Road traffic crashes are a major global concern, costing countries an estimated 2–5% of their gross domestic product, with the relative burden generally higher in low- and middle-income countries than in high-income settings (1). Around 50 million people experience a Road Traffic Injury (RTI) every year (2). These injuries were the main cause of global disease burden (as measured by disability-adjusted life year) for individuals aged 10–49 years between 1990 and 2019 (3). Disability from RTI results in considerable economic burden for societies. In Australia, RTIs cost about AU$11.8 billion annually between 2016 and 2020, including AU$2.3 billion in medical costs and AU$1.54 billion in disability-related expenses (4). Additionally, reduced work ability due to RTI is reported to negatively influence the injured persons’ health condition, financial situation, their family and workplace (5). On the other hand, return to work (RTW) is associated with an increase in the injured persons’ confidence while decreasing their dependence on social support (6). For this reason, RTW is considered a critical milestone in the rehabilitation process. Therefore, obtaining a better understanding of the factors impacting RTW following RTI is critical in working towards the recovery of injured individuals and reducing the associated personal and societal costs.

A broad range of factors potentially influencing RTW following RTI have been examined in the literature. A recent systematic review of studies published between 1997 and 2020, covering 11 studies from Australia, the UK, Canada, and Denmark, found strong evidence that better health status and higher RTW expectancy predict earlier RTW, with follow-up periods ranging from one month to three years (7). The review also reported strong evidence for no association between RTW and demographic factors such as age or gender and found no consistent link with fault status. While these findings highlight the importance of health and individual expectations, they also point to a relative lack of attention to system-related influences. Consequently, there remains limited knowledge on the role of legal, insurance, workplace, and healthcare factors in shaping RTW outcomes after RTI. For instance, it is suggested that differences in compensation schemes may result in identifying different barriers and facilitators to RTW (8, 9). In Australia, the majority of studies that investigated these factors have been conducted in jurisdictions operating a ‘no-fault’ scheme (6, 10–12) in which injured individuals have access to medical and financial support regardless of their fault status in the crash. Therefore, the findings may not be generalizable to other states like Queensland that operate a “fault-based” scheme. In this scheme for nonwork-related RTI, only injured people who are not at fault in the crash are supported financially and medically through the Compulsory Third Party (CTP) insurer of the at-fault driver. This may lead at-fault individuals to experience other types of challenges like financial difficulties and stress arising from the claim process which have been shown can significantly influence work outcomes (13–16). Therefore, there is a need to determine the factors associated with RTW after a RTI in a “fault-based” scheme.

It has been proposed that factors associated with RTW may vary with the way the concept of work is measured (6, 10). Previous studies have often used dichotomous outcomes (RTW vs Not RTW), self-reported work disability days, or compensated days, with most utilising the date of first RTW as the main measure of RTW (6, 9, 13, 17). However, RTW is both an endpoint and a process (18). According to previous findings, injured individuals may take different RTW trajectories after a RTI (16). Earlier studies show large heterogeneity in RTW trajectories after RTI with some individuals requiring multiple RTW attempts and periods of time away from work (6, 10, 12). This suggests that depending on individual variations, more or different interventions may be needed to facilitate RTW following RTI. However, so far only a few studies investigated the RTW trajectory of injured people following RTI (6, 10). To address the knowledge gaps, a prospective cohort study was conducted in Queensland, Australia to better understand the impact of road traffic crashes on RTW of injured people using different work outcome measures assessed repeatedly within one year of RTI. The objectives of this study were to:

Of 728 patients screened from the emergency department records, 127 eligible people responded to the invitation and consented to participate in this study (Fig. 1). Of those, 77 participants completed the baseline questionnaire (60%). As this study focused on work outcomes, participants not working pre-injury were not included in this study (n = 14). Hence, the results of this study are based on the subset of 63 participants who were employed prior to the injury. The lowest response rate throughout this study was for the final 12-month follow-up assessment (n = 41), bringing the retention rate to about 32% towards the end of study. Figure 1 illustrates the recruitment and sample size at all assessment timepoints. The main reason for the lost to follow up was inability of the researchers to make contact with these participants despite several attempts and using various modes of contact.

Baseline characteristics and health status of respondents compared to non-respondents at six- and 12-months post-baseline is presented in Table 1. No significant difference was observed between respondents and non-respondents’ groups except for the level of education (p < 0.05). At the six-month post-baseline assessment, the respondent group had significantly higher level of education compared to the non-respondent group.

The aim of this study was to quantify a set of vocational outcomes after RTI; to explore RTW trajectories over 12 months; and to identify predictors of RTW status and disability days at baseline, six and 12 months post-RTI. Thirty-three percent of participants did not RTW at baseline (n = 21) and around 10% at six- (n = 4) and 12-months (n = 5) post-baseline. The mean disability days was 48 (SD = 93) one year after RTI. Participants had different RTW trajectories with most using at least one type of work modification to return/stay at work, and around 13% having at least one RTW failure one year from their RTI. RTW at baseline was predicted by lower severity of injury, lower level of pain and disability, and younger age; at 6 months by being a casual/part-time employee, and at 12 months by earning higher level of income pre-injury. Having more disability days was predicted at baseline by being male, being admitted to hospital, sustaining a more severe injury, lodging a claim for compensation, having greater disability; and greater feelings of distress related to intrusion; at 6 months by being older and having lower level of RTW self-efficacy; and at 12 months by being older, having lower level of education, sustaining more severe injury, and being in a casual employment pre-injury.

This study provided a comprehensive understanding of the RTW process following mild to serious RTI through the application of multiple vocational outcome measures over a one-year period. Overall, 88% of participants in this study returned to work one year after the RTI. This rate aligns with previously reported RTW rates for mild to serious RTI, which range from 78% to 95% (13, 14, 38–43). Although there was a gradual improvement in work performance and a reduction in impaired work productivity over time, findings indicated that 17% of those who returned to work were not employed in their pre-injury role or job one year after the injury (Table 3). Additionally, measuring the number of disability days revealed that some individuals continued to require time off work due to recurrence or exacerbation of their RTI, even after initially returning. These findings reinforce that first RTW alone is not an adequate indicator of vocational outcome (12, 44) and highlight the importance of using multiple, longitudinal measures to capture the complex and ongoing impact of RTI on work participation.

Visualising RTW patterns over the 12-month period revealed heterogeneous RTW trajectories, similar to those previously reported in individuals with musculoskeletal work-related injuries (45). While most participants had returned to work by 12 months post-injury, approximately one in eight (13%) were not in sustained employment. To our knowledge, the only other study investigating RTW patterns after RTI was conducted by Gray et al. (10). Their study used claimants’ income replacement data derived from an insurance company database, finding that 17% (n = 5401) of participants had at least one RTW failure two years post-injury. Differences between studies likely reflect variations in follow-up duration and outcome measurement approaches. In the present study, RTW status by timepoint (Table 3) and individual RTW trajectories (Fig. 2) showed that early RTW was predominantly with modifications during the first month following the crash, followed by a progressive shift toward RTW without modifications over subsequent months. This pattern indicates that early access to suitable work modifications supports both initial RTW and sustained participation in the workforce. These findings underscore the significance of work modification availability, particularly during the early post-injury phase, in facilitating a successful RTW. This is especially relevant in jurisdictions with fault-based compensation schemes, where employers are not legally obligated to offer modified duties to employees recovering from non–work-related RTI. Future studies should examine what educational, financial, or legal supports could be provided to employers to encourage early, modified RTW opportunities for this group.

This study showed that the predictive strength of vocational outcome measures (i.e., RTW status and number of disability days) varied over time within the same population. RTW status demonstrated relatively stronger predictive strength compared with disability days. Although the number of predictors in the final models differed between the two outcome measures, the most common baseline predictors were related to physical health. Specifically, individuals with more severe injuries, greater levels of pain and disability, and older age were less likely to RTW and more likely to record a higher number of disability days. This finding aligns with a systematic review reporting strong evidence for an association between better health status and improved RTW outcomes after mild to serious RTI (7). However, contrary to that review, the present study found that older age was associated with poorer RTW outcomes, consistent with other studies showing that prolonged work disability (assessed by different measures) tends to be more pronounced in older workers (14, 46, 47). These findings highlight the importance of providing timely and appropriate interventions particularly within the first month following RTI to optimise recovery and support early RTW (48). Beyond the early phase, key predictors at six and twelve months were primarily work-related: participants in casual or part-time employment were less likely to RTW at six months and more likely to report more disability days at twelve months, whereas higher pre-injury income predicted RTW. These results are consistent with Prang et al. (49), although Murgatroyd et al. (50) reported no association between income/employment status and time to RTW following orthopaedic RTI; discrepancies may reflect sample composition and predictor categorisation, with Murgatroyd et al. including a larger proportion of severe–critical injuries. These results point to a staged, systems-oriented approach to RTW after RTI. In the first month, timely rehabilitation and early coordination with employers to trial temporary work modifications may help facilitate initial RTW. From six to twelve months, attention could increasingly shift toward workplace solutions (e.g., job redesign, flexible scheduling) and targeted support for workers in insecure or part-time employment. Ongoing communication among workers, clinicians, and employers appears likely to support sustained participation. In fault-based schemes, mechanisms that enable or incentivise early employer engagement and low-cost modifications may be beneficial.

To the best of our knowledge, this is the first study that provided a holistic picture of vocational outcomes after one year of mild to serious RTI. Different vocational outcome measures used in this study served as a basis to compare the appropriateness of each measure in indicating possible impacts of RTI on work within a single population. Visualisation of RTW trajectories highlighted the necessity of work modification in RTW process leading to introducing a current system-related gap associated with unavailability of employers’ support for those with non-work-related RTI in a fault-based scheme. In addition, this study found that some people may experience one or multiple RTW failures following their first RTW. Future studies are needed to identify group based RTW trajectories using new statistical methods and predictors of these trajectories. The multidimensional nature of data (health, work, and system-related factors) collected in this study resulted in identifying some important predictors of vocational outcomes following RTI which can be considered in developing future RTW interventions. A limitation of this study was the small sample size and the relatively high attrition rate across follow-ups. The main reason for this attrition was difficulty in re-contacting participants after discharge, particularly those with minor injuries who often recovered quickly and perceived little ongoing benefit in continued participation. This challenge is well-documented in longitudinal studies recruiting from emergency departments, where attrition rates of up to 55% have been reported in studies of patients after severe injury (51). Despite this limitation, the overall trends and associations observed in this study were consistent with findings from larger cohorts, supporting the robustness of the results.