, 1992, pp.1062–1067.
• Singh GK, Kochanek KD, MacDorman MF. Advance Report of Final Mortality Statistics, 1994. Monthly Vital Statistics Report 1996; 45.
• Sonnenberg A, Everhart JE. The Prevalence of Self-Reported Peptic Ulcer in the United States. American Journal of Public Health 1996; 86:200–5. [PMC free article: PMC1380328] [PubMed: 8633736]
• Staat MA, McQuillan GM. A Population-Based Serologic Survey of Helicobacter pylori Infection in Children and Adolescents in the United States. The Journal of Infectious Diseases 1996; 174:1120–1123. [PubMed: 8896521]

Footnotes

See Appendix 28 for more information.