Thursday, April 8, 2010

What's In An Experiment?

As a CFer, I get impatient when it takes so long for new drugs to come out. The whole process takes years. And sometimes the drug doesn't even get approval from the FDA. It's a frustrating process, when every day counts.

While writing up a plan for the exercise bike challenge, I thought about what makes a good experiment. Being a scientists, I know that a lot goes into the experimental process. An experiment must be able to be reproduced by another scientist and still have relatively the same results. What else makes a good experiment? I've decided to use the bike challenge as an example.

What is the hypothesis?

A good experiment needs a hypothesis.  The hypothesis doesn't need to be correct, it just provides direction.  For the bike experiment the hypothesis would be, "Performing aerobic exercise while inhalation of medication will improve lung function more so than performing aerobic exercise or inhaling medication alone."

How will the hypothesis be tested? 

Since the idea was presented to me in the form of an exercise bike, that's what I decided to use.  Also, in the case of CF females, some coughing attacks are really brutal on the bladder.  Sitting allows for more control and fewer "accidents."  Pulmonary Function Tests and O2 sats are a good way for measuring lung function.  PFTs measure how much air the lungs can take in.  O2 sats measure how much of that oxygen the lungs take in is actually going into the bloodstream.  Ideally, the measurements would be taken before starting the experiment and every two weeks during the experiment.

I chose Hyper-Sal for the inhaled medication because, again, that is what my doctor recommended.  Hyper-Sal is a good choice because it's a saline solution, relatively cheap, and I won't feel guilty if the hypothesis is incorrect (no way am I risking the waste of my Pulmozyme).

What are the controls?

When working with CFers there are several variables to consider: age, sex, lung function, medications, diet, activity level, etc.  Since it would be impossible to set controls for every possible variable, I'm listing the two controls that are absolutely needed.  One control would do the exercise bike according to the schedule provided, however, they would not be taking any inhaled medications during their rides.  Another group would stick to their normal routines.  No bike therapy added.  All participants would use the same brand and model exercise bikes.  They would all use the same brand compressor machine and the same brand nebulizers.  All participants would use the schedule provided by the experimenter.

What are the methods used?

Participants would follow a 12 week course provided to them.  They would use equipment provided to them. Every two weeks they would check in for PFTs and O2 sats.

Every experiment would have its results and conclusions.  Some conclusions include ideas for more testing.  Testing different medications or grouping people by lung function would be another way to try this experiment.  If the hypothesis was proved incorrect, then explanations as to why are in order.  If correct, then testing on how many times daily would provide the most benefit while still being feasible with a person's schedule would be needed.  Also, if the hypothesis proved correct experimentation would need to be done to answer why the hypothesis is correct.

Obviously, this isn't by any means a formal presentation of an experiment.  I thought it would be a good idea to give some insight on what goes into the planning of an experiment.  It gets more complex with new medications.