Review of APA Statistical Guidelines: “Predictive Value of Alexithymia: A Prospective Study in Somatizing Patients”
The August 1999 article in the American Psychologist discusses proper statistical methods and how they should be utilized in journal articles. Using some of the guidelines put forth in the article, I will attempt to show the extent to which Bach & Bach (1995) follow these principles.
The article in question investigates the role of alexithymia as a predictor of persistent somatization. The study was conducted over a two-year period with the consent of thirty patients exhibiting somatoform and anxiety disorders. The personality trait of alexithymia is a disorder in which a person shows an inability to express any emotion that they might be feeling. They also show a limited ability to express participation in fantasy experiences.
It is not made clear exactly what kind of study the researchers are presenting. It is easy to assume, however, that the study is a test of a hypothesis. This made known by the statement of purpose at the end of the introduction. It is said that the purpose is to evaluate the differences in alexithymia scores between different patients over a two-year period and to determine if those scores predict outcome independent from other disorders. So the hypothesis being tested is that high alexithymia scores can predict long term chronicity of a somatoform disorder.
Is the population that the researchers are concerned with made clear? No, not really, the population must be assumed by the subject matter. We are to assume that the study is concerned with people who have a somatoform disorder or anxiety.
The sample is definitely outlined well in the article. The authors make it known to us that the participants for the study were volunteers from a previous study about somatoform disorders. They clearly state the age ranges, sex, and education of all the patients.
For the purposes of this study, nonrandom assignment was used. This was not stated but rather an obvious point. The procedure called for the participants to all receive the same treatment throughout the study. A control group was not used so suspicions must be raised as to the validity of the research.
In terms of variables, the study uses a simple approach to tackle this task. Each patient was grouped by whether or not they exhibited a certain diagnostic disorder at the time of the testing. They were either a yes or a no for five different types of disorders.
As far as questionnaires, these are the only procedural devices used in the study. The authors make it very clear as to what psychometric tests were used. They describe each one and its purpose. The tests used were the Toronto Alexithymia Scale, the Whiteley Index, the Hopkins Symptom Checklist 90, and the Structured Clinical Interview for Diagnoses
In reporting the results, the authors took great care in making sure all data was represented. As the guidelines state, it is better to use common techniques that are proven to work and are understood by most researchers. The data was displayed in an easy to read table that outlined the alexithymia scores for the patients with each of the five diagnoses at outset and after two years. This was more efficient than showing the results in a graphical form which can get misleading.
The analysis that was used was the Pearson’s test for correlation. The test only showed a trend towards significance in the positive corollary direction when comparing the pre-treatment alexithymia scores with chronic somatization. When the authors looked at the other assessment procedures that were used they used a chi-square analysis. All the information was presented in a common format that most readers of research should be familiar.
The discussion of the findings are the most important part of all research papers because it is here that the author must accurately explain what has been presented and competently defend their point. The guidelines set forth by the task force make it clear that the discussion and any conclusions must be in favor and support of further research on the topic at hand.
Bach ; Bach (1995) follow the guidelines most succinctly in their discussion of the paper. They begin by stating that their immediate findings are in agreement with previous research on the topic.
They go on to explain their conclusions about alexithymia saying that the research does not confidently support the hypothesis that alexithymia is a predictor for chronic somatization. They state that the evidence only leans towards a conclusive answer on the topic. They continue to follow the guidelines by not mentioning the need for further research on the topic.
The article is closed with a short paragraph on the possible shortcomings of the research. The authors do not close the door on criticism of the article but instead set the stage for possible extensions of the research in the future.
I would have to say that although the article does not cover all the topics outlined in the APA article it does have statistical merit. The presentation of the data and the analyses used were effective but common enough for anyone interested in the topic to quickly understand the effect shown. Although the research itself does not reach any groundbreaking findings, the paper is presented well enough to definitely insight further, more useful research.