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.

Example Input: Results from GOG 178 showed a prolongation of progression-free survival (PFS) with the immediate use of chemotherapy (CT) following a complete clinical response (CR) in patients with stage III-IV ovarian cancer. We wanted to evaluate our strategy of reserving second line (2nd line) chemotherapy to the time of clinical recurrence by determining PFS intervals following first, second, and third line agents and to compare these finding to results of GOG 178.', 'We conducted a retrospective parallel study to GOG 178 using identical criteria for PFS definitions. Patients (pts) with stage III-IV cancer achieving a CR following surgery and five to eight cycles of platinum-based CT were identified. Patients not obtaining a CR and those with a CR who underwent second look surgery were excluded. Rather than immediately beginning consolidation CT after CR, second line agents were started at recurrence and were followed by a third line when pts progressed. Clinical-pathologic characteristics were abstracted, and time intervals including time to recurrence, time to use of second line CT, time to use of third line (3rd line) CT, and survival were recorded. Time intervals were studied by Kaplan-Meier method.', 'Of 217 reviewed pts (1991-2001), 59 eligible pts were identified. Forty-nine patients had stage III disease and ten had stage IV. At completion of surgery, 44 were optimally debulked. With a median follow-up of 51 months, the median PFS (from CR) of all patients was 20 months. At 5 years, 36% of pts remain disease-free, and 66% of pts are alive. Twenty-three pts have not received second line agents, and thirty-six have received them. For all pts, the median time from CR to start of second line chemotherapy was 21 months, and the median time to start of third line agents was 43 months. Recurrences occurred after 6 months from completion of first line (1st line) therapy in 87% of cases and after 12 months in 50%.
Example Output: Is timing n't everything : an analysis of when to start salvage chemotherapy in ovarian cancer?

Example Input: The role of sleep in the enhancement of motor skills has been studied extensively in adults. We aimed to determine involvement of sleep and characteristics of spindles and slow waves in a motor skill in children.', 'We hypothesized sleep-dependence of skill enhancement and an association of interindividual differences in skill and sleep characteristics.', '30 children (19 females, 10.7 ± 0.8 years of age; mean ± SD) performed finger sequence tapping tasks in a repeated-measures design spanning 4 days including 1 polysomnography (PSG) night. Initial and delayed performance were assessed over 12 h of wake; 12 h with sleep; and 24 h with wake and sleep. For the 12 h with sleep, children were assigned to one of three conditions: modulation of slow waves and spindles was attempted using acoustic perturbation, and compared to yoked and no-sound control conditions.', 'Mixed effect regression models evaluated the association of sleep, its macrostructure and spindles and slow wave parameters with initial and delayed speed and accuracy.
Example Output: Do sleep spindle and slow wave frequency reflect motor skill performance in primary school-age children?

Example Input: It is controversial whether high salt intake is directly associated with cardiovascular (CV) events and how far this relation is independent of blood pressure (BP). As Portugal has higher salt consumption and higher mortality by stroke than other European countries, we examined whether salt intake could predict the development of stroke and CV events in a hypertensive population.', 'In a longitudinal retrospective study of a cohort of 608 adult treated hypertensive patients 54.1±14.3 years of age, BMI 29.3±8.3\u2009kg/m, 56.3% women and 17.1% diabetics, we evaluate the long-term prognostic significance of urinary sodium (UNa) excretion measured in 24\u2009h valid samples within the first 3 months after admission along with 24\u2009h ambulatory blood pressure monitoring and pulse wave velocity [(PWV), complior)] measurements.', 'The mean follow-up duration was 7.2 years (0.5-11.1 years), during which 122 CV events occurred including 80 strokes and 36 coronary events. In 608 patients (group A=507 without events and group B=101 with events: 69 strokes, 26 coronary events, six others), the mean 24\u2009h UNa was 208±79\u2009mmol/day, corresponding to a salt intake of 12.1±4.6\u2009g/day. Twenty-four hours UNa correlated positively with BMI, PWV and systolic blood pressure (SBP) particularly with night-time SBP. Group B versus A showed higher UNa (260+98 vs. 198+71\u2009mmol/day, P<0.001) and higher PWV, BP office, 24\u2009h, daytime and night-time SBP. Logistic regression analysis identified age, night-time SBP and 24\u2009h UNa+ [HR=1.09 (95% CI, 1.06-1.12, P<0.001)] for each 10\u2009mmol increase of UNa+ as the only independent predictors of CV events. UNa+ above the median (189\u2009mmol sodium/day) predicted CV events with HR=2.99 (95% CI, 1.75-5.13, P<0.001) with worse CV event-free survival rates (log rank statistics of 17.44, P<0.001).
Example Output:
Is high salt intake associated with a higher risk of cardiovascular events : a 7.2-year evaluation of a cohort of hypertensive patients?