Birken CS, Parkin PC, Macarthur C Asthma severity scores for preschoolers displayed weaknesses in reliability, validity, and responsiveness. J Clin Epidemiol. 2004 Nov;57(11):1177-81. Review.
Cairns CB, Kraft M Magnesium attenuates the neutrophil respiratory burst in adult asthmatic patients. Acad Emerg Med. 1996 Dec;3(12):1093-7.
Chalut DS, Ducharme FM, Davis GM The Preschool Respiratory Assessment Measure (PRAM): a responsive index of acute asthma severity. J Pediatr. 2000 Dec;137(6):762-8.
Goodacre S, Cohen J, Bradburn M, Gray A, Benger J, Coats T; 3Mg Research Team Intravenous or nebulised magnesium sulphate versus standard therapy for severe acute asthma (3Mg trial): a double-blind, randomised controlled trial. Lancet Respir Med. 2013 Jun;1(4):293-300. doi: 10.1016/S2213-2600(13)70070-5. Epub 2013 May 17.
Gorelick MH, Stevens MW, Schultz TR, Scribano PV Performance of a novel clinical score, the Pediatric Asthma Severity Score (PASS), in the evaluation of acute asthma. Acad Emerg Med. 2004 Jan;11(1):10-8.
Mohammed S, Goodacre S Intravenous and nebulised magnesium sulphate for acute asthma: systematic review and meta-analysis. Emerg Med J. 2007 Dec;24(12):823-30. Review.
Rowe BH Intravenous and inhaled MgSO4 for acute asthma. Lancet Respir Med. 2013 Jun;1(4):276-7. doi: 10.1016/S2213-2600(13)70097-3. Epub 2013 May 17. Review.
Shan Z, Rong Y, Yang W, Wang D, Yao P, Xie J, Liu L Intravenous and nebulized magnesium sulfate for treating acute asthma in adults and children: a systematic review and meta-analysis. Respir Med. 2013 Mar;107(3):321-30. doi: 10.1016/j.rmed.2012.12.001. Epub 2013 Jan 3. Review.
Smith SR, Baty JD, Hodge D 3rd Validation of the pulmonary score: an asthma severity score for children. Acad Emerg Med. 2002 Feb;9(2):99-104.
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.
