Dencker A, Berg M, Bergqvist L, Ladfors L, Thorsén LS, Lilja H Early versus delayed oxytocin augmentation in nulliparous women with prolonged labour--a randomised controlled trial. BJOG. 2009 Mar;116(4):530-6. doi: 10.1111/j.1471-0528.2008.01962.x.
Dencker A, Berg M, Bergqvist L, Lilja H Identification of latent phase factors associated with active labor duration in low-risk nulliparous women with spontaneous contractions. Acta Obstet Gynecol Scand. 2010 Aug;89(8):1034-9. doi: 10.3109/00016349.2010
Dencker A, Taft C, Bergqvist L, Lilja H, Berg M Childbirth experience questionnaire (CEQ): development and evaluation of a multidimensional instrument. BMC Pregnancy Childbirth. 2010 Dec 10;10:81. doi: 10.1186/1471-2393-10-81.
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.