Accepted Manuscript Employment trajectories after spinal cord injury: results from a 5-year prospective cohort study Astri Ferdiana , MD, MPH Marcel WM. Post , Ph.D Trynke Hoekstra , Ph.D Luc van der Woude , Ph.D Jac JL. van der Klink , MD, Ph.D Ute Bültmann , Ph.D PII:
S0003-9993(14)00341-4
DOI:
10.1016/j.apmr.2014.04.021
Reference:
YAPMR 55826
To appear in:
ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION
Received Date: 22 January 2014 Revised Date:
22 April 2014
Accepted Date: 23 April 2014
Please cite this article as: Ferdiana A, Post MW, Hoekstra T, van der Woude L, van der Klink JJ, Bültmann U, Employment trajectories after spinal cord injury: results from a 5-year prospective cohort study, ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION (2014), doi: 10.1016/ j.apmr.2014.04.021. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Running Head
RI PT
Employment trajectories in spinal cord injury
Title
SC
Employment trajectories after spinal cord injury: results from a 5-year prospective cohort study
M AN U
Authors Astri Ferdiana, MD, MPH1 Marcel WM Post, Ph.D2
Luc van der Woude, Ph.D5 Jac JL van der Klink, MD, Ph.D1
AC C
Affiliations
EP
Ute Bültmann, Ph.D1
TE D
Trynke Hoekstra, Ph.D3,4
1 Department of Health Sciences, Community and Occupational Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands 2 Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and De Hoogstraat, Utrecht, The Netherlands
ACCEPTED MANUSCRIPT
3 Vrije University, Faculty of Earth and Life Sciences, Department of Health Sciences and the EMGO Institute for Health and Care Research, Amsterdam, the Netherlands
the Netherlands
RI PT
4 Vrije University Medical Center, Department of Epidemiology and Biostatistics, Amsterdam,
5 Center for Human Movement Sciences, Center for Rehabilitation, University Medical Centre
SC
Groningen, University of Groningen, Groningen, The Netherlands
M AN U
Acknowledgement
Results of this study were presented at the 23rd Conference on Epidemiology in Occupational Health (EPICOH), Utrecht, the Netherlands, 18-21 June 2013.
The authors would like to thank the participating Dutch rehabilitation centers and the research
TE D
assistants in these centers who collected all data: Rehabilitation Center De Hoogstraat (Utrecht), Reade, Centre for Rehabilitation and Rheumatology (Amsterdam), Rehabilitation Center Het Roessingh (Enschede), Adelante (Hoensbroek), Rehabilitation Center Sint
EP
Maartenskliniek (Nijmegen), Center for Rehabilitation Beatrixoord (Haren), Rehabilitation Center Heliomare (Wijk aan Zee), and Rehabilitation Center Rijndam (Rotterdam).
analyses.
AC C
We also would like to thank Josue Almanza Ortiz for his technical assistance in the statistical
The Umbrella study was supported by Dutch Health Research and Development Council, ZONMW Rehabilitation program (grant numbers: 1435.0003 and 1435.0044) All authors declare no conflict of interest.
ACCEPTED MANUSCRIPT
Correspondence Astri Ferdiana, Department of Health Sciences, Community and Occupational Medicine,
RI PT
University Medical Center Groningen, University of Groningen, Groningen, The Netherlands, Telephone number: +31 (0) 50 363 9013, Fax number: +31 (0) 50 363 6251, E-Mail:
AC C
EP
TE D
M AN U
SC
[email protected].
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1
Employment trajectories after spinal cord injury: results from a 5-year prospective cohort
2
study
RI PT
3 4 5
Abstract
SC
6 7
Objective: To identify different employment trajectories in individuals with spinal cord injury
9
(SCI) after discharge from initial rehabilitation and to determine predictors of different
M AN U
8
trajectories from demographic, injury, functional and psychological characteristics.
11
Design: Prospective cohort study with baseline measurement at the start of active
12
rehabilitation, a measurement at discharge and follow-up measurements at 1, 2 and 5 years
13
after discharge.
14
Setting: Eight rehabilitation centres with SCI units in the Netherlands.
15
Participants: A total of 176 people with acute SCI, aged between 18 and 60 years at baseline,
16
who completed at least two follow-up measurements.
17
Interventions: Not applicable
18
Main Outcome Measure: Employment was defined as having paid work for ≥12 hours/week.
19
Results: Using latent class growth mixture modeling, three distinct employment trajectories
20
were identified: 1) no employment group (22.2%), i.e., participants without employment pre-SCI
21
and during 5-year follow-up; 2) low employment group (56.3%), i.e., participants with pre-SCI
22
employment and a low, slightly increasing probability of employment during 5-year follow-up;
AC C
EP
TE D
10
1
ACCEPTED MANUSCRIPT
and 3) steady employment group (21.6%), i.e., participants with continuous employment pre-
24
SCI and within 5-year follow-up. Predictors of steady employment versus low employment were
25
having secondary education (OR=4.32, 95% CI 1.69-11.02) and a higher Functional
26
Independence Measure motor-score (OR=1.04, 95% CI 1.01-1.06) at discharge.
27
Conclusion: Distinct employment trajectories following SCI were identified. More than half of
28
individuals with SCI had a low employment trajectory, and only one-fifth of individuals with SCI
29
had a steady employment trajectory. Secondary education and higher functional independence
30
level predicted steady employment.
31
Key Words: Employment; spinal cord injuries; disabled persons; rehabilitation;
32
prospective/observational
M AN U
33
TE D
34 35 36
40 41
AC C
39
EP
37 38
SC
RI PT
23
42 43 44
2
ACCEPTED MANUSCRIPT
45
List of Abbreviations
46
BLRT
Bootstrap Likelihood Ratio Tests
FIM
Functional Independence Measure
LCGMM
Latent Class Growth Mixture Modeling
RTW
Return to work
SCI
Spinal cord injury
VR
Vocational Rehabilitation
48
TE D
49 50 51
55 56
AC C
54
EP
52 53
SC
Bayesian Information Criterion
M AN U
BIC
RI PT
47
57 58 59
3
ACCEPTED MANUSCRIPT
Substantial information exists on level of employment and its determinants in people
61
with spinal cord injury (SCI)1–3. Employment rates vary from 21-67%1, yet on average, 35-40% of
62
individuals with SCI have some kind of employment2,4. The average time to obtain the first post-
63
injury job range from 3.8 to 4.9 years after SCI5–7, but this differs by several factors including
64
educational level and pre-injury employment6.
RI PT
60
66
SC
65
Even in the case of successful (re)integration into the labor market, stability of employment is by no means guaranteed. People with disability or chronic conditions often
68
experience symptom recurrences, comorbidity and psychological disorders8,9, which can lead to
69
multiple episodes of sickness absence and hospitalization9,10. Many individuals with SCI have to
70
endure long term functional limitations and frequent secondary health conditions such as
71
pressure sores, pain and bladder or bowel disorders11,12 and therefore job retention can be
72
more challenging12. Work can also be delayed for those being in education at the time of
73
injury, or discontinued by re-education or vocational rehabilitation (VR)6,13. Thus, it can be
74
expected that people experience different employment trajectories until a more or less stable
75
employment situation is achieved.
77
TE D
EP
AC C
76
M AN U
67
Most knowledge on employment and return to work (RTW) in SCI originates from cross-
78
sectional studies, which measured employment at a single time point and did not capture the
79
overtime change in post-injury employment1–3,14. Earlier cohort studies followed individuals
80
with SCI over a relatively short time15–17, during which the employment potential was not fully
4
ACCEPTED MANUSCRIPT
81
regained, or the course of employment was reported for the whole sample15,18,19, assuming that
82
individuals with SCI would have a similar course of employment.
84
RI PT
83
To the best of our knowledge, there has been no study investigating distinct
employment trajectories in SCI. For the planning of effective VR interventions, it is important to
86
identify groups that show unfavorable trajectories, i.e. those with delayed entry to employment
87
or unsustainable employment, and to determine factors associated with these trajectories. We
88
also examined whether demographic, injury, functional and psychological characteristics
89
predict employment trajectories after SCI.
90 91
Methods
93 94
97 98
EP
96
Study design and participants
AC C
95
TE D
92
M AN U
SC
85
The study was conducted within the sampling frame of a prospective cohort study
99
“Restoration of Mobility in the Rehabilitation of Persons with a Spinal Cord Injury”, with 5-year
100
follow-up after discharge from initial SCI rehabilitation20. Participants with the following criteria
101
were recruited from 8 SCI rehabilitation centers in the Netherlands between August 2000 and
102
July 2003: diagnosis of acute SCI, aged 18-65 years at the onset of injury, wheelchair-dependent
5
ACCEPTED MANUSCRIPT
103
and able to understand Dutch. For our study, we included only participants with age of onset
104
between 18-60 years, because the retirement age in the Netherlands is 65 years old.
106
RI PT
105
All eligible participants who were admitted into these 8 centers during the study
recruitment period were asked to participate by their attending physician. Individuals with SCI
108
due to a malignant tumor or progressive disease and psychiatric diseases were excluded from
109
the study. The study protocol was approved by the medical ethics committee of the Stichting
110
Revalidatie Limburg/Institute for Rehabilitation Research in Hoensbroek. All participants gave
111
written informed consent after being informed about the study.
M AN U
SC
107
112 113
Procedure
TE D
114 115 116
Demographic information was collected at baseline (at the start of active inpatient
118
rehabilitation i.e. when the patient was able to sit for 3-4 hours). Injury-related, functional and
119
psychological measurements were performed at discharge from inpatient rehabilitation.
120
Follow-up measurements were performed at 1, 2 and 5 years after discharge. Data were
121
collected by medical examination, physical measurements, oral interview by a trained research
122
assistants and a self-administered questionnaire.
AC C
EP
117
123 124
6
ACCEPTED MANUSCRIPT
125
Main outcome measures
126
128
RI PT
127
Employment status was measured as part of the oral interview at baseline (for pre-injury work) and at 1, 2, and 5 years after discharge using a single item “How many hours per week do
130
you spend working in a job for which you get paid?” from the Utrecht Activities List21.
131
Participants of the current study were classified as employed if they had paid work for ≥12 hour
132
per week, in line with the Dutch standard definition of employment22.
M AN U
SC
129
133 134 135
Variables
TE D
136 137
Demographic information included age, gender and secondary education. Neurological
139
level and completeness of injury were measured according to the International Standards for
140
Neurological Classification of Spinal Cord Injury at discharge23. A lesion below T1 was
141
categorized as paraplegia and a lesion at T1 or above as tetraplegia. Completeness of injury was
142
classified using the American Spinal Cord Injury (ASIA) classification and categorized into motor
143
complete (ASIA grade A and B) and motor incomplete (ASIA grade C and D)23. Functional
144
limitations were assessed at discharge using the motor-score of the Functional Independent
145
Measure (FIM motor-score)24.
AC C
EP
138
146
7
ACCEPTED MANUSCRIPT
147
Self-efficacy was conceptualized as the belief in one’s ability to cope with a broad range of challenging tasks and assessed by the Sherer’s General Self-Efficacy Scale (GSES), which
149
contains 16 items rated on a 5-point Likert scale25. Assessment of self-efficacy was performed
150
at discharge.
RI PT
148
151
Pre-injury work characteristics included occupational level, physical intensity of pre-injury
153
occupation and number of hours worked. Type of occupation was asked with an open question
154
and categorized using the Dutch Standard Classification of Occupations26. Occupational level
155
was classified into low, middle and high based on the most adequate educational/training
156
qualification needed to perform the work tasks26. Physical intensity of pre-injury occupation
157
was classified into low and moderate/high using adapted definitions from Tomassen et al27.
158
Low physical intensity involved mainly sedentary work, carrying light weight and little
159
movements. Moderate/high physical intensity involved moving, carrying weight/heavy objects
160
and climbing stairs. Hours worked before injury were dichotomized into ≥35 hours/week and
161
S0003-9993(14)00341-4
DOI:
10.1016/j.apmr.2014.04.021
Reference:
YAPMR 55826
To appear in:
ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION
Received Date: 22 January 2014 Revised Date:
22 April 2014
Accepted Date: 23 April 2014
Please cite this article as: Ferdiana A, Post MW, Hoekstra T, van der Woude L, van der Klink JJ, Bültmann U, Employment trajectories after spinal cord injury: results from a 5-year prospective cohort study, ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION (2014), doi: 10.1016/ j.apmr.2014.04.021. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Running Head
RI PT
Employment trajectories in spinal cord injury
Title
SC
Employment trajectories after spinal cord injury: results from a 5-year prospective cohort study
M AN U
Authors Astri Ferdiana, MD, MPH1 Marcel WM Post, Ph.D2
Luc van der Woude, Ph.D5 Jac JL van der Klink, MD, Ph.D1
AC C
Affiliations
EP
Ute Bültmann, Ph.D1
TE D
Trynke Hoekstra, Ph.D3,4
1 Department of Health Sciences, Community and Occupational Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands 2 Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and De Hoogstraat, Utrecht, The Netherlands
ACCEPTED MANUSCRIPT
3 Vrije University, Faculty of Earth and Life Sciences, Department of Health Sciences and the EMGO Institute for Health and Care Research, Amsterdam, the Netherlands
the Netherlands
RI PT
4 Vrije University Medical Center, Department of Epidemiology and Biostatistics, Amsterdam,
5 Center for Human Movement Sciences, Center for Rehabilitation, University Medical Centre
SC
Groningen, University of Groningen, Groningen, The Netherlands
M AN U
Acknowledgement
Results of this study were presented at the 23rd Conference on Epidemiology in Occupational Health (EPICOH), Utrecht, the Netherlands, 18-21 June 2013.
The authors would like to thank the participating Dutch rehabilitation centers and the research
TE D
assistants in these centers who collected all data: Rehabilitation Center De Hoogstraat (Utrecht), Reade, Centre for Rehabilitation and Rheumatology (Amsterdam), Rehabilitation Center Het Roessingh (Enschede), Adelante (Hoensbroek), Rehabilitation Center Sint
EP
Maartenskliniek (Nijmegen), Center for Rehabilitation Beatrixoord (Haren), Rehabilitation Center Heliomare (Wijk aan Zee), and Rehabilitation Center Rijndam (Rotterdam).
analyses.
AC C
We also would like to thank Josue Almanza Ortiz for his technical assistance in the statistical
The Umbrella study was supported by Dutch Health Research and Development Council, ZONMW Rehabilitation program (grant numbers: 1435.0003 and 1435.0044) All authors declare no conflict of interest.
ACCEPTED MANUSCRIPT
Correspondence Astri Ferdiana, Department of Health Sciences, Community and Occupational Medicine,
RI PT
University Medical Center Groningen, University of Groningen, Groningen, The Netherlands, Telephone number: +31 (0) 50 363 9013, Fax number: +31 (0) 50 363 6251, E-Mail:
AC C
EP
TE D
M AN U
SC
[email protected].
ACCEPTED MANUSCRIPT
1
Employment trajectories after spinal cord injury: results from a 5-year prospective cohort
2
study
RI PT
3 4 5
Abstract
SC
6 7
Objective: To identify different employment trajectories in individuals with spinal cord injury
9
(SCI) after discharge from initial rehabilitation and to determine predictors of different
M AN U
8
trajectories from demographic, injury, functional and psychological characteristics.
11
Design: Prospective cohort study with baseline measurement at the start of active
12
rehabilitation, a measurement at discharge and follow-up measurements at 1, 2 and 5 years
13
after discharge.
14
Setting: Eight rehabilitation centres with SCI units in the Netherlands.
15
Participants: A total of 176 people with acute SCI, aged between 18 and 60 years at baseline,
16
who completed at least two follow-up measurements.
17
Interventions: Not applicable
18
Main Outcome Measure: Employment was defined as having paid work for ≥12 hours/week.
19
Results: Using latent class growth mixture modeling, three distinct employment trajectories
20
were identified: 1) no employment group (22.2%), i.e., participants without employment pre-SCI
21
and during 5-year follow-up; 2) low employment group (56.3%), i.e., participants with pre-SCI
22
employment and a low, slightly increasing probability of employment during 5-year follow-up;
AC C
EP
TE D
10
1
ACCEPTED MANUSCRIPT
and 3) steady employment group (21.6%), i.e., participants with continuous employment pre-
24
SCI and within 5-year follow-up. Predictors of steady employment versus low employment were
25
having secondary education (OR=4.32, 95% CI 1.69-11.02) and a higher Functional
26
Independence Measure motor-score (OR=1.04, 95% CI 1.01-1.06) at discharge.
27
Conclusion: Distinct employment trajectories following SCI were identified. More than half of
28
individuals with SCI had a low employment trajectory, and only one-fifth of individuals with SCI
29
had a steady employment trajectory. Secondary education and higher functional independence
30
level predicted steady employment.
31
Key Words: Employment; spinal cord injuries; disabled persons; rehabilitation;
32
prospective/observational
M AN U
33
TE D
34 35 36
40 41
AC C
39
EP
37 38
SC
RI PT
23
42 43 44
2
ACCEPTED MANUSCRIPT
45
List of Abbreviations
46
BLRT
Bootstrap Likelihood Ratio Tests
FIM
Functional Independence Measure
LCGMM
Latent Class Growth Mixture Modeling
RTW
Return to work
SCI
Spinal cord injury
VR
Vocational Rehabilitation
48
TE D
49 50 51
55 56
AC C
54
EP
52 53
SC
Bayesian Information Criterion
M AN U
BIC
RI PT
47
57 58 59
3
ACCEPTED MANUSCRIPT
Substantial information exists on level of employment and its determinants in people
61
with spinal cord injury (SCI)1–3. Employment rates vary from 21-67%1, yet on average, 35-40% of
62
individuals with SCI have some kind of employment2,4. The average time to obtain the first post-
63
injury job range from 3.8 to 4.9 years after SCI5–7, but this differs by several factors including
64
educational level and pre-injury employment6.
RI PT
60
66
SC
65
Even in the case of successful (re)integration into the labor market, stability of employment is by no means guaranteed. People with disability or chronic conditions often
68
experience symptom recurrences, comorbidity and psychological disorders8,9, which can lead to
69
multiple episodes of sickness absence and hospitalization9,10. Many individuals with SCI have to
70
endure long term functional limitations and frequent secondary health conditions such as
71
pressure sores, pain and bladder or bowel disorders11,12 and therefore job retention can be
72
more challenging12. Work can also be delayed for those being in education at the time of
73
injury, or discontinued by re-education or vocational rehabilitation (VR)6,13. Thus, it can be
74
expected that people experience different employment trajectories until a more or less stable
75
employment situation is achieved.
77
TE D
EP
AC C
76
M AN U
67
Most knowledge on employment and return to work (RTW) in SCI originates from cross-
78
sectional studies, which measured employment at a single time point and did not capture the
79
overtime change in post-injury employment1–3,14. Earlier cohort studies followed individuals
80
with SCI over a relatively short time15–17, during which the employment potential was not fully
4
ACCEPTED MANUSCRIPT
81
regained, or the course of employment was reported for the whole sample15,18,19, assuming that
82
individuals with SCI would have a similar course of employment.
84
RI PT
83
To the best of our knowledge, there has been no study investigating distinct
employment trajectories in SCI. For the planning of effective VR interventions, it is important to
86
identify groups that show unfavorable trajectories, i.e. those with delayed entry to employment
87
or unsustainable employment, and to determine factors associated with these trajectories. We
88
also examined whether demographic, injury, functional and psychological characteristics
89
predict employment trajectories after SCI.
90 91
Methods
93 94
97 98
EP
96
Study design and participants
AC C
95
TE D
92
M AN U
SC
85
The study was conducted within the sampling frame of a prospective cohort study
99
“Restoration of Mobility in the Rehabilitation of Persons with a Spinal Cord Injury”, with 5-year
100
follow-up after discharge from initial SCI rehabilitation20. Participants with the following criteria
101
were recruited from 8 SCI rehabilitation centers in the Netherlands between August 2000 and
102
July 2003: diagnosis of acute SCI, aged 18-65 years at the onset of injury, wheelchair-dependent
5
ACCEPTED MANUSCRIPT
103
and able to understand Dutch. For our study, we included only participants with age of onset
104
between 18-60 years, because the retirement age in the Netherlands is 65 years old.
106
RI PT
105
All eligible participants who were admitted into these 8 centers during the study
recruitment period were asked to participate by their attending physician. Individuals with SCI
108
due to a malignant tumor or progressive disease and psychiatric diseases were excluded from
109
the study. The study protocol was approved by the medical ethics committee of the Stichting
110
Revalidatie Limburg/Institute for Rehabilitation Research in Hoensbroek. All participants gave
111
written informed consent after being informed about the study.
M AN U
SC
107
112 113
Procedure
TE D
114 115 116
Demographic information was collected at baseline (at the start of active inpatient
118
rehabilitation i.e. when the patient was able to sit for 3-4 hours). Injury-related, functional and
119
psychological measurements were performed at discharge from inpatient rehabilitation.
120
Follow-up measurements were performed at 1, 2 and 5 years after discharge. Data were
121
collected by medical examination, physical measurements, oral interview by a trained research
122
assistants and a self-administered questionnaire.
AC C
EP
117
123 124
6
ACCEPTED MANUSCRIPT
125
Main outcome measures
126
128
RI PT
127
Employment status was measured as part of the oral interview at baseline (for pre-injury work) and at 1, 2, and 5 years after discharge using a single item “How many hours per week do
130
you spend working in a job for which you get paid?” from the Utrecht Activities List21.
131
Participants of the current study were classified as employed if they had paid work for ≥12 hour
132
per week, in line with the Dutch standard definition of employment22.
M AN U
SC
129
133 134 135
Variables
TE D
136 137
Demographic information included age, gender and secondary education. Neurological
139
level and completeness of injury were measured according to the International Standards for
140
Neurological Classification of Spinal Cord Injury at discharge23. A lesion below T1 was
141
categorized as paraplegia and a lesion at T1 or above as tetraplegia. Completeness of injury was
142
classified using the American Spinal Cord Injury (ASIA) classification and categorized into motor
143
complete (ASIA grade A and B) and motor incomplete (ASIA grade C and D)23. Functional
144
limitations were assessed at discharge using the motor-score of the Functional Independent
145
Measure (FIM motor-score)24.
AC C
EP
138
146
7
ACCEPTED MANUSCRIPT
147
Self-efficacy was conceptualized as the belief in one’s ability to cope with a broad range of challenging tasks and assessed by the Sherer’s General Self-Efficacy Scale (GSES), which
149
contains 16 items rated on a 5-point Likert scale25. Assessment of self-efficacy was performed
150
at discharge.
RI PT
148
151
Pre-injury work characteristics included occupational level, physical intensity of pre-injury
153
occupation and number of hours worked. Type of occupation was asked with an open question
154
and categorized using the Dutch Standard Classification of Occupations26. Occupational level
155
was classified into low, middle and high based on the most adequate educational/training
156
qualification needed to perform the work tasks26. Physical intensity of pre-injury occupation
157
was classified into low and moderate/high using adapted definitions from Tomassen et al27.
158
Low physical intensity involved mainly sedentary work, carrying light weight and little
159
movements. Moderate/high physical intensity involved moving, carrying weight/heavy objects
160
and climbing stairs. Hours worked before injury were dichotomized into ≥35 hours/week and
161
