Berk LS Studying the biology of hope: An interview with Lee S. Berk, DrPH, MPH. Interview by Sheldon Lewis. Adv Mind Body Med. 2007 Summer;22(2):28-31.
Clark A, Seidler A, Miller M Inverse association between sense of humor and coronary heart disease. Int J Cardiol. 2001 Aug;80(1):87-8.
Cortés O, Arthur HM Determinants of referral to cardiac rehabilitation programs in patients with coronary artery disease: a systematic review. Am Heart J. 2006 Feb;151(2):249-56. Review.
Fry WF Jr The physiologic effects of humor, mirth, and laughter. JAMA. 1992 Apr 1;267(13):1857-8.
Lebowitz KR, Suh S, Diaz PT, Emery CF Effects of humor and laughter on psychological functioning, quality of life, health status, and pulmonary functioning among patients with chronic obstructive pulmonary disease: a preliminary investigation. Heart Lung. 2011 Jul-Aug;40(4):310-9. doi: 10.1016/j.hrtlng.2010.07.010.
Lu WA, Kuo CD The effect of Tai Chi Chuan on the autonomic nervous modulation in older persons. Med Sci Sports Exerc. 2003 Dec;35(12):1972-6.
Martin RA Humor, laughter, and physical health: methodological issues and research findings. Psychol Bull. 2001 Jul;127(4):504-19. Review.
Sakuragi S, Sugiyama Y, Takeuchi K Effects of laughing and weeping on mood and heart rate variability. J Physiol Anthropol Appl Human Sci. 2002 May;21(3):159-65.
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.
