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.

Ex Input:
To determine whether the number and location of positive surgical margins (PSMs) in radical prostatectomy (RP) surgical specimens affect biochemical recurrence (BCR) rates.', 'The locations of PSMs were recorded for 1308 consecutive men who underwent RP between October 2000 and December 2006. BCR was defined as three consecutive prostate-specific antigen (PSA) level rises with the peak level >or=0.15 ng/mL. Multivariate regression analyses were used to identify preoperative predictors of PSMs and BCR. The estimated 5-year risk of BCR was calculated using the Kaplan-Meier method.', 'In all, 128 (9.8%) men had one or more PSMs. The mean body mass index, mean preoperative serum PSA level, the distributions of clinical stage and biopsy Gleason scores, and the presence or absence of biopsy perineural invasion were significantly different between men with or with no PSMs. In multivariate analysis, baseline serum PSA level, Gleason score and perineural invasion were independent preoperative predictors of PSMs. The 5-year actuarial BCR rates were dependent on the site of the PSM (P = 0.035) and not the number of PSMs (P = 0.18). The rank order of estimated 5-year BCR rates according to the site of PSMs were base > anterior > posterolateral > apex approximately posterior.

Ex Output:
Does site of positive surgical margins influence biochemical recurrence after radical prostatectomy?

Ex Input:
The Los Angeles Motor Scale (LAMS) is a brief 3-item stroke severity assessment measure designed for prehospital and Emergency Department use.', 'The LAMS and NIHSS were scored in under-12-hour acute anterior circulation ischemic stroke patients. Stroke severity ratings were correlated with cervicocerebral vascular occlusion on CTA, MRA, and catheter angiography. Receiver operating curves, c statistics, and likelihood ratios were used to evaluate the predictive value for vascular occlusion of stroke severity ratings.', 'Among 119 patients, mean age was 67 (+/-18), 45% were male. Time from onset to ED arrival was mean 190 minutes (range 10 to 660). Persisting large vessel occlusions (PLVOs) were present in 62% of patients. LAMS stroke severity scores were higher in patients harboring a vascular occlusion, median 5 (IQR 4 to 5) versus 2 (IQR 1 to 3). Similarly, NIHSS stroke severity scores were higher in PLVO patients, 19 (14 to 24) versus 5 (3 to 7). ROC curves demonstrated that the LAMS was highly effective in identifying patients with PLVOs, c statistic 0.854. At the optimal threshold of 4 or higher, LAMS scores showed sensitivity 0.81, specificity 0.89, and overall accuracy 0.85. LAMS performance was comparable to NIHSS performance (c statistic 0.933). The positive likelihood ratio associated with a LAMS score > or = 4 was 7.36 and the negative likelihood ratio 0.21.

Ex Output:
Does a brief prehospital stroke severity scale identify ischemic stroke patients harboring persisting large arterial occlusions?

Ex Input:
Research evidence supports a positive link between soft drinks and depressive symptoms. However, data thus far are only from Caucasian populations. We investigated whether high levels of consumption of soft drinks were associated with the depressive symptoms among adults in China.', 'A cross-sectional survey was conducted with 3667 adults in Tianjin, China. Dietary intake was assessed using a valid self-administered food frequency questionnaire, and depressive symptoms were assessed with the Zung Self-Rating Depression Scale (SDS), cut-off point of 40, 45 or 50 indicating elevated depressive symptoms.', 'The prevalence of elevated depressive symptoms was 7.6% (SDS 50). After adjustments for potentially confounding factors, the odds ratios (95% confidence interval) of having elevated depressive symptoms by increasing levels of soft drink consumption were 1.00, 1.43 (1.01, 2.01) and 2.00 (1.15, 3.37) (p for trend <0.01). Similar relations were observed when SDS 40 or 45 were used as a definition of depressive symptoms.

Ex Output:
Is soft drink consumption associated with depressive symptoms among adults in China?