Perceived Suitability and Usefulness of DSM-III vs. DSM-II in Child Psychopathology

Transcription

1 Perceived Suitability and Usefulness of DSM-III vs. DSM-II in Child Psychopathology ADA C. MEZZICH, PH.D., AND JUAN E. MEZZICH, M.D., PH.D. The comparative suitability, clarity, and usefulness of DSM-III vs. DSM-II and of the various axes of the former system were assessed on the basis of the perceptions of regional random samples of clinical child psychologists and child psychiatrists. The conceptual appropriateness, definitional clarity, and usefulness of psychiatric disorder categories were perceived to be higher in DSM-III than in DSM-II. Axis V was particularly high in these regards. The sampled psychologists and psychiatrists appeared to show similar levels of acceptability for DSM-III. Journal of the American Academy of Child Psychiatry, 24, 3: , An important criterion in the evaluation of a diagnostic system is its clinical acceptability, i.e., its suitability and usefulness as perceived by qualified clinicians. Certainly there are other critical evaluative concerns, such as interrater reliability (a prerequisite for validity) and predictive validity (the ability to predict course and outcome). However, clinical acceptability is particularly critical regarding the actual implementation of a diagnostic system in regular professional work. The literature shows three studies of the perceived suitability and usefulness of multiaxial systems, explicitly or implicitly compared with traditional uniaxial systems. Rutter et a1. (1975) compared their tetraxial system for child psychiatry to the Eighth Revision of the International Classification of Diseases (lcd-8) and found, in general terms, that the multiaxial system was much preferred by the 22 participating child psychiatrists, both in theory and in practice. Cantwell et a1. (1979) compared the 1977 draft of DSM-III to DSM-II, on the basis of ratings made by 20 child psychiatrists of the University of California at Los Angeles, and found that in 70% of the ratings DSM-III was considered to be more useful than DSMII. While the level of overall difficulty reported for the whole multiaxial system was only mild, many of the participants reported difficulties when rating specific axes, particularly "Clinical Psychiatric Syndromes" (46%) and "Psychosocial Stressors" (27%). Finally, Spitzer and Forman (1979), through the national field trials that preceded the adoption of DSM-III, found that out of the 271 psychiatrists who volunteered to participate and who completed a questionnaire, 81% indicated that the multiaxial system was a useful addition to traditional psychiatric diagnosis. The above-mentioned studies provided a broad indication of the perceived clinical usefulness of multiaxial systems in general, the last two with particular reference to DSM-III. However, they were based on the judgments of groups of clinicians who were not systematically representative of large populations of qualified professionals. Furthermore, the information they provided about specific axes was quite limited and indirect. The present study was aimed at assessing certain aspects of the suitability and usefulness of the axes of DSM-III vs. DSM-II, as perceived by a regional random sample of clinical child psychologists and child psychiatrists upon rating a set of child and adolescent case histories. Method This study was based on the participation of qualified clinical child psychologists and child psychiatrists randomly sampled from the Directories of the American Psychological Association and the American Academy of Child Psychiatry, respectively, and living in the westernmost states of the United States (i.e., Hawaii, Alaska, Washington, Oregon, California, and Nevada). A total of 134 clinicians completed the study, including 35 psychologists and 32 psychiatrists who used, by design, DSM-II (American Psychiatric Association, 1968) and 37 psychologists and 30 psychia- Received Sept. 27, 1983; revised Feb. 20, 1984; accepted April 17, Frum the Western Psychiatric Institute and Clinic, University of Pittsburgh, 3811 O'Hara St., Pittsburgh, PA The authors wish to thank the 134 sampled psychologists and psychiatrists who completed the study; Doctors Michael Rutter and Daoid Shaffer for furnishing the 27 case histories used in this study; Dr. Robert L. Spitzer and the American Psychiatric Association for the DSM-III Manuals they provided for each of the participating clinicians; and Mr. Gerald A. Coffman for his a.~sistance in data analysis. This study wa.~ sponsored in part by NIMH grant MH # /85/ $02.00/ by the American Academy of Child Psychiatry. 281

2 282 A. C. MEZZICH AND J. E. MEZZICH trists who used DSM-III (American Psychiatric Association, 1978). Ratings were made by these clinicians on 27 case histories of child and adolescent psychiatric patients, kindly furnished by Doctors Michael Rutter and David Shaffer. Details on the case histories, the participating clinicians, and the schedule for the allocation and rating of case histories are presented in the preceding paper (Mezzich et al., 1985). For each assigned case history the participating clinician was asked to complete a study questionnaire which, in addition to a diagnostic formulation, required ratings on several aspects of the suitability, usefulness, and clarity of specific components of either DSM-II or DSM-III. The items investigated included the following: 1. Quality of the categorization of psychiatric disorders (DSM-II and Axes I and II of DSM-III): a. Suitability of the available categories of psychiatric disorder for the case at hand; b. Conceptual appropriateness (consistency with clinical experience) of the diagnostic categories used for the case; c. Clarity of the definitions or criteria for the diagnostic categories used for the case; and, d. Scope of the DSM-III criteria used for diagnosing a case. 2. Usefulness of the instructions for diagnosing physical disorders (DSM-III Axis III). 3. Quality of Axes IV and V of DSM-III. For each axis, the following aspects were investigated: a. Appropriateness of the conceptual framework; and, b. Clarity of the scale. Also investigated were the time taken to complete each diagnostic formulation, the manageability of the diagnostic manual used, and the value of the nondiagnostic-criteria information contained in the DSMIII Manual (e.g., associated features and differential diagnosis for each psychiatric disorder, and decision trees). For each item, the following 4-point scale was used (with the wording adjusted to reflect the subject of the question): 1 = very inappropriate, 2 = more inappropriate than appropriate, 3 = more appropriate than inappropriate, and 4 = very appropriate. The only exceptions were the time taken to complete the diagnostic formulation, which was measured in minutes, and the scope of the DSM-III diagnostic criteria, which was assessed using a 5-point scale, from 1 = too broad to 5 = too narrow. Data analysis first involved a determination of the frequency distribution of the ratings made by the participating psychologists and psychiatrists (both separately and combined) on selected aspects of DSMII and DSM-III. Furthermore, the significance of the differences between mean values of the ratings made by the two professional groups for DSM-II and DSMIII were assessed via t-tests. Results Table 1 presents the ratings made by psychologists and psychiatrists on the conceptual value and clarity of the diagnostic categories of psychiatric disorder in DSM-II and DSM-III. Regarding the suitability of the available psychiatric disorder categories, 73% of the psychologists and psychiatrists rated DSM-III as either "more suitable than unsuitable" or as "very suitable," while 41% of those clinicians rating DSMII employed these ratings. Concerning the conceptual correctness (the consistency with clinical experience) of the diagnostic categories used for the case at hand, 83% of the combined clinicians rated DSM-III at the two highest levels, while this was the case for only 56% of those rating DSM-II. Finally, with regard to the clarity of the definitions of the categories used for diagnosing the case histories, 77% of the clinicians rated DSM-III at the two highest levels, while this was true for only 55% of those rating DSM-II. For each one of these three variables, the mean values for DSM-III were significantly higher than those for DSM-II, as judged by psychologists and psychiatrists separately and together. Also, for all three variables no statistically significant difference between the ratings of psychologists and psychiatrists was noted. The diagnostic criteria of DSM-III were additionally appraised regarding their scope, which was found to be "satisfactory" by 57% of the raters, "somewhat or very broad" by 19%, and "somewhat or very narrow" by 24%. Again, no significant difference was obtained between psychologists and psychiatrists. Table 2 displays ratings on the value of additional material in the DSM-III Manual, intended to assist in the characterization and differential diagnosis of psychiatric disorders. Regarding the perceived usefulness of syndrome descriptive information other than diagnostic criteria (e.g., associated features, differential diagnosis discussions, etc.), 76% of the raters considered this "more useful than useless" or "very useful." Concerning the consistency between decision trees and the corresponding diagnostic criteria and other descriptive statements for psychiatric syndromes, 69% of the clinicans rating DSM-III used the two highest levels of the consistency scale. In regard to the usefulness of the decision trees for diagnosing the case at hand, 48% of the clinicians rated them with the two highest levels of usefulness. In no case

3 PERCEIVED SUITABILITY OF DSM-III AND DSM -II 283 TABLE 1 Concept ual Value and Clarity of the Diagnostic Categories of Psychiatric Disorder in DSM-ll and DSM-lll as Judged by Psych ologists, Psychiatr ists, and Both Groups Combined Psych ologists Psychologists and DSM-I1 DSM -III DSM -I1 DSM -III DSM -I1 DSM III (N = 105) (N = 110) (N = 96) (N = 90) (N = 201) (N = 200) A. Suitability of the Ava ilahle Categories 1. Very un su itahle 18.1% 2.8% 17.9% 1.2% 18.0% 2.1% 2. More un su itable than suita- 38.1% 23.9% 44.2 % 26.7% 41.0 % 25.1% hie 3. More suitable t han un suita- 37.1% 53.2% 33.7% 46.5% 35.5% 50.3% hie 4. Very suitable 6.7% 20.2% 4.2% 25.6% 5.5% 22.6 % Mean score " ' " ' " B. Conceptual Correctness of t he Diagnostic Definition s Used 1. Very incorrect 10.5% 1.9% 10.4% 2.2% 10.4% 2.0% 2. More inco rrect than correct 27.6% 14.8% 39.6% 14.6% 33.3% 14.7% 3. Mor e correct than inco rrect 58.1% 66.7% 43.8% 61.8 % 51.2% 64.5% 4. Very correct 3.8% 16.7% 6.3% 21.3% 5.2% 18.8% Mean score " '" '" C. Clarity of Diagnosti c Criteria or Defini t ion s Used 1. Very unclear 12.4% 1.9% 13.7% 1.1% 13.0% 1.5% 2. More unclear than clear 25.7% 16.8% 40.0% 27.3% 32.5% 21.5% 3. More clear than unclear 53.3% 60.7 % 35.8% 54.5% 45.0% 57.9% 4. Very clear 8.6% 20.6% 10.5% 17.0% 9.5% 19.0% Mean sco re ' ' " Note: DSM III's ratings were significantly higher than DSM -I1's, at p < 0.05 ('), P < 0.01 ("), and p < ("'). was there a significant difference between the ratings made by psychologists and psychiatrists. Table 3 gives the ratings of various aspects of the descriptive value of Axes III, IV, and V as perceived by psychologists, psychiatrists, and both groups combined. The instructions for diagnosing physical disorders (Axis III) were judged as "more useful than useless" or "very useful " by 45% of clinicians from both professional groups combined. The conceptual framework of Axis IV (overall severity of psychosocial stressors) was judged to be either "more appropriate than inappropriate" or "very appropriate" by 70% of t he participating clinicians. The clarity of the Axis IV scale was perceived as either "more clear than unclear" or "very clear" by 78% of t he participating clinicians. The appropriateness of the conceptual framework of Axis V (highest level of adaptive functioning in the past year) was judged to be in the two highest levels of the appropriateness scale by 85% of psychologists and psychiatrists combined. The clari ty of the Axis V scale was perceived as being in the two highest levels of the clarity scale by 84% of both professional groups. In none of these was a statistically significant difference found between the ratings made by psychologists and psychiatrists. The perceived manageability of the diagnostic manuals was assessed using a four-point scale (from 1 = very unmanageable to 4 = very manageable), and found to be significantly higher for DSM-II (mean = 2.8) than for DSM-III (mean = 2.5). The time taken to appraise each case history and formulate a full diagnosis for it was sign ificantly shorter for DSM-II (mean = 24 minutes) than for DSM-III (mean = 48 minutes). Discussion A major finding of the present study was t hat t he conceptual value and definitional clarity of psychiatric syndromes were perceived by both psychiatrists and psychologists as being higher in DSM -III t han in DSM-II. Additional comments formulated by the participants pointed out the greater usefulness of certain DSM-III categories of psychiatric disorder. Of particular mention were the enhanced descriptive differentiation afforded by the greater number of disorders of childhood and adolescence in DSM-III and the inclusion of a separate axis on specific developmental and personality disorders. On the other hand, higher manageability and efficiency were accorded to DSM-II, which may reflect the greater complexity of the DSM-

4 284 A. C. MEZZICH AND J. E. MEZZICH TABLE 2 Value of Additional Material Contained in the DSM-/ II Manual for the Characterization and Differential Diagnosis of Psychiatric Disorders, as Judged by Psychologists,. and Both Groups Combined A. Usefulness of Additional Information, Other than Diagnostic Criteria, Contained in the DSM -III Manual : ~. More useful than useless B. Consistency between Decision Trees and Corresponding Descriptive Information 1. Very inconsistent 2. More inconsi stent than consistent 3. More consistent than inconsistent 4. Very consistent C. Usefulness of the Decision Trees 3. More useful than useless Psychologists (N = 110) (N=90) Psychologists and (N= 200) 0.9% 2.2% 1.5% 25.5% 18.0% 22.1% 54.5% 56.2% 55.3% 19.1% 23.6% 21.1% % 10.0% 7.6% 25.3% 22.5% 24.0% 50.5% 52.5% 51.5% 18.7% 15.0% 17.0% % 12.3% 14.5% 32.7% 43.2% 37.4% 35.7% 35.8% 35.8% 15.3% 8.6% 12.3% III Manual and the DSM-III diagnostic formulation, as well as the participant's lesser familiarity with this system. The usefulness of the DSM-III decision trees as aids in the diagnostic process appeared to be doubtful. The differential ratings of perceived suitability obtained for the various axes of DSM-III are also noteworthy. Axis V was rated highest in both conceptual appropriateness and clarity (although there may be stronger alternative formats for this axis, such as one focused on current functioning). On the other hand, Axis IV was rated relatively low in both regards, particularly in conceptual appropriateness. Special concern about Axis IV was often mentioned, including the problematic definition of stressors vis-a-vis the age of the child, the pertinence of acute vs. chronic stressors, and the demands on the evaluator imposed by the need to consider sociocultural framework. Axis III was not evaluated in the above two regards, but the manual instructions for its use tended to be judged as being of limited helpfulness. The absence of significant differences between the ratings made by the samples of psychologists and psychiatrists suggests similar levels of acceptability of DSM-III by broad populations of clinical child psychologists and child psychiatrists. In their general narrative comments, the participating clinicians were more favorable to DSM-III than to DSM-II. They emphasized the importance of the inclusion of Axis II (specific developmental disorders), Axis IV (psychosocial stressors), and Axis V (highest level of functioning in the past year) in DSM-III, and considered this inclusion as an improvement in diagnostic systems. The findings of the present study are in line with the higher perceived usefulness of multiaxial systems over traditional uniaxial ones reported by Cantwell et al. (1979), Rutter et al. (1975), and Spitzer and Forman (1979). However, the findings presented here are more specific and differentiated regarding the conceptual suitability and definitional clarity of individual axes. They are also more systematic and representative, since they are based on statistical samples of child psychiatrists and clinical child psychologists from a large geographical area. Of course, there are other important aspects of clinical acceptability that were not addressed in the present study, such as the feasibility and actual use of the diagnostic system in regular clinical work, These

5 PERCEIVED SUITABILITY OF DSM-III AND DSM-n 285 TABLE 3 Descriptive Value of Axes III, IV, and Vof DSM-III as Perceived by Psychologists,, and Both Groups Combined A, Usefulness of the Instructions for Axis III :t More useful than useless B. Appropriateness of the Conceptual Framework of Axis IV 1. Very inappropriate 2. More inappropriate than appropriate :1. More appropriate than inappropriate 4. Very appropriate C. Clarity of the Axis IV Scale 1. Very unclear 2. More unclear than clear 3. More clear than unclear 4. Very clear D. Appropriateness of the Conceptual Framework of Axis V 1. Very inappropriate 2. More inappropriate than appropriate 3. More appropriate than inappropriate 4. Very appropriate E. Clarity of the Axis V Scale 1. Very unclear 2. More unclear than clear 3. More clear than unclear 4. Very clear Psychologists (N = 110) (N = 90) Psychologists and (N = 200) 24.0% 17.4% 20.9% 37.5% 31.4% 34.6% 33.3% 36.0% 34.6% 5.2% 15.1 % 9.9% % 2.2% 4.6% 24.8% 26.7% 25.6% 53.3% 52.2% 52.8% 15.2% 18.9% 16.9% % 2.2% 2.6% 19.8% 20.0% 19.9% 52.8% 56.7% 54.6% 24.5% 21.1% 23.0% % 2.3% 2.6% 12.3% 13.6% 12.9% 63.2% 65.9% 64.4% 21.7% 18.2% 20.1% % 4.5% 2.1% 16.0% 11.2% 13.8% 57.5% 65.2% 61.0% 26.4% 19.1% 23.1% issues, as well as the validity of the system for predicting treatment response and course of illness, should be considered in further evaluation studies. References CANTWELL, D. P., MATTISON, R., RUSSELL, A. T. & WILL, L. A. (1979), Comparison of DSM-n and DSM-III in the diagnosis of childhood psychiatric disorders; IV. Difficulties in use, global comparison, and conclusions. Arch. Gen. Psychiat. 36: MEZZICH, A. C., MEZZICH, J. E. & COFFMAN, G. A. (1985), Relia bility of DSM-III vs. DSM n in Child Psychopathology. This Journal, 24: RUTTER, M., SHAFFER, D. & SHEPHERD, M. (1975), A Multiaxial Classification of Child Psychiatry. Geneva: World Health Organization. SPITZER,R. L. & FORMAN,.J. B. W. (1979), DSM-III field trials; II. Initial experience with the multiaxial system. Amer. J. Psychiatr. 136: