Anxiety Rates

Beck Anxiety Inventory and the Incidence Rate of Anxiety
Michael Bell
Carlow University

Beck Anxiety Inventory and the Incidence Rate of Anxiety
Anxiety is defined as “an abnormal and overwhelming sense of apprehension and fear often marked by physiological signs (as sweating, tension, and increased pulse), by doubt concerning the reality and nature of the threat, and by self-doubt about one's capacity to cope with it (Merriam-Webster's Collegiate Dictionary (11th edition), n.d.).  The Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM- IV) states that the criterion for Generalized Anxiety Disorder (GAD) includes excessive anxiety and worry which occurs for at least 6 months.  GAD is characterized by the subject finding it difficult to control the worry and it typically presents the following symptoms: restlessness, fatigue, trouble concentrating, muscle tension, insomnia, and irritability (American Psychiatric Association [DSM-IV], 2000).
Narrow, 1988 found that anxiety affects nearly 19 million Americans. A second study suggests that the incidence rate of anxiety is nine cases per 1000 persons per year (Murphy et al., 1988). The DSM –IV suggests that anxiety disorders are one of the most prevalent disorders diagnosed (American Psychiatric Association [DSM-IV], 2000).
Anxiety can be measured using the Beck Anxiety Inventory (BAI). The BAI consists of 21 items, each of which describes a symptom of anxiety.  The participant is asked to rate each of these items based on how much he or she is bothered by each symptom over the past week on a four-point scale ranging from zero to three. The items are totaled to obtain a score which can range from zero to 63. The BAI is recommended for use in an adult population in a clinical or research setting ("Beck anxiety inventory," n.d. ). Alternative instruments of measurement for anxiety include the Hamilton Anxiety Scale (HAM-A), the Hopkins Symptom Checklist (SCL-90), and the Hospital Anxiety Depression Scale (HAD).   The BAI was used to measure anxiety in this study.
Anxiety, if left untreated, can lead to serious psychological and health consequences. A recent study suggests that in 57% of people who have depression, anxiety disorders preceded the depression and that in 18%, depression preceded their anxiety disorders (Lamers et al, 2011).  There is also a suggestion of comorbidity with depression. Another recent study found that of subjects with a depressive disorder, 67% had a current and 75% had a lifetime comorbid anxiety disorder. Of subjects with a current anxiety disorder, 63% had a current and 81% had a lifetime depressive disorder (Lamers, 2011).  Other studies suggest that anxiety can lead to increased risk for hypertension and coronary disease because of hormones released during periods of excess anxiety (Player and Peterson, 2008). Data from several studies also indicate an association of headache with anxiety disorders. A recent study examined 100 migraineres using the Penn State Worry Questionnaire as a screening tool and found that 37.0% of those participants had generalized anxiety disorder (Mehlsteibl, 2011).
The purpose of this study is to examine the incidence of anxiety in a convenience sample comprised of friends and acquaintances to the graduate student researchers.
            Seventy-four friends and acquaintances of graduate students in a research methods class participated in the study. Participants were collected by a sample of convenience.  All participants were over the age of eighteen.  Participants had no known anxiety disorder or preexisting issue with anxiety.

This study used the Beck Anxiety Inventory (BAI: Beck Anxiety Inventory).  The purpose of the BAI is to measure anxiety and to discriminate anxiety from depression. The BAI is recommended for use in clinical and research settings with adults age eighteen or older. The BAI has high internal consistency and item-total correlations ranging from .30 to .71.  The correlation of the BAI with the HARS-R and HRSD-R was .51 and .25.  The correlation of the BAI with the BDI was .48.
Sixteen graduate students in a research methods class approached friends and acquaintances using a sample of convenience. Participants had no known health concerns and were age eighteen or older. Participants were provided with informed consent.  Participation in the study was used as consent. Participants were given the BAI and were instructed to complete it to the best of their ability. Students collected the BAI in a manner to insure confidentiality and anonymity.
Descriptive statistics were applied to the data that yielded the following results:
N                     M                     MDN               SD
74                    12.66               9                      9.75
            This study had a sample of seventy four participants and found a mean of 12.66, a median of 9 and a standard deviation of 9.75.
            Using one standard deviation, one and one half standard deviation, and two standard deviations to define slightly elevated, moderately elevated, severely elevated, the following cut scores are assigned:
Slightly elevated: scores that fell between 22.41 and 27.29                                                moderately elevated: scores that fell between 27.29 and 32.16
severely elevated: scores that fell at or above 32.16
Cut scores of this study found that 22.5 % of participants had slightly elevated scores, 9.9 % had moderately elevated scores, and 4.1 % had severely elevated scores.
            A group of 16 graduate students, in a research methods class, collected a convenience sample of BAI scores from friends and acquaintances to explain the incidence rate of anxiety in a population. The current findings suggest that 4.1% are at significant risk for anxiety.  In addition, 32.4 % of the sample had scores that would suggest the need for future evaluation to rule out anxiety disorder.
            Prior research suggests that anxiety disorders affect nearly 19 million American adults (Narrow, 1988). Another study using data gathered in a 16-year follow-up of an adult sample found an incidence rate for anxiety disorder and depression to be approximately nine cases per 1,000 persons per year. Incidence tended to be higher among relatively young persons. A prevalence rate of approximately 10% to 15% was found for depression and anxiety disorders aggregated together (Murphy et al., 1988).
            This study did have some limitations. First, this study used a small sample size that was not random and also used a sample of convenience. Secondly, standardized procedures were not used when administering the BAI and participants were given only one measure of anxiety. Also, it is unknown if participants’ anxiety was situational.
            Future research should use a larger sample size as well as a random sample.  More than one measurement of anxiety should be incorporated and standardized procedures should be utilized when administering the study.

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Beck anxiety inventory. (n.d.). Retrieved from http://www.cps.nova.edu/~cpphelp/BAI.html
Lamers, F., van Oppen, P., Comijs, H. C., Smit, J. H., Spinhoven, P., van Balkom, A. M., &
            Penninx, B. H. (2011). Comorbidity patterns of anxiety and depressive disorders in
            A large cohort study: The Netherlands Study of Depression and Anxiety (NESDA).
Mehlsteibl, D. D., Schankin, C. C., Herring, P. P., Sostak, P. P., & Straube, A. A. (2011).
            Anxiety disorders in headache patients in a specialized clinic: prevalence and
            symptoms in comparison to patients in a general neurological clinic. Journal Of
            Headache and Pain, 12(3), 323-329.
Merriam-Webster’s Collegiate Dictionary (11th ed.). (2005). Springfield, MA: Merriam Webster.
Murphy, J. M., Oliver, D. C., Monson, R. R., Sobol, A. M., & Leighton, A. H. (1988). Incidence
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            disorders. One-year prevalence best estimates calculated from ECA and NCS data.
            Population estimates based on U. S. Census estimated residential population age 18
            to 54 on July 1, 1998. Unpublished.

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