Healy CM, Montesinos DP, Middleman AB Parent and provider perspectives on immunization: are providers overestimating parental concerns? Vaccine. 2014 Jan 23;32(5):579-84. doi: 10.1016/j.vaccine.2013.11.076. Epub 2013 Dec 4.
McCauley MM, Kennedy A, Basket M, Sheedy K Exploring the choice to refuse or delay vaccines: a national survey of parents of 6- through 23-month-olds. Acad Pediatr. 2012 Sep-Oct;12(5):375-83. doi: 10.1016/j.acap.2012.06.007. Epub 2012 Aug 22.
Opel DJ, Taylor JA, Zhou C, Catz S, Myaing M, Mangione-Smith R The relationship between parent attitudes about childhood vaccines survey scores and future child immunization status: a validation study. JAMA Pediatr. 2013 Nov;167(11):1065-71. doi: 10.1001/jamapediatrics.2013.2483.
Use of a Novel Parent-Report Measure to Improve Childhood Vaccine Uptake: The Screening for Hesitancy to Optimize Talk (SHOT) Study
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.