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.

Example Input: Context: Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). Patients with early postoperative shrinkage may experience fewer subsequent complications, and consequently require less intensive surveillance.', 'Patients undergoing EVAR from 2000 to 2011 at three vascular centres (in 2 countries), who had two imaging examinations (postoperative and after 6-18 months), were included. Maximum diameter, complications and secondary interventions during follow-up were registered. Patients were categorized according to early sac dynamics. The primary endpoint was freedom from late complications. Secondary endpoints were freedom from secondary intervention, postimplant rupture and direct (type I/III) endoleaks.', 'Some 597 EVARs (71.1 per cent of all EVARs) were included. No shrinkage was observed in 284 patients (47.6 per cent), moderate shrinkage (5-9 mm) in 142 (23.8 per cent) and major shrinkage (at least 10 mm) in 171 patients (28.6 per cent). Four years after the index imaging, the rate of freedom from complications was 84.3 (95 per cent confidence interval 78.7 to 89.8), 88.1 (80.6 to 95.5) and 94.4 (90.1 to 98.7) per cent respectively. No shrinkage was an independent risk factor for late complications compared with major shrinkage (hazard ratio (HR) 3.11; P < 0.001). Moderate compared with major shrinkage (HR 2.10; P = 0.022), early postoperative complications (HR 3.34; P < 0.001) and increasing abdominal aortic aneurysm baseline diameter (HR 1.02; P = 0.001) were also risk factors for late complications. Freedom from secondary interventions and direct endoleaks was greater for patients with major sac shrinkage.
Answer: Early change in aneurysm sac diameter is a strong predictor of late complications after EVAR. Patients with major sac shrinkage have a very low risk of complications for up to 5 years. This parameter may be used to tailor postoperative surveillance.
Example Output: Does early sac shrinkage predict a low risk of late complications after endovascular aortic aneurysm repair?

Example Input: Context: Scutellaria barbata D.Don has been applied to treat cancers, inflammation and urinary disease. However, its antitumor mechanism still remains unclear.', 'With methylene chloride fraction of Herba Scutellariae barbatae (MCSB), apoptosis-related experiments were carried out on human U937 leukemia cells by (a) 2,3-bis[2-4-nitro-5-sulphophenyl]2H-tetrazolium-5-carboxanilide (XTT) assay for cytotoxicity; (b) terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL) assay for morphological changes; (c) cell cycle analysis; (d) Western blot analysis of poly(ADP-ribose) polymerase (PARP), caspase-8, caspase-9, caspase-3 and Bax, Bcl-2 and cytochrome c expressions for apoptosis signaling pathway.', 'MCSB inhibited the proliferation of human U937 leukemia cells in a dose-dependent manner (IC50 = approximately 10 microg/ml). MCSB dose-dependently increased the sub-G1 DNA contents by cell cycle analysis. DNA fragments indicating induction of apoptosis were observed in MCSB-treated U937 cells by TUNEL assay. Caspase-9 and caspase-3 were activated while caspase-8 was intact by MCSB. Similarly, MCSB effectively cleaved PARP, increased the ratio of Bax/Bcl-2 and released the cytochrome c from mitochondria during apoptosis in U937 cells.
Answer: Our results suggest that MCSB can induce apoptosis via the mitochondria-mediated signaling pathway.
Example Output: Does methylene chloride fraction of Scutellaria barbata induce apoptosis in human U937 leukemia cells via the mitochondrial signaling pathway?

Example Input: Context: To describe the prevalence of prolonged fatigue, chronic fatigue syndrome (CFS)-like illness, and associated symptom patterns in adolescents attending primary care.', 'The design was cross-sectional. A questionnaire designed by the authors assessing fatigue and associated symptoms was administered to 901 adolescents (aged 11-18 years) attending 12 primary care clinics in the Chicago area. Prevalence rates for prolonged fatigue and CFS-like illness were calculated. Univariate comparisons involving sociodemographic data and fatigue severity were made between adolescents with and without prolonged fatigue, and sociodemographic and symptom predictors of prolonged fatigue were identified using logistic regression analysis.', 'Prolonged fatigue (> or = 1 month) occurred at a rate of 8.0% and CFS-like illness occurred at a rate of 4.4%. Adolescents with prolonged fatigue were significantly older and also reported greater fatigue severity than those without fatigue. Findings from logistic regression indicated that, in addition to increasing age, headaches, muscle pains, fever, and fatigue made worse by exercise were significantly associated with prolonged fatigue.
Answer: Abnormal fatigue is a disabling and prevalent condition in adolescents in primary care. It is associated with a number of additional symptoms, many of which may have viral origins.
Example Output:
Does sociodemographic and symptom correlate of fatigue in an adolescent primary care sample?