99
Psychiatry Research, 34:99-106 Elsevier
The Yale-Brown Obsessive-Compulsive and Validity Study Suck Won Kim, Maurice Received
W. Dysken,
Scale: A Reliability
and Michael
Kuskowski
March 8, 1989; revised version received July 6, 1990; accepted August II, 1990.
Abstract. Twenty-eight nondepressed patients with DSM-IZZobsessive-compulsive disorder completed both the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the Leyton Obsessional Inventory (LOI) once a week for a total of three times change. In general, the correlations between the Y-BOCS change scores and the Global Ratings were significantly greater than between the LOI and the Global scores, the Y-BOCS was found to be more reliable than the LOI. Correlations were also obtained for the baseline period between the Y-BOCS and Leyton scores. At the end of a 1Cweek trial of clomipramine, the Y-BOCS and the LO1 were again administered along with a Physician and Patient Global Rating of change. In general, the correlations between the Y-BOCS change scores and the Global Ratings were significantly greater than between the LO1 and the Global Ratings. This last finding suggests that the Y-BOCS is a better measure of clinical change than is the LOI. Key Words. Yale-Brown Obsessive-Compulsive Scale, Leyton Inventory, obsessive-compulsive disorder, reliability, validity.
Obsessional
The Leyton Obsessional Inventory (LOI) was developed by Cooper (1970) to assess the nature and severity of obsessive-compulsive symptoms. To correct for deficiencies in earlier inventories, the LO1 included sections on feelings of resistance and interference with activities. In this regard, the LO1 was intended not only to serve as a diagnostic screening instrument, but also to measure severity as well as change during treatment. The LO1 was shown to differentiate well between a group of selected obsessional patients and normal subjects. Test-retest reliability (n = 30) was good for the symptom score (r = 0.87) and also for the trait score (r = 0.91) (Cooper, 1970). The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was developed in 1986 by Goodman, Rasmussen, and their colleagues (Goodman et al., 1989a, 19896) to assess not only symptom severity, but especially response to treatment. It was not designed,
Suck Won Kim, M.D., is Assistant Professor, Dept. of Psychiatry, Hennepin County Medical and Dept. of Psychiatry, University of Minnesota, Minneapolis, MN. Maurice W. Dysken, Associate Professor, Dept. of Psychiatry, University Of-Minnesota, and Psychopharmacologist, Research, Education, and Clinical Center, Minneapolis VA Medical Center, Minneapolis, MN. Kuskowski, Ph.D., is Psychophysiologist, Geriatric Research, Education, and Clinical Minneapolis VA Medical Center, Minneapolis, MN. (Reprint requests to Dr. S.W. Kim, Psychiatry, Hennepin County Medical Center, 701 Park Ave., Minneapolis, MN 55415, USA.) 0165-1781/90/$03.50
@ 1990 Elsevier Scientific
Publishers
Ireland
Ltd.
Center, M.D., is Geriatric Michael Center, Dept. of
100 however, as an instrument to diagnose obsessive-compulsive disorder (OCD). It was used most recently to measure clinical response in OCD patients who participated in multicenter clomipramine and fluvoximine studies. The reliability (Goodman et al., 1989b) and validity interrater reliability for total Y-BOCS
(Goodman et al., 1989~) data of the Y-BOCS show excellent between four raters (n = 40, intraclass correlation coefficients score = 0.98, p < 0.0001) and Y-BOCS
scores that were conver-
gent with two out of three other OCD scales tested. Although a number of OCD rating scales have been used in drug trials in the past, investigators who conducted OCD drug studies in recent years have described difficulties with the existing rating scales in assessing symptoms (Thor& et al., 1980; Insel et al., 1983). Early experiences suggested that the Y-BOCS was sensitive to symptom change in patients with established OCD (Goodman et al., 1989a, 1989b). To compare the Y-BOCS with the LOI, we administered both instruments to nondepressed OCD patients during the drug-free interval before they began treatment with clomipramine.
Methods Twenty-eight patients (12 men, 16 women) who met D&WZZZcriteria (American Psychiatric Association, 1980) and Schedule for Affective Disorders and Schizophrenia-Lifetime Version (SADS-L) criteria (Spitzer and Endicott, 1978) for OCD and who scored 16 or below on the 17-item Hamilton Rating Scale for Depression (Hamilton, 1960) were selected for the study. The mean age at the time of the study was 36 (range = 22-57), the mean age of onset for minor symptoms that did not interfere with functioning was 13 (23 for major symptoms), and the mean duration of illness was 14 years (duration of major symptoms, range = 4-31 years). The mean total Y-BOCS score (k SD) was 28 f 4.2 and mean total Leyton symptom score (* SD) was 33 f 6.6 (moderately severe to severe level). The Y-BOCS and LOI were given once a week throughout the 14-week clomipramine trial. The first three testing results were obtained during the drug-free baseline period and were used for the present study. The Y-BOCS, which was given by one of us (S.W.K.), is a clinicianadministered rating scale that assesses intensity of illness, interference, subjective distress, resistance, and control over the past 7 days. Interference with activities means impairment of social and occupational functioning; feelings of resistance refer to the patient’s effort in counteracting obsessional thinking and compulsive behavior. The rating scale is divided into obsessive and compulsive sections in which the total scores for each section range from 0 to 20. The LOI, which was designed to be administered by either a clinician or an assistant, was given to subjects with the aid of a computer. The three sections of the LOI gather information about obsessive-compulsive symptoms, resistance, and interference. In the first part of the LOI, patients answer each item as either present or absent. The first 46 items yield a symptom score, and the following 23 items, a trait score. The trait score refers to ego-syntonic symptoms that are commonly associated with compulsive personality disorder, whereas the symptom score refers to distressing, ego-dystonic symptoms associated with OCD. Unlike the Y-BOCS, the resistance and interference scores are determined for a number of selected items that the patient indicated were present. The maximum score for part 1 (symptom + trait scores) is 69; the maximum score for the resistance subtest is 114 for men (117 for women); and the maximum score for the interference subtest is also 114 for men (117 for women). The reliabilities of both the Y-BOCS and the LO1 were measured using the three repeated test scores from each subject. The variability of these scores from the subject’s mean value was determined and expressed as a pooled standard deviation. This gives an estimate of the
101 repeatability of the test results for a given subject and is known as the test-retest or withinsubject standard deviation (SD) (Snedecor and Cochran, 1980). Due to the difference in means and ranges of the two instruments, the coefficient of variation (CV) was computed for each subject to adjust for the different measurement scales and to allow for a statistical comparison of reliability between the LO1 and the Y-BOCS. The intraclass correlation (ICC; Bartko and Carpenter, 1976) was calculated for each test as another measure of reliability. The Fisher’s r-to-z transformation (modified for the number of repeated measures) was applied to the ICCs to compare reliabilities between the two scales. Differences between the three testing sessions due to an order or a learning effect were checked using a nonparametric approach. For the validity study, a correlation between the total Leyton symptom score and the total Y-BOCS score (minus resistance and interference scores) was obtained. A correlation between the Leyton total score (symptom and trait scores) and the total Y-BOCS score was also obtained. The scoring of the resistance sections in the two rating scales was significantly different. In the Y-BOCS, the higher the resistance, the lower the score; whereas in the LOI, the higher the resistance, in general, the higher the score. To measure the validity of the resistance and interference scores, the results of the two tests were categorized as above or not above the median value and cross-classified to reflect the amount of agreement. At the end of the 1Cweek clomipramine trial, global change scores were obtained from the patient (Patient Global Rating) and from the physician (Physician Global Rating). Both scales ranged from 1 to 7, with 1 = very much improved, 2 = much improved, 3 = minimally improved, 4 = unchanged, 5 = minimally worse, 6 = much worse, and 7 = very much worse. Changes in Y-BOCS and LO1 scores from baseline to week 14 were calculated as simple change scores and as % change from baseline. Spearman correlations between these change scores and the global ratings from the patient and physician were calculated and compared using Fisher’s r-to-z transformation.
Results Table 1 presents the test-retest reliabilities of the Y-BOCS and the LO1 total scores, resistance scores, and interference scores. The average CVs for the total resistance, and interference scores showed statistically significant differences, suggesting that the Y-BOCS measures of total symptoms, resistance, and interference may be more reliable than the corresponding Leyton measures. For the Y-BOG total score,
Table 1. Test-retest reliabilities of the LOI and Y-BOCS total score, resistance score. and interference score Rating scale scores Total score
3.36 (SD) 0.09 (CV) 0.73 (r)
Resistance score
Interference
LOI
score
7.51 (SD) 0.14
(CV)
0.84
(r)
7.64
(SD)
0.12
(CV)
0.79
IfI
Y-BOCS **
t.
.*
0.63
(SD)
0.02
(CV)
0.90
(r)
0.18
(SD)
0.01
(CV)
0.90
(I)
0.39
(SD)
0.03
(CV)
0.89
Irl
Note. LOI = Leyion Obsessional Inventory. Y-BOCS = Yale-Brown Obsessive-Compulsive Scale. SD = standard deviation of within-patient variability. CV = average coefficient of variation. r = interclass correlation. *’
p < 0.01
(paired t test).
102 15/28 (54%) agreed completely for all three administrations and 5/28 (18%) differed by only 1 point in one of the test sessions. For the resistance subscale, 21/28 (75%) agreed completely for all three administrations and 6/28 (21%) differed by only 1 point in one of the test sessions. For the interference subscale, 20/28 (71%) agreed completely, 5/28 (18%) differed by only 1 point in one of the sessions, and 3/28 (11%) differed by 2 points. The difference between the ICCs for the total, resistance and interference scores of the LO1 and Y-BOCS did not reach statistical significance. There was no statistical evidence of an order effect between the three testing sessions as determined by the Friedman test. For the validity study comparing baseline Y-BOCS scores to LO1 scores, Spearman correlations between the Y-BOCS total score and the Leyton total (symptom and trait) and Leyton symptom scores were found to be low (r = 0.33 and 0.38, respectively). After both the resistance scores and the interference scores were subtracted from the Y-BOCS total scores, the Spearman correlations between the Y-BOCS and the Leyton total (symptom and trait) and Leyton symptom scores improved (T = 0.44 and 0.44, respectively). When the resistance and interference scores of the two tests were compared, there was a 63.1% agreement &* = 7.2, p < 0.01) in interference scores (Fig. I), but only a 38.1 % agreement &* = 5.2,~ < 0.05) in resistance scores (Fig. 2). When the total Y-BOCS scores were compared to the resistance and interference subscale scores of the LOI, the Spearman correlation coefficients were 0.01 and 0.43, respectively. Fig. 1. Comparison of the Y-BOCS interference scores with the LOI interference scores Y-BOCS InterferenceScore
Below or = to median
Below or =
Above
to median
median
38
5
43
28
15
41
64
20
84
Leyton Interference Score Above
63.1% agreement (X2 = 7.2, p < 0.01) Y-BOCS = Yale-Brown Obsessive-Compulsive Scale. LOI = Leyton Obsessional Inventory.
103 Fig. 2. Comparison of the Y-BOCS resistance scores with the LOI resistance scores Y-BOCS ResistanceScore
Below or = to median
Below or =
Above
to median
median
22
20
42
32
10
42
54
30
84
Leyton Resistance Score Above median
38.1% agreement
(X2 = 5.2, p < 0.05)
Y-BOCS = Yale-Brown Obsessive-Compulsive Scale. LOI = Leyton Obsessional Inventory.
For the validity study comparing changes during treatment between the Y-BOCS and LO1 scores, Tables 2 and 3 present Spearman correlation coefficients between the two OCD rating scales and the Physician Global Rating and the Patient Global Rating Scales, respectively. Fisher r-to-z transformations were calculated to detect any significant differences between the correlations in Y-BOCS and LO1 scores vs. the Global Ratings of change. In all but one comparison (Table 2, AY-BOCS vs. Table 2. Spearman correlation coefficients for Y-BOCS and Leyton change scores vs. the Physician Global Rating of change (n = 15) Rating scale
Rho
Rating scale
Rho
A Y-BOCS
-0.732
A Leyton (sym)
-0.32
3.723
A Leyton (res)
-0.24
4.483
A Leyton (int)
-0.54’
1.73
%A Leyton (sym)
-0.25
4.083
%A Leyton (res)
-0.24
4.183
%A Leyton (int)
-0.23
4.283
%A Y-BOCS
-0.702
Fisher r-to-z
Note. A = simple change score. %A = percent change score. Y-BOG = Yale-Brown Obsessive-Compulsive Scale. Leyton (sym) = Leyton Obsessional Inventory symptom score. Leyton (res) = Leyton Obsessional Inventory resistance score. Leyton (int) = Leyton Obsessional Inventory interference score. l.p
Psychiatry Research, 34:99-106 Elsevier
The Yale-Brown Obsessive-Compulsive and Validity Study Suck Won Kim, Maurice Received
W. Dysken,
Scale: A Reliability
and Michael
Kuskowski
March 8, 1989; revised version received July 6, 1990; accepted August II, 1990.
Abstract. Twenty-eight nondepressed patients with DSM-IZZobsessive-compulsive disorder completed both the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the Leyton Obsessional Inventory (LOI) once a week for a total of three times change. In general, the correlations between the Y-BOCS change scores and the Global Ratings were significantly greater than between the LOI and the Global scores, the Y-BOCS was found to be more reliable than the LOI. Correlations were also obtained for the baseline period between the Y-BOCS and Leyton scores. At the end of a 1Cweek trial of clomipramine, the Y-BOCS and the LO1 were again administered along with a Physician and Patient Global Rating of change. In general, the correlations between the Y-BOCS change scores and the Global Ratings were significantly greater than between the LO1 and the Global Ratings. This last finding suggests that the Y-BOCS is a better measure of clinical change than is the LOI. Key Words. Yale-Brown Obsessive-Compulsive Scale, Leyton Inventory, obsessive-compulsive disorder, reliability, validity.
Obsessional
The Leyton Obsessional Inventory (LOI) was developed by Cooper (1970) to assess the nature and severity of obsessive-compulsive symptoms. To correct for deficiencies in earlier inventories, the LO1 included sections on feelings of resistance and interference with activities. In this regard, the LO1 was intended not only to serve as a diagnostic screening instrument, but also to measure severity as well as change during treatment. The LO1 was shown to differentiate well between a group of selected obsessional patients and normal subjects. Test-retest reliability (n = 30) was good for the symptom score (r = 0.87) and also for the trait score (r = 0.91) (Cooper, 1970). The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was developed in 1986 by Goodman, Rasmussen, and their colleagues (Goodman et al., 1989a, 19896) to assess not only symptom severity, but especially response to treatment. It was not designed,
Suck Won Kim, M.D., is Assistant Professor, Dept. of Psychiatry, Hennepin County Medical and Dept. of Psychiatry, University of Minnesota, Minneapolis, MN. Maurice W. Dysken, Associate Professor, Dept. of Psychiatry, University Of-Minnesota, and Psychopharmacologist, Research, Education, and Clinical Center, Minneapolis VA Medical Center, Minneapolis, MN. Kuskowski, Ph.D., is Psychophysiologist, Geriatric Research, Education, and Clinical Minneapolis VA Medical Center, Minneapolis, MN. (Reprint requests to Dr. S.W. Kim, Psychiatry, Hennepin County Medical Center, 701 Park Ave., Minneapolis, MN 55415, USA.) 0165-1781/90/$03.50
@ 1990 Elsevier Scientific
Publishers
Ireland
Ltd.
Center, M.D., is Geriatric Michael Center, Dept. of
100 however, as an instrument to diagnose obsessive-compulsive disorder (OCD). It was used most recently to measure clinical response in OCD patients who participated in multicenter clomipramine and fluvoximine studies. The reliability (Goodman et al., 1989b) and validity interrater reliability for total Y-BOCS
(Goodman et al., 1989~) data of the Y-BOCS show excellent between four raters (n = 40, intraclass correlation coefficients score = 0.98, p < 0.0001) and Y-BOCS
scores that were conver-
gent with two out of three other OCD scales tested. Although a number of OCD rating scales have been used in drug trials in the past, investigators who conducted OCD drug studies in recent years have described difficulties with the existing rating scales in assessing symptoms (Thor& et al., 1980; Insel et al., 1983). Early experiences suggested that the Y-BOCS was sensitive to symptom change in patients with established OCD (Goodman et al., 1989a, 1989b). To compare the Y-BOCS with the LOI, we administered both instruments to nondepressed OCD patients during the drug-free interval before they began treatment with clomipramine.
Methods Twenty-eight patients (12 men, 16 women) who met D&WZZZcriteria (American Psychiatric Association, 1980) and Schedule for Affective Disorders and Schizophrenia-Lifetime Version (SADS-L) criteria (Spitzer and Endicott, 1978) for OCD and who scored 16 or below on the 17-item Hamilton Rating Scale for Depression (Hamilton, 1960) were selected for the study. The mean age at the time of the study was 36 (range = 22-57), the mean age of onset for minor symptoms that did not interfere with functioning was 13 (23 for major symptoms), and the mean duration of illness was 14 years (duration of major symptoms, range = 4-31 years). The mean total Y-BOCS score (k SD) was 28 f 4.2 and mean total Leyton symptom score (* SD) was 33 f 6.6 (moderately severe to severe level). The Y-BOCS and LOI were given once a week throughout the 14-week clomipramine trial. The first three testing results were obtained during the drug-free baseline period and were used for the present study. The Y-BOCS, which was given by one of us (S.W.K.), is a clinicianadministered rating scale that assesses intensity of illness, interference, subjective distress, resistance, and control over the past 7 days. Interference with activities means impairment of social and occupational functioning; feelings of resistance refer to the patient’s effort in counteracting obsessional thinking and compulsive behavior. The rating scale is divided into obsessive and compulsive sections in which the total scores for each section range from 0 to 20. The LOI, which was designed to be administered by either a clinician or an assistant, was given to subjects with the aid of a computer. The three sections of the LOI gather information about obsessive-compulsive symptoms, resistance, and interference. In the first part of the LOI, patients answer each item as either present or absent. The first 46 items yield a symptom score, and the following 23 items, a trait score. The trait score refers to ego-syntonic symptoms that are commonly associated with compulsive personality disorder, whereas the symptom score refers to distressing, ego-dystonic symptoms associated with OCD. Unlike the Y-BOCS, the resistance and interference scores are determined for a number of selected items that the patient indicated were present. The maximum score for part 1 (symptom + trait scores) is 69; the maximum score for the resistance subtest is 114 for men (117 for women); and the maximum score for the interference subtest is also 114 for men (117 for women). The reliabilities of both the Y-BOCS and the LO1 were measured using the three repeated test scores from each subject. The variability of these scores from the subject’s mean value was determined and expressed as a pooled standard deviation. This gives an estimate of the
101 repeatability of the test results for a given subject and is known as the test-retest or withinsubject standard deviation (SD) (Snedecor and Cochran, 1980). Due to the difference in means and ranges of the two instruments, the coefficient of variation (CV) was computed for each subject to adjust for the different measurement scales and to allow for a statistical comparison of reliability between the LO1 and the Y-BOCS. The intraclass correlation (ICC; Bartko and Carpenter, 1976) was calculated for each test as another measure of reliability. The Fisher’s r-to-z transformation (modified for the number of repeated measures) was applied to the ICCs to compare reliabilities between the two scales. Differences between the three testing sessions due to an order or a learning effect were checked using a nonparametric approach. For the validity study, a correlation between the total Leyton symptom score and the total Y-BOCS score (minus resistance and interference scores) was obtained. A correlation between the Leyton total score (symptom and trait scores) and the total Y-BOCS score was also obtained. The scoring of the resistance sections in the two rating scales was significantly different. In the Y-BOCS, the higher the resistance, the lower the score; whereas in the LOI, the higher the resistance, in general, the higher the score. To measure the validity of the resistance and interference scores, the results of the two tests were categorized as above or not above the median value and cross-classified to reflect the amount of agreement. At the end of the 1Cweek clomipramine trial, global change scores were obtained from the patient (Patient Global Rating) and from the physician (Physician Global Rating). Both scales ranged from 1 to 7, with 1 = very much improved, 2 = much improved, 3 = minimally improved, 4 = unchanged, 5 = minimally worse, 6 = much worse, and 7 = very much worse. Changes in Y-BOCS and LO1 scores from baseline to week 14 were calculated as simple change scores and as % change from baseline. Spearman correlations between these change scores and the global ratings from the patient and physician were calculated and compared using Fisher’s r-to-z transformation.
Results Table 1 presents the test-retest reliabilities of the Y-BOCS and the LO1 total scores, resistance scores, and interference scores. The average CVs for the total resistance, and interference scores showed statistically significant differences, suggesting that the Y-BOCS measures of total symptoms, resistance, and interference may be more reliable than the corresponding Leyton measures. For the Y-BOG total score,
Table 1. Test-retest reliabilities of the LOI and Y-BOCS total score, resistance score. and interference score Rating scale scores Total score
3.36 (SD) 0.09 (CV) 0.73 (r)
Resistance score
Interference
LOI
score
7.51 (SD) 0.14
(CV)
0.84
(r)
7.64
(SD)
0.12
(CV)
0.79
IfI
Y-BOCS **
t.
.*
0.63
(SD)
0.02
(CV)
0.90
(r)
0.18
(SD)
0.01
(CV)
0.90
(I)
0.39
(SD)
0.03
(CV)
0.89
Irl
Note. LOI = Leyion Obsessional Inventory. Y-BOCS = Yale-Brown Obsessive-Compulsive Scale. SD = standard deviation of within-patient variability. CV = average coefficient of variation. r = interclass correlation. *’
p < 0.01
(paired t test).
102 15/28 (54%) agreed completely for all three administrations and 5/28 (18%) differed by only 1 point in one of the test sessions. For the resistance subscale, 21/28 (75%) agreed completely for all three administrations and 6/28 (21%) differed by only 1 point in one of the test sessions. For the interference subscale, 20/28 (71%) agreed completely, 5/28 (18%) differed by only 1 point in one of the sessions, and 3/28 (11%) differed by 2 points. The difference between the ICCs for the total, resistance and interference scores of the LO1 and Y-BOCS did not reach statistical significance. There was no statistical evidence of an order effect between the three testing sessions as determined by the Friedman test. For the validity study comparing baseline Y-BOCS scores to LO1 scores, Spearman correlations between the Y-BOCS total score and the Leyton total (symptom and trait) and Leyton symptom scores were found to be low (r = 0.33 and 0.38, respectively). After both the resistance scores and the interference scores were subtracted from the Y-BOCS total scores, the Spearman correlations between the Y-BOCS and the Leyton total (symptom and trait) and Leyton symptom scores improved (T = 0.44 and 0.44, respectively). When the resistance and interference scores of the two tests were compared, there was a 63.1% agreement &* = 7.2, p < 0.01) in interference scores (Fig. I), but only a 38.1 % agreement &* = 5.2,~ < 0.05) in resistance scores (Fig. 2). When the total Y-BOCS scores were compared to the resistance and interference subscale scores of the LOI, the Spearman correlation coefficients were 0.01 and 0.43, respectively. Fig. 1. Comparison of the Y-BOCS interference scores with the LOI interference scores Y-BOCS InterferenceScore
Below or = to median
Below or =
Above
to median
median
38
5
43
28
15
41
64
20
84
Leyton Interference Score Above
63.1% agreement (X2 = 7.2, p < 0.01) Y-BOCS = Yale-Brown Obsessive-Compulsive Scale. LOI = Leyton Obsessional Inventory.
103 Fig. 2. Comparison of the Y-BOCS resistance scores with the LOI resistance scores Y-BOCS ResistanceScore
Below or = to median
Below or =
Above
to median
median
22
20
42
32
10
42
54
30
84
Leyton Resistance Score Above median
38.1% agreement
(X2 = 5.2, p < 0.05)
Y-BOCS = Yale-Brown Obsessive-Compulsive Scale. LOI = Leyton Obsessional Inventory.
For the validity study comparing changes during treatment between the Y-BOCS and LO1 scores, Tables 2 and 3 present Spearman correlation coefficients between the two OCD rating scales and the Physician Global Rating and the Patient Global Rating Scales, respectively. Fisher r-to-z transformations were calculated to detect any significant differences between the correlations in Y-BOCS and LO1 scores vs. the Global Ratings of change. In all but one comparison (Table 2, AY-BOCS vs. Table 2. Spearman correlation coefficients for Y-BOCS and Leyton change scores vs. the Physician Global Rating of change (n = 15) Rating scale
Rho
Rating scale
Rho
A Y-BOCS
-0.732
A Leyton (sym)
-0.32
3.723
A Leyton (res)
-0.24
4.483
A Leyton (int)
-0.54’
1.73
%A Leyton (sym)
-0.25
4.083
%A Leyton (res)
-0.24
4.183
%A Leyton (int)
-0.23
4.283
%A Y-BOCS
-0.702
Fisher r-to-z
Note. A = simple change score. %A = percent change score. Y-BOG = Yale-Brown Obsessive-Compulsive Scale. Leyton (sym) = Leyton Obsessional Inventory symptom score. Leyton (res) = Leyton Obsessional Inventory resistance score. Leyton (int) = Leyton Obsessional Inventory interference score. l.p
