instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: Patient-prosthesis mismatch has been identified as a risk factor for mortality after aortic valve replacement and for structural valve deterioration (SVD) in patients receiving a bioprosthetic aortic valve. The aim of the present study was to compare the incidence of aortic valve bioprosthesis replacement for SVD in patients with mismatch to a population without mismatch.', 'Three hundred eighty-seven adult patients who underwent aortic valve replacement with a bioprosthesis from 1974 to 2009 were retrospectively reviewed. Mismatch was considered to be present if the anticipated indexed effective orifice area was <0.70\u2009cm(2) /m(2) . The median follow-up period was 7.2 years. Follow-up was 97% complete.', "Patient-prosthesis mismatch was present in 12% of the study population (n\u2009=\u200947). Ten-year freedom from reoperation for aortic bioprosthesis replacement was 74.3\u2009±\u20093.2%. During follow-up, 111 patients underwent reoperation for aortic bioprosthesis replacement. Causes of aortic bioprosthesis replacement were SVD of the bioprosthesis (n\u2009=\u200996), paravalvular leak (n\u2009=\u200910), and acute endocarditis (n\u2009=\u20095). According to unadjusted Kaplan-Meier analysis, patients with mismatch had a higher incidence of aortic bioprosthesis replacement for SVD when compared with patients without mismatch (log rank test: p 0.05). This result was confirmed by multivariable Cox regression analysis, which identified two independent predictors of aortic bioprosthesis replacement for SVD: patients' age (hazard ratio (HR) 0.967) and patient-prosthesis mismatch (HR 2.161).\Question: Does patient-prosthesis mismatch in patients undergoing bioprosthetic aortic valve implantation increase risk of reoperation for structural valve deterioration?
answer:
Patients suffering from mismatch were twice as likely to undergo reoperation for aortic bioprosthesis replacement for SVD than those without mismatch.


question:
Context: Studies over many years have demonstrated that preoptimization and attention to appropriate perioperative care is associated with a substantial decrease in surgical mortality. This review discusses ways in which patient preparation and perioperative support can minimize surgical mortality and morbidity.', 'Scoring systems continue to be developed in order to classify categories of surgical risk. Objective physiologically based assessments can also identify high-risk groups of patients. Debate continues over the indications for specific interventions such as beta-blockade or statin therapy. There is continuing interest in perioperative optimization of oxygen delivery. A multimodality approach paying attention to a range of possible interventions appears to be beneficial. Audit, training, experience and a sufficient volume of procedures are all factors associated with surgical mortality.\Question: Does excellent anaesthesia need patient preparation and postoperative support to influence outcome?
answer:
The provision of a high-quality service throughout the perioperative period is vital for a successful outcome. Patients need to be assessed well before major elective surgery to determine if they fall into a high-risk category. Some patients may benefit from a change in management. Postoperatively, critical-care support should be available backed by level 1 (enhanced ward) care with input from outreach or medical emergency teams 24 hours per day, seven days a week.


question:
Context: Previous studies have shown that giving other foods while breastfeeding increases the risk of mother-to-child transmission of human immunodeficiency virus (HIV) type 1. The mechanism is speculated to be increased inflammation of the gastrointestinal tract.', 'In a prospective longitudinal study, we compared fecal calprotectin, a marker of intestinal inflammatory disease, in healthy U.S. infants 0-6 months of age who were exclusively breastfed compared to those given additional liquids or solids.', 'In comparison to infants who were mixed-fed, fecal calprotectin was significantly higher in the exclusively breastfed group (p = 0.01) by a mean of 60 mg/kg (SE = 23).\Question: Are fecal calprotectin concentrations higher in exclusively breastfed infants compared to those who are mixed-fed?
answer:

Introducing complementary food does not increase intestinal inflammation according to this marker. Studies to assess fecal calprotectin levels in breastfeeding and mixed-fed infants born to HIV-infected mothers living in resource-constrained settings, and to evaluate potential protective effects of calprotectin in early infancy, are recommended in the continuing effort to elucidate the mechanisms responsible for increased risk of HIV transmission through mixed-feeding.