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: Thyroid-stimulating hormone (TSH) levels within populations do not follow Gaussian distribution, and normal limits are derived after mathematical normalization. The clinical relevance of these limits is unknown. The objective of this study was to compare upper and lower TSH limits by four data normalization methods with non-normalized data and assess their clinical relevance.', 'Results of blood samples taken by community physicians and stored in a computerized database were analysed after removing samples from patients with evidence of thyroid illness. TSH values were normalized by the Hoffmann and Tukey methods and each method with natural log transformation. Non-normalized data for TSH in the uppermost and lowermost percentile were also calculated. Clinical relevance was determined by alterations in thyroid hormone levels at, below and above the limits for each method.', 'The maximal reduction from non-normalized data for the upper normal limit (UNL) was by the Hoffman method 43% = 31 mIU/l). The maximal increase for the lower normal limit (LNL) was also by the Hoffman method (708% = 081 mIU/l). There was very limited difference in average FT3 and FT4 between patients with TSH within, below or above the normal range for all methods.
Example Output: Do normal limits for serum thyrotropin vary greatly depending on method?

Example Input: Anal intraepithelial neoplasia precedes the development of anal squamous cell carcinoma. Detection of the lesion is essential to management. This paper describes a prospective study to detect and ablate anal squamous intraepithelial lesions (SILs) using white light narrow band imaging (NBI) and NBI with acetic acid (NBIA).', 'Sixty patients with abnormal anal cytology and risk factors for anal dysplasia underwent examination of the anoderm with a high definition gastroscope and NBIA. Targeted biopsies were taken and the lesions were ablated and characterized histopathologically. Visualization of the anal transitional zone was facilitated by retroflexion and examination through a disposable anoscope.', 'Targeted biopsies were taken from lesions in 58 patients. No lesion was seen in two patients. Histopathology showed SIL in 48 (80.0%) of 60 biopsies. One biopsy showed lymphoid aggregates. Biopsies in nine (15%) of the 60 patients showed normal mucosa. Lesions were seen in white light in 27 (45%) of the 60 cases, NBI in 39 (65%) and NBIA in 57 (95%). There was no major morbidity. Sensitivity analysis showed that all methods were significantly different from each other.
Example Output: Is detection of anal dysplasia enhanced by narrow band imaging and acetic acid?

Example Input: To examine the relationship between cardiovascular fitness (VO(2)max) and abdominal obesity (waist circumference) and individual cardiovascular disease (CVD) risk factors, as well as a clustered risk factor profile, and to study the impact of gender, age and smoking on these relationships.', 'Cross-sectional.', 'Astrand Laboratory of Work Physiology, Swedish School of Sport and Health Sciences, Stockholm, Sweden.', 'Men (n = 781) and women (n = 890) from two random population-based samples of Swedish women and men aged 20 to 65 years.', 'Odds ratios.', 'Each unit of higher fitness was associated with a decrease in all individual risk factors ranging from 2% to 4% independent of waist circumference, each unit of higher waist circumference was associated with an increased risk ranging from 2% to 5% independent of fitness. For clustering of three or more of the risk factors, each unit of fitness was associated with a 5% decrease in risk and each unit of waist circumference with a 5% increase in risk. The clustered risk was higher in unfit participants who were older or smoked daily, regardless of waist circumference. Obese participants were at higher risk if they were men or older, regardless of fitness level. However, neither a higher fitness level nor lean status reduced the risk associated with smoking.
Example Output:
Are fitness and abdominal obesity independently associated with cardiovascular risk?