Selected Excerpts From:

"A Comparison of the Kennedy Axis V and the Global Assessment of Functioning Scale"

"As changes in the mental health field require more accountability and efficiency, there is an increasing need for short, but accurate indicators of the severity of mental illness (Jones, et al., 1995). Clinician-scored "global" assessment instruments provide a quick and easy way to track and communicate the progress of clients. In this article, we describe a study in which we evaluated and compared two instruments that can be used to briefly assess the overall functioning of clients with serious mental illness.

The best known and probably most frequently used global assessment instrument is the Global Assessment of Functioning (GAF) Scale (Hall, 1995). This instrument has been available for many years and is widely used both clinically and in research projects (Spitzer, et al., 1994). Another global assessment instrument, the Kennedy Axis V (K Axis), is relatively new and, as yet, little research is available documenting its effectiveness. In this study, we compare certain statistical and qualitative characteristics of these two instruments."

*per personal communication from the author, J. A. Kennedy, (5/3/99), an initial analysis of a validation project has been completed and will appear in his book, KENNEDY AXIS V, [renamed MASTERING THE KENNEDY AXIS V and subsequently published by American Psychiatric Publishing, Inc., 2003]...


"The K Axis (originally known as the Axis V Subscales) was developed by James A. Kennedy, MD, for use with the DSM-III-R Axis V and was published in FUNDAMENTALS OF PSYCHIATRIC TREATMENT PLANNING (Kennedy, 1992). It was subsequently upgraded to the DSM-IV and renamed the Kennedy Axis V. The K Axis is a clinician-scored instrument measuring general client functioning in six areas**:

1. psychological impairment

2. social skills

3. violence

4. activities of daily living (ADL)-occupational skills

5. substance abuse

6. medical impairment

Ratings can range from a low of 5 (dysfunctional) to a high of 100 (no symptoms). The scale provides anchor definitions for each of the ten intervals. Rather than a continuous scale such as used for the GAF, scores are rounded to the nearest multiple of 5 (e.g., 43 becomes 45, 62 becomes 60). Scores of the first four subscales are added and divided by four to generate a score that is roughly equivalent to the GAF Score (GAF-EQ). Other custom scale scores and profiles can be developed using various combinations of subscales. The scoring sheet provides space to include a brief description of relevant symptoms and behaviors under each subscale score. The K Axis can be rated by the client's primary therapist or case manager, or by a treatment team, with each member of the team assessing the subscales with which he or she is most familiar."

**An optional seventh subscale, "Ancillary Impairment," to measure the client's environmental, financial, and legal situation, has been added in the current version of the K Axis.



"Since the K Axis is a multidimensional measure (i.e., it provides a score for each of six different dimensions), it generates a more complete clinical picture than can be obtained from a single score. Clinicians in the present study reported that the K Axis was also relatively short and easy to score, and estimated that, WHEN THEY WERE FAMILIAR WITH A CLIENT, it took 2-5 minutes to complete the K Axis, a completion time similar to that of the GAF. However, the author indicated that considerably more time could be required if the clinicians included narrative descriptions with each subscale."


"There are several moderate to high correlations between the Current GAF score and the following four K Axis subscale scores:

. Subscale 1 (psychological impairment) r = .86

. Subscale 2 (social skills) r = .72

. Subscale 3 (violence) r = .50

. Subscale 4 (ADL-occupational skills) r = .64

Relatively low correlations exist between the current GAF scores and K Axis Subscale 5 (substance abuse) (r = .27) and K Axis Subscale 6 (medical problems) (r = .19), indicating that these subscales are measuring something different from the GAF score.

There are also high correlations between the GAF-EQ score and the Current GAF (r = .82), which seems to indicate they are measuring something similar."

"…the present study found high correlations between GAF scores and scores on the K Axis Subscale 1 (psychological impairment), indicating they are measuring a common construct."


"One formal inter-rater reliability study has been completed on the K Axis (John Marc Bilezikian, Ph.D., Dissertation, Illinois School of Professional Psychology, Chicago, 1998). That study found that the K Axis has satisfactory reliability. Inter-rater reliability results of that study were psychological impairment (r = .90), social skills (r = .89), violence (r = .80), ADL-occupational skills (r = .87), substance abuse (r = .83), medical impairment (r = .91), and GAF (r = .93).

The author of the measure has also indicated that informal assessments found that interrater reliability was good if raters received a reasonable amount of training (Kennedy, personal communication, 1999). The methodology of our study did not allow for independent verification of interrater reliability. Since these subscales are based on a single score, reliability based on internal consistency would not be appropriate.

Kennedy also reported that initial results of the validation study* mentioned earlier indicated that the scale has predictive validity. Preliminary work indicates that there is a significant relationship between length of hospital stay and level of functioning as measured by scores on each of the first four subscales on the K Axis and the GAF-EQ. In our study, we found high correlations between K Axis subscale 1 (psychological impairment) and the current GAF scores, indicating a degree of construct validity. Additionally, expert reviewers agree that the scales appear to have face validity."


"Most of the differential functioning differences made sense. The primary differences involved diagnosis, age, and to some extent gender:

. Clients with diagnoses of mood disorders scored higher on all subscales except for medical impairment.

. Older age groups scored higher on all subscales except for medical impairment. The difference was more clearly linear within diagnostic category 2 (Mood Disorders), but this may be related to the small number within certain age groups within diagnostic category 1.

. Females tended to score higher on all subscales except for medical impairment.

. Mean scores on Subscale 6 (medical impairment) typically reversed trend of other subscales."



. SCORING. The GAF is somewhat faster to score, especially until clinicians become familiar with the K Axis subscales.

. RESEARCH SUPPORT. There is considerably more published research and clinical history for the GAF.


. CLINICAL USEFULNESS OF DATA. The K Axis provides a more complete clinical picture (multidimensional), as well as a GAF equivalent score for situations requiring a single score

. USEFULNESS FOR QUALITY IMPROVEMENT OR PROGRAM EVALUATION. Again, the K Axis provides more specific information for quality improvement, and when appropriate, can generate custom scales using various sets of the subscales.


. TRAINING OF CLINICIANS. Training is important in order to obtain adequate reliability for either instrument. Although the K Axis is probably more difficult to learn to score initially, it may be easier to rate accurately in the long run because of the greater specificity of its scales.

After an evaluation of the strengths and weaknesses of the two instruments, initial results on the K Axis look promising. It appears to be a good compromise between providing a more complete picture of the client, yet still being relatively quick to complete. An approximation of the GAF score can be computed which would be useful for clinical and research comparisons. Additional research should be conducted to evaluate the interrater reliability of the K Axis, as well as its ability to discriminate between the functioning of individuals across placement settings and specific forms of functional impairment."


1. Jones SH, Thornicroft G, Coffey J, Dunn G. A brief mental health outcome scale: Reliability and validity of the Global Assessment of Functioning (GAF). Br J Psychiatry 1995;166:654-9.

2. Hall RCW. Global assessment of functioning: A modified scale. Psychosomatics 1995;36:267-75.

3. Kennedy JA. Fundamentals of Psychiatric Treatment Planning. Washington, DC: American Psychiatric Press: 1992.

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