Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: Context: The role of Helicobacter pylori in gastro-oesophageal reflux disease (GERD) is controversial.', 'To compare the severity of GERD in infected vs. non-infected patients, as part of an ongoing randomized controlled trial that examines the impact of H. pylori eradication on GERD-related outcomes.', 'Consecutive GERD patients underwent urea breath testing and completed validated GERD symptom severity, and quality of life questionnaires as well as, 24-h pH-metry. These parameters, as well as demographics and endoscopic findings were assessed in double-blinded fashion and compared between H. pylori-infected and non-infected subjects.', "Helicobacter pylori-infected GERD patients (n=50) were significantly older and less educated than non-infected patients (n=51). They also used proton pump inhibitors less often but had no difference in symptoms (as measured with both the Spechler's Activity Index and the Gastrointestinal Symptom Rating Scale), quality of life, endoscopic findings or 24-h pH-metry findings.
Answer: This prospective, double-blind study demonstrates, using excellent GERD quantifying measures including validated symptom severity scores, endoscopy, and 24-h pH-metry, that there exist no clinically significant differences in clinical or laboratory-related GERD manifestations between H. pylori-infected and non-infected GERD patients.
[EX A]: Is there no difference in the disease severity of gastro-oesophageal reflux disease between patients infected and not infected with Helicobacter pylori?

[EX Q]: Context: Visceral obesity is shown to be a predictor of morbidity and mortality. We evaluated the association of measurements of generalized adiposity and visceral fat area (VFA), with abnormalities of metabolic syndrome (MS).', 'Seventy-six women (47.9 +/- 9.2 years) with BMI of 38.7 +/- 5.4 kg/m(2) underwent anthropometric measurements, laboratory procedures, bioeletrical impedance, and abdominal computed tomography (CT) scan. Diagnosis of MS was based on the presence of abdominal obesity and at least two of the following components: hypertension, dyslipidemia, and glucose intolerance and/or hyperinsulinemia.', 'BMI was correlated with both components of adipose tissue--subcutaneous (r = 0.66, P < 0.01) and VFA (r = 0.33, P < 0.02)--and leptin levels (r = 0.38, P < 0.01). In contrast, VFA was correlated with 2-h glucose and insulin levels (r = 0.32 and 0.35, P < 0.05, respectively), triglyceride, HDL cholesterol, and uric acid (r = 0.33, -0.34 and 0.24, P < 0.05, respectively). Subjects with high VFA, matched for BMI, showed greater plasma glucose area under the curve (621 +/- 127 vs. 558 +/- 129 mg x h(-1) x dl(-1), P < 0.05), 2-h insulin (804 +/- 599 vs. 579 +/- 347 pmol/l, P < 0.05), and uric acid levels (0.33 +/- 0.07 vs. 0.26 +/- 0.06 mmol/l, P < 0.05) than subjects with low VFA. In logistic regression analysis, waist circumference, VFA, and 2-h insulin were identified as independent predictors of MS. Receiver operating characteristic curve analysis pointed out the values of 104 cm for waist circumference (58.1% specificity, 84.1% sensitivity), 158.5 cm(2) for VFA (78.1% specificity, 52.3% sensitivity), and 559.8 pmol/l for 2-h insulin (71.9% specificity, 69.8% sensitivity); the presence of at least two of the three variables resulted in a degree of concordance of 76%.
Answer: While BMI was unable to differentiate between obese people and those at higher risk for MS, abdominal fat was shown to be associated with its metabolic abnormalities. The usefulness of abdominal fat in the identification of high-risk subjects may be improved when combined with 2-h insulin determination.
[EX A]: Does two-hour insulin determination improve the ability of abdominal fat measurement to identify risk for the metabolic syndrome?

[EX Q]: Context: Rectal cancer has a higher risk of developing lung metastasis compared with colon cancer. It is unclear whether the prognosis after pulmonary metastasectomy for these distinct tumors is different.', 'Patients who underwent pulmonary metastasectomy for colorectal carcinoma were analyzed for survival and patterns of recurrence depending on the location of the primary colorectal cancer. Multivariate regression analysis was performed to identify clinical variables predictive of survival after pulmonary metastasectomy.', 'Between 1985 and 2012, 698 patients underwent pulmonary metastasectomy for metastatic colorectal cancer. Complete information was available in 626 patients. These patients were divided into groups based on whether the primary tumor was colon or rectal in origin. Median follow-up was 45.5 months (range, 23 to 287 months). There were no statistical differences between the two groups in terms of number of lung metastases, tumor size, or lymph node involvement. There was no difference in overall survival (p\xa0= 0.545). Five-year disease-free survival for colon cancer patients was 67.2% compared with 60.1% for rectal cancer (p\xa0= 0.004). The most common sites of recurrence after pulmonary metastasectomy were liver in colon cancer and lung in rectal cancer. Multivariate Cox proportional hazards analysis indicated that rectal cancer (hazard ratio, 1.39; 95% confidence interval, 1.07 to 1.83; p\xa0= 0.015) and multiple metastases (>3; hazard ratio, 1.41; 95% confidence interval, 1.04 to 1.89; p\xa0= 0.027) were independent adverse risk factors affecting disease-free survival after pulmonary metastasectomy.
Answer: Disease-free survival and site of recurrence after pulmonary metastasectomy for colorectal carcinoma are dependent on the site of the primary tumor. Lung metastases from rectal cancer have a worse disease-free survival compared with colon cancer. This may influence treatment and follow-up strategies.
[EX A]:
Does the prognosis of pulmonary metastasectomy depend on the location of the primary colorectal cancer?