Adolescent Idiopathic Scoliosis (AIS) and Brace Treatment
Studies on Bracing in AIS
Melanie Donnelly, MPH, Lori Dolan, MA, PhDC., Stuart
Weinstein, MD
Peer Review Status: Internally Peer Reviewed
Before discussing these studies it is important for the reader to
appreciate the different types of scientific studies that can be
performed.
| Case series | - These studies look back at charts of patients who were seen for a condition (retrospective data collection). This is not the best way to collect information because usually there is a lot of missing information or inaccurate information.
- These studies follow patients who had a particular treatment to see what happens to them.
- They are not very good because there is no comparison group. That means we don't know if the patients who used a brace would have done just as well without one.
| | Case control study | - This type of study involves comparing 2 groups of patients.
- Usually the comparison is between those who have had a particular treatment and those who have NOT had that treatment.
- In this kind of study the data is collected "retrospectively." This means that researchers collect information about patients by looking in charts. This is not the best way to collect information because usually there is a lot of missing information or inaccurate information.
- Although these studies are improvement over case series studies, we should not draw conclusions based on them.
| | Prospective studies/Observational trials | - These studies follow patients over time who are getting particular treatments, such as bracing. The data is collected as patients are being treated instead of retrospectively.
- In this type of study patients and doctors decide which treatment is best. This is an OK design for a study, but the best type of study is described below.
- A good example of a problem that used these kinds of studies is hormone replacement therapy. There have been a lot of problems with the recommendations that were made based on these studies, and now these recommendations are being questioned.
- There are times in medicine when treatments have been, and are, being used based only on observational studies. When those treatments are examined with a randomized trial it sometimes is found that they in fact were not effective treatments. The NY Times recently published an article examining the use of observational studies. The article highlights a treatment that was started based on observational studies. The effectiveness and safety of that treatment is now being questioned based on information from randomized trials (the best kind of trial). This article is called "In Public Health, Definitive Data Can Be Elusive" and the author is Gina Kolata. The article was published on April 23, 2002. The article can be found at your library or puchased at the site www.nytimes.com.
| | Randomized trials | - These studies are considered the best science. They involve comparisions between 2 or more types of treatements for a single disease.
- They are called randomized trials because the type of treatment a patient recieves is based on chance, like the flip of a coin. This ensures that the two groups of patients are the same EXCEPT for the treatment they receive. This allows for good conclusions concerning which treatment (if any) is best.
- These are the BEST kinds of studies. They have the least numbers of scientific problems.
- Sometimes patients might have a difficult time leaving their treatment decision to chance. However, these studies are only done for problems that have no certain treatment.
- Patients need to understand that randomized trials are done because that is the only way to find out if a treatment is effective.
- If randomized trials were not done then patients would continue to receive questionable treatments. They would also continue to suffer from the side effects of those treatments even if the treatment doesn't work.
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Here is a short description of some other important studies that
have been done on bracing.
1. Case Series study- Lonstein and Winter
http://www.ejbjs.org/cgi/content/abstract/76/8/1207
Finding: They recommend that AIS patients who have a curve of 25 degrees or more and a Risser sign (maturity indicator) of 0 receive brace treatment. Strength: Included many patients over a long time period. Weakness: Treatment failure was defined as an increase of 5 degrees in the curve. This is not always a clinically important change. For example, the curve could progress from 25 to 30 degrees and require no further treatment. This is not the same as a curve progressing from 38 to 43 degrees which then might need surgery.
2. Case Series study - Noonan et al.
http://www.ejbjs.org/cgi/content/abstract/78/4/557
Finding: They found that curves that were braced often had the same outcome as curves that weren't braced. 30% of their braced patients still require surgery. Strength: Looked at a variety of outcomes and those at high risk for getting worse. Counted up the number of patients whose curves got bad enough to require surgery. Weakness: Some patients were as young as 8 years of age when treatment begun. (Usually a patient is considered to have AIS if they are diagnosed after 10 years of age.) The sample size was somewhat small.
3. Case Control Study- Fernandez-Feliberti et al. ( Journal of
Pediatric Orthopedics, Volume 15, 1995)
Finding: They showed that patients who wore a brace were 30% less likely to need surgery than those who weren't braced. Strength: Good follow-up on patients and a nice statistical analysis. Weakness: Control group was made of patients who declined treatment. We know that those who decline treatment usually have different results from those who accept treatment, even if their problems are similar.
4. Case Control Study- Goldberg et al.
http://www.spinejournal.com/
(go to journal contents and then Jan 1, 2001 journal)
Finding: This study found no significant differences between a group of braced patients and a group that was not braced for surgical rates and for greater than 10 degrees of curve progression. Strength: This study matched controls (those who didn't have treatment) to cases (those who wore a brace) in order to assure comparability between groups. Weakness: Small numbers for some outcomes (progression to greater than 45 degrees and surgery)
5. Prospective trial- Nachemson et al.
http://www.ejbjs.org/cgi/content/abstract/77/6/815
Finding: Treatment with a brace successfully halts progression of curves by more than 6 degrees in female patients with single right thoracic curves of 25-35 degrees in magnitude. Strength: Prospective study of usual care in multiple centers. Weakness: Considered failure to be greater than 6 degrees of progression. This may or may not be a clinically relevant outcome. For instance, if a female with a 25 degree curve progresses to 33 and stops is this a failure? If so, why? Is this different from a girl with a 35 degree curve who progresses to 43 degrees? Is this a failure? This study was limited to one type of curve, and did not include lumbar, thoracolumbar or double curves.
6. Randomized Trial
Not yet done- The conflicting evidence from the above studies and others points to the need for a major randomized trial of bracing.
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