Research in Nursing & Health, 1992, 15, 199-207
Attentional Fatigue Following Breast Cancer Surgery Bernadine Cimprich
Attentional fatigue usually follows intense use of mental effort and is manifested as a decreased capacity to concentrate, that is, to direct attention. The purpose of this study was to examine the capacity to direct attention in persons with cancer during the initial phase of illness. The sample consisted of 32 women without cognitive or affective disorders who underwent surgery for localized (Stage I or It) breast cancer. Subjects manifested attentional deficits of varying intensity on a battery of tests of directed attention on the day before discharge from the hospital, which was a mean of 3 days following mastectomy or breast conservation surgery. Unexpectedly, the two surgical groups did not differ significantly in attentional capacity and functioning. Attentional test scores were not significantly correlated with narcotic pain medication interval, mood state, or self-ratings of attentional functioning. However, as number of days postsurgery increased, attentional performance decreased. The theoretical basis for further examination of attentional fatigue in people with cancer or other life-threatening illnesses is discussed.
Over one million people in the United States are diagnosed with cancer each year (Boring, Squires, & Tong, 1991). In dealing with a chronic and life-threatening disease such as cancer, individuals must direct attention to multiple, and often competing, demands imposed by both the illness and its treatment. Directed attention is needed to deal with informational needs, the realities of treatment, therapeutic self-care, and a myriad of adjustments in daily life. Intense mental exertion in response to multiple demands for attention can lead to attentional fatigue characterized by a decline in the capacity to direct attention (Kaplan & Kaplan, 1982). Although the intense mental demands associated with diagnosis and treatment of cancer have been documented (Derdiarian, 1987; Frank-Stromborg, Wright, Segalla, & Diekman, 1984; Heinrich, Schag, & Ganz, 1984; Mages & Mendolsohn, 1979; Weisman & Worden, 1976-77), there have been no studies of the effects of these demands on attentional capacity and functioning. The purpose of this study was to examine the capacity to direct attention in the initial phase of treatment in a selected group
of persons with cancer, specifically women with breast cancer. The capacity to actively focus and concentrate, or to direct attention, is intuitively understood as essential for effective functioning in daily life. The simple act of “paying attention,” however, involves complex neurocognitive processes (Posner & Boies, 1971) and, as William James (1890/ 1983) noted a century ago, requires expenditure of mental effort. Theoretically, the capacity to direct attention depends on a global neural inhibitory mechanism that acts to block competing stimuli during purposeful activity (Kaplan & Kaplan, 1982; Posner & Presti, 1987; Posner & Snyder, 1975). Thus, when a person directs attention to important information in the environment, distracting or competing stimuli must be actively blocked or inhibited. As distractions increase, greater mental (inhibitory) effort is required to prevent the distracting stimuli from interfering with intended activity. Though often taken for granted, directed attentional capacity supports purposeful activity in all facets of daily living. Directed attention permits a person to perceive,
Bernardine Cimprich, PhD, RN, is an assistant professor, School of Nursing, University of Wisconsin-Madison. This research was supported by the National Cancer Institute, NIH, National Research Service Award, No. CA08390. This article was received on June 10, 1991, was revised, and accepted for publication December 20, 1991. Requests for reprints can be addressed to Dr. Bernadine Cimprich, University of Wisconsin-Madison, School of Nursing, 600 Highland Ave., Madison, WI 53792.
0 1992 John Wiley & Sons, Inc. CCC 0160-6891/92/030199-09 $04.00
200
RESEARCH IN NURSING 8 HEALTH
think clearly, and maintain intended activity despite distractions in the internal or external environment. Because directed attention requires continuous application of mental effort, prolonged or intense use of this capacity can lead to attentional fatigue, resulting in reduced effectiveness in purposeful activity (Kaplan & Kaplan, 1982). During diagnostic and treatment phases of lifethreatening illness such as cancer, multiple factors-informational, affective, and behavioralincrease the requirements for use of directed attention over long periods of time. Informational demands associated with treatment and therapeutic self-care may be intense (Derdiarian, 1987). At the same time, affective factors such as uncertainty about the future and painful thoughts associated with anticipated or actual losses can act as continuous distractions to purposeful activity (FrankStromborg et al., 1984). Finally, illness poses multiple constraints on normal functioning stemming from physical discomfort, from losses of privacy and territory, and prolonged transactions with threatening or confusing health care environments (Heinrich et al., 1984; Mages & Mendolsohn, 1979; Weisman & Worden, 1976- 1977). Prolonged use of directed attention can lead to fatigue of the global neural inhibitory mechanism which underlies normal attentional capacity (Kap lan & Kaplan, 1982). The characteristic effect of overuse and fatigue of this mechanism is a decreased capacity to inhibit competing stimuli or distractions. Attentional fatigue can be differentiated from physical fatigue in that it involves a reduced capacity to exert mental (inhibitory) effort rather than physical effort. Thus, a person with attentional fatigue may not be physically tired but would have difficulty in doing activities that require directed attention such as planning, problem solving, carrying out purposeful activity, and selfmonitoring of behavior (Lezak, 1982). Attentional fatigue has been observed in healthy individuals under experimental conditions requiring prolonged use of directed attention (e.g., Fiske & Schneider, 1981; Jerison & Picket, 1964; Mackworth, 1948; Parasuraman, 1986). Although attentional fatigue has not been previously studied within the context of illness, converging clinical evidence suggests that patients with cancer can experience significant attentional problems during various phases of illness. The inability to concentrate has been identified as a persistent source of distress during periods of active treatment for cancer (McCorkle & Young, 1978) and following a course of treatment (Mages & Mendolsohn, 1979; Oberst & James, 1985). Also, loss of concentration has been associated with unexplained, chronic
fatigue in persons with cancer (Aistars, 1987); however, the nature of this relationship is not clear, since loss of the capacity to direct attention need not be accompanied by decreased capacity to exert physical effort, or vice versa. Overall, the apparent pervasiveness of attentional problems underscores the need for systematic examination of the possible effects of cancer and its treatment on directed attentional capacity and functioning. This study provides an initial assessment of attentional capacity and functioning in women being treated for localized breast cancer. The sample was delimited to ensure a more homogeneous group of individuals who were coping with the same type of cancer and who were in the same phase of illness. Also, the intense mental demands experienced during treatment of breast cancer have been well documented (e.g., Scott, 1983). The major research question addressed in this descriptive study was: Are deficits in the capacity to direct attention manifested in the initial period of treatment for breast cancer, that is, on the day before discharge from the hospital following mastectomy or breast conservation surgery? Because of the exploratory nature of the study, data also were examined to address the following questions: (a) What are the possible differential effects of type of surgery, mastectomy versus breast conservation, on directed attentional capacity and functioning? (b) Is depressed mood associated with directed attentional capacity and functioning following breast cancer surgery? (c) What is the relationship between selected variables such as, age, educational level, narcotic pain medication, proximity of testing to surgery, and attentional performance following breast cancer surgery?
METHOD Sample The convenience sample of 32 female volunteers with newly diagnosed breast cancer was drawn from the population of patients at a university medical center that had a comprehensive cancer treatment program. All eligible women being treated for Stage I or II breast cancer were recruited during a 9-month period. Subjects were excluded for preexisting conditions that could affect attentional capacity or performance on the measures, specifically: documented cognitive, mental or affective disorder; uncorrected hearing or visual impairments; prescribed drugs known to impair or enhance attention; and insufficient command of
201
ATTENTIONAL FATIGUE / ClMPRlCH
the English language. Of the 44 subjects who were eligible, 73% agreed to participate. Of those who did not participate, the majority expressed an inability to deal with any additional tasks. The subjects ranged in age from 29 to 84 years, M = 54, SD = 14. Subjects averaged 14 years of formal education, and 50% were college graduates. All were born in the United States (90% Caucasian, 6% black). The majority were married (69%), and more than half were employed outside of the home (56%). All were in good health prior to diagnosis of breast cancer. Diagnosis was confirmed on outpatient biopsy for all subjects prior to surgical treatment. Almost equal numbers were treated with modified radical mastectomy (59%) and breast conservation surgery (41%), that is, lumpectomy. All had axillary node dissection on the affected side. Most (81%) had a pathologic diagnosis of Stage I breast cancer, while 19% had Stage 11 disease.
based on studies of healthy adults ranging in age from 16 to 74 years (Lezak, 1983; Spitz, 1972; Wechsler, 1955). Scores for Digit Span Forward (DSF) and Backward (DSB) were the number of digits repeated correctly before two consecutive failed trials (Wechsler, 1955). Alphabet Backward, a common measure of cognitive function, involves a mental reversing operation requiring sustained directed attentional capacity (Lezak, 1983). In this study, individuals were asked to recite the alphabet backward from a specified letter (i.e., y ) . The score was the number of letters recited without error in reverse sequence during a 20-s interval. The Symbol Digit Modalities Test (Smith, 1973), a standardized neurocognitive test, involves directed attention in substituting numbers for 10 geometric symbols, including three mirror image pairs, according to a specified key. Normative data have been reported based on a study of 420 healthy adults ranging in age from 18 to 74 (Lezak, 1983). The score was the number of correct substitutions in a 90-s period using standard testing procedures (Smith, 1973). The Letter Cancellation task was adapted from the Finding A's Test (Ekstrom, French, Harman, & Dermen, 1976). The task involves cancelling two specified letters that occur randomly in words in a paragraph (16 lines) of meaningful text. Theoretically, words are perceived as a whole, and increased attentional effort is necessary to detect an individual letter within a word (Kahneman & Treisman, 1984). Accuracy in letter cancellation was determined by the ratio of the number of specified letters cancelled to the total number of specified letters in the section completed during a 2-min interval. Perceived effectiveness in common activities requiring directed attention (Lezak, 1982) was measured using a self-rating scale, the Attentional Function Index (AFI), developed specifically for the study. The instrument consists of 14 linear analogue scales (each 100 mms) labeled at either
Measures The capacity to direct attention was measured using a battery of tests requiring inhibition of competing or distracting stimuli, as well as a subjective measure of perceived effectiveness in attentional functioning. The battery included standard measures, that is, Digit Span, Alphabet Backward, Symbol Digit Modalities Test, and Letter Cancellation, that have known validity and reliability (Lezak, 1983). Intercorrelations among the measures in this study ranged from .12 to .56 (see Table 1). The standardized internal consistency coefficient for the battery was .70, suggesting adequate beginning construct validity. The Digit Span, a standardized clinical test of attention (Mesulam, 19851, comprises two different measures. Forward span measures the number of bits of information a person can attend to at one time, while backward span requires sustained attention to perform a mental reversing operation. Normative data for Digit Span have been reported
Table 1. Correlation of Attentlonal Testsa Test
DSF
Digit Span Forward (DSF) Digit Span Backward (DSB) Alphabet Backward (AB) Symbol Digit Modalities Test (SDMT) Letter Cancellation (LC)
.35' .12 .27 .37'
'Pearson r coefficient. *N =
32,df
=
30,p < .05.
DSB
AB
SDMT
LC
.18 .42' .31
.35'
-
.20
.56*
-
202
RESEARCH IN NURSING 8 HEALTH
end with polar opposite phrases (e.g., not at all, extremely well) and includes items such as, concentrating on details, keeping track of what you’re saying or doing, keeping your mind on what others are saying. The respondents were asked to place a mark through the horizontal line at whatever point best described “how you are doing in each area at the present time.” Items were scored from the low end (range 0-loo), and a single overall score was computed consisting of the average score of the 14 linear analogue scales. The internal consistency coefficient of the index in this sample was .89, indicating satisfactory reliability. Because attentional performance may be influenced by diminished arousal associated with depression (Cohen, Weingartner, Smallberg, Pickar, & Murphy, 1982), a single item mood scale, the Visual Analog Mood Scale (VAMS) (Aitken, 1969; Folstein & Luria, 1973) served as an indicator of depressed mood state. The subject was asked to rate “mood right now” on a 100mm linear analogue scale from worst to best (0 to 100, respectively). In studies of patients with affective and nonaffective psychoses, the VAMS was particularly sensitive to depression (e.g., correlations between the VAMS and Zung Self-Rating Depression Scale ranged from -0.61 to -0.63) (Luria, 1975). Test-retest reliability coefficients for the VAMS ranged from 0.73 to 0.91 for a 2hr interval and 0.56 to 0.72 for 24 hr (Luria, 1975).
Procedure Potential volunteers were informed about the purpose of the study, the nature of the attentional tasks, and the amount of time required for testing (an average of 20 min). Written consent was obtained from all volunteers. All subjects were tested on the day before scheduled discharge from the hospital following breast cancer surgery. Testing
was done in a quiet, private room on the patient unit. The Attentional Function Index was administered first to obtain as clear a score as possible on this subjective measure. The objective tests were then administered in random order. All measures were administered using standard formats and verbatim instructions. Data were analyzed using descriptive statistics, t test, Pearson correlation coefficient, and regression. Digit Span and Symbol Digit Modalities Test scores were compared with published normative data to determine deviations from the norm.
R ESULTS Subjects showed attentional deficits of varying severity on the day before discharge following breast cancer surgery (see Table 2 for means, standard deviations, ranges, and medians of test scores). In Digit Span, adults normally can repeat seven digits in forward sequence without difficulty and 5 or better in reverse sequence. When testing for cognitive dysfunction in adults, a forward span of 5 is considered marginal, 4 is “definitely borderline” and 3 is defective (Lezak, 1983, p. 268). In backward span, a score of 3 is considered impaired (Lezak, 1983; Mesulam, 1985). In this sample, a significant proportion (56%) of the scores on DSF were at the lower end of the range (6 or less); a similar proportion (50%)of the scores on DSB were in the lower range (4 or less). Furthermore, 25% ( n = 8) of the subjects scored 5 or less in DSF, while 19% ( n = 6) scored 3 in DSB, suggesting severe impairment of directed attention. In Alphabet Backward (AB), although one subject actually scored 21, 34% ( n = 11) scored zero (0), and 75% (n = 24) scored 4 or less. Symbol Digit Modalities Test (SDMT) scores ranged from 22 to 67. Twenty-five percent (n = 8) scored below the age norm for SDMT (Lezak,
Table 2. Scores on Attentlonal Measures 3 Days Following Surgery for Breast Cancer
Digit Span Forward Digit Span Backward Alphabet Backward Symbol Digit Modalities Test Letter Cancellation Accuracy Ratio Attentional Function Indexa
Mean
Standard Deviation
Minimum-Maximum
Median
6.3 4.7 3.7
1.4 1.3 4.5
3-9 3-7 0-21
6.0 4.0 2.0
47.7
12.0
22-67
50.0
0.90 57.0
0.09 16.0
.63-.99 27-85
0.93 55.0
‘Average score on 14 linear analogue scales, each 100 mm’s, scored from the low end.
203
ATTENTIONAL FATIGUE / ClMPRlCH
Table 3. Correlationaof Attentional Test Scores with Attentional Function Index (AFI) and Visual Analog Mood Scale (VAMS) Attentional Tests
AFI
VAMS
Digit Span Forward Digits Span Backward Alphabet Backward Symbol Digit Modalities Test Letter Cancellation Accuracy Ratio Attentional Function Index (AFI)
- .05 -.18 .03 .17
.12 - .03 .25 .23
a
*
.26
.09
-
.52'
Pearson r coefficient. N = 32,df = 30, p
Attentional Fatigue Following Breast Cancer Surgery Bernadine Cimprich
Attentional fatigue usually follows intense use of mental effort and is manifested as a decreased capacity to concentrate, that is, to direct attention. The purpose of this study was to examine the capacity to direct attention in persons with cancer during the initial phase of illness. The sample consisted of 32 women without cognitive or affective disorders who underwent surgery for localized (Stage I or It) breast cancer. Subjects manifested attentional deficits of varying intensity on a battery of tests of directed attention on the day before discharge from the hospital, which was a mean of 3 days following mastectomy or breast conservation surgery. Unexpectedly, the two surgical groups did not differ significantly in attentional capacity and functioning. Attentional test scores were not significantly correlated with narcotic pain medication interval, mood state, or self-ratings of attentional functioning. However, as number of days postsurgery increased, attentional performance decreased. The theoretical basis for further examination of attentional fatigue in people with cancer or other life-threatening illnesses is discussed.
Over one million people in the United States are diagnosed with cancer each year (Boring, Squires, & Tong, 1991). In dealing with a chronic and life-threatening disease such as cancer, individuals must direct attention to multiple, and often competing, demands imposed by both the illness and its treatment. Directed attention is needed to deal with informational needs, the realities of treatment, therapeutic self-care, and a myriad of adjustments in daily life. Intense mental exertion in response to multiple demands for attention can lead to attentional fatigue characterized by a decline in the capacity to direct attention (Kaplan & Kaplan, 1982). Although the intense mental demands associated with diagnosis and treatment of cancer have been documented (Derdiarian, 1987; Frank-Stromborg, Wright, Segalla, & Diekman, 1984; Heinrich, Schag, & Ganz, 1984; Mages & Mendolsohn, 1979; Weisman & Worden, 1976-77), there have been no studies of the effects of these demands on attentional capacity and functioning. The purpose of this study was to examine the capacity to direct attention in the initial phase of treatment in a selected group
of persons with cancer, specifically women with breast cancer. The capacity to actively focus and concentrate, or to direct attention, is intuitively understood as essential for effective functioning in daily life. The simple act of “paying attention,” however, involves complex neurocognitive processes (Posner & Boies, 1971) and, as William James (1890/ 1983) noted a century ago, requires expenditure of mental effort. Theoretically, the capacity to direct attention depends on a global neural inhibitory mechanism that acts to block competing stimuli during purposeful activity (Kaplan & Kaplan, 1982; Posner & Presti, 1987; Posner & Snyder, 1975). Thus, when a person directs attention to important information in the environment, distracting or competing stimuli must be actively blocked or inhibited. As distractions increase, greater mental (inhibitory) effort is required to prevent the distracting stimuli from interfering with intended activity. Though often taken for granted, directed attentional capacity supports purposeful activity in all facets of daily living. Directed attention permits a person to perceive,
Bernardine Cimprich, PhD, RN, is an assistant professor, School of Nursing, University of Wisconsin-Madison. This research was supported by the National Cancer Institute, NIH, National Research Service Award, No. CA08390. This article was received on June 10, 1991, was revised, and accepted for publication December 20, 1991. Requests for reprints can be addressed to Dr. Bernadine Cimprich, University of Wisconsin-Madison, School of Nursing, 600 Highland Ave., Madison, WI 53792.
0 1992 John Wiley & Sons, Inc. CCC 0160-6891/92/030199-09 $04.00
200
RESEARCH IN NURSING 8 HEALTH
think clearly, and maintain intended activity despite distractions in the internal or external environment. Because directed attention requires continuous application of mental effort, prolonged or intense use of this capacity can lead to attentional fatigue, resulting in reduced effectiveness in purposeful activity (Kaplan & Kaplan, 1982). During diagnostic and treatment phases of lifethreatening illness such as cancer, multiple factors-informational, affective, and behavioralincrease the requirements for use of directed attention over long periods of time. Informational demands associated with treatment and therapeutic self-care may be intense (Derdiarian, 1987). At the same time, affective factors such as uncertainty about the future and painful thoughts associated with anticipated or actual losses can act as continuous distractions to purposeful activity (FrankStromborg et al., 1984). Finally, illness poses multiple constraints on normal functioning stemming from physical discomfort, from losses of privacy and territory, and prolonged transactions with threatening or confusing health care environments (Heinrich et al., 1984; Mages & Mendolsohn, 1979; Weisman & Worden, 1976- 1977). Prolonged use of directed attention can lead to fatigue of the global neural inhibitory mechanism which underlies normal attentional capacity (Kap lan & Kaplan, 1982). The characteristic effect of overuse and fatigue of this mechanism is a decreased capacity to inhibit competing stimuli or distractions. Attentional fatigue can be differentiated from physical fatigue in that it involves a reduced capacity to exert mental (inhibitory) effort rather than physical effort. Thus, a person with attentional fatigue may not be physically tired but would have difficulty in doing activities that require directed attention such as planning, problem solving, carrying out purposeful activity, and selfmonitoring of behavior (Lezak, 1982). Attentional fatigue has been observed in healthy individuals under experimental conditions requiring prolonged use of directed attention (e.g., Fiske & Schneider, 1981; Jerison & Picket, 1964; Mackworth, 1948; Parasuraman, 1986). Although attentional fatigue has not been previously studied within the context of illness, converging clinical evidence suggests that patients with cancer can experience significant attentional problems during various phases of illness. The inability to concentrate has been identified as a persistent source of distress during periods of active treatment for cancer (McCorkle & Young, 1978) and following a course of treatment (Mages & Mendolsohn, 1979; Oberst & James, 1985). Also, loss of concentration has been associated with unexplained, chronic
fatigue in persons with cancer (Aistars, 1987); however, the nature of this relationship is not clear, since loss of the capacity to direct attention need not be accompanied by decreased capacity to exert physical effort, or vice versa. Overall, the apparent pervasiveness of attentional problems underscores the need for systematic examination of the possible effects of cancer and its treatment on directed attentional capacity and functioning. This study provides an initial assessment of attentional capacity and functioning in women being treated for localized breast cancer. The sample was delimited to ensure a more homogeneous group of individuals who were coping with the same type of cancer and who were in the same phase of illness. Also, the intense mental demands experienced during treatment of breast cancer have been well documented (e.g., Scott, 1983). The major research question addressed in this descriptive study was: Are deficits in the capacity to direct attention manifested in the initial period of treatment for breast cancer, that is, on the day before discharge from the hospital following mastectomy or breast conservation surgery? Because of the exploratory nature of the study, data also were examined to address the following questions: (a) What are the possible differential effects of type of surgery, mastectomy versus breast conservation, on directed attentional capacity and functioning? (b) Is depressed mood associated with directed attentional capacity and functioning following breast cancer surgery? (c) What is the relationship between selected variables such as, age, educational level, narcotic pain medication, proximity of testing to surgery, and attentional performance following breast cancer surgery?
METHOD Sample The convenience sample of 32 female volunteers with newly diagnosed breast cancer was drawn from the population of patients at a university medical center that had a comprehensive cancer treatment program. All eligible women being treated for Stage I or II breast cancer were recruited during a 9-month period. Subjects were excluded for preexisting conditions that could affect attentional capacity or performance on the measures, specifically: documented cognitive, mental or affective disorder; uncorrected hearing or visual impairments; prescribed drugs known to impair or enhance attention; and insufficient command of
201
ATTENTIONAL FATIGUE / ClMPRlCH
the English language. Of the 44 subjects who were eligible, 73% agreed to participate. Of those who did not participate, the majority expressed an inability to deal with any additional tasks. The subjects ranged in age from 29 to 84 years, M = 54, SD = 14. Subjects averaged 14 years of formal education, and 50% were college graduates. All were born in the United States (90% Caucasian, 6% black). The majority were married (69%), and more than half were employed outside of the home (56%). All were in good health prior to diagnosis of breast cancer. Diagnosis was confirmed on outpatient biopsy for all subjects prior to surgical treatment. Almost equal numbers were treated with modified radical mastectomy (59%) and breast conservation surgery (41%), that is, lumpectomy. All had axillary node dissection on the affected side. Most (81%) had a pathologic diagnosis of Stage I breast cancer, while 19% had Stage 11 disease.
based on studies of healthy adults ranging in age from 16 to 74 years (Lezak, 1983; Spitz, 1972; Wechsler, 1955). Scores for Digit Span Forward (DSF) and Backward (DSB) were the number of digits repeated correctly before two consecutive failed trials (Wechsler, 1955). Alphabet Backward, a common measure of cognitive function, involves a mental reversing operation requiring sustained directed attentional capacity (Lezak, 1983). In this study, individuals were asked to recite the alphabet backward from a specified letter (i.e., y ) . The score was the number of letters recited without error in reverse sequence during a 20-s interval. The Symbol Digit Modalities Test (Smith, 1973), a standardized neurocognitive test, involves directed attention in substituting numbers for 10 geometric symbols, including three mirror image pairs, according to a specified key. Normative data have been reported based on a study of 420 healthy adults ranging in age from 18 to 74 (Lezak, 1983). The score was the number of correct substitutions in a 90-s period using standard testing procedures (Smith, 1973). The Letter Cancellation task was adapted from the Finding A's Test (Ekstrom, French, Harman, & Dermen, 1976). The task involves cancelling two specified letters that occur randomly in words in a paragraph (16 lines) of meaningful text. Theoretically, words are perceived as a whole, and increased attentional effort is necessary to detect an individual letter within a word (Kahneman & Treisman, 1984). Accuracy in letter cancellation was determined by the ratio of the number of specified letters cancelled to the total number of specified letters in the section completed during a 2-min interval. Perceived effectiveness in common activities requiring directed attention (Lezak, 1982) was measured using a self-rating scale, the Attentional Function Index (AFI), developed specifically for the study. The instrument consists of 14 linear analogue scales (each 100 mms) labeled at either
Measures The capacity to direct attention was measured using a battery of tests requiring inhibition of competing or distracting stimuli, as well as a subjective measure of perceived effectiveness in attentional functioning. The battery included standard measures, that is, Digit Span, Alphabet Backward, Symbol Digit Modalities Test, and Letter Cancellation, that have known validity and reliability (Lezak, 1983). Intercorrelations among the measures in this study ranged from .12 to .56 (see Table 1). The standardized internal consistency coefficient for the battery was .70, suggesting adequate beginning construct validity. The Digit Span, a standardized clinical test of attention (Mesulam, 19851, comprises two different measures. Forward span measures the number of bits of information a person can attend to at one time, while backward span requires sustained attention to perform a mental reversing operation. Normative data for Digit Span have been reported
Table 1. Correlation of Attentlonal Testsa Test
DSF
Digit Span Forward (DSF) Digit Span Backward (DSB) Alphabet Backward (AB) Symbol Digit Modalities Test (SDMT) Letter Cancellation (LC)
.35' .12 .27 .37'
'Pearson r coefficient. *N =
32,df
=
30,p < .05.
DSB
AB
SDMT
LC
.18 .42' .31
.35'
-
.20
.56*
-
202
RESEARCH IN NURSING 8 HEALTH
end with polar opposite phrases (e.g., not at all, extremely well) and includes items such as, concentrating on details, keeping track of what you’re saying or doing, keeping your mind on what others are saying. The respondents were asked to place a mark through the horizontal line at whatever point best described “how you are doing in each area at the present time.” Items were scored from the low end (range 0-loo), and a single overall score was computed consisting of the average score of the 14 linear analogue scales. The internal consistency coefficient of the index in this sample was .89, indicating satisfactory reliability. Because attentional performance may be influenced by diminished arousal associated with depression (Cohen, Weingartner, Smallberg, Pickar, & Murphy, 1982), a single item mood scale, the Visual Analog Mood Scale (VAMS) (Aitken, 1969; Folstein & Luria, 1973) served as an indicator of depressed mood state. The subject was asked to rate “mood right now” on a 100mm linear analogue scale from worst to best (0 to 100, respectively). In studies of patients with affective and nonaffective psychoses, the VAMS was particularly sensitive to depression (e.g., correlations between the VAMS and Zung Self-Rating Depression Scale ranged from -0.61 to -0.63) (Luria, 1975). Test-retest reliability coefficients for the VAMS ranged from 0.73 to 0.91 for a 2hr interval and 0.56 to 0.72 for 24 hr (Luria, 1975).
Procedure Potential volunteers were informed about the purpose of the study, the nature of the attentional tasks, and the amount of time required for testing (an average of 20 min). Written consent was obtained from all volunteers. All subjects were tested on the day before scheduled discharge from the hospital following breast cancer surgery. Testing
was done in a quiet, private room on the patient unit. The Attentional Function Index was administered first to obtain as clear a score as possible on this subjective measure. The objective tests were then administered in random order. All measures were administered using standard formats and verbatim instructions. Data were analyzed using descriptive statistics, t test, Pearson correlation coefficient, and regression. Digit Span and Symbol Digit Modalities Test scores were compared with published normative data to determine deviations from the norm.
R ESULTS Subjects showed attentional deficits of varying severity on the day before discharge following breast cancer surgery (see Table 2 for means, standard deviations, ranges, and medians of test scores). In Digit Span, adults normally can repeat seven digits in forward sequence without difficulty and 5 or better in reverse sequence. When testing for cognitive dysfunction in adults, a forward span of 5 is considered marginal, 4 is “definitely borderline” and 3 is defective (Lezak, 1983, p. 268). In backward span, a score of 3 is considered impaired (Lezak, 1983; Mesulam, 1985). In this sample, a significant proportion (56%) of the scores on DSF were at the lower end of the range (6 or less); a similar proportion (50%)of the scores on DSB were in the lower range (4 or less). Furthermore, 25% ( n = 8) of the subjects scored 5 or less in DSF, while 19% ( n = 6) scored 3 in DSB, suggesting severe impairment of directed attention. In Alphabet Backward (AB), although one subject actually scored 21, 34% ( n = 11) scored zero (0), and 75% (n = 24) scored 4 or less. Symbol Digit Modalities Test (SDMT) scores ranged from 22 to 67. Twenty-five percent (n = 8) scored below the age norm for SDMT (Lezak,
Table 2. Scores on Attentlonal Measures 3 Days Following Surgery for Breast Cancer
Digit Span Forward Digit Span Backward Alphabet Backward Symbol Digit Modalities Test Letter Cancellation Accuracy Ratio Attentional Function Indexa
Mean
Standard Deviation
Minimum-Maximum
Median
6.3 4.7 3.7
1.4 1.3 4.5
3-9 3-7 0-21
6.0 4.0 2.0
47.7
12.0
22-67
50.0
0.90 57.0
0.09 16.0
.63-.99 27-85
0.93 55.0
‘Average score on 14 linear analogue scales, each 100 mm’s, scored from the low end.
203
ATTENTIONAL FATIGUE / ClMPRlCH
Table 3. Correlationaof Attentional Test Scores with Attentional Function Index (AFI) and Visual Analog Mood Scale (VAMS) Attentional Tests
AFI
VAMS
Digit Span Forward Digits Span Backward Alphabet Backward Symbol Digit Modalities Test Letter Cancellation Accuracy Ratio Attentional Function Index (AFI)
- .05 -.18 .03 .17
.12 - .03 .25 .23
a
*
.26
.09
-
.52'
Pearson r coefficient. N = 32,df = 30, p
