Psychometric measurement of PEI in chronic musculoskeletal pain
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Table III. Change and outcome after treatment in self-reported health, work ability and Patient Enablement Instrument (PEI) in the
participants who completed the Neck Disability Index (NDI) or Functional Rating Index (FRI), the Global Perceived Effect (GPE), and all
items of the PEI after treatment
All
Mean (SD)
Disability
NDI or FRI baseline (1)
NDI or FRI after treatment (2)
NDI or FRI change (1–2)
Mental health
Anxiety (HADS) baseline
Anxiety (HADS) after treatment
Anxiety (HADS) change (1–2)
Depression (HADS) baseline (1)
Depression (HADS) after treatment (2)
Depression (HADS) change (1–2)
PCS baseline (1)
PCS after treatment (2)
PCS change (1–2)
WAD
Mean (SD)
–
–
–
32.3 (12.9)
27.4 (15.3)
–4.9 (10.6)
–
–
–
–
–
–
–
–
–
SES baseline (1)
SES after treatment (2)
SES change (1–2)
CSQ Catastrophising thoughts baseline (1)
CSQ Catastrophising thoughts after treatment (2)
CSQ Catastrophising thoughts change (1–2)
Health
EQ-5D Index baseline (1)
EQ-5D Index after treatment (2)
EQ-5D Index change (1–2)
EQ VAS baseline (1)
EQ VAS after treatment (2)
EQ VAS change (1–2)
Self-reported current work ability at baseline (1) –
–
–
–
–
–
Self-reported current work ability after treatment (2)
Self-reported current work ability change (1–2) –
–
6.9 (4.6)
–
–
4.9 (4.1)
–
–
18.4 (11.1)
14.3 (11.2)
–4.1 (9.3)
153 (33)
160 (35)
8 (25)
–
–
–
0.365 (0.340)
0.486 (0.337)
0.121 (0.284)
48 (21)
57 (23)
9 (223
4.4 (2.8)
CR
Mean (SD) MixCP
Mean (SD)
41.8 (14.4)
28.3 (16.4)
–13.5 (16.3) 62.9 (17.6)
59.5 (21.1)
–3.5 (15.7)
–
–
–
–
–
–
–
–
– 10.1 (5.0)
9.1 (5.0)
–0.9 (3.2)
7.7 (4.3)
6.7 (4.2)
–1.0 (3.1)
–
–
–
129 (37)
–
–
14.6 (7.9)
8.3 (7.6)
6.3 (9.0) –
–
–
–
–
–
0.595 (0.267)
0.681 (0.225)
0.088 (0.237)
62 (18)
67 (19)
5.3 (20)
7.0 (2.1)
7.3 (2.0)
0.3 (1.8)
0.412 (0.306)
0.647 (0.254)
0.234 (0.327)
47 (21)
69 (21)
21 (27)
4.0 (2.8)
–
–
0.252 (0.327)
0.344 (0.336)
0.092 (0.274)
42 (19)
48 (21)
6 (18)
3.6 (2.5)
4.2 (2.5)
0.6 (1.9)
NDI: 0–100%, FRI: 0–100%, higher value indicates higher disability. WAD: whiplash-associated disorders; CR: cervical radiculopathy; MixCP: mixed chronic
pain; HADS: Hospital Anxiety and Depression Scale; PCS: Pain Catastrophizing Scale; SES: Self-Efficacy Scale; CSQ: Coping Strategies Questionnaire; EQ-5D:
European Quality of Life 5 Dimensions; VAS: visual analogue scale; SD: standard deviation.
(74.6%) were women. Fifty-five percent of subjects
were often or quite often worried about their financial
situation, and 49% were on sick leave. Of the partici-
pants, 62% reported a small to large improvement in
their problems after treatment, 30% reported that their
condition had not changed, and 8% reported that they
had more problems than before treatment.
The participants improved significantly between
baseline vs after treatment in function (FRI), anxiety
and depression (HADS), general health (EQ-5D Index
and VAS) and self-reported work ability (Table III, all
p < 0.001). For the WAD, CR and MixCP groups the
median PEI was 4, 6 and 3, respectively.
Patient Enablement Instrument
Content validity. Most participants did not use the re-
sponse “not applicable”. For all participants, between
5 and 22 (0.9–3.8%) gave a “not applicable” response
to at least 1 of the 6 PEI questions. The question most
commonly characterized as being not applicable was
“able to keep yourself healthy” (Table IV).
For all participants, 6.9% (n = 40/579) did not answer
at least one of the 6 PEI questions, and question 4 “able
to keep yourself healthy” had the highest percentage of
missing answers (4.7%, n = 27, Table IV). The highest
and lowest missing values were found in question
Table IV. Number of respondents (percentage) in the different studies after treatment who said the Patient Enablement Instrument
(PEI) questions were not applicable and missing values
Able to cope with life
Able to understand your illness
Able to cope with your illness
Able to keep yourself healthy
Confident about your health
Able to help yourself
All n = 579 WAD n = 131 CR n = 137 Not applicable Missing n (%) n (%) Not applicable Missing n (%) n (%) Not applicable Missing n (%) n (%) Not applicable Missing
n (%) n (%)
6 (1.0)
10 (1.7)
8 (1.4)
22 (3.8)
5 (0.9)
9 (1.6) 22
26
21
27
21
23 4
2
1
5
1
1 5
7
7
7
8
8 7
5
6
9
0
5 7 (5.1)
11 (8.0)
6 (4.4)
10 (7.3)
6 (4.4)
9 (6.6) 2
3
1
8
4
3 10 (3.2)
8 (2.6)
8 (2.6)
10 (3.2)
7 (2.3)
6 (1.9)
(3.8)
(4.5)
(3.6)
(4.7)
(3.6)
(4.0)
(3.1)
(1.5)
(0.8)
(3.8)
(0.8)
(0.8)
(3.8)
(5.3)
(5.3)
(5.3)
(6.3)
(6.3)
(5.1)
(3.6)
(4.4)
(6.6)
(0.0)
(3.6)
MixCP n = 311
(0.6)
(1.0)
(0.3)
(2.6)
(1.3)
(1.0)
WAD: whiplash-associated disorders; CR: cervical radiculopathy; MixCP: mixed chronic pain.
J Rehabil Med 51, 2019