Supplementary Material.pdf

Full text

_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Brief assessment of depression: Psychometric
properties of the Portuguese version of the
Patient Health Questionnaire (PHQ-9)
Tiago Ferreira1,2, Marlene Sousa1,2, Liliana Meira1,2, Carla Cunha1,2, Anita Santos1,2, Sara
Silva1,2, Ana Bela Couto1,2, Pedro Gomes1, Liliana Costa1,2, Eunice Barbosa1,2, Isabel
Basto1,2, João Salgado1,2
1 Instituto Universitário da Maia, Portugal
2 Centro de Psicologia da Universidade do Porto, Portugal
Corresponding author: João Salgado | jsalgado@ismai.pt
Received:
30 October 2017
Accepted:
27 December 2018
Supplementary Material

Brief assessment of depression: psychometric properties of the PHQ-9
_____________________________________________________________________________________________________
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Exploratory analysis of the Patient Health Questionnaire chart (PHQ-9): Primary health
care
Table S1. Matrix of polychoric correlations and matrix of partial correlations related to the exploratory
analysis of the network of the Patient Health Questionnaire (PHQ-9) (primary health care)
Item
1
2
3
4
5
6
7
8
9
1
Anhedonia
.680
.321
.432
.208
.325
.331
.284
.498
2
Depressed mood
.431
.253
.435
.127
.359
.371
.365
.502
3
Sleep Problems
.047
.000
.311
.174
.264
.301
.283
.358
4
Fatigue
.120
.119
.075
.249
.112
.452
.338
.277
5
Appetite changes
.000
.000
.000
.058
.180
.105
.293
.028
6
Self-devaluation
.000
.000
.000
.000
.000
.272
.340
.679
7
Difficulty in concentration
.000
.042
.049
.209
.000
.000
.477
.378
8
Psychomotor retardation or agitation
.000
.069
.043
.042
.113
.078
.247
.325
9
Suicide ideation
.144
.140
.099
.000
.000
.474
.078
.000
Note. The table section above the diagonal line shows the values for the polychoric correlations between the PHQ-9 items. The section of
the table below the diagonal line shows the values relative to the median partial correlations between the PHQ-9 items.

Ferreira et al
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Figure S1. 95%IC for the partial correlations of the Patient
Health Questionnaire (PHQ-9) network (primary health care)

Brief assessment of depression: psychometric properties of the PHQ-9
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Semi-confirmatory factorial analysis of the Patient Health Questionnaire (PHQ-9): Primary
health care
Table S2. Matrix of polychoric correlations related to the semi-confirmatory factorial analysis of the
Patient Health Questionnaire (PHQ-9) (primary health care)
Item
1
2
3
4
5
6
7
8
9
1
Anhedonia
1.000
2
Depressed mood
.626
1.000
3
Sleep Problems
.312
.257
1.000
4
Fatigue
.431
.402
.314
1.000
5
Appetite changes
.213
.128
.178
.247
1.000
6
Self-devaluation
.332
.327
.265
.112
.179
1.000
7
Difficulty in concentration
.303
.340
.307
.446
.100
.275
1.000
8
Psychomotor retardation or agitation
.278
.321
.277
.294
.288
.340
.480
1.000
9
Suicide ideation
.397
.382
.282
.172
.050
.627
.354
.344
1.000

Ferreira et al
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Exploratory analysis of the Patient Health Questionnaire network (PHQ-9): University clinic
Table S3. Matrix of polychoric correlations and matrix of partial correlations related to the exploratory
analysis of the network of the Patient Health Questionnaire (PHQ-9) (university clinic)
Item
1
2
3
4
5
6
7
8
9
1
Anhedonia
.869
.281
.626
.354
.741
.627
.461
.547
2
Depressed mood
.479
.476
.565
.384
.781
.660
.570
.618
3
Sleep Problems
.000
.077
.489
.418
.446
.286
.296
.350
4
Fatigue
.151
.034
.171
.521
.591
.471
.413
.514
5
Appetite changes
.000
.000
.109
.164
.392
.445
.577
.499
6
Self-devaluation
.195
.304
.070
.130
.000
.531
.350
.478
7
Difficulty in concentration
.112
.144
.000
.000
.000
.000
.562
.612
8
Psychomotor retardation or agitation
.000
.095
.000
.000
.278
.000
.178
.517
9
Suicide ideation
.005
.124
.000
.091
.118
.000
.236
.093
Note. The table section above the diagonal line shows the values for the polychoric correlations between the PHQ-9 items. The section of
the table below the diagonal line shows the values relative to the median partial correlations between the PHQ-9 items.

Brief assessment of depression: psychometric properties of the PHQ-9
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Figure S2. 95%IC for the partial correlations of the
Patient Health Questionnaire (PHQ-9) network
(university clinic)

Ferreira et al
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Semi-confirmatory factorial analysis of the Patient Health Questionnaire (PHQ-9):
University clinic
Table S4. Matrix of polychoric correlations related to the semi-confirmatory factorial analysis of the
Patient Health Questionnaire (PHQ-9) (university clinic)
Item
1
2
3
4
5
6
7
8
9
1
Anhedonia
1.000
2
Depressed mood
.812
1.000
3
Sleep Problems
.265
.435
1.000
4
Fatigue
.582
.518
.447
1.000
5
Appetite changes
.361
.384
.382
.485
1.000
6
Self-devaluation
.696
.737
.447
.584
.384
1.000
7
Difficulty in concentration
.573
.610
.282
.436
.445
.526
1.000
8
Psychomotor retardation or agitation
.416
.509
.267
.371
.548
.352
.527
1.000
9
Suicide ideation
.453
.507
.288
.423
.460
.425
.554
.496
1.000

Brief assessment of depression: psychometric properties of the PHQ-9
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Information regarding the Patient Health Questionnaire (PHQ-9)
Table S5. Characteristics of the Patient Health Questionnaire items (PHQ-9)
Study
Item
Average Scale
if Item is Deleted
Variance of Scale
if Item is Deleted
Corrected
Item-Total
Correlation
Multiple to
Square
Correlation
Cronbach’s Alpha
if Item is Deleted
(99%CI BCa)
Omega Categorical
if Item is Deleted
(99%CI BCa)
Primary health
care
1
9.634
21.168
.544
.453
.704 (.591, .788)
.742 (.598, .827)
2
9.523
21.698
.536
.449
.707 (.604, .793)
.744 (.604, .831)
3
9.458
21.539
.381
.157
.733 (.636, .805)
.786 (.649, .865)
4
9.242
21.645
.460
.281
.718 (.617, .797)
.763 (.617, .842)
5
9.824
23.291
.237
.118
.757 (.669, .829)
.803 (.662, .872)
6
10.183
21.769
.395
.304
.730 (.626, .806)
.742 (.600, .833)
7
10.007
21.454
.469
.288
.716 (.613, .797)
.742 (.595, .827)
8
10.275
22.003
.459
.255
.719 (.616, .797)
.742 (.599, .834)
9
10.850
23.826
.414
.309
.729 (.628, .807)
.742 (.605, .830)
University clinic
1
10.806
33.186
.689
.681
.847 (.770, .898)
.883 (.784, .924)
2
10.796
32.369
.773
.738
.839 (.756, .894)
.877 (.755, .925)
3
10.824
36.445
.436
.312
.870 (.804, .914)
.912 (.819, .952)
4
10.833
34.720
.622
.441
.854 (.788, .899)
.897 (.784, .944)
5
11.241
34.913
.524
.368
.863 (.797, .906)
.894 (.811, .931)
6
11.065
33.295
.662
.548
.850 (.779, .898)
.891 (.762, .936)
7
11.213
34.150
.637
.454
.852 (.776, .900)
.897 (.790, .947)
8
11.528
35.167
.537
.395
.862 (.798, .907)
.894 (.785, .936)
9
11.917
36.245
.566
.344
.859 (.781, .909)
.901 (.752, .947)
Note. 99%CI BCa = Bias corrected and accelerated confidence intervals for 99% confidence.

Ferreira et al
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Information regarding the Patient Health Questionnaire (PHQ-9)
Table S6. Z and T scores & percentiles related to the Patient Health Questionnaire (PHQ-9)
Primary Health Care
University Clinic
Total
Total
Score
Z
T
Frequency
Percentile
Z
T
Frequency
Percentile
Z
T
Frequency
Percentile
0
-2.14
29
2
1
-1.91
31
1
0
-2.01
30
3
1
1
-1.95
31
1
2
-1.76
32
7
4
-1.84
32
8
3
2
-1.75
32
5
4
-1.61
34
1
8
-1.67
33
6
5
3
-1.56
34
3
6
-1.45
35
3
10
-1.49
35
6
8
4
-1.37
36
1
8
-1.30
37
1
12
-1,.32
37
2
9
5
-1.18
38
7
10
-1.15
39
2
13
-1.15
38
9
11
6
-0.99
40
11
16
-1.00
40
6
17
-0.98
40
17
16
7
-0.79
42
6
22
-0.84
42
8
23
-0.81
42
14
22
8
-0.60
44
14
28
-0.69
43
2
28
-0.64
44
16
28
9
-0.41
46
20
39
-0.54
45
2
30
-0.46
45
22
35
10
-0.22
48
4
47
-0.39
46
5
33
-0.29
47
9
41
11
-0.02
50
9
51
-0.23
48
8
39
-0.12
49
17
46
12
0.17
52
12
58
-0.08
49
12
48
0.05
51
24
54
13
0.36
54
10
65
0.07
51
4
56
0.22
52
14
61
14
0.55
56
6
71
0.22
52
5
60
0.39
54
11
66
15
0.75
57
7
75
0.38
54
3
63
0.57
56
10
70
16
0.94
59
10
80
0.53
55
7
68
0.74
57
17
75
17
1.13
61
7
86
0.68
57
5
74
0.91
59
12
81
18
1.32
63
5
90
0.83
58
6
79
1.08
61
11
85
19
1.51
65
4
93
0.99
60
4
83
1.25
63
8
89
20
1.71
67
3
95
1.14
61
3
87
1.42
64
6
92
21
1.90
69
2
97
1.29
63
2
89
1.59
66
4
93
22
2.09
71
0
97
1.45
64
2
91
1.77
68
2
95
23
2.28
73
3
98
1.60
66
3
93
1.94
69
6
96
24
2.48
75
0
99
1.75
68
2
95
2.11
71
2
98
25
2.67
77
1
100
1.90
69
3
98
2.28
73
4
99
26
---
---
---
---
2.06
71
0
99
2.45
75
0
100
27
---
---
---
---
2.21
72
1
100
2.62
76
1
100
Note. The information was calculated on bases of the omega categorical for a 99% confidence interval: .788 (99%CI BCa [.661 – .857]) for
primary health care, .837 (99%CI BCa [.760 – .876]) for the university clinic and .837 (99%CI BCa [.760 – .876]) for the complete sample.

Brief assessment of depression: psychometric properties of the PHQ-9
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Figure S3. Distribution of total scores in the Patient Health Questionnaire (PHQ-9) in primary health
care and the university clinic
11
14
40
47
55
38
31
12
12
1
8
5
16
9
24
15
15
7
8
1
3
9
24
38
31
23
16
5
4
0
[ 0 - 1 ] [ 2 - 4 ] [ 5 - 7 ] [ 8 - 1 0] [ 11 - 1 3] [ 14 - 1 6] [ 17 - 1 9] [ 20 - 2 2] [ 23 - 2 5] [2 6 - 27 ]
FREQUENCY
TOTAL SCORE
Complete Sample University Clinic Primary Care

Ferreira et al
_____________________________________________________________________________________________________
www.psyprjournal.com
PPRJ. Vol 1. Number 1. December 2018 | DOI: https://doi.org/10.33525/pprj.v1i2.36.s36
Cut-off points for identifying Major Depressive Disorder in the Patient Health
Questionnaire (PHQ-9)
Table S7. Confidence intervals for the sensitivity and specificity of several cut-off points for identifying
Major Depressive Disorder in the Patient Health Questionnaire (PHQ-9)
Cutoff
Sensitivity
(99%CI)
Specificity
(99%CI)
3
.344 (.105, .600)
1.000 (1.000, 1.000)
5
.462 (.200, .714)
.988 (.948, 1.000)
6
.500 (.240, .760)
.976 (.925, 1.000)
7
.696 (.448, .909)
.964 (.900, 1.000)
8
.850 (.636, 1.000)
.917 (.827, .987)
9
.889 (.696, 1.000)
.904 (.808, .976)
13
.927 (.762, 1.000)
.588 (.443, .727)
17
.964 (.833, 1.000)
.367 (.229, .507)
19
1.000 (1.000, 1.000)
.244 (.128, .371)