THE ANNUAL INCIDENCE of spinal cord injury (SCI),

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1 1185 A Correction Procedure for the Minnesota Multiphasic Personality Inventory 2 for Persons With Spinal Cord Injury Steven W. Barncord, PsyD, Richard L. Wanlass, PhD ABSTRACT. Barncord SB, Wanlass RL. A correction procedure for the Minnesota Multiphasic Personality Inventory 2 for persons with spinal cord injury. Arch Phys Med Rehabil 2000;81: Objective: To develop a procedure that adjusts scoring of the Minnesota Multiphasic Personality Inventory 2 (MMPI-2) for the items related to spinal cord injury (SCI) that skew interpretations with this population, and to assess the accuracy of interpretations resulting from this procedure, standard MMPI-2 scoring, and a previously offered procedure. Design: A criterion study with masked comparisons. Setting: Hospital inpatient physical medicine and rehabilitation unit. Patients: Thirty-four SCI patients between the ages of 18 and 77 years, 19 with complete SCI and 15 with incomplete SCI. Other Participants: Twenty-one nurses, 23 physicians, and 17 psychologists. Main Outcome Measures: Masked MMPI-2 profiles, judged by clinicians for accuracy. Paired t tests comparing profile scales. Results: A correction procedure was arrived at for the MMPI-2 and MMPI-A incorporating adjustments for physical complaints frequently arising from SCI. The new procedure was judged superior to both the standard procedure and the previously offered procedure. Paired t tests of MMPI-2 scales showed that differences from scoring procedures were significant with many scales measuring significance at the p.0001 level. Conclusions: Statistically significant changes in MMPI-2 profiles occur when somatic complaints related to SCI are corrected for. Preliminary results suggest that the application of the new correction procedure increases clinical accuracy. Key Words: MMPI; Spinal cord injuries; Rehabilitation by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation THE ANNUAL INCIDENCE of spinal cord injury (SCI), excluding individuals who die at the scene, is approximately 10,000 new cases yearly, resulting in a prevalence rate of 183,000 to 203,000 persons. 1 During their stay in either the hospital or rehabilitation unit, which average 15 and 44 days, respectively, 1 many of these patients are seen by a mental health professional who typically performs some type of psychologic assessment that may or may not include formal testing. Testing From the Department of Physical Medicine and Rehabilitation, University of California, Davis, Medical Center, Sacramento, CA. Accepted December 1, No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated. Reprint requests to Richard L. Wanlass, PhD, University of California, Davis, Medical Center, 4860 Y St, Suite 1100, Department of Physical Medicine and Rehabilitation, Sacramento, CA /00/ $3.00/0 doi: /apmr can vary from a perfunctory mental status exam to an extensive neuropsychologic evaluation. Since SCI patients personality factors have been linked to rehabilitation outcomes, 2 a thorough evaluation often includes a personality assessment. Measures of distress and depression have been found predictive of both duration of inpatient rehabilitation and performance of self-care at discharge. 2 The Minnesota Multiphasic Personality Inventory (MMPI) and updated MMPI-A and MMPI-2 are among the most widely employed instruments for measuring personality factors, with literally thousands of research reports published in the scientific literature. 3 Physical disease has been linked to changes in MMPI and MMPI-2 profiles, 4-7 and MMPI scores are significantly moderated by SCI. 8,9 Specific research 10 cites MMPI scales Sc, D, Hs, and Hy as the ones most likely to be affected by neurologically relevant responses. Demographic variables also influence MMPI profiles significantly. 11 Development of the MMPI began in Since then many correction procedures have been offered to control for profile interpretation changes for individuals with physical disabilities such as traumatic brain injury, 4,5,12,13 cerebrovascular disease, 6 multiple sclerosis, 7 rheumatoid arthritis, 14 and various neurologic symptoms. 15 Procedures to correct for SCI have been offered by Taylor 9 and by Rodevich and Wanlass. 16 Both Taylor and Rodevich and Wanlass relied on the judgment of physical medicine and rehabilitation specialists to identify items that described physical conditions associated with SCI. Taylor used 9 specialists and Rodevich and Wanlass used 12 physiatrists to construct their correction procedures. Taylor devised a correction procedure for the MMPI incorporating 12 items he referred to as somatically relevant, while Rodevich and Wanlass identified 28 items from the MMPI-2. Taylor s procedure entailed the removal of somatically relevant items, while Rodevich and Wanlass chose to have the specific somatic questions answered by the subjects retrospectively, that is, answered as they would have responded before the SCI. Unfortunately, in developing their correction procedures, neither Taylor nor Rodevich and Wanlass included females in their studies, nor did they account for the impact of comorbid physical ailments such as fractures or brain trauma, nor did they employ subjects other than volunteers who may have represented a self-selecting, higher functioning subject pool. In Taylor s study, the patient sample consisted of 28 white men at or more than 3 months postinjury. Taylor s control group consisted of 20 white, college-educated men. Although Taylor acknowledged Gough s 17 findings that education is significantly correlated with elevations on scales K and Mf, and negatively correlated with elevations on scale F, his study did not control for the significant difference in education between his control and research populations or between his study population and the general population of persons with SCI. All Taylor s subjects had traumatically acquired SCI. Taylor s correction procedure subtracted 12 items, resulting in a suppressed profile that did not recognize that any of the deleted items might have been endorsed before the person had SCI, or independently of the SCI s specific physical effects. Rodevich and Wanlass used a subject pool of 40 males,

2 1186 MMPI-2 CORRECTION PROCEDURE, Barncord categorizing them on the length of time since injury. However, ranges were statistically convenient, but not necessarily correspondent with time frames addressed in other research These authors research excluded persons with SCI who were also under the age of 18 years. Unfortunately, this subject population produced results that could not be generalized to adolescents taking the MMPI-A or to women taking the MMPI-2. The impetus for the current study was the lack of clinical validation of previously offered correction procedures and their exclusion of female subjects. While procedures offered both by Taylor and by Rodevich and Wanlass offered face validity when applied to males with SCI, neither had been scrutinized to see if the altered profiles more correctly reflected the individuals tested. Given this lack of tested ecological validity it was impossible to posit a strong argument for using either procedure instead of the standard procedure. We also questioned whether correction procedures based on the queries of so few clinicians, taken from a single discipline, would produce the most effective correction procedure for the MMPI-2. We hypothesized that a procedure developed from data from a larger number of health professionals in varied fields, such as nurses, physicians, psychologists, and social workers, would produce a more comprehensive procedure. A validation study of the revised interpretations for male and female SCI subjects could then give clinician some assurance that the new interpretations better reflected the SCI patient than those of the standard procedure. The present study endeavored to include many clinical providers in the test s development, to address symptoms of both males and females, and to test the preliminary validity of the resulting procedure. The present study was conducted in three parts: first, to develop a correction procedure that would consider issues not addressed by either Taylor or Rodevich and Wanlass; second, to verify the construct validity of interpretations based on the Rodevich and Wanlass correction procedure; and third, to verify the construct validity of interpretations based on the new correction procedure. PART 1: DEVELOPING THE CORRECTION PROCEDURE Methods Subjects. Members of the American Paraplegia Society, the American Association of Spinal Cord Injury Nurses, and the American Association of Spinal Cord Injury Psychologists and Social Workers, were contacted via addresses obtained from 1998 membership directories. The research questionnaire was successfully transmitted to 132 members, including 50 nurses, 47 physicians, 21 psychologists and 22 social workers. Instruments. Each question from the MMPI-A and MMPI-2 was judged by two doctoral-level psychology staff persons from the Department of Physical Medicine and Rehabilitation to determine its fit as a physical symptom that could result from a SCI. These items were then thematically clustered into 30 domains (eg, Motor Coordination: My hands have not become clumsy or awkward; I frequently notice my hand shakes when I try to do something). Questionnaires were then constructed from the 30 domains encompassing possible physical sequelae. Additionally, respondents were queried about what degree they practice under, when they received their degree, their field of specialization, and how many SCI patients they had treated. Procedure. Questionnaires were sent to nurses, physicians, psychologists, and social workers. Respondents were asked to assign each domain a value representing how often the symptom occurred (in males and females) from SCIs of any etiology (traumatic, surgical, congenital). Responses were separately requested for symptoms found within the first 24 months postinjury and for symptoms present more than 24 months postinjury. The frequency scale was as follows: 0 almost never; 1 sometimes; 2 often; 3 almost always. Results A total of 21 nurses, 23 physicians and 17 psychologists responded. Excluding four incomplete questionnaires that were discarded, response rates were 42% for nurses, 48.9% for physicians, 80.9% for psychologists, and 0% for social workers. Data from completed questionnaires were pooled, and arithmetic means were calculated for each domain. In order to retain only the most robust domains, an exclusion criterion of a mean frequency score 1.5 was applied to each domain. This resulted in the retention of 20 domains on the MMPI-A for 0 to 24 months postinjury and 14 domains for 24 months postinjury. Twenty domains were retained for the MMPI-2 at 0 to 24 months postinjury and 15 domains for 24 months postinjury (table 1). Specific items corresponding to each domain are in table 2. The average number of years that respondents had practiced since receiving their degree was for nurses, 9.40 for physicians, and for psychologists. The average number of patients with SCI reportedly treated by these clinicians was 557 for nurses, 350 for physicians, and 418 for psychologists. PART 2: VERIFYING THE PROCEDURE S VALIDITY Methods Subjects. The subjects consisted of 17 persons (12 men, 5 women) between the ages of 18 and 77 years. Their mean age Table 1: Scores in Domains Above Cutoff of Months Postinjury 24 Months Postinjury Mean SD SEM Mean SD SEM Strength Bowel function Exercise Sexuality Fatigue Balance Ability to work Health Motor Sleep Skin Spasticity Temperature regulation Weight Heart rate/blood pressure Liquid consumption Dizziness Stomach Head/neck pain Shortness of breath Abbreviations: SD, standard deviation; SEM, standard error of the mean.

3 MMPI-2 CORRECTION PROCEDURE, Barncord 1187 Table 2: Items To Be Answered Retrospectively Months Postinjury* Domain MMPI-2 Items MMPI-A Items Yes Yes Ability to Work: Yes Yes Exercise: 188, , 187, 261 Yes Yes Fatigue: 152, Yes Yes Sleep: 3, 39 3, 36 Yes Yes Strength: 175, , 275, 231 Yes Yes Balance: 179, Yes Yes Health: 33, 45, 118, 148 4, 42, 112, 142, 244, 422, 443 Yes Yes Skin: 194, 247, Yes Yes Spasticity: 91 87, 175 Yes Yes Temperature Regulation: 8, 44, 53, 178, 238 8, 41, 50, 222 Yes Yes Motor: 172, 177, 282, , 169 Yes Yes Bowel Function: Yes Yes Heart Rate/Blood Pressure: Yes /////// Head/Neck Pain: 40, 57, 97, 101, 149, 176, 224, , 54, 93, 97, 143, 168, 210 Yes /////// Dizziness: 159, Yes /////// Stomach: 28, 59, , 56, 106 Yes /////// Shortness of Breath: Yes /////// Liquid Consumption: Yes Yes Sexuality: 12, 166, 268 Yes Yes Weight: 143 * Yes indicates a retained domain; ///////, domain not retained. was years and mean education was years. Nine subjects were Caucasian, 5 were Latino, and 3 were African American. Three subjects had acquired SCI through motor vehicle accidents, 3 through a surgical procedure, 5 through violence, 2 through falls, 3 in sporting accidents, and 1 through a disease process. The subjects mean length of time since injury was months. Ten of the subjects had tetraplegia; 7 subjects had paraplegia. Each subject was being treated for SCI or related complications at the University of California, Davis, Medical Center. Subjects were tested in the order in which they presented for treatment on the Physical Medicine and Rehabilitation Service. Procedure. MMPI-2 protocols were gathered with subjects completing their own protocols or being assisted as needed in marking the response sheets. Subjects also completed the 28 items necessary for the Rodevich and Wanlass correction procedure. T-scores were calculated and then coded into interpretive software 22 for analysis. Interpretations were generated for the standard protocols, as well as for those derived from the Rodevich and Wanlass correction procedure. Graphs and T-scores were removed from the interpretations, which were randomly marked A or B and were randomly given to 3 of 5 social work and psychology interns who were masked from the scoring process. Each subject was interviewed for approximately 45 minutes by all 3 interns as a group. The interns were then asked individually to indicate which interpretation more accurately represented the subject. An interpretation was considered accepted when 2 or more interns agreed that it provided the more accurate description. Results Of the 17 subjects tested, 11 were judged to be accurately represented by the interpretation arrived at through the standard scoring protocol, while 6 were judged to be accurately characterized by the interpretation arrived at through application of the Rodevich and Wanlass correction procedure. By gender, the agreement rates for the Rodevich and Wanlass correction procedure were 33.3% for male subjects and 40% for female subjects. This resulted in an overall agreement rate of 35.29% for the Rodevich and Wanlass correction procedure, well below the 64.70% agreement rate of the standard protocol (fig 1). PART 3: TESTING THE NEW PROCEDURE S VALIDITY Methods Subjects. The subjects consisted of 17 individuals (12 men, 5 women) between the ages of 18 and 77 years, with a mean age of years and mean education of years. A total of 9 subjects were Caucasian, 7 were Latino, and 1 was African American. Five subjects had acquired SCI through motor vehicle accidents, 2 through disease process, 3 through violence, 3 through sporting accidents, 2 through falls, and 2 through a surgical procedure. The subjects mean length of time since injury was months. Nine of the subjects had tetraplegia; 8 subjects had paraplegia. Each subject was being treated for SCI or related complications at the University of California, Davis, Medical Center. Subjects were gathered in the order in which they presented for treatment on the Physical Medicine and Rehabilitation Service. Subjects who had participated in Part 2 of this study were not allowed to participate in Part 3. Procedure. MMPI-2 protocols were obtained with subjects completing their own protocols or being assisted as needed in marking the response sheets. Subjects also completed the items necessary for the new correction procedure. For individuals 0-24 months postinjury this required retrospective responses to 49 items while individuals 24 months postinjury retrospectively responded to 39 items. Scale scores were calculated and then coded into the MMPI-2 interpretive software 22 for analysis. Interpretations were generated for the standard protocols, as well as for those employing the new correction procedure. Graphs and T-scores were removed from the interpretations, which were randomly marked A or B and were randomly given to 3 of 5 social work and psychology interns who were masked from the scoring process. The same 5 interns used in Part 2 of this study were retained for Part 3. Each subject was interviewed for approximately 45 minutes by all 3 interns as a

4 1188 MMPI-2 CORRECTION PROCEDURE, Barncord Fig 1. Rodevich and Wanlass MMPI-2 procedure. group. The interns were then asked individually to indicate which interpretation more accurately represented the subject. An interpretation was considered accepted when 2 or more interns agreed that it provided the more accurate description. Paired t tests of the T-scores from the standard protocols versus the corrected or accepted versions of the Rodevich and Wanlass and those generated from the new procedures were conducted. Results Of the 17 subjects tested, 15 were judged to be accurately represented by the interpretation arrived at by the new correction procedure, whereas 2 subjects were judged to be accurately represented by the interpretation arrived at through the standard scoring protocol. By gender, the agreement rates for the new correction procedure were 83.3% for male subjects and 100% for female subjects. This 88.23% agreement rate for the corrected interpretations was well above the 11.76% agreement rate of the standard protocol, and the 35.29% agreement rate of the Rodevich and Wanlass correction procedure (fig 2). The paired t tests of the T-scores revealed significant differences (tables 3, 4). DISCUSSION The physical and psychosocial complaints after SCI, including those related to comorbid physical insults, likely have a significant impact on MMPI-2 or MMPI-A responses. While the Taylor and the Rodevich and Wanlass correction procedures attempt to mitigate these concerns, Taylor s procedure is not applicable to the updated versions of the MMPI (MMPI-2, MMPI-A) and the Rodevich and Wanlass procedure may not produce accurate interpretive statements. The present study s findings were consistent with previous assertions 8 that scales Sc, D, Hs, and Hy were likely to be affected by neurologically relevant responses. The new correction procedure s protocols accepted by health care professionals as accurately representing subjects differed significantly from the standard protocols on 9 of the 13 scales generated. Therefore, not only is the new correction procedure arriving at more accurate profiles, but the profiles are significantly different from those produced by the standard administration. The new correction procedure s improved validity may be attributed to more relevant variables derived from a broader base of professionals. In developing the new procedure we addressed the previous exclusion of females, who constitute approximately 19% of the SCI population, 1 we required clinicians to respond to symptoms found in patients of either gender, and we included both genders (29.5% female, 70.5% male) in the clinical validity studies. The present study addressed the exclusion of individuals under the age of 18 years. These individuals represent a portion of those affected with SCI each year who are between the ages of 16 and 30, which account for 61.1% of all SCI injuries, 23 as well as the 4.9% of the total affected population who represent the 0 to 15 years of age group, 24 by requesting that clinicians respond to symptom categories that could then be applied to items in the MMPI-2 or MMPI-A. Individuals under the age of 18 years were not, however, included in the validity samples.

5 MMPI-2 CORRECTION PROCEDURE, Barncord 1189 Fig 2. Barncord and Wanlass MMPI-2 procedure. Because this section of the present research is preliminary, we are unable to speak to this technique s clinical validity with the MMPI-A, but further study in this area is expected. Many articles have addressed changes in physical and psychologic symptoms, 19,20,28-31 and subjective experience of quality of life 18,30 in the SCI population over time. Previous correction procedures that did not change their formats accordingly risked invalidating results because of temporal changes. MMPI-2 Scale Table 3: Paired t Tests of MMPI-2 Protocol t Scores Barncord & Wanlass Standard: Corrected Rodevich & Wanlass t Value p Value t Value p Value L * * * * F K HS D HY PD MF PA * * * * PT SC MA * * SI * * * * * Not significant at p.05. This conclusion was supported by the different symptom profiles generated for 0 to 24 months postinjury and 24 months postinjury by respondents to the questionnaire. While Taylor s procedure may be valid when applied to individuals tested during the first 3 months postinjury, its applicability is questionable after that time. Perhaps the single most important difference between the present study and those of Taylor or Rodevich and Wanlass is in MMPI-2 Scale Table 4: Paired t Tests of MMPI-2 Protocol t Scores Barncord & Wanlass Standard: Accepted Rodevich & Wanlass t Value p Value t Value p Value L * * * * F K HS D HY PD MF * * * * PA * * * * PT * * SC MA * * SI * * * * * Not significant at p.05.

6 1190 MMPI-2 CORRECTION PROCEDURE, Barncord the area of clinical validation. No previous attempts were made to judge the clinical accuracy of interpretations that were based on tests altered by previous correction procedures. While the data provided in the validity section of the present pilot study must be questioned because of a small number of subjects, pooled from a single locale, the present study is the only one to attempt validation of a correction procedure to date. The present study expanded the breadth and scale of input used to arrive at a corrected interpretation. While the previously offered procedures used 9 or 12 physiatrists to construct their procedures, the present study drew from 61 clinicians including nurses, physicians, and psychologists. Clearly the authority of our conclusions would benefit from a larger trial; ultimately, the most important conclusion from the present research is that standard administration of the MMPI, MMPI-A, and MMPI-2 must be questioned when applied to persons with SCI, and that the clinician must become, in the words of Roger Greene, 32 an informed skeptic when interpreting MMPI profiles. Acknowledgments: The authors acknowledge the assistance and support of the faculty and staff of the University of California, Davis Medical Center, Department of Physical Medicine and Rehabilitation. References 1. National Spinal Cord Injury Statistical Center. Spinal cord injury: facts and figures at a glance. Birmingham (AL): University of Alabama at Birmingham; Malec J, Neimeyer R. Psychological prediction of duration of inpatient spinal cord injury rehabilitation and performance of self-care. Arch Phys Med Rehabil 1983;64: Ben-Porath YS, Graham JR. Forensic applications of the MMPI-2. 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