ESA Style Question

Mrs Cole, a 56 year old woman presents to her GP with a burning epigastric pain, for the previous two weeks. The pain is worse at night and is relieved with food. She has also had some nausea and vomiting. The GP suspects a peptic duodenal ulcer.

i) Define the term ulcerii) What is the most common cause of a duodenal ulcer

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i) An ulcer is a break in an epithelial lining

ii) H. pylori

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Mrs Cole, a 56 year old woman presents to her GP with a burning epigastric pain, for the previous two weeks. The pain is worse at night and is relieved with food. She has also had some nausea and vomiting. The GP suspects a peptic duodenal ulcer.

i) Define the term ulcerii) What is the most common cause of a duodenal ulcer

List three tests to confirm the presence of a H. pylori infection

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• Urea breath test• Serological test for IgG antibodies• Stool antibody test• Biopsy• Culture

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List three tests to confirm the presence of a H. pylori infecion

Describe the mechanism of acid secretion by parietal cells

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In the parietal cell, CO2 and H2O react to form H+ and HCO3- (1)

catalyzed by carbonic anhydrase (1). H+ is secreted into the lumen by a H+/K+-ATPase (1). HCO3

- moves out of the cell, across the basolateral membrane via antiport with Cl- (1). Cl- diffuses passively into the lumen via a Cl- channel (1).

Describe the mechanism of acid secretion by parietal cells

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A diagnosis of H. pylori infection is confirmed. The GP decides the best treatment option is H. pylori eradication therapy. In discussing treatment with Mrs Cole she tells you she is concerned about taking antibiotics as she has difficulty taking tablets.

List four reasons why it is important to take account of patients perspectives.

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• Patients have the right to be involved in their care• Patients should be treated as experts in their care• Aids diagnosis > better medical outcomes for the patient• Increases compliance• Greater patient satisfaction

A diagnosis of H. pylori infection is confirmed. The GP decides the best treatment option is H. pylori eradication therapy. In discussing treatment with Mrs Cole she tells you she is concerned about taking antibiotics as she has difficulty taking tablets.

List four reasons why it is important to take account of patients perspectives.

Max.Mark

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A cohort study was previously performed to determine if patients with previous peptic ulcer disease had an increased risk of developing stomach cancer. 500 patients were followed up for 5 years. 200 had previous peptic ulcer disease of which 60 developed stomach cancer. 300 had no previous peptic ulcer disease and 30 developed stomach cancer. Calculate the 95% confidence interval

A cohort study was previously performed to determine if patients with previous peptic ulcer disease had an increased risk of developing stomach cancer. 500 patients were followed up for 5 years. 200 had previous peptic ulcer disease of which 60 developed stomach cancer. 300 had no previous peptic ulcer disease and 30 developed stomach cnacer. Calculate the 95% confidence interval

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Exposed p-y = 200 x 5 = 1000 60 developed disease Non-exposed p-y = 300 x 5 = 1500 30 developed disease

Incidence rate (IR) IRe = 60/1000 = 60 per 1000 p-yIRn = 30/1500 = 15

per 1000 p-y

Incidence rate ratio (IRR) = 60/15 = 4

Error factor (EF) = 1.95

Confidence interval (CI) = (4÷1.95) – (4x1.95) = (2.05 – 7.8)

Are the results statistically significant. State the reason for your answer.

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Are the results statistically significant. State the reason for your answer.

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Stomach cancer is ~2 times more likely in people with a previous history of peptic ulcer disease. The CI covers the range 2.05 – 7.8 and excludes the null hypothesis (null hypothesis =1). Therefore the results are statistically significant.