Given the task definition and input, reply with output. 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.

Several studies have reported that ventriculoperitoneal shunt insertion for treatment of normal-pressure hydrocephalus results in improvement of gait and, less frequently, improvement of cognition. We sought to identify the demographic factors associated with cognitive improvement after shunt insertion to improve assessment of prognosis for cognitive gains with treatment.', 'We report cognitive testing before and after ventriculoperitoneal shunt insertion in 36 patients with normal pressure hydrocephalus, who previously had improvement of any clinical symptom--gait, urinary incontinence, cognition--after a diagnostic trial of continuous cerebrospinal fluid drainage.
Do demographic factors influence cognitive recovery after shunt for normal-pressure hydrocephalus?