Issa MM Technological advances in transurethral resection of the prostate: bipolar versus monopolar TURP. J Endourol. 2008 Aug;22(8):1587-95. doi: 10.1089/end.2008.0192.
Liu JF, Liu CX, Tan ZH, Li SX, Li XZ, Chi N [Transurethral bipolar plasmakinetic enucleation and resection versus transurethral bipolar plasmakinetic resection of the prostate for BPH: a randomized controlled trial on the incidence of postoperative urinary incontinence]. Zhonghua Nan Ke Xue. 2014 Feb;20(2):165-8. Chinese.
Malaeb BS, Yu X, McBean AM, Elliott SP National trends in surgical therapy for benign prostatic hyperplasia in the United States (2000-2008). Urology. 2012 May;79(5):1111-6. doi: 10.1016/j.urology.2011.11.084.
Nam JK, Kim HW, Lee DH, Han JY, Lee JZ, Park SW Risk Factors for Transient Urinary Incontinence after Holmium Laser Enucleation of the Prostate. World J Mens Health. 2015 Aug;33(2):88-94. doi: 10.5534/wjmh.2015.33.2.88. Epub 2015 Aug 19.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.