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: Several studies have shown excess mortality among hip fracture patients compared with the normal population of the same age. Finnish guidelines for medical treatment of hip fracture patients recommend anti-osteoporosis medication and the daily concomitant use of prescribed calcium and vitamin D supplements. However, whether post-fracture use of calcium and vitamin D supplements is associated with survival in such patients has not been evaluated.', "To study the association between survival in hip fracture patients and patients' sex and age, pre-fracture vitamin D status, American Society of Anesthesiologists - Physical Status (ASA-PS) class, type of fracture and post-fracture use of prescribed calcium plus vitamin D and anti-osteoporotic medication.", "The study population was 221 hip fracture patients primarily treated in acute care for a new hip fracture in 2003-4 in two Finnish hospitals. After a median of 27.5 months from the fracture, a questionnaire was sent to all patients who were still alive at the time (n = 137). The patients were queried about their use of prescribed calcium plus vitamin D supplementation and of anti-osteoporotic drugs. The follow-up time for use of anti-osteoporotic medication and prescribed calcium and vitamin D was 19.5-36 months (median 27.5 months). Data on the use of prescribed calcium plus vitamin D supplementation and anti-osteoporotic drugs were checked against information on reimbursement of drug prescriptions held by the Finnish Social Insurance Institution. A total of 4 years' (48 months') survival data for all patients in the study population was also obtained, with the dates of patient deaths being checked against Official National and Regional population statistics. Patient survival was analysed using both the Bayesian multivariate analysis and the life table method.", 'In the multivariate analysis, the combination of variables that best explained post-fracture survival was as follows: age <80 years; ASA-PS class 1-2 (ASA-PS class 1 and 2 data were combined in calculations); post-fracture use of prescribed calcium plus vitamin D supplements concomitantly with anti-osteoporotic drugs; post-fracture use of prescribed calcium plus vitamin D supplements; post-fracture use of anti-osteoporotic drugs only; and type of fracture (femoral neck or subtrochanteric). This model correctly predicted 74% of cases. At 36 months, we observed a 36% reduction in deaths in females who used prescribed calcium plus vitamin D supplementation and a corresponding 43% reduction in males. Survival of females who used anti-osteoporotic drugs concomitantly was even greater (43% reduction in deaths) over the entire follow-up period. Excess mortality was highest in females and males who used neither anti-osteoporotic drugs nor prescribed calcium and vitamin D.
Answer: Our results indicate a potential relationship between reduced mortality and post-fracture use of prescribed calcium plus vitamin D supplementation and, in females, concomitant use of anti-osteoporotic drugs. However, further investigations are needed to understand the reason for the reduction in the risk of death. Population-based, randomized, placebo-controlled trials with total mortality as the main endpoint should be conducted to verify our results.
[EX A]: Is post-fracture prescribed calcium and vitamin D supplements alone or , in females , with concomitant anti-osteoporotic drugs associated with lower mortality in elderly hip fracture patients : a prospective analysis?

[EX Q]: Context: To conduct clinical and genetic studies in a European family with autosomal dominant Stargardt-like macular dystrophy (adSTGD-like MD) and to investigate the functional consequences of a novel ELOVL4 mutation.', 'Ophthalmic examination and mutation screening by direct sequencing of the ELOVL4 gene was performed in two affected individuals. Wild-type and mutant ELOVL4 genes were expressed as enhanced green fluorescent protein (EGFP) fusion proteins in transient transfection in NIH-3T3 and HEK293 cells. To determine the subcellular localization of ELOVL4, an endoplasmic-reticulum (ER)-specific marker for pDsRed2-ER was cotransfected with ELOVL4 constructs. Transfected cells were viewed by confocal microscopy. Western blot analysis was performed to assess protein expression using an anti-GFP antibody.', 'Affected patients exhibited macular atrophy with surrounding flecks characteristic of adSTGD-like MD. A novel ELOVL4 p.Tyr270X mutation was detected in affected individuals. In cell-transfection studies, wild-type ELOVL4 localized preferentially to the ER. In contrast, the mutant protein appeared to be mislocalized within transfected cells.
Answer: In a European family with adSTGD-like MD, a novel ELOVL4 mutation was found to underlie the disorder. Transfection studies indicated that, unlike wild-type ELOVL4, the mutant protein does not localize to the ER but rather appears to be sequestered elsewhere in an aggregated pattern in the cytoplasm. Further analysis of the function of normal and mutant ELOVL4 will provide insight into the mechanism of macular degeneration.
[EX A]: Does a novel mutation in the ELOVL4 gene cause autosomal dominant Stargardt-like macular dystrophy?

[EX Q]: Context: The authors investigated the additive prognostic value of the 6-minute walk test (6MWT) to Euroscore in patients with severe aortic stenosis undergoing aortic valve replacement (AVR) METHODS AND RESULTS: 208 patients with severe AS underwent the 6MWT before AVR, as part of a randomised trial (ASSERT) comparing stented and stentless aortic valves. Clinical follow-up was available for 200 patients up to 12 months. The rate of death, myocardial infarction (MI) or stroke (time to first event) was 13% (n = 14) in patients walking <300 metres compared to 4% (n = 4) in those who walked > or =300 metres (p = 0.017). When rate of death, MI or stroke by Euroscore risk was stratified by 6-minute walking distance, the 6MWT added prognostic information. In a Cox regression analysis 6MWT distance was the only variable retained as an independent predictor of the composite outcome of death, MI or stroke at 12 months (HR 0.28 95% CI 0.09 to 0.85, p = 0.025).
Answer: The 6MWT is safe and feasible to carry out in patients with severe aortic stenosis before AVR, and provides potentially important functional and prognostic information to clinical assessment and the Euroscore risk score.
[EX A]:
Does preoperative 6-minute walk test add prognostic information to Euroscore in patients undergoing aortic valve replacement?