Given a passage, 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.

[Q]: The 6-min walk test (6MWT) has prognostic value in various pulmonary disorders including idiopathic pulmonary fibrosis (IPF). We determined the individual prognostic accuracy of distance walked and oxygen saturation during the 6MWT in patients with IPF. We defined a new composite index, the distance-saturation product (DSP), which is the product of distance walked and lowest oxygen saturation during the 6-min walk test. We compared the performance of the DSP to the individual 6MWT parameters in predicting mortality.', 'We evaluated pulmonary function tests, 6-min walk parameters and the DSP between survivors and non-survivors. The ability of each measure to discriminate outcomes was determined by receiver operator curves.', '81 patients (48 survivors, 33 non-survivors) were included. Pulmonary function tests were similar and did not correlate with survival. Desaturation was greater (89.4% versus 83.7%, P<0.001) and distance walked was lower (406.9 versus 181.3m, P = 0.005) in non-survivors. The DSP was significantly lower among non-survivors (364.8 versus 153.5m%, P < 0.001) and predicted mortality more accurately than either individual 6MWT component (P = 0.035 versus desaturation, P=0.040 versus distance). A DSP <200 m% was associated with a seven-fold greater risk of 12-month mortality and an 18.0% shorter median survival compared with a DSP > 200 m% (P < 0.001).
[A]: Does the distance-saturation product predict mortality in idiopathic pulmonary fibrosis?


[Q]: Despite much clinical experience, there are few published accounts of the surgical manifestations of HIV/AIDS in children and still fewer guidelines for the best or most appropriate treatment. Our primary objective was to document the incidence of HIV infection in children who presented with a surgical emergency to a major pediatric surgical unit in South Africa. If possible, we aimed to provide a description of the impact of the disease in a surgical pediatric population and to raise awareness of the mode of presentation of HIV to the pediatric surgeon in a developing nation, now that specific antiretroviral therapies are available.', 'This was a prospective observational study of consecutive surgical emergency admissions to the Division of Paediatric Surgery at the University of the Witwatersrand, Johannesburg, South Africa, between April 1 and May 31, 2005. Consent for inclusion in the study was sought in all cases. The clinical profile of children presenting during the study period was recorded. If relevant, permission was sought from the parent/guardian to undertake HIV status testing if this were not already known.', 'Three hundred ninety-one children were admitted as emergency cases during the study period. Thirty-seven (9.5%) of 391 were excluded, because consent could not be obtained, leaving 354 children. Ages ranged between 1 day and 17 years, with a median age of 3 years. The diagnosis in most was trauma/burns (42%) and abdominal emergencies (27%). Infections occurred in 13% of these patients. Human immunodeficiency virus status was already known in 10 (3%) of 354 patients, and only 18 (5%) of 344 children were tested; of these, 10 (55%) were positive. As expected, the predominant surgical presentation of HIV positive children was sepsis. The prevalence of HIV/AIDS in those children not tested is unknown.
[A]: Are surgeons failing to recognize children with HIV infection?


[Q]: To examine the concentration of C-reactive protein (CRP) in relation to gestational weeks during pregnancy among Chinese women.', 'From a randomized control trial of prenatal supplementation with folic acid, iron-folic acid, and multiple micronutrients in China, we examined 834 pregnant women with CRP measured initially between 5 and 20 weeks and at follow-up between 28 and 32 weeks gestation. We calculated and plotted CRP geometric means by gestational weeks. The same analysis was repeated for women who had normal pregnancies (624 women) by excluding women with stillbirth, preterm, small for gestational age, body mass index <18.5 kg/m(2) or >30 kg/m(2) at enrollment, and hypertension or anemia during pregnancy.', 'We observed a significant positive trend between log-transformed CRP and gestational age from 5 to 20 weeks and from 28 to 32 weeks both in the full sample and in the subset of women who had normal pregnancies. CRP geometric mean was 0.81 mg/l at 5-7 weeks of gestation, 2.85 mg/l at 19-20 weeks of gestation, and 3.89 mg/l at 32 weeks of gestation. A similar increasing trend in the CRP median or percentage of elevated CRP were also observed.
[A]:
Does c-reactive protein increase with gestational age during pregnancy among Chinese women?