Summary of findings
To our knowledge this is the first systematic review of systematic reviews that assessed
RTW outcomes across health conditions and injuries. We critically reviewed 94 systematic
reviews and conducted a best evidence synthesis on 56 reviews with a low risk of bias
relating to RTW; over half of these addressed MSKDs. The other half explored mental
health disorders, brain injury, cardiovascular conditions, cancer, stroke, and multiple
sclerosis. While our search included all conditions, only few have actually been studied.
Many factors have been assessed, but only a few were common across conditions. Where
factors have been reviewed across conditions, the results are generally in the same
direction for a number of factors, suggesting that other common factors may exist
across conditions. RTW outcomes were influenced by prognostic factors in all four
ICF domains. Common factors associated with positive RTW outcomes were higher education
and socioeconomic status, higher self-efficacy and optimistic expectations for recovery
and RTW, lower severity of the injury/illness, RTW coordination, and multidisciplinary
interventions that include the workplace and stakeholders. Common factors associated
with negative RTW outcomes were older age, being female, higher pain or disability,
depression, higher physical work demands, previous sick leave and unemployment, and
activity limitations. Factors related to the specific illness or injury did not impact
RTW outcomes. In other words, in many cases, it is likely that the health condition
itself is not that important in influencing RTW. Our findings confirm those of Briand
et al. 14], that prognostic factors other than disease-specific factors are associated with
RTW outcomes. Our results also align, in that the important components of RTW interventions
are RTW coordination, occupational training or conditioning, workplace-based interventions,
work accommodations, and contact between the various stakeholders. A major finding
our review adds is that these factors are relevant for other conditions, not just
MSKDs.
“New” modifiable prognostic factors
Identifying modifiable prognostic factors is of utmost importance because these could
respond to new interventions targeted at modifying them. We found that expectations
of recovery and RTW, pain and disability levels, depression, workplace factors, and
access to multidisciplinary resources are important modifiable factors in progressing
RTW across health and injury conditions.
Having optimistic expectations for recovery and RTW was commonly associated with positive
RTW outcomes, and these findings are represented by evidence from studies on myocardial
infarction 28] as well as mental health 29] and MSKDs 30], 31]. This factor is also potentially modifiable 32]–35]. Those expecting to recover more slowly after injury often do 36]–38], and not expecting to RTW leads to a slower recovery 39] and a higher risk of receiving sick leave benefits 40]. This suggests the importance of identifying RTW expectations early on. Negative
RTW expectations were also associated with longer time to RTW across MSK and mental
health disorders and other physical injuries 34]. Thus, regardless of the health condition or injury, asking whether a worker expects
to recover and RTW, especially early on, can help identify those at high risk for
delayed RTW. Clinicians should also be trained to better understand this process and
not, inadvertently, contribute to negative RTW expectations. For example, a recent
study found that a significant proportion of clinicians believed that people with
a psychotic disorder are not capable of any kind of work 41]. Thus, stigma and discrimination in mental health conditions may have an impact on
expectations of RTW, and on RTW outcomes.
The level of pain, impairment, or disability and one’s experiences is often multi-factorial
and not directly or completely attributable to disease-specific factors, especially
in the long term 42]. For example, in individuals with mild traumatic brain injury, more severe injuries
were associated with a higher level of physical and cognitive symptoms at 3 months,
but not at later follow-ups 43]. Conceivably, general interventions targeting one’s ability to cope with pain or
disability early on, regardless of the contributing disease-specific factor, may ultimately
help to improve RTW outcomes. Likewise, identifying and managing depression (regardless
of the initial source of depression) in ill or injured workers, irrespective of the
traceable disease-specific factor, may additionally lead to improved RTW outcomes.
Multidisciplinary RTW interventions, especially occurring at the workplace, are supported
from studies of cancer 24], MSKDs 14] and mental health disorders 44]. Our findings suggest it is important to at least provide access to multiple resources
including health and occupational professionals who can deliver a combination of interventions
when and to whom it is required; of particular importance is ensuring these resources
are available for conditions with a less favourable prognosis. For example, interventions
beyond information and advice are not required to improve RTW outcomes in those with
mild traumatic brain injury 45]. In contrast, more complex interventions involving physical, vocational and psychological
elements do improve RTW outcomes in patients with cancer 24]. Similarly, multidisciplinary RTW coordination programs improve outcomes across more
chronic MSKDs 46]. Thus, providing access to multidisciplinary resources may better address the multi-factorial
nature of RTW 29], 47]–49] and help improve outcomes across complex conditions such as chronic LBP, which contributes
enormously to the burden of work disability 1], 50]. Clinicians should, however, remain mindful that too much health care too early after
an injury (e.g., mild traumatic brain injury, whiplash) can delay recovery 51].
Work accommodation is an important factor for improved RTW outcomes across health
and injury conditions. The availability of different levels of work accommodation
are supported by systematic reviews on mental health 52], MSKDs 26], cancer 53], as well as other chronic illnesses and disability 26]. Work accommodation can include for example offering lighter or modified duties for
those who suffered a work-related MSK injury (e.g., acute low back pain), as well
as offering graded work exposure or an onsite work evaluation for those with work-related
post-traumatic stress disorder 52]. We also found that the presence of a RTW plan and/or case-coordinator was important.
Developing a RTW plan and/or having a case-coordinator in place to implement this
plan, helped improve RTW outcomes for employees with general disability 46], MSKDs 54] and brain injuries 48], 55]. Similarly, for MSKDs, Briand et al. 14] found that centralizing the management of the RTW process by way of a multidisciplinary
team working in collaboration with the workplace can improve RTW outcomes. Within
these teams, there is access to multiple resources that can assess the multiple causes
of work disability as well as implement specific interventions as required. Applying
this same centralized team approach may help improve RTW outcomes in other complex
non-MSKD conditions as well as foster collaboration with the workplace. In turn, this
may also help improve stakeholder awareness 56] as well as interpersonal communication. We found interpersonal communication involving
early contact and with multiple stakeholders to be another common prognostic factor
associated with positive RTW outcomes.
Other than older age and being female, the majority of negative RTW factors we found
are also modifiable. These include having higher physical work demands, previous sick
leave, or activity limitations/participation restriction. Taken together, the modifiable
factors discussed here could be extended further to other conditions and likely help
inform better RTW processes.
Comparison with the “seven principles of successful RTW”
Our findings support the “seven principles for successful RTW” previously established
for MSKDs 13] for the most part. We did not come across any studies related to two of the principles
– supporting the returning worker without disadvantaging co-workers and supervisors;
and having supervisors trained in work disability prevention. Our literature search
did not include any systematic reviews prior to 2004 and did not include any qualitative
studies. Nonetheless, it is commonsensical to want to avoid disadvantaging others
while supporting the returning worker. Further, it is reasonable for supervisors to
receive some work disability prevention training to try to improve RTW outcomes.
Strengths and limitations
Our review has several strengths including comprehensive search strategies and an
in-depth methodological quality assessment of individual systematic reviews. Our review
also has limitations. First, only one reviewer screened the titles and abstracts.
However, citations were only deemed irrelevant if the title or abstract did not include
any information on RTW outcomes. Therefore, the potential for excluding relevant studies
was low. Second, we did not assess the risk of bias for the primary studies cited
in the systematic reviews we accepted; thus we cannot be certain of their quality.
We based our findings on the authors’ conclusions of the systematic reviews. Third,
the majority of reviewed studies were based on MSKDs. As a result, some of these systematic
reviews may have reviewed the same studies and even interpreted the quality of the
evidence differently. Other limitations include possible publication bias and the
potential for missing relevant reviews and/or primary studies not captured in the
systematic reviews we included in this paper. Despite these potential limitations,
we believe our findings are robust enough to help inform both RTW strategies across
health conditions and injuries and future research efforts.
Clinical implications
Primary studies identifying more non-modifiable prognostic factors (e.g., age, sex,
and specific disease-related factors), especially in MSKDs, offer little added value
in helping to improve RTW outcomes and address the burden of work disability. Work-related
factors (e.g., RTW coordination, work accommodations), depression, pain and disability,
as well as certain psychosocial factors (e.g., expectations of recovery and RTW) are
important RTW predictors and some of these can already be modified with specific interventions.
Modifiable factors may be influenced by policy and practices which may vary between
countries. By targeting modifiable factors with this in mind, RTW outcomes may be
improved. Given our findings, we support an expanded set of common RTW principles
across health conditions for use by employers, health care providers and other stakeholders
(Table 3). This set includes the seven original principles by the IWH, and an additional principle
given our findings – the worker has access to multidisciplinary resources (including
clinical interventions for the management of pain, disability, depression and poor
expectations for recovery), where necessary, working in combination with the other
stakeholders. We emphasize that while providing multidisciplinary resources in concert
with the workplace is important, clinicians need to be educated about the risk of
iatrogenic disability 51] and take steps to prevent this. For example, workers should only remain off work
if it is medically necessary 57], and clinicians should refrain from giving carte blanche permission for their patients
to remain off work indefinitely to receive ongoing therapy of marginal value. Overall,
multiple countries endorse similar recommendations for injured/ill workers but these
are most distinctly expressed by the IWH in Canada through their seven principles
of successful RTW. For this reason, we chose to relate our findings to these seven
principles and incorporate our results.
Table 3. Common principles for successful return to work
Future direction for research
Psychosocial and pain- and work-related factors can be tested together in clinical
trials across a variety of health and injury conditions. Studies also need to identify
which factors (e.g., health history, cultural, work and family influences, pain beliefs,
etc. 58]) influence recovery and RTW expectations and might be modified with specific interventions.
A previous consensus panel of expert opinion found that expectations of recovery are
likely modifiable, and as these have a high impact on RTW should be a priority for
future research 59]. Large prospective cohort studies would be helpful in detecting prognostic factors
over longer periods of time, such as in the Whitehall studies 60], where evidence of differentials in socioeconomic status, earnings, and decision
latitude impacting on work outcomes has emerged strongly. Qualitative or mixed methods
studies may offer insight into the mechanisms that may explain how modifiable factors
operate and contextual variations. Since RTW coordinators appear important to improving
RTW outcomes; core competencies established for these individuals can be applied broadly
to help improve RTW outcomes 61]. Finally, inconclusive and conflicting results are likely due in part to the heterogeneity
of the study populations, varying measurement of the outcomes, and other methodological
variations. Therefore, more high-quality evidence is still needed regarding prognostic
factors for which the findings are still inconclusive, and to identify modifiable
RTW prognostic factors across other, non-MSKDs.