单对直肠指诊获取的大便样本进行大便隐血筛查的准确性:与推荐的样本检查的比较

Background: Many expert panels recommend colorectal cancer screening for average-risk asymptomatic individuals older than 50 years of age. Recent studies have found that 24%to 64%of primary care providers use only the digital fecal occult blood test (FOBT) as their primary screening test. The effectiveness of a single digital FOBT is unknown. Objective: To compare the sensitivity and specificity of digital FOBT and the recommended 6-sample at-home FOBT for advanced neoplasia in asymptomatic persons. Design: Prospective cohort study. Setting: 13 Veterans Affairs medical centers. Patients: 3121 asymptomatic patients 50 to 75 years of age. Intervention: 2665 patients had 6-sample at-home FOBT and digital FOBT, followed by complete colonoscopy. Measurements: We measured the sensitivity of digital and 6-sample FOBT for advanced neoplasia and the specificity for no neoplasia. We calculated predictive values and likelihood ratios for advanced neoplasia, defined as tubular adenomas 10 mm or greater, adenomas with villous histology or high-grade dysplasia, or invasive cancer. Results: Of all participants, 96.8%were men; their average age was 63.1 years. The 6-sample FOBT and the single digital FOBT had specificities of 93.9%and 97.5%, respectively, as defined by studying 1656 patients with no neoplasia. Sensitivities for detection of advanced neoplasia in 284 patients were 23.9%for the 6-sample FOBT and 4.9%for the digital FOBT. The likelihood ratio for advanced neoplasia was 1.68 (95%CI, 0.96 to 2.94) for positive results on digital FOBT and 0.98 (CI, 0.95 to 1.01) for negative results. Limitations: Most patients were men. Conclusions: Single digital FOBT is a poor screening method for colorectal neoplasia and cannot be recommended as the only test. When digital FOBT is performed as part of a primary care physical examination, negative results do not decrease the odds of advanced neoplasia. Persons with these results should be offered at-home 6-sample FOBT or another type of screening test.

行白内障囊外手术时玻璃体脱出对术后1年视力的影响

The purpose of this study was to determine the effects that vitreous presentation (VP) during extracapsular cataract surgery has on patients’ 1- year postoperative vision. The study was a prospective, long- term, clinical trial. The study took place at 19 Department of Veterans Affairs medical centers. Patients having VP during cataract surgery and receiving a posterior chamber (PC) intraocular lens (IOL) (230 patients) were prospectively compared with a 5% random sample of nonvitreous presentation (NVP) cataract surgery patients (521 patients). Best- corrected visual acuity (BCVA) at 1 year was obtained by a masked, certified examiner. There was no statistical difference (P=.089) between the VP patients receiving PC IOL and the NVP patients in percentage of patients having BCVA of 20/40 or better at 1 year (91.1% vs 94.9% ). There were significantly more PC IOL VP patients than NVP patients with BCVA of 20/50 or worse at some time during the first postoperative year (21.6% vs 10.9% ; P=.000 3), significantly fewer with BCVA of 20/20 or better at 1 year (27.8% vs 38.8% ; P=.013), and significantly more with cystoid macular edema (11.5% vs 3.6% ; P=.0002), retinal detachment (4.3% vs 0.2% ; P=.0002), and uveitis (3.4% vs 0.6% ; P=.012). The NVP patients rated their vision as very good or excellent significantly more often than the VP patients (71% vs 58% ; P=.025). Vitreous presentation during extracapsular cataract surgery leads to somewhat worse overall outcomes in patients, although the majority of patients with VP do reasonably well.

强力霉素治疗海湾战争综合征的利弊:一项随机、双盲、安慰剂对照试验研究

Background: It has been hypothesized that certain Mycoplasma species may cause Gulf War veterans’ illnesses (GWVIs), chronic diseases characterized by pain, fatigue, and cognitive symptoms, and that affected patients may benefit from doxycycline treatment. Objective: To determine whether a 12 month course of doxycycline improves functional status in Gulf War veterans with GWVIs. Design: A randomized, double blind, placebo controlled clinical trial with 12 months of treatment and 6 additional months of follow up. Setting: 26 U.S. Department of Veterans Affairs and 2 U.S. Department of Defense medical centers. Participants: 491 deployed Gulf War veterans with GWVIs and detectable Mycoplasma DNA in the blood. Intervention: Doxycycline, 200 mg, or matching placebo daily for 12 months. Measurements: The primary outcome was the proportion of participants who improved more than 7 units on the Physical Component Summary score of the Veterans Short Form 36 General Health Survey 12 months after randomization. Secondary outcomes were measures of pain, fatigue, and cognitive function and change in positivity for Mycoplasma species at 6, 12, and 18 months after randomization. Results: No statistically significant differences were found between the doxycycline and placebo groups for the primary outcome measure (43 of 238 participants vs. 42 of 243 participants ; difference, 0.8 percentage point [95% CI, 6.5 to 8.0 percentage points]; P > 0.2) or for secondary outcome measures at 1 year. In addition, possible differences in outcomes at 3 and 6 months were not apparent at 9 or 18 months. Participants in the doxycycline group had a higher incidence of nausea and photo sensitivity. Limitations: Adherence to treatment after 6 months was poor. Conclusion: Long term treatment with doxycycline did not improve outcomes of GWVIs at 1 year.