Arbyn M, Paraskevaidis E, Martin-Hirsch P, Prendiville W, Dillner J Clinical utility of HPV-DNA detection: triage of minor cervical lesions, follow-up of women treated for high-grade CIN: an update of pooled evidence. Gynecol Oncol. 2005 Dec;99(3 Suppl 1):S7-11. Epub 2005 Sep 9.
Jeong NH, Lee NW, Kim HJ, Kim T, Lee KW High-risk human papillomavirus testing for monitoring patients treated for high-grade cervical intraepithelial neoplasia. J Obstet Gynaecol Res. 2009 Aug;35(4):706-11. doi: 10.1111/j.1447-0756.2008.00989.x.
Kang WD, Oh MJ, Kim SM, Nam JH, Park CS, Choi HS Significance of human papillomavirus genotyping with high-grade cervical intraepithelial neoplasia treated by a loop electrosurgical excision procedure. Am J Obstet Gynecol. 2010 Jul;203(1):72.e1-6. doi: 10.1016/j.ajog.2010.01.063. Epub 2010 Apr 24.
Kocken M, Uijterwaal MH, de Vries AL, Berkhof J, Ket JC, Helmerhorst TJ, Meijer CJ High-risk human papillomavirus testing versus cytology in predicting post-treatment disease in women treated for high-grade cervical disease: a systematic review and meta-analysis. Gynecol Oncol. 2012 May;125(2):500-7. doi: 10.1016/j.ygyno.2012.01.015. Epub 2012 Jan 18. Review.
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.