Exploring the Factors Affecting Labour Market Participation for Individuals with Cerebral Palsy: A Scoping Review

Stage 1: Identifying the research question

The aim of this scoping review is to investigate existing literature on the factors influencing labour market participation among individuals with CP and to address the potential gaps in this literature. The following research questions were formulated:

• Which factors have been identified in existing literature as affecting the labour market participation of individuals with CP?

• What limitations and gaps can be identified in existing literature regarding factors influencing labour market participation of individuals with CP, and how can these findings provide implications for future research?

The results section will investigate the factors that influence the labour market participation of individuals with CP (research question 1). The discussion will examine these findings further to highlight literature gaps and provide implications for future research (research question 2).

Stage 2: Identifying relevant studies

Literature searches were conducted in September–October 2023. Relevant databases, including Scopus, PubMed, ProQuest, Google Scholar, and AUB Primo (Aalborg University Database), were utilised. Keywords were constrained and simplified to maintain a broad approach, as recommended in the scoping study method (Peters et al. 2015). The primary keyword was ‘Cerebral Palsy’, supplemented by the secondary keyword as presented in Table 1. In some databases, ‘OR CP’ was added; however, this was not applicable to all databases, such as PubMed and ProQuest, where it resulted in many imprecise search results due to ‘CP’ being an abbreviation for terms other than Cerebral Palsy. To refine the search, the keyword ‘NOT children’ was added to focus on adults. If an advanced search feature was available, a search criterion was set to ensure that ‘cerebral palsy’ and ‘employment’ were referenced in the abstract, title, or keywords. In Google Scholar, the specification required both keywords to be present in the title, as the alternative allowed for either keyword to appear anywhere in the text, resulting in 17,800 imprecise search results. This approach was adopted to narrow down the search to relevant peer-reviewed studies where individuals with CP and employment play a key role. In some initial searches without employing this advanced search feature, several irrelevant results emerged.

Stage 3: Study selection

Studies published before the year 2000 were excluded. It was assessed that research prior to this year had limited relevance due to being several decades old, with significant developments having occurred in the fields of employment, disability and cerebral palsy in general. Furthermore, literature considered non-research, such as non-academic book chapters or grey literature like conference papers, was excluded due to relevance. Studies solely focusing on children were also excluded. Five literature reviews were examined to identify relevant references; however, these were not included in the final selection of studies.

Due to limited time and resources, the literature search was restricted to studies published in English as seen in Table 2. Conducting a multilingual search and translating non-English articles was considered too time-consuming. Moreover, English functions as the dominant language in international academic publishing (Hyland 2016) and was therefore considered appropriate for capturing a broad body of literature. However, it is acknowledged that this decision may have excluded valuable insights from non-English literature.

The process of study selection was carried out in three steps by the author. In the first step, a preliminary screening was conducted in each of the databases, involving the review of titles and abstracts to identify relevant publications. Promising and relevant articles were saved for further examination. In the second step, the studies considered relevant were set aside for detailed full-text reading. Lastly, a citation chaining method was employed to review the selected literature for references. However, this did not result in any additional references. This process resulted in the final selection of 24 studies. The process of study selection is presented in Figure 1, and the final studies are summarised in Table 4.

Figure 1

The PCC model is a framework utilised in scoping reviews to delineate the primary elements of the research by defining the specific group of individuals under study (Population), the main focus of the research (Concept), and the relevant setting (Context) (JBI 2024; Peters et al. 2015). In this review, the PCC model was used to guide the formulation of the research question and inclusion criteria, as outlined in Table 3.

Stage 4: Charting the data

Data from the selected studies were mapped using Excel, as presented in Table 4. The data-mapping process revealed various characteristics. In terms of the studies’ methodologies, quantitative methods, including surveys and questionnaires, together with national registries, are most often used. Only six out of the 24 studies employ qualitative methods, such as interviews. Regarding study populations, the studies encompass a wide diversity, ranging from young adults (aged 16–20) to middle-aged (aged 20–45) and older adults. Gender distribution in the studies varies with a gender imbalance. Eighteen of the 24 studies have more males than females. Only one study has more females, while the others lack information regarding gender. However, it should be noted that this could be due to a higher prevalence of males with CP (Jarvis et al. 2005). All studies primarily focus on individuals with CP. However, a few studies also included individuals with spina bifida (SB). Sample sizes are quite diverse, ranging from small groups of a few individuals to large populations exceeding 13,000 individuals.

Following the data-mapping, articles were coded using NVivo. In line with scoping study guidelines, the coding process was conducted broadly, with a relatively limited number of codes (JBI 2024; Peters et al. 2015). These included: 1) factors related to the individual with CP and 2) factors related to the individual’s context.

Stage 5: Collating, summarising, and reporting the results

This stage is represented in the rest of the review.

Factors Related to Individuals with CP

The most prevalent factors in the existing literature that affect labour market participation among individuals with CP are: severity of CP, gender, education, and age.

Severity of CP, which includes having a high level of physical functioning (low GMFCS level) and the absence of intellectual impairment, is the most prevalent factor in existing literature. Individuals with high-functioning CP are more likely to be employed (e.g., Bertels et al. 2023; Magill-Evans et al. 2008; Pagliano et al. 2021; Pettersson and Rodby-Bousquet 2021; Verhoef et al. 2014). Building on this, the visibility of the disability may also intertwine with the severity. Individuals with severe CP may exhibit a more visible disability, which seems to have a negative effect on employment.

Bertels et al. (2023) evaluated factors influencing employment in a study of 80 adults (aged 21–65, without intellectual impairment). They divided individuals with CP into three groups: 1) employed, 2) in sheltered or voluntary employment, and 3) unemployed. The study identified that the group of individuals with CP in employment consisted of significantly more males compared to the unemployed group. Furthermore, the functional and educational level in the employed group was higher, with 60.5% having a GMFCS score of one (highest level), and 53.5% having more advanced educational levels compared to the two other groups. Finally, the study found that 38% of the variability in weekly working hours could be explained by factors such as gender, educational level, and GMFCS level. This indicates that high-functioning adults, particularly males, who have a higher education, are more likely to be employed.

Several studies (e.g. Andersson and Mattsson 2001; Benner et al. 2017; Bertels et al. 2023; Pagliano et al. 2021) support that high-functioning males are more likely to be employed, making gender a recurrent factor in the existing literature. Pagliano et al. (2021) followed 109 individuals from childhood to adulthood and determined that males with high-functioning CP are more frequently employed compared to females and individuals with more severe CP. Pettersson and Rodby-Bousquet (2021) conducted a registry study of 1,888 people and found that women were half as likely to be employed as their male counterparts.

Education is another factor often found in the existing literature that affects labour market participation among individuals with CP. Individuals with CP who have higher levels of education are more likely to be employed. This may correlate with the ‘severity of CP factor’, as individuals with higher-functioning CP are more inclined to pursue higher education (e.g., Asuman et al. 2023; Bottos et al. 2001; Michelsen et al. 2005; Michelsen et al. 2006; Murphy et al. 2000; Reddihough et al. 2013). In general, studies find that individuals with CP tend to have lower educational attainment levels compared to those without CP (Asuman et al. 2023; Mesterman 2010; Michelsen et al. 2006; Michelsen et al. 2005; Reddihough et al. 2013). Additionally, studies also find that individuals with high-functioning CP are more likely to achieve higher levels of education and experience higher employment rates than those with severe CP (Asuman et al. 2023; Michelsen et al. 2005; Michelsen et al. 2006; Murphy et al. 2000; Opheim et al. 2009; Reddihough et al. 2013; Van Der Slot et al. 2010).

Age also plays a role in labour market participation. The youngest adults (aged 16–20) are more frequently unemployed compared to middle-aged individuals (Verhoef et al. 2014). This may relate to younger individuals being in school rather than in the workforce. Furthermore, studies also find that as individuals with CP get older (after age 45), they often work fewer hours, and a greater number retire from employment (Asuman et al. 2023; Törnbom et al. 2014). This indicates that middle-aged individuals (aged 20–45) are the ones most likely to be in employment.

Verhoef et al. (2014) examined the work participation development of 74 young individuals (aged 16–20 at the beginning) over a four-year period. They found a strong significant correlation between age (with the youngest adults experiencing higher unemployment rates), educational level, and GMFCS level.

In a study by Benner et al. (2017), 65 adults were followed over a 14-year period to investigate the development of employment throughout their lifespan. The study found that as adults with CP reach the age of 45, employment stability increases, while weekly working hours decrease, particularly for women.

The decrease in work hours with the ageing of individuals with CP is supported by additional studies. Törnbom et al. (2014) followed 85 adults (without intellectual impairment) from 1997–2009 and found that overall employment decreases with ageing. This decline manifested not only in reduced working hours but also in a higher number of individuals retiring from the labour market. They suggested that this decrease in both work hours and employability might be attributed to the secondary conditions accompanying CP, which tend to worsen with age.

This is also observed in a recent registry study by Asuman et al. (2023) that examined employment over a 25-year period for individuals with CP residing in Sweden between 1990–2015 (13,000 individuals). Age and possible worsening of secondary conditions may therefore create a barrier to maintaining consistent employment throughout the lifespan of adults with CP.

Factors Related to the Context of Individuals with CP

Only seven studies were found to investigate how the context of individuals with CP affects their labour market participation, which provides insufficient evidence to fully understand these factors impact. However, three key factors affecting the labour market participation of individuals with CP can be identified: discrimination and stigmatisation in employment and education, transportation difficulties, and supportive networks and accommodations.

Mik-Meyer (2016) investigated how individuals with CP were perceived by colleagues and leaders within their workplace. The study was based on interviews conducted with 76 individuals from 13 different companies, including 14 individuals with CP. The findings showed that individuals with CP are viewed as ‘different’ due to their visible disabilities. This perception significantly impacted their professional standing within the workplace. Additionally, the study highlighted how this visible distinctiveness often led to doubts about intelligence, professional competence, and the ability to perform job tasks. This indicates that employer and colleague attitudes, including discrimination and stigmatisation, affect the labour market participation of individuals with CP.

Other studies also found that people with CP experience discrimination and stigmatisation. Lowman, West, and McMahon (2005) analysed the Equal Employment Opportunity Commission (EEOC) database, examining employment discrimination complaints filed by individuals with CP in the United States between 1992 and 2003. Of the 1,392 complaints included in the dataset, hiring discrimination accounted for 15.4%, a significantly higher proportion compared to the 5.3% observed among complaints from individuals with other types of disabilities. The study highlighted the role of employer assumptions about incapacity as a key barrier to employment.

In a study by Törnbom et al. (2017) individuals with CP reflected upon their experiences of participation in relation to employment. Several participants reported being fired from a job due to disability discrimination by employers.

Shrader et al. (2021) found that, despite a high level of education, unemployment for individuals with CP is still much higher than for individuals without CP with similar educational backgrounds. They divided 126 adults into two groups: those who used an assistant to answer the survey (41 participants) and those who self-reported (85 participants). Participants in the self-reported group had education levels that were similar or even higher than the national average. Shrader et al. (2021) suggested that this indicates discrimination in employment opportunities for adults with CP who have advanced education and are high functioning, but despite this, still have a high unemployment rate. Several other studies found that high-functioning individuals with CP tend to have significantly lower educational levels compared to individuals without CP, and possibly even lower than individuals with other lifelong disabilities (Michelsen et al. 2006; Michelsen et al. 2005; Rasalingam et al. 2021). This may indicate discrimination in education affecting the group’s labour market participation despite having high physical function and no intellectual impairment.

Magill-Evans et al. (2008) investigated the factors that promote or hinder employment prospects for 76 young adults with CP or SB. The study used a mixed-method design. A hierarchical regression analysis found that gender, with females being less likely to be employed, having an intellectual impairment, and transportation dependence, collectively explained 42% of the variance in employment outcomes. The study interviews highlighted two key findings on employment barriers. The first one being transportation. Participants revealed the challenges they faced in commuting to work, including the time and number of buses required, and difficulties in aligning bus schedules with work schedules. Many participants lacked a driver’s licence, which limited their employment opportunities. Social reactions to disabilities were also found to be a barrier. Several individuals reported experiences with employers hesitant to hire due to lacking knowledge and fears. The study also highlighted the challenge of securing a job when disclosing a disability on resumes and employers’ tendency to focus on the disability rather than considering possible accommodations.

McNaughton et al. (2009) also found that transportation difficulties are a key barrier to labour market participation. They explored the employment experiences of eight full-time employees with CP in a focus group interview. In this study, transportation difficulties were frequently mentioned. Participants also highlighted the value of internships or volunteering when obtaining employment, which contributed to gaining practical skills, work experience, and networking with potential employers. Support from social networks within the community were also found to play a positive role when job seeking. Lastly, the workplaces’ ability to offer support from coworkers such as mentors was highlighted as a positive factor for labour market participation.

Huang et al. (2013) identified similar types of support and accommodations. The study identified five types of vocational rehabilitation that significantly increased employment for adults with CP: 1) on-the-job training, 2) job search assistance, 3) on-the-job support and job coaching, 4) support services such as maintenance and follow-up services, and 5) job accommodations (adjusting job tasks, working hours, and work pace).