Scientific Method: Asthma

 You have learned in class that the Scientific Method is the logical tool kit scientists use to answer questions. By using the scientific method, researchers accept a universal standard for designing, executing, and evaluating experiments to test their hypotheses. When they publish their results and conclusions, researchers lay bare their "scientific souls" for critical review by their peers in the scientific community. This cycle of conducting experiments, publishing the results, followed by peer review is at the core of scientific progress; it's how hypotheses eventually become theories. In the case you will study in this lesson, it may become part of the knowledge base your family physician uses to treat a diagnosis of asthma.

No where is the proper use of the Scientific Method more important than medical research. After all, properly studying the causes and treatment of disease can lead to life or death consequences for patients who rely on the outcome of this work. In this exercise you will examine a study published in the New England Journal of Medicine, July 2011. This study was done to evaluate various treatments for asthma. You probably have friends and classmates who suffer from asthma; it is one of the most common and potentially dangerous respiratory diseases. Nearly 10% of children in the US suffer from asthma and more than 3000 people die in this country annually from complications of the disease (statistics from the CDC).


Lesson One: What is Asthma?

Before you analyze the published asthma study, it will be helpful to have some background about this disease. Go to the National Institutes of Health for some basic information about asthma. Pay particular attention to the symptoms, causes, and treatments of the disease. Use this material to answer the following questions. Remember, when you complete all of the lessons in this exercise, you must email me your answers using your school account.
  1. Briefly explain what asthma is.
  2. What are some of the "risk" factors for developing asthma?
  3. Are all asthma cases caused by some sort of allergy? Explain.
  4. Can an asthma patient be cured? Explain.


Lesson Two: The Study: Design.

As you probably know, the most common treatment for chronic asthma are the various brands of bronchodilators that open constricted airways and in some cases reduce the inflammation. However, there has been a growing trend in the US to seek "alternative" or "complementary" treatments for all kinds of medical problems, and asthma is no exception. These alternatives include such practices as acupuncture, chiropractic treatments, yoga, dietary supplements, etc. Although it is certainly true that mainstream medicine often includes exercise, meditation, and diet as treatment for some diseases, these alternative therapies are often promoted for conditions where there is little or no scientific evidence for their effectiveness. 

The research you will study in this lesson seeks to evaluate the effectiveness of acupuncture compared to a standard prescription drug, Albuterol, as well as the role of the "placebo effect" on patients' perception of their asthma after receiving treatment. Read the Background and Methods sections of the study. The study itself is quite straight forward. Each of 39 asthma patients were treated with an inhaler containing Albuterol, an inhaler without Albuterol (Placebo), Sham Acupuncture (the needles retract and don't actually pierce the body), or No Intervention group. Be sure you understand that the participants in this study did not know if the inhaler they received contained Albuterol or not. They also did not know that the acupuncture needles were retracting. Each patient received these four treatments in randomized order on different days during the study, and then this sequence was repeated two more times. In other words, each patient received all four treatments three times in random order. After each treatment, its effectiveness was measured in two ways: the "maximum forced expiration volume" (FEV, the maximum volume of air the patient can breath out in 1 second) and a subjective self evaluation by the patient. Before you go onto the rest of the summary, answer the following questions.

  1. Explain why this study included the inhaler without Albuterol (Placebo group) and the No Intervention group. Be specific.
  2. What is the "placebo effect" and how was this study designed to identify it? 
  3. What is the hypothesis for this study? Be careful, this is not as obvious as you might think.
  4. What are the independent (manipulated) variables and the dependent (responding) variables in this experiment?
PS: 
Although the design of this experiment is quite simple, research with human subjects, especially subjects with a medical condition, has all sorts of complicating issues. In this study, patients were screened for other medical conditions and medications, the severity of their asthma, tobacco use, experience with acupuncture, and many other factors. You can assume that all 39 participants were matched closely enough that minor differences among them did not affect the results of the research. 

Lesson Three: Results & Conclusions.

Now finish reading the remainder of the summary. In the results section, you will see something called the "P value." In this case, the authors are using a P < .001 for the FEV and the self reported improvement data. Essentially what this means is that differences among groups that reach the .001 level of significance are unlikely (a less than 0.1% chance) to be due to random variation in the data; in other words the differences are "real."  For the FEV there was a P < .001 for the difference between the Albuterol group and the other three groups (there were no significant differences among the remaining 3 groups). For the self reporting data there was a P < .001 between the Albuterol, Placebo, and Acupuncture groups compared to the No Intervention group (there were no significant differences among the first three groups).

You can see these results very clearly in two graphs that come from this study. Graph #1 shows the results of the FEV spirometry test. Graph #2 shows the results of the subjective, self reported improvement. In both graphs the Y axis records the percent improvement from before the treatment to after the treatment. Study the results and conclusions and then answer the following questions.

  1. When you consider just the FEV data, was there a placebo effect? Explain.
  2. When you consider just the self reported improvement data, was there a placebo effect? Explain.
  3. If you were a physician treating a patient recently diagnosed with asthma, would you recommend Albuterol inhalers for treatment or would you have the pharmacy give the patient an inhaler without Albuterol but tell the patient that it did contained the drug? Explain your answer using the data presented in the research summary and the two graphs.
  4. If you were a physician treating a patient recently diagnosed with asthma, would you recommend Albuterol inhalers for treatment or would you recommend acupuncture? Explain your answer using the data presented in the research summary and the two graphs.
  5. The section following the Conclusions lists the pharmaceutical companies from whom the authors have received consulting and lecture fees. Why do you think journals such as the New England Journal of Medicine require this sort of information from scientists who publish their research in their journals?