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.

[Q]: Context: Noninvasive pacemaker stress echocardiography is a newly introduced method for the diagnosis of coronary artery disease in patients with a permanent pacemaker. The prognostic value of pacemaker stress echocardiography has not been studied.', 'We studied 136 patients (mean age 64+/-12 years) with a permanent pacemaker who underwent pacemaker stress echocardiography for evaluation of coronary artery disease. All patients underwent pacemaker stress echocardiography by external programming (pacing heart rate up to ischemia or target heart rate).', 'Thirty-one patients (23%) had normal study results. Ischemia was detected in 75 patients (55%). During a mean follow-up of 3.5+/-2.4 years, 35 deaths (26%) (20 the result of cardiac causes) and 2 nonfatal myocardial infarctions (1%) occurred. The annual cardiac death rate was 1.3% in patients without ischemia and 4.6% in patients with ischemia (P=.01). The annual all-cause mortality rate was 3.1% in patients without ischemia and 7% in patients with ischemia (P=.004). The presence of ischemia during pacemaker stress echocardiography was the strongest independent predictor of cardiac death (hazard ratio 4.1, confidence interval 1.2-14.5) and all-cause mortality (hazard ratio 2.7, confidence interval 1.2-6.0) in a multivariable model.
Answer: Myocardial ischemia during pacemaker stress echocardiography is an independent predictor of cardiac death and all-cause mortality in patients with a permanent pacemaker.
[A]: Does pacemaker stress echocardiography predict cardiac events in patients with permanent pacemaker?

[Q]: Context: There is a strong association between migraine and depression. The aim of this study is to identify migraine-specific factors involved in this association.', 'We conducted a cross-sectional study in a large, well-defined cohort of migraine patients (n=2533). We assessed lifetime depression using validated questionnaires, and diagnosed migraine based on the International Classification of Headache Disorders III-beta criteria. Multivariate regression analyses were conducted.', 'Of the 2533 migraineurs that were eligible, 1137 (45%) suffered from lifetime depression. The following independent factors were associated with an increased depression prevalence: i) migraine-specific risk factors: high migraine attack frequency and the presence of allodynia, ii) general factors: being a bad sleeper, female gender, high BMI, being single, smoking, and a low alcohol consumption.
Answer: This study identified allodynia, in addition to high migraine attack frequency, as a new migraine-specific factor associated with depression.
[A]: Is allodynia associated with a higher prevalence of depression in migraine patients?

[Q]: Context: To estimate the prevalence of asthma, allergic rhinitis, and atopic dermatitis among school children in the region of Primorsko-goranska County in Croatia, and compare the results with data from other countries.', 'The study was conducted during the 2001-2002 school year, in complete adherence to the Phase One protocol of the International Study of Asthma and Allergies in Childhood (ISAAC). The target population comprised two age groups (6-7 and 13-14 years) in the region of Primorsko-Goranska County in Croatia. Data were collected using standardized ISAAC written questionnaire and asthma video questionnaire.', 'There were 1,634 participating children in the 6-7 age group (response rate 80.3%) and 2,194 participating children in the 13-14 age group (response rate 89.8%). Estimated 12-month prevalence rates of symptoms were: wheezing 9.7% and 8.4%, allergic rhinitis symptoms 16.9% and 17.5%, allergic rhinoconjunctivitis symptoms 5.6% and 6.7%, and atopic dermatitis symptoms 5.4% and 3.4%, for younger and older age group, respectively.
Answer: Results suggest an increase in the prevalence of atopic disease symptoms in north-west part of Croatia over the last few decades when compared to prior studies. The results are suitable for international comparison, suggesting that this part of Croatia is a county with a moderate prevalence of atopic diseases in the pediatric population. The results represent a baseline for further epidemiological research of asthma and allergic diseases.
[A]:
Is prevalence of asthma and allergic diseases in Croatian children increasing : survey study?