Part 1 in a series on clinical trials in wound care
For part 2, click here
by Michel H.E. Hermans, MD
To do a Randomized Controlled Trial within a reasonable time frame, the disease to be studied should be common and the patient population large and accessible. In addition, preferably the effect of the treatment should be fast and specific.
In the pharmaceutical environment these circumstances often exist. Nearly 68 million people in the US suffer from hypertension1,2 and it should be easy to find patients for a clinical trial. The study objective is also relatively simple: lowering blood pressure (of course I am simplifying here).
Studying the effect of a treatment on wounds (acute, i.e. burns, as well as chronic, i.e. pressure) is much more difficult. The lesions are less common and the right patient more difficult to find. Trials also frequently are an afterthought in the development of a new product or indication or, if their execution is included in a business plan, the cost and complexity of virtually any type of trial is often underestimated. However, trials often are necessary for product registration and/or reimbursement.
In this blog, I describe a number of typical problems that occur when doing a wound care trial. In this context it is important to realize that, in many aspects, trauma trials may be different from ulcer (so called chronic wounds) trials.
The Prevalence of Lesions as a Factor in Conducting a Clinical Trial
The prevalence of acute wounds is uncertain within a specific time frame. The patient population in trauma and burn centers varies widely over time, as well as with respect to the type of lesion(s). For example, barbecue accidents (often resulting in partial-thickness flash burns) are more common during the summer while house fires, often leading to deep burns, are more common during the winter. The prevalence of ulcers is much more consistent.
The unpredictable availability of patients that fit inclusion/exclusion criteria often leads to trials that take much more time than originally predicted, with consequences for the study budget and timing of registration and reimbursement. In addition, many investigators overestimate the number of lesions they can generate. Because of the nature of the disease (the wound) and its treatment (surgery, dressings) it is also very difficult to do blinded studies.
The Typical Trauma Patient vs. The Typical Ulcer Patient
A typical trauma patient is relatively young when compared to a typical ulcer patient. As an example: partial-thickness burns are a relatively common occurrence in young children. Consequently, the type of patients that could be enrolled in a partial-thickness burn trial is different from a "standard" trial since many trials do not allow children (patients under 18 years) to be enrolled. Again, for certain types of trauma this has timing consequences.
In contrast, most patients with ulcers are elderly (although, paraplegic patients with pressure ulcers often are younger) with the consequence of concomitant diseases as mentioned before. Particularly for elderly patients, limitations in mobility often make the trip to the wound care center a difficult or expensive (taxi's) one.
1. Centers for Disease Control. 2011. www.cdc .gov/Features/HighBloodPressure.
2. Egan BM, Zhao Y, Axon RN. 2010. U.S. trends in prevalence, awareness, treatment, and control of hypertension, 1988–2008. Journal of the American Medical Associa¬tion 303(20): 2043–50.
3. U.S. National Institutes of Health. 2011. Fast Facts on Diabetes. Available at http:// diabetes.niddk.nih.gov/dm/pubs/statistics/ #Diagnosed20.
About the Author
Michel H.E. Hermans, MD, is an expert in wound care and related topics, trained in general surgery, trauma care and burn care in the Netherlands. He has more than 25 years of senior management experience in the wound care industry. He has conducted a large number of clinical trials relating to devices and drugs aimed at wound care and related indications and diseases. Dr. Hermans speaks internationally and has authored many published works relating to wound management.
The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.