Journal of Rehabilitation Medicine 51-4inkOmslag | Page 48

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M. Rivano Fischer et al.
no improvements were observed for men on health-
status or costs. One meta-analysis on low back pain
rehabilitation in Europe (7) showed limited effects on
RTW, but the effect was larger if restricted only to Scan-
dinavian settings. In addition, positive effects of MMR
on RTW were reported to persist 3, 6 and 10 years after
intervention (6, 8, 9), economic benefits being estimated
as €3,799–€7,515 per treated patient and year (9).
However, the positive effect of MMR on RTW is
questioned (10, 11), and there is no consensus on how
to assess changes in sick-leave benefits due to MMR.
Different methods to track RTW and work ability are
used, from self-reports to information from social
insurance agencies (6, 7, 12).
Since previous studies exploring patterns of sick
leave have usually focussed on changes observed in
the years following MMR, there is a need for studies
that include a time-period prior to admission in order
to increase knowledge about the sick-leave process for
patients included in MMR and to further investigate
the influence of MMR on RTW.
This study aimed to investigate: (i) changes in pat-
terns of sick leave from 1 year prior to MMR to ad-
mission to MMR; (ii) changes in patterns of sick leave
from admission to 1 and 2 years after MMR; (iii) sex
differences in patterns of sick leave; (iv) the impact
of policy changes in the sick-leave benefit system on
patterns of sick leave.
METHODS
This is a multicentre, register study with a retrospective design.
Data were collected from the 31 rehabilitation units at specialist
care level reporting to the Swedish Quality Registry for Pain
(SQRP) during 2007–11.
Swedish Quality Registry for Pain
The SQRP aims to monitor health status prior to and after MMR
for patients with chronic pain, to allow for comparisons between
units and to enable audits for single units as well as outcome
studies in Sweden (13). All units offered an MMR programme
with at least 3 professionals working with a cognitive beha-
vioural therapy (CBT)-based approach. Physicians, physical
therapists, psychologists, occupational therapists, socials wor-
kers and nurses usually staffed the rehabilitation teams. Medical
secretaries were available to all teams.
The registry was established in 1998 and became web-based
in 2009. Ninety percent of the operationally active tertiary units
at that time in Sweden (31 in June 2015), reported patient data
during the data collection period.
The questionnaires used in the SQRP cover variables re-
commended by national and international guidelines for the
description of health-related domains of patients with chronic
pain and for the follow-up of outcomes of pain rehabilitation
(14, 15). Furthermore, the health-related categories (physical
and psychological functioning, activity and participation) in
the International Classification of Functioning, Disability and
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Health (ICF) are included, as well as socio-economic and socio-
demographic variables (16).
The patients participating in MMR complete questionnaires
before, after and at a 1-year follow-up after MMR. The units
collect data following SQPR’s written instructions (22). The
questionnaires are either posted to patients prior to a first visit or
administered on site. After MMR the questionnaires are mostly
administered on site. The 1-year follow-up is usually sent by
post, including one reminder.
Questionnaires in Swedish Quality Registry for Pain
The SQRP questionnaire includes socio-demographic factors
(sex, age, educational level and referral sources), pain dura-
tion, intensity and location, as described by Nyberg et al. (13).
The Hospital Anxiety and Depression Scale (HADS) and the
Multidimensional Pain Inventory (MPI), also included in the
SQPR, were used here.
The HADS aims to detect symptoms of anxiety and depression
in non-psychiatric medical settings (17). It includes 14 items,
ranging from 0 to 3. A total score is calculated both for anxiety
(7 items) and for depression (7 items). Cut-off levels for no, mild
and severe symptoms are 0–7, 8–10 and 11–21, respectively.
Both the English original and the translated Swedish version
have acceptable validity and reliability (17, 18).
The MPI (version 2) measures pain-related functioning (19),
including 61 items and 13 subscales. All items ranges from 0
(never) to 6 (very often). Four subscales were used in this study:
pain severity, life interference, life control, and affective distress.
The original MPI with satisfactory psychometric properties (19,
20), is translated to Swedish and described by Nyberg et al. (21).
Swedish Social Insurance Agency database
People in Sweden with a sick-leave period longer than 2 weeks
are included in the Swedish Social Insurance Agency (SSIA)
database. In Sweden sick-leave benefits are decided according
to cut-off levels of 25%, 50%, 75% and 100%, based on the
actual level of employment.
In this study, data were retrieved from the SSIA database and
included all patients registered in the SQRP with discharge from
a MMR programme at the pain rehabilitation units from 2007 to
2011. The extent of sick leave reported in the SSIA database for
each patient 1 year prior to admission, before the first visit to the
units, 1 year and 2 years after discharge was used for statistical
analyses. The extent of sick leave before MMR was also analysed
by comparing 3-month periods for 12 months prior to MMR.
Participants
Patients who participated in MMR at specialist (tertiary) level
in Sweden and who were registered in the SQRP and the SSIA
between 2007 and 2011 were considered eligible. In total 7,297
patients undergoing MMR during the specified time-frame were
included in the study (Fig. 1).
Procedure
Data from the SQRP were linked to the SSIA database to obtain
information as to what extent patients were benefitting from sick
leave prior to and after MMR. The linked data from the SQRP
and the SSIA resulted in a database used for statistical analysis.
According to Swedish law, the first 14 days of sick leave are not
registered by the SSIA, but paid for by the employer. Long-term
sick leave was defined in this study as a period of 28 or more