下尿路症狀不論在男女各年齡層都是盛行率高且易造成病人相當的困擾。然而，正確診斷其原因是否是由「膀胱出口阻塞」所致是相當重要的，因為這會決定後續合適的治療方式以及影響治療結果。例如，男性具下尿路症狀病人，若決定接受經尿道前列腺刮除手術，則在術前尿路動力學下確診有膀胱出口阻塞情形的病人會有較好的手術結果。「尿路動力學檢查」是診斷膀胱出口阻塞的黃金標準，然而，這是一種較侵入性的檢查。執行尿路動力學檢查時需要置放導管於尿道內，常會造成病人焦慮、不適感、嚴重下尿路症狀、血尿、甚至泌尿道感染等併發症。因此，有許多非侵入性的檢查方式希望能取代較侵入性的尿路動力學檢查來診斷膀胱出口阻塞。此篇系統性回顧文章是發表在2016年泌尿科最具權威的國際期刊European Urology，其目的就是希望能夠統整目前已知可用於診斷膀胱出口阻塞的非侵入性的檢查，評定其應用於男性下尿路症狀病人族群的診斷率，希望能夠達到正確診斷膀胱出口阻塞且減少不必要的侵入性檢查而避免過多的併發症。

此篇系統性回顧是蒐集並分析EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central, Google Scholar, and WHO International Clinical Trials Registry Platform Search Portal databases等資料庫內的相關文章(非侵入性檢查用以診斷膀胱出口阻塞在男性下尿路症狀病人的診斷率)，最後選入42篇，總分析人數是4444人。總體來說，各種非侵入性檢查方式的診斷率會因為異質性的納入族群、實驗設計、及定義而有所差異。膀胱逼尿肌厚度(detrusor wall thickness) (敏感度82%，特異度92%)、近紅外光譜儀(near-infrared spectroscopy) (敏感度85%，特異度87%)、以及陰莖壓脈帶檢查(penile cuff test) (敏感度88%，特異度75%)是在診斷膀胱出口阻塞的方式中具有較高的敏感度及特異度的。最大尿流速<10毫升/秒(敏感度68%，特異度70%)以及膀胱內前列腺突出(intravesical prostatic protrusion)>10毫米(敏感度68%，特異度75%)都是診斷率較低的方式。

總結，對於診斷膀胱出口阻塞，目前有許多非侵入性診斷方式具有高敏感度及高特異度。然而，由於各研究間的實驗設計異質性高，故上述分析之證據強度會受影響。對於診斷膀胱出口阻塞，侵入性的尿路動力學檢查仍然是診斷上的黃金標準。

CONTEXT:
Several noninvasive tests have been developed for diagnosing bladder outlet obstruction (BOO) in men to avoid the burden and morbidity associated with invasive urodynamics. The diagnostic accuracy of these tests, however, remains uncertain.
OBJECTIVE:
To systematically review available evidence regarding the diagnostic accuracy of noninvasive tests in diagnosing BOO in men with lower urinary tract symptoms (LUTS) using a pressure-flow study as the reference standard.
EVIDENCE ACQUISITION:
The EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central, Google Scholar, and WHO International Clinical Trials Registry Platform Search Portal databases were searched up to May 18, 2016. All studies reporting diagnostic accuracy for noninvasive tests for BOO or detrusor underactivity in men with LUTS compared to pressure-flow studies were included. Two reviewers independently screened all articles, searched the reference lists of retrieved articles, and performed the data extraction. The quality of evidence and risk of bias were assessed using the QUADAS-2 tool.
EVIDENCE SYNTHESIS:
The search yielded 2774 potentially relevant reports. After screening titles and abstracts, 53 reports were retrieved for full-text screening, of which 42 (recruiting a total of 4444 patients) were eligible. Overall, the results were predominantly based on findings from nonrandomised experimental studies and, within the limits of such study designs, the quality of evidence was typically moderate across the literature. Differences in noninvasive test threshold values and variations in the urodynamic definition of BOO between studies limited the comparability of the data. Detrusor wall thickness (median sensitivity 82%, specificity 92%), near-infrared spectroscopy (median sensitivity 85%, specificity 87%), and the penile cuff test (median sensitivity 88%, specificity 75%) were all found to have high sensitivity and specificity in diagnosing BOO. Uroflowmetry with a maximum flow rate of <10ml/s was reported to have lower median sensitivity and specificity of 68% and 70%, respectively. Intravesical prostatic protrusion of >10mm was reported to have similar diagnostic accuracy, with median sensitivity of 68% and specificity of 75%.
CONCLUSIONS:
According to the literature, a number of noninvasive tests have high sensitivity and specificity in diagnosing BOO in men. However, although the majority of studies have a low overall risk of bias, the available evidence is limited by heterogeneity. While several tests have shown promising results regarding noninvasive assessment of BOO, invasive urodynamics remain the gold standard.