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Decision and attribution bias in neurorehabilitation
521
Decision and Attribution Bias in Neurorehabilitation Stephen N. Macciocchi, PhD, Bradford Eaton, PhD ABSTRACT. Macciocchi SN, Eaton B. Decision and attribution bias in neurorehabilitation. Arch Phys Med Rehabil 1995;76:521-4. • Objective: Examine neurorehabilitation therapists' clinical predictions and attributions for outcomes. Design: Single sample, repeated measures. Participants: A sample of 51 neurorehabilitation therapists selected from representative disciplines including occupational therapy, physical therapy, speech therapy, and recreation therapy. Main Outcome Measures: Self-report questionnaire on factors related to positive and negative outcomes in neurorehabilitation. Rank order listing of factors influencing outcome in neurorehabilitation. Results: Without cuing, therapists did not identify injury severity as factor in outcome (p < .0001). Therapists also made internal attributions for positive outcomes and external attributions for negative outcomes (p < .0001). Conclusions: Neurorehabilitation therapists tend to ignore injury severity as factor in outcome unless encouraged to do so. Therapists accept personal responsibility for positive outcomes, but not for negative outcomes. Neurorehabilitation teams may benefit from education on factors affecting prognosis and attribution bias found in clinical practice. © 1995 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and
Rehabilitation Neurorehabilitation is a generic term referring to a variety of endeavors focused on rehabilitating patients with a broad spectrum of neurologically based disorders, principally cerebral trauma and stroke. As in other areas of medicine, clinical judgment and decision making play a significant role in diagnosis, intervention planning, and eventual outcome. Unlike other areas of medicine, clinical decisions in neurorehabilitation are often made by interdisciplinary teams rather than a single clinician. Although physicians traditionally lead interdisciplinary teams, individual therapists are relied on to provide diagnostic and prognostic information necessary for intervention and disposition planning. As such, the clinical judgment of individual clinicians (team members) is critical to team effectiveness. Unfortunately, a limited number of studies have focused on clinical decision making in neurorehabilitation. Despite the paucity of research specifically focused on the clinical judgment of neurorehabilitation professionals, research examining various aspects of clinical decision making has been accumulating for some time. Although comprehensive review of this research is beyond the scope of the present discussion, various researchers have identified consistent errors in clinical judgment including failure to consider base rate information, attribution bias, inadequate assessment of covariation, and confirmatory as well as hindsite bias. 1-4 Because there is a high demand for prognostic decision making in neurorehabilitation, especially with respect to treatment and disposition planning, underutilization of base rate information and self-serving attribution bias are From the Departments of Physical Medicine and Psychiatric Medicine (Dr. Macciocchi), University of Virginia Medical School, Charlottesville; and the Siskin Hospital for Physical Rehabilitation (Dr. Eaton), Chattanooga, TN. Submitted for publication August 15, 1994. Accepted in revised form February 3, 1995. 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 S. N. Macciocchi, PhD, Associate Professor, University of Virginia, Health Sciences Center, Box 30 BRH, Charlottesville, VA 22901. © 1995 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation 0003-9993/95/7606-319353.00/0
of particular interest when examining the clinical decision making of neurorehabilitation clinicians. Neurorehabilitation clinicians are often asked whether a patient will recover "fully," return to previous employment, or function independently. These prognostic questions are often asked by family or health care professionals (case managers, primary care physicians) shortly after the injury occurs as well as throughout the rehabilitation process. When considering prognostic questions, antecedent probabilities (base rates) are critical to the decision-making process. Base rates refer to the known (empirically established) probability of an outcome. In cases where the base rate of the outcome in question is high (impairment in cognition, behavior and vocational functioning), one can usually make prognostic decisions without additional clinical or assessment data. In fact, additional data can confuse decision makers and lead to reduced prognostic accuracy. 4-5 For example, if outcome data (base rate) suggest that patients with severe cerebral trauma (Glascow Coma Score --<8) have a .95 probability of evidencing significant neurobehavioral sequelae at 1 year, 6-8 clinicians who predict otherwise based on clinical observations or test data are likely to be wrong significantly more often than they are right, particularly as the number of decisions increase. Despite the established relationship between injury characteristics (nature-severity) and outcome, neurorehabilitation team decisions and clinical predictions are often based on clinicians' assessments, frequently related to a patient's very recent performance in therapy rather than empirically validated predictive variables. Anyone who has spent time in neurorehabilitation rounds surely recognizes prognostic decision points when critically relevant historical data is either not considered or discarded in favor of subjective opinions based on estimates of patient motivation, changes in patient' s energy level from one day to the next, or allusions to other patients who may or may not have had a similar injury and premorbid characteristics. In fact, when patients evidence restitution in cognitive functioning (eg, memory) during hospitalization, these changes are often used to predict outcome, although the magnitude of change, however encouraging, Arch Phys Med Rehabil Vol 76, June 1995
522
DECISION BIAS, Macciocchi
may not relate to ultimate neuropsychological outcome. 9 Prediction of outcome in neurorehabilitation is a difficult process that is only complicated by the infusion of nonvalidated, subjective observations by neurorehabilitation team members. Like failure to consider base rates, self-serving attribution bias is a well-documented phenomena. ~°-~4Self-serving attribution bias refers to the tendency to attribute successful outcomes or experiences to internal factors (oneself) while attributing unsuccessful outcomes or experiences to external (patient, environmental) factors. Self-serving attribution bias can also be observed in multidisciplinary rounds. For example, there appears to be an implicit (sometimes explicit) assumption that when patients demonstrate restitution in neurobehavioral function, this recovery is wholly attributable to therapy. The tendency to attribute recovery of function to treatment, even when empirically validated factors such as physical restitution of a damaged central nervous system (CNS) are clearly operative, is particularly disturbing. Unfortunately, this failure to consider the role of CNS reorganization and maturation after injury may result in erroneous affirmation of treatment efficacy. Parenthetically, there is a paucity of research examining the efficacy of neurorehabilitation programs, and consequently, attributing restitution in functional systems (cognitive, emotional, motor) to therapeutic interventions is quite premature. ~5~6 In any case, because inattention to base rates and selfserving attribution bias has been found to be common in neurorehabilitation, this study was designed to investigate the extent to which individual rehabilitation therapists evidence errors in clinical decision making. More specifically, therapists' ability to accurately perceive the determinants of the patient's clinical outcome after cerebral trauma was assessed. In addition, therapists' attributional style in accounting for outcomes was systematically documented. It was hypothesized that therapists would not use historical variables (nature and extent of injury, pre-injury cognitivebehavioral functioning) unless provided with cues. It was also hypothesized that therapists would evidence self-serving attribution bias; that is, therapists would attribute positive outcomes to their efforts while disavowing personal responsibility for unsuccessful outcomes.
METHOD All therapists employed at three private and three university-affiliated rehabilitation hospitals were considered for inclusion in the study (n = 127). Therapists were included in Table 1: Therapists Age, Education, and Experience by Discipline Age
Occupational therapy (n = 19) Physical therapy (n = 12) Recreational therapy (n = 7) Speech therapy (n = 13)
Education
Experience
Mean
SD
Mean
SD
Mean
SD
30.4
6.3
16.4
1.3
5.0
4.6
33.9
10.5
17.0
1.4
7.0
5.1
31.7
7.2
16.7
.7
4.5
3.2
29.6
12.4
17.4
.7
6.8
4.5
Arch Phys Med Rehabil Vol 76, June 1995
Table 2: Therapists Ranking of Outcome Variables Nature-extent of brain injury Early involvement of family in treatment Patient motivation Pre-injury cognitive-behavioral functioning Experience of staff Adequate control of behavior problems Frequent, intense cognitive interventions Frequent interdisciplinary conferences Presence of physiatfist on team
Mean
Median
2.3 3.7 4.4 4.9 5.0 5.0 5.9 6.3 7.1
1.0 3.0 4.0 5.0 5.0 5.0 6.0 7.0 8.0
the study only if 50% or more of their clinical effort was devoted to neurorehabilitation of traumatic brain injury patients. None of the eligible subjects refused to participate, and consent was obtained before participation. Fifty-one neurorehabilitation therapists selected from representative disciplines including occupational therapy, speech therapy, physical therapy, and recreational therapy participated in the study. Subjects' mean age and education levels were 31.2 (range 23 to 55), and 17 (range 16 to 20), respectively. Subjects had a mean experience level of 5.9 years (range 1 to 28). Means and standard deviations for participants' ages, education, and experience levels are presented in table 1. There were no significant differences in age, education, or experience between disciplines. Subjects initially were asked to list "at lease five factors that are most important in successful outcome" and "five factors that are most important in unsuccessful outcome in neurorehabilitation." "Outcome" was not defined in order to allow therapists from individual disciplines the opportunity to address outcome within their specific clinical focus. By not defining outcome in any specific terms, therapists were not cued to focus on any particular indicator or outcome variable. Moreover, the variable of experimental interest, ie, injury severity, has been shown to have a pervasive effect on all outcome variables including cognitive functioning, social-behavioral skills, and vocational adjustment. 8"17-~8 After the uncued response condition, therapists were allowed to view a list of nine factors "potentially" related to outcome in neurorehabilitation. These factors were selected on the basis of clinical research, 6-9"17A8theoretical perspectives on neurorehabilitation, ~9and clinical experience in treatment team conferences. Therapists were asked to rank order (in order of importance) these nine factors including historical variables such as "nature-extent of brain injury," "premorbid cognitive-behavioral functioning," as well as treatment factors such as "frequency of team conferences." Table 2 contains mean subject rankings of factors related to outcome. Subjects' spontaneous (uncued) responses were analyzed and assigned internal or external attribution designations by behavioral raters who demonstrated a high interrater reliability (r = .90). Responses were scored as internal only if the response reflected a trait or behavior directly attributable to the therapist or under the therapist's direct control. For example, frequently mentioned factors such as "therapist skill," "experience of staff," team communication," or "effective teamwork" would receive an internal designation, whereas "supportive family," "patient motivation," "funding," or "medical complications" would be
DECISION BIAS, Maeciocchi rated as an external attribution. Chi-square analyses were used to compare participants responses in the cued and uncued conditions. Dependent t tests were employed to compare attributions (internal) for different outcomes. Multiple regression was used to examine the association between responses and demographic variables.
RESULTS Results indicated that subjects were significantly less likely to consider injury characteristics or premorbid functioning as factors in outcome when they were not provided cues (X2 = 24.8; p < .0001). Only 20% of therapists spontaneously identified injury severity as a factor in outcome, but when injury severity was listed as a potential factor in outcome (cued condition), 80% of therapists ranked injury severity as the most important factor in outcome. When therapists did spontaneously identify injury severity as a factor in outcome, they were significantly more likely to do so with unsuccessful outcomes (X 2 = 5.6; p < .02). Comparisons of the mean number of internal attributions for successful and unsuccessful outcomes showed that participants made a significantly greater number of internal attributions for successful outcomes than for unsuccessful outcomes (t = 5.2; p < .0001). Finally, neither therapist attributions (R = .39, p < .08) nor ranking of outcome factors (R = .35, p < . 17) were significantly associated with age, experience, or educational level. DISCUSSION Several interesting findings emerged when therapist's predictions and attributions for outcomes were systematically assessed. Therapists did not report nature-severity of injury or premorbid cognitive-behavioral functioning as factors in outcome after brain injury unless they were cued to do so. In addition, therapists tended to attribute successful outcomes to the effect of clinical interventions but ascribed negative outcomes to patient characteristics. The data support clinical observations that clinicians frequently misperceive the determinants of patients' neurobehavioral dysfunction and eventual outcome. These results suggest that the interdisciplinary teams should pay greater attention to information known (empirically) to be related to outcome. In fact, neurorehabilitation teams may benefit from an assessment designed to determine whether therapists actually use similar strategies when planning treatment protocols, designing interventions, estimating discharge goals, and communicating outcome information to patients' families. If disparity among team members exists, interdisciplinary training designed to enhance accuracy in decision making can be conducted. In addition to ignoring injury severity as a factor in outcome, therapists also attributed positive outcomes in neurorehabilitation to their skill, treatment programs, and team process while attributing unsuccessful outcomes to factors outside the therapist's control. At first glance, these findings may not appear unique to neurorehabilitation.l°'ll Nonetheless, therapists' awareness of their potential attribution biases are important process variables that may ultimately have a significant impact on intervention program design and goal
523
setting. For example, if successful outcomes are inappropriately attributed to therapeutic interventions, the efficacy of these interventions will not be challenged and patients may be subjected to ineffective treatments. Moreover, if patients are inaccurately perceived to be responsible for poor outcomes, therapists may not modify interventions and goals to maximize treatment response. In such cases, patients may be prematurely discharged from treatment or viewed as refractory to neurobehavioral interventions. Because of the observed attribution bias, neurorehabilitation specialists may benefit from specific education and training regarding the interpersonal dynamics of neurorehabilitation teams and factors such as paternalism, counterdependence, and projection, which influence the attribution process) ° Education regarding attribution processes would have the effect of reducing the likelihood of judgments being based on salient but less pertinent patient characteristics. In addition, potential for motivational distortions (self-serving) in the causal inference process is reduced when persons anticipate public discussion of their interpretations.12 Therefore, a potential strategy for reducing the likelihood of inaccurate/biased attributions could include group discussion of causal factors (for both initial impairment and eventual recovery) by the entire interdisciplinary team. Awareness of the potential for contradiction and the desire to be accurate may promote greater reliance on empirically validated variables. In this manner, neurorehabilitation therapists may acquire skills to improve prognostic accuracy and treatment efficacy while minimizing self-serving attribution bias. In conclusion, clinical observations suggesting that decision and attribution bias is operative in neurorehabilitation were supported by empirical evidence. Most importantly, therapists failed to consider historical variables as a factor in outcome, including pervasive contributors, such as injury severity. Second, therapists also demonstrated a pattern of self-serving attribution bias. Overall, neurorehabilitation teams may benefit from specific educational modules designed to systematize decision making and attributions for outcomes. Acknowledgment: The authors wish to thank Drs. D. Reid, D. LewisLawida, A. Guiliano, G. Ashkanazi, and W. Meneese for their assistance with data collection. References 1. Arkes HR, Wortmann RL, Saville PD, Harkness AR. Hindsight bias among physicians weighing the likelihood of diagnoses. J Appl Psychol 1981; 66:252-4. 2. Faust D. Research on human judgment and its application to clinical practice. Profess Psychol: Research Pratt 17:420-30. 3. Hawkins SA, Hastie R. Hindsight: biased judgments of past events after the outcomes are known. Psychol Bull 1990; 107:311-27. 4. Meehl P. Why I do not attend case conferences [selected papers]. Minneapolis: University of Minnesota Press, 1973. 5. Meehl P, Rosen A. Antecendent probability and the efficiency of psychometric signs, patterns or cutting scores. Psychol Bull 1955; 52:194216. 6. Levin HS. Neurobehavioral recovery. J Neurotrauma 1992;9:$359-73. 7. Levin HS. Neurobehavioral sequelae of closed head injury. In: Cooper PR, editor. Head injury. Baltimore: Williams and Wilkins, 1993:525552. 8. Ross B, Temkin NR, Newell D, Dikmen S. Neuropsychological outcome in relation to head injury severity: contributions of coma length and focal abnormalities, Am J Phys Med Rehabil 1994;73:341-7.
Arch Phys Med Rehabil Vol 76, June 1995
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DECISION BIAS, Macciocchi
9. Ruff RM, Young D, Gautille T, Marshall LF, Barth JT, Jane JA. Verbal learning deficits following severe head injury: heterogeneity in recovery over one year. J Neurosurg 1991;75:$50-5. 10. Curtis A. Altering beliefs about the importance of a strategy: an attributional intervention. J Appl Soc Psychol 1992;22:953-72. 11. Grove B, Hanrahan S, Mclnman A. Success/failure bias in attributions across involvement categories in split personality. Soc Psychol Bull 1991; 17:93-7. 12. Snyder M, Walter S, Rosenfield D. Attributional egotism. In: Ickes HJ, Kidd W, editors. New directions in attribution research; vol 2. Hillsdale, NJ: Lawrence Erlbaum, 1978;91-117. 13. Wells G. Anticipated discussion of interpretation eliminates actor-observer differences in the attribution of causality. Unpublished manuscript. Columbus, OH: Ohio State University 1977. 14. Heider F. Social perception and phenomenal causality. Psychol Rev 1944;51:358-74.
Arch Phys Med Rehabil Vol 76, June 1995
15. Levin H. Cognitive rehabilitation: unproved but promising. Arch Neurol 1990;47:223-4. 16. Volpe BT, McDowell FH. The efficacy of cognitive rehabilitation in patients with traumatic brain injury. Arch Neurol 1990;47:220-2. 17. Macciocchi SN, Reid DB, Barth JT. Disability following head injury. Curt Opin Neurol Neurosurg 1993;6:773-7. 18. Klonoff H, Campbell C, Klonoff P. Long-term outcome of head injuries: a 23-year follow-up study of children with head injuries. J Neurol Neurosurg Psychiatry 1993;56:410-5. 19. Jozelczyk PB. Interdisciplinary team approach to rehabilitation. In: Good DC, Courch JR Jr, editors. Handbook of neurorehabilitation. New York: Marcel Dekker, 1994; 153-63. 20. Caplan B, Shechter J. Reflections on the "Depressed," "Unrealistic," "Inappropriate," "Manipulative," "Unmotivated," "Non Compliant," Denying," "Maladjusted," "Regressed," etc. Patient. Arch Phys Med 1993;74:1123-4.
Decision and Attribution Bias in Neurorehabilitation Stephen N. Macciocchi, PhD, Bradford Eaton, PhD ABSTRACT. Macciocchi SN, Eaton B. Decision and attribution bias in neurorehabilitation. Arch Phys Med Rehabil 1995;76:521-4. • Objective: Examine neurorehabilitation therapists' clinical predictions and attributions for outcomes. Design: Single sample, repeated measures. Participants: A sample of 51 neurorehabilitation therapists selected from representative disciplines including occupational therapy, physical therapy, speech therapy, and recreation therapy. Main Outcome Measures: Self-report questionnaire on factors related to positive and negative outcomes in neurorehabilitation. Rank order listing of factors influencing outcome in neurorehabilitation. Results: Without cuing, therapists did not identify injury severity as factor in outcome (p < .0001). Therapists also made internal attributions for positive outcomes and external attributions for negative outcomes (p < .0001). Conclusions: Neurorehabilitation therapists tend to ignore injury severity as factor in outcome unless encouraged to do so. Therapists accept personal responsibility for positive outcomes, but not for negative outcomes. Neurorehabilitation teams may benefit from education on factors affecting prognosis and attribution bias found in clinical practice. © 1995 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and
Rehabilitation Neurorehabilitation is a generic term referring to a variety of endeavors focused on rehabilitating patients with a broad spectrum of neurologically based disorders, principally cerebral trauma and stroke. As in other areas of medicine, clinical judgment and decision making play a significant role in diagnosis, intervention planning, and eventual outcome. Unlike other areas of medicine, clinical decisions in neurorehabilitation are often made by interdisciplinary teams rather than a single clinician. Although physicians traditionally lead interdisciplinary teams, individual therapists are relied on to provide diagnostic and prognostic information necessary for intervention and disposition planning. As such, the clinical judgment of individual clinicians (team members) is critical to team effectiveness. Unfortunately, a limited number of studies have focused on clinical decision making in neurorehabilitation. Despite the paucity of research specifically focused on the clinical judgment of neurorehabilitation professionals, research examining various aspects of clinical decision making has been accumulating for some time. Although comprehensive review of this research is beyond the scope of the present discussion, various researchers have identified consistent errors in clinical judgment including failure to consider base rate information, attribution bias, inadequate assessment of covariation, and confirmatory as well as hindsite bias. 1-4 Because there is a high demand for prognostic decision making in neurorehabilitation, especially with respect to treatment and disposition planning, underutilization of base rate information and self-serving attribution bias are From the Departments of Physical Medicine and Psychiatric Medicine (Dr. Macciocchi), University of Virginia Medical School, Charlottesville; and the Siskin Hospital for Physical Rehabilitation (Dr. Eaton), Chattanooga, TN. Submitted for publication August 15, 1994. Accepted in revised form February 3, 1995. 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 S. N. Macciocchi, PhD, Associate Professor, University of Virginia, Health Sciences Center, Box 30 BRH, Charlottesville, VA 22901. © 1995 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation 0003-9993/95/7606-319353.00/0
of particular interest when examining the clinical decision making of neurorehabilitation clinicians. Neurorehabilitation clinicians are often asked whether a patient will recover "fully," return to previous employment, or function independently. These prognostic questions are often asked by family or health care professionals (case managers, primary care physicians) shortly after the injury occurs as well as throughout the rehabilitation process. When considering prognostic questions, antecedent probabilities (base rates) are critical to the decision-making process. Base rates refer to the known (empirically established) probability of an outcome. In cases where the base rate of the outcome in question is high (impairment in cognition, behavior and vocational functioning), one can usually make prognostic decisions without additional clinical or assessment data. In fact, additional data can confuse decision makers and lead to reduced prognostic accuracy. 4-5 For example, if outcome data (base rate) suggest that patients with severe cerebral trauma (Glascow Coma Score --<8) have a .95 probability of evidencing significant neurobehavioral sequelae at 1 year, 6-8 clinicians who predict otherwise based on clinical observations or test data are likely to be wrong significantly more often than they are right, particularly as the number of decisions increase. Despite the established relationship between injury characteristics (nature-severity) and outcome, neurorehabilitation team decisions and clinical predictions are often based on clinicians' assessments, frequently related to a patient's very recent performance in therapy rather than empirically validated predictive variables. Anyone who has spent time in neurorehabilitation rounds surely recognizes prognostic decision points when critically relevant historical data is either not considered or discarded in favor of subjective opinions based on estimates of patient motivation, changes in patient' s energy level from one day to the next, or allusions to other patients who may or may not have had a similar injury and premorbid characteristics. In fact, when patients evidence restitution in cognitive functioning (eg, memory) during hospitalization, these changes are often used to predict outcome, although the magnitude of change, however encouraging, Arch Phys Med Rehabil Vol 76, June 1995
522
DECISION BIAS, Macciocchi
may not relate to ultimate neuropsychological outcome. 9 Prediction of outcome in neurorehabilitation is a difficult process that is only complicated by the infusion of nonvalidated, subjective observations by neurorehabilitation team members. Like failure to consider base rates, self-serving attribution bias is a well-documented phenomena. ~°-~4Self-serving attribution bias refers to the tendency to attribute successful outcomes or experiences to internal factors (oneself) while attributing unsuccessful outcomes or experiences to external (patient, environmental) factors. Self-serving attribution bias can also be observed in multidisciplinary rounds. For example, there appears to be an implicit (sometimes explicit) assumption that when patients demonstrate restitution in neurobehavioral function, this recovery is wholly attributable to therapy. The tendency to attribute recovery of function to treatment, even when empirically validated factors such as physical restitution of a damaged central nervous system (CNS) are clearly operative, is particularly disturbing. Unfortunately, this failure to consider the role of CNS reorganization and maturation after injury may result in erroneous affirmation of treatment efficacy. Parenthetically, there is a paucity of research examining the efficacy of neurorehabilitation programs, and consequently, attributing restitution in functional systems (cognitive, emotional, motor) to therapeutic interventions is quite premature. ~5~6 In any case, because inattention to base rates and selfserving attribution bias has been found to be common in neurorehabilitation, this study was designed to investigate the extent to which individual rehabilitation therapists evidence errors in clinical decision making. More specifically, therapists' ability to accurately perceive the determinants of the patient's clinical outcome after cerebral trauma was assessed. In addition, therapists' attributional style in accounting for outcomes was systematically documented. It was hypothesized that therapists would not use historical variables (nature and extent of injury, pre-injury cognitivebehavioral functioning) unless provided with cues. It was also hypothesized that therapists would evidence self-serving attribution bias; that is, therapists would attribute positive outcomes to their efforts while disavowing personal responsibility for unsuccessful outcomes.
METHOD All therapists employed at three private and three university-affiliated rehabilitation hospitals were considered for inclusion in the study (n = 127). Therapists were included in Table 1: Therapists Age, Education, and Experience by Discipline Age
Occupational therapy (n = 19) Physical therapy (n = 12) Recreational therapy (n = 7) Speech therapy (n = 13)
Education
Experience
Mean
SD
Mean
SD
Mean
SD
30.4
6.3
16.4
1.3
5.0
4.6
33.9
10.5
17.0
1.4
7.0
5.1
31.7
7.2
16.7
.7
4.5
3.2
29.6
12.4
17.4
.7
6.8
4.5
Arch Phys Med Rehabil Vol 76, June 1995
Table 2: Therapists Ranking of Outcome Variables Nature-extent of brain injury Early involvement of family in treatment Patient motivation Pre-injury cognitive-behavioral functioning Experience of staff Adequate control of behavior problems Frequent, intense cognitive interventions Frequent interdisciplinary conferences Presence of physiatfist on team
Mean
Median
2.3 3.7 4.4 4.9 5.0 5.0 5.9 6.3 7.1
1.0 3.0 4.0 5.0 5.0 5.0 6.0 7.0 8.0
the study only if 50% or more of their clinical effort was devoted to neurorehabilitation of traumatic brain injury patients. None of the eligible subjects refused to participate, and consent was obtained before participation. Fifty-one neurorehabilitation therapists selected from representative disciplines including occupational therapy, speech therapy, physical therapy, and recreational therapy participated in the study. Subjects' mean age and education levels were 31.2 (range 23 to 55), and 17 (range 16 to 20), respectively. Subjects had a mean experience level of 5.9 years (range 1 to 28). Means and standard deviations for participants' ages, education, and experience levels are presented in table 1. There were no significant differences in age, education, or experience between disciplines. Subjects initially were asked to list "at lease five factors that are most important in successful outcome" and "five factors that are most important in unsuccessful outcome in neurorehabilitation." "Outcome" was not defined in order to allow therapists from individual disciplines the opportunity to address outcome within their specific clinical focus. By not defining outcome in any specific terms, therapists were not cued to focus on any particular indicator or outcome variable. Moreover, the variable of experimental interest, ie, injury severity, has been shown to have a pervasive effect on all outcome variables including cognitive functioning, social-behavioral skills, and vocational adjustment. 8"17-~8 After the uncued response condition, therapists were allowed to view a list of nine factors "potentially" related to outcome in neurorehabilitation. These factors were selected on the basis of clinical research, 6-9"17A8theoretical perspectives on neurorehabilitation, ~9and clinical experience in treatment team conferences. Therapists were asked to rank order (in order of importance) these nine factors including historical variables such as "nature-extent of brain injury," "premorbid cognitive-behavioral functioning," as well as treatment factors such as "frequency of team conferences." Table 2 contains mean subject rankings of factors related to outcome. Subjects' spontaneous (uncued) responses were analyzed and assigned internal or external attribution designations by behavioral raters who demonstrated a high interrater reliability (r = .90). Responses were scored as internal only if the response reflected a trait or behavior directly attributable to the therapist or under the therapist's direct control. For example, frequently mentioned factors such as "therapist skill," "experience of staff," team communication," or "effective teamwork" would receive an internal designation, whereas "supportive family," "patient motivation," "funding," or "medical complications" would be
DECISION BIAS, Maeciocchi rated as an external attribution. Chi-square analyses were used to compare participants responses in the cued and uncued conditions. Dependent t tests were employed to compare attributions (internal) for different outcomes. Multiple regression was used to examine the association between responses and demographic variables.
RESULTS Results indicated that subjects were significantly less likely to consider injury characteristics or premorbid functioning as factors in outcome when they were not provided cues (X2 = 24.8; p < .0001). Only 20% of therapists spontaneously identified injury severity as a factor in outcome, but when injury severity was listed as a potential factor in outcome (cued condition), 80% of therapists ranked injury severity as the most important factor in outcome. When therapists did spontaneously identify injury severity as a factor in outcome, they were significantly more likely to do so with unsuccessful outcomes (X 2 = 5.6; p < .02). Comparisons of the mean number of internal attributions for successful and unsuccessful outcomes showed that participants made a significantly greater number of internal attributions for successful outcomes than for unsuccessful outcomes (t = 5.2; p < .0001). Finally, neither therapist attributions (R = .39, p < .08) nor ranking of outcome factors (R = .35, p < . 17) were significantly associated with age, experience, or educational level. DISCUSSION Several interesting findings emerged when therapist's predictions and attributions for outcomes were systematically assessed. Therapists did not report nature-severity of injury or premorbid cognitive-behavioral functioning as factors in outcome after brain injury unless they were cued to do so. In addition, therapists tended to attribute successful outcomes to the effect of clinical interventions but ascribed negative outcomes to patient characteristics. The data support clinical observations that clinicians frequently misperceive the determinants of patients' neurobehavioral dysfunction and eventual outcome. These results suggest that the interdisciplinary teams should pay greater attention to information known (empirically) to be related to outcome. In fact, neurorehabilitation teams may benefit from an assessment designed to determine whether therapists actually use similar strategies when planning treatment protocols, designing interventions, estimating discharge goals, and communicating outcome information to patients' families. If disparity among team members exists, interdisciplinary training designed to enhance accuracy in decision making can be conducted. In addition to ignoring injury severity as a factor in outcome, therapists also attributed positive outcomes in neurorehabilitation to their skill, treatment programs, and team process while attributing unsuccessful outcomes to factors outside the therapist's control. At first glance, these findings may not appear unique to neurorehabilitation.l°'ll Nonetheless, therapists' awareness of their potential attribution biases are important process variables that may ultimately have a significant impact on intervention program design and goal
523
setting. For example, if successful outcomes are inappropriately attributed to therapeutic interventions, the efficacy of these interventions will not be challenged and patients may be subjected to ineffective treatments. Moreover, if patients are inaccurately perceived to be responsible for poor outcomes, therapists may not modify interventions and goals to maximize treatment response. In such cases, patients may be prematurely discharged from treatment or viewed as refractory to neurobehavioral interventions. Because of the observed attribution bias, neurorehabilitation specialists may benefit from specific education and training regarding the interpersonal dynamics of neurorehabilitation teams and factors such as paternalism, counterdependence, and projection, which influence the attribution process) ° Education regarding attribution processes would have the effect of reducing the likelihood of judgments being based on salient but less pertinent patient characteristics. In addition, potential for motivational distortions (self-serving) in the causal inference process is reduced when persons anticipate public discussion of their interpretations.12 Therefore, a potential strategy for reducing the likelihood of inaccurate/biased attributions could include group discussion of causal factors (for both initial impairment and eventual recovery) by the entire interdisciplinary team. Awareness of the potential for contradiction and the desire to be accurate may promote greater reliance on empirically validated variables. In this manner, neurorehabilitation therapists may acquire skills to improve prognostic accuracy and treatment efficacy while minimizing self-serving attribution bias. In conclusion, clinical observations suggesting that decision and attribution bias is operative in neurorehabilitation were supported by empirical evidence. Most importantly, therapists failed to consider historical variables as a factor in outcome, including pervasive contributors, such as injury severity. Second, therapists also demonstrated a pattern of self-serving attribution bias. Overall, neurorehabilitation teams may benefit from specific educational modules designed to systematize decision making and attributions for outcomes. Acknowledgment: The authors wish to thank Drs. D. Reid, D. LewisLawida, A. Guiliano, G. Ashkanazi, and W. Meneese for their assistance with data collection. References 1. Arkes HR, Wortmann RL, Saville PD, Harkness AR. Hindsight bias among physicians weighing the likelihood of diagnoses. J Appl Psychol 1981; 66:252-4. 2. Faust D. Research on human judgment and its application to clinical practice. Profess Psychol: Research Pratt 17:420-30. 3. Hawkins SA, Hastie R. Hindsight: biased judgments of past events after the outcomes are known. Psychol Bull 1990; 107:311-27. 4. Meehl P. Why I do not attend case conferences [selected papers]. Minneapolis: University of Minnesota Press, 1973. 5. Meehl P, Rosen A. Antecendent probability and the efficiency of psychometric signs, patterns or cutting scores. Psychol Bull 1955; 52:194216. 6. Levin HS. Neurobehavioral recovery. J Neurotrauma 1992;9:$359-73. 7. Levin HS. Neurobehavioral sequelae of closed head injury. In: Cooper PR, editor. Head injury. Baltimore: Williams and Wilkins, 1993:525552. 8. Ross B, Temkin NR, Newell D, Dikmen S. Neuropsychological outcome in relation to head injury severity: contributions of coma length and focal abnormalities, Am J Phys Med Rehabil 1994;73:341-7.
Arch Phys Med Rehabil Vol 76, June 1995
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9. Ruff RM, Young D, Gautille T, Marshall LF, Barth JT, Jane JA. Verbal learning deficits following severe head injury: heterogeneity in recovery over one year. J Neurosurg 1991;75:$50-5. 10. Curtis A. Altering beliefs about the importance of a strategy: an attributional intervention. J Appl Soc Psychol 1992;22:953-72. 11. Grove B, Hanrahan S, Mclnman A. Success/failure bias in attributions across involvement categories in split personality. Soc Psychol Bull 1991; 17:93-7. 12. Snyder M, Walter S, Rosenfield D. Attributional egotism. In: Ickes HJ, Kidd W, editors. New directions in attribution research; vol 2. Hillsdale, NJ: Lawrence Erlbaum, 1978;91-117. 13. Wells G. Anticipated discussion of interpretation eliminates actor-observer differences in the attribution of causality. Unpublished manuscript. Columbus, OH: Ohio State University 1977. 14. Heider F. Social perception and phenomenal causality. Psychol Rev 1944;51:358-74.
Arch Phys Med Rehabil Vol 76, June 1995
15. Levin H. Cognitive rehabilitation: unproved but promising. Arch Neurol 1990;47:223-4. 16. Volpe BT, McDowell FH. The efficacy of cognitive rehabilitation in patients with traumatic brain injury. Arch Neurol 1990;47:220-2. 17. Macciocchi SN, Reid DB, Barth JT. Disability following head injury. Curt Opin Neurol Neurosurg 1993;6:773-7. 18. Klonoff H, Campbell C, Klonoff P. Long-term outcome of head injuries: a 23-year follow-up study of children with head injuries. J Neurol Neurosurg Psychiatry 1993;56:410-5. 19. Jozelczyk PB. Interdisciplinary team approach to rehabilitation. In: Good DC, Courch JR Jr, editors. Handbook of neurorehabilitation. New York: Marcel Dekker, 1994; 153-63. 20. Caplan B, Shechter J. Reflections on the "Depressed," "Unrealistic," "Inappropriate," "Manipulative," "Unmotivated," "Non Compliant," Denying," "Maladjusted," "Regressed," etc. Patient. Arch Phys Med 1993;74:1123-4.