Introduction
Survival rates of cancer patients are increasing, due to improvements in cancer diagnosis and treatment [
1,
2]. More than 60% of cancer patients return to work (RTW) within 1–2 years after cancer diagnosis globally [
3]. However, cancer patients can experience difficulties when returning to work due to cancer treatment or as a result of psychological symptoms related to cancer diagnosis [
4,
5]. Health-related work functioning (hereafter referred to as work functioning) measures the ability to meet the demands of work for a given state of health [
6‐
8]. Work functioning reflects the interplay between work and health and might therefore be seen as a highly valuable outcome [
6‐
8].
Earlier, we have identified three distinct work functioning trajectories in the year following RTW of cancer patients, and baseline cognitive symptoms, time between diagnosis and RTW, and changed meaning of work were associated with these trajectories [
9]. To date, knowledge about the course of work functioning in cancer patients during the first 18 months after RTW is lacking. Moreover, little is known about how health status and work-related factors (i.e., work demands and social support) change over time and information about their influence on work functioning over time in cancer patients is lacking. This knowledge is important for physicians who treat cancer patients with paid work and for the development of interventions to improve work functioning of cancer patients.
Therefore, the aims of this study are (1) to investigate the course of work functioning, health status, and work-related factors in cancer patients during 18 months after RTW and (2) to examine the associations between health status and work-related factors with work functioning over time.
Results
Characteristics of cancer patients
A total of 384 cancer patients were included in the WOLICA study. At baseline,
n = 319 (83%) had complete WRFQ, health status, and work-related factors data,
n = 290 (76%) at 6 months,
n = 262 (68%) at 12 months, and
n = 258 (67%) at 18 months after RTW. Cancer patients had a mean age of 50.7 (
SD = 8.6) years and 63% were female (Table
1). Breast cancer was most prevalent (46%), followed by gastrointestinal cancer (15%), hematological cancer (11%), and urogenital cancer (11%). Seventy-one percent of the cancer patients were treated with systemic therapy exclusively or in combination with radiotherapy and/or surgery. The time between diagnosis and return to work was on average 7 months. Two-thirds of the cancer patients had completed their treatment at baseline.
Table 1
Baseline socio-demographics (n = 384)
Gender (female), n (%) | 243 (63) |
Education, n (%) |
Low | 105 (27) |
Medium | 129 (34) |
High | 149 (39) |
Marital status, n (%) |
Married/cohabitating | 305 (80) |
Single/divorced/separated | 78 (20) |
Cancer site, n (%) |
Breast cancer | 178 (46) |
Gastrointestinal cancer | 58 (15) |
Gynecological cancer | 12 (3) |
Hematological cancer | 42 (11) |
Skin cancer | 16 (4) |
Head and neck cancer | 15 (4) |
Urogenital cancer | 41 (11) |
Lung cancer | 13 (3) |
Other cancer | 8 (2) |
Type of treatment, n (%) |
Surgery | 59 (15) |
Radiotherapy exclusively, or in combination with surgery | 48 (13) |
Systemic therapy exclusively, or in combination with radiotherapy and/or surgery | 271 (71) |
Treatment completed (yes), n (%) | 246 (64) |
At baseline, cancer patients had a WRFQ score of 78.4 (CI: 76.6, 80.2), indicating that on average 22% of the time they had difficulties meeting the demands of the job due to (physical or emotional) health problems (Table
2). Cancer patients worked on average 19.0 (CI: 17.8, 20.1; interquartile range (IQR): 12–24) hours per week at baseline. At that time, they reported a mean fatigue score of 30.2 (CI: 29.0, 31.4; IQR: 22.0–37.8), a mean depressive symptoms score of 4.6 (CI: 4.3, 5.0; IQR: 2.0–7.0), and a mean cognitive symptom score of 24.7 (CI: 23.0, 26.4; IQR: 13.2–24.0).
Table 2
Work functioning, health status, and work-related factors at baseline, 6-, 12-, and 18-month follow-up of 384 cancer patients (estimated means with CI)
Work functioning | 78.4 (76.6, 80.2) | 82.1 (80.2, 83.9) | 3.6*** | 85.2 (83.3, 87.1) | 6.8*** | 3.2** | 85.2 (83.3, 87.2) | 6.8*** | 3.2** | 0 |
Health status |
Fatigue | 30.2 (29.0, 31.4) | 28.2 (27.0, 29.4) | − 2.0** | 27.9 (26.7, 29.1) | − 2.3** | − 0.3 | 27.8 (26.5, 29.0) | − 2.4** | − 0.4 | − 0.1 |
Depressive symptoms | 4.6 (4.3, 5.0) | 4.3 (3.9, 4.7) | − 0.4 | 3.8 (3.4, 4.2) | − 0.8*** | − 0.5 | 4.1 (3.7, 4.5) | − 0.6* | − 0.2 | 0.3 |
Cognitive symptoms | 24.7 (23.0, 26.4) | 24.5 (22.7, 26.3) | − 0.23 | 24.4 (22.7, 26.2) | − 0.3 | − 0.1 | 24.2 (22.4, 26.1) | − 0.5 | − 0.2 | − 0.3 |
Work-related factors |
Working hours (p/w) | 19.0 (17.8, 20.1) | 26.9 (25.8, 28.1) | 8.0*** | 27.2 (26.0, 28.4) | 8.2*** | 0.3 | 26.2 (24.9, 27.4) | 7.2*** | − 0.8 | − 1.0 |
Quantitative demands | 2.7 (2.5, 2.8) | 2.7 (2.5, 2.8) | 0.0 | 2.6 (2.4, 2.8) | 0.1 | − 0.1 | 2.6 (2.4, 2.8) | − 0.1 | − 0.1 | 0.0 |
Work pace | 4.5 (4.3, 4.6) | 4.6 (4.4, 4.8) | 0.1 | 4.7 (4.5, 4.9) | 0.2 | 0.1 | 4.6 (4.4, 4.8) | 0.1 | 0.0 | − 0.1 |
Influence at work | 4.5 (4.3, 4.7) | 4.5 (4.3, 4.7) | 0.0 | 4.4 (4.2, 4.6) | 0.1 | − 0.1 | 4.3 (4.1, 4.5) | − 0.2 | − 0.1 | − 0.1 |
Meaning of work | 6.2 (6.0, 6.3) | 5.9 (5.8, 6.1) | − 0.2 | 5.8 (5.7, 6.0) | − 0.3** | − 0.1 | 5.8 (5.6, 5.9) | − 0.4*** | − 0.2 | − 0.1 |
Social support supervisor | 5.3 (5.1, 5.5) | 4.8 (4.6, 5.1) | − 0.4*** | 4.8 (4.6, 5.0) | − 0.5*** | 0.0 | 4.7 (4.4, 4.9) | − 0.6*** | − 0.2 | − 0.2 |
Social support colleagues | 5.6 (5.4, 5.8) | 5.2 (5.0, 5.4) | − 0.4** | 5.2 (5.0, 5.4) | − 0.4** | 0.0 | 5.2 (4.9, 5.4) | − 0.5*** | 0.0 | − 0.1 |
The course of work functioning, health status, and work-related factors
In the first 12 months after RTW, cancer patients reported an increase in work functioning (Δ0–12: 6.8) and a decrease in fatigue (Δ0–12: − 2.3) and depressive symptoms (Δ0–12: − 0.8). Work functioning, fatigue, and depressive symptoms remained stable between 12 and 18 months after RTW. Cognitive symptoms were stable during the first 18 months after RTW.
Cancer patients reported an increase in working hours in the first 6 months after RTW (Δ0–6: 8.0). During that period, they reported a decrease in social support from both the supervisor (Δ0–6: − 0.4) and colleagues (Δ0–6: − 0.4). Working hours and social support from supervisor and colleagues were stable between 6 and 18 months after RTW. Additionally, cancer patients reported a decreased meaning of work in the first 12 months (Δ0–12: − 0.3), which was stable between 12 and 18 months after RTW. Quantitative demands, work pace, and influence at work remained stable during the first 18 months after RTW.
The association among health status and work-related factors and the course of work functioning
The unconditional growth model showed an increase in work functioning in the first 12 months after RTW, and work functioning remained stable between 12 and 18 months (Table
3, model 1;
n = 1186 person-measurement observations, 77%). Age, gender, education, and marital status did not change the course of work functioning (model 2).
Table 3
Association among health status and work-related factors with work functioning over time of 384 cancer patients
Intercept | 78.42 (76.63, 80.22)*** | 80.28 (71.00, 89.56)*** | 101.06 (95.26, 106.87)*** | 68.48 (57.45, 79.51)*** | 91.97 (83.91, 100.03)*** | 93.01 (84.58, 101.44)*** |
Time baseline | Ref | Ref | Ref | Ref | Ref | Ref |
6 months | 3.62 (1.79, 5.46)*** | 3.60 (1.73, 5.46)*** | 2.67 (0.98, 4.35)** | 0.88 (− 1.31, 3.08) | 1.30 (− 0.61, 3.21) | 2.51 (− 0.43, 5.45) |
12 months | 6.83 (5.09–8.57)*** | 6.81 (5.05, 8.57)*** | 5.19 (3.65, 6.73)*** | 4.03 (2.07, 5.99)*** | 3.83 (2.06, 5.60)*** | 0.64 (− 2.03, 3.30) |
18 months | 6.82 (4.84, 8.80)*** | 6.74 (4.74, 8.73)*** | 5.28 (3.58, 6.98)*** | 4.13 (1.87, 6.38)*** | 3.98 (2.03, 5.93)*** | 2.81 (− 0.22, 5.74) |
Gender |
Female | | 0.09 (− 3.16, 3.34) | 0.95 (− 1.17, 3.08) | 2.31 (− 0.62, 5.26) | 2.16 (− 0.17, 4.48) | 2.09 (− 0.24, 4.43) |
Male | | Ref | Ref | Ref | Ref | Ref |
Age | | − 0.03 (− 0.21, 0.15) | − 0.04 (− 0.15, 0.08) | 0.01 (− 0.14, 0.16) | 0.00 (− 0.10, 0.10) | − 0.01 (− 0.11, 0.10) |
Education |
Low | | 2.03 (− 1.72, 5.78) | 2.47 (0.07, 4.88)* | 1.33 (− 1.95, 4.61) | 2.42 (− 0.01, 4.85) | 2.39 (− 0.03, 4.80) |
Medium | | − 2.03 (− 5.59, 1.52) | − 0.84 (− 3.23, 4, 1.55) | − 1.75 (− 4.93, 1.44) | − 0.48 (− 2.82, 1.87) | − 0.55 (− 2.88, 1.78) |
High | | Ref | Ref | Ref | Ref | Ref |
Marital status |
Single/divorced | | − 1.32 (− 4.85, 2.22) | 1.28 (− 1.15, 3.71) | − 1.06 (− 4.13, 2.01) | 0.96 (− 1.39, 3.31) | 0.98 (− 1.36, 3.31) |
Married/cohabiting | | Ref | Ref | Ref | Ref | Ref |
Fatiguea | | | − 0.19 (− 0.27, − 0.11)*** | | − 0.16 (− 0.24, − 0.08)*** | − 0.16 (− 0.24, − 0.08)*** |
Depressive symptomsb | | | − 1.34 (− 1.67, − 1.00)*** | | − 1.15 (− 1.48, − 0.81)*** | − 1.13 (− 1.74, − 0.77)*** |
Depressive symptoms * baseline | | | | | | Ref |
Depressive symptoms * 6 months | | | | | | 0.05 (− 0.56, 0.66) |
Depressive symptoms * 12 months | | | | | | 0.35 (− 0.19, 0.90) |
Depressive symptoms * 18 months | | | | | | 0.18 (− 0.41, 0.77) |
Cognitive symptomsc | | | − 0.41 (− 0.49, − 0.34)*** | | − 0.39 (− 0.46, − 0.33)*** | − 0.40 (− 0.50, − 0.31) *** |
Cognitive symptomsc * baseline | | | | | | Ref |
Cognitive symptomsc * 6 months | | | | | | − 0.06 (− 0.18, 0.06) |
Cognitive symptomsc * 12 months | | | | | | 0.08 (− 0.04, 0.19) |
Cognitive symptomsc * 18 months | | | | | | 0.02 (− 0.12, 0.16) |
Working hoursd | | | | 0.29 (0.17, 0.41)*** | 0.15 (0.05, 0.25)** | 0.14 (0.04, 0.24)** |
Quantitative demandse | | | | − 2.65 (− 3.33, − 1.97)*** | − 0.99 (− 1.54, − 0.44)*** | − 0.98 (− 1.53, − 0.42)** |
Work pacee | | | | − 0.32 (− 0.90, 0.27) | − 0.28 (− 0.76, 0.19) | − 0.26 (− 0.72, 0.21) |
Influence at worke | | | | 0.49 (− 0.03, 1.00) | 0.41 (0.00, 0.81) | 0.39 (− 0.02, 0.80) |
Meaning of worke | | | | 1.08 (0.36, 1.80)** | 0.35 (− 0.25, 0.94) | 0.36 (− 0.24, 0.95) |
Social support supervisore | | | | 1.00 (0.46, 1.55)*** | 0.64 (0.21, 1.07)** | 0.71 (0.29, 1.13)** |
Social support colleaguese | | | | − 0.45 (− 0.96, 0.06) | − 0.32 (− 0.74, 0.11) | − 0.37 (− 0.78, 0.04) |
After adding health status (model 3), an increase in fatigue (regression coefficient b: − 0.19; CI: − 0.27, − 0.11), depressive symptoms (− 1.34; − 1.67, − 1.00), and cognitive symptoms (− 0.41; − 0.49, − 0.34) was associated with a decrease in work functioning. When adding work-related factors (model 4), an increase in working hours (0.29; 0.17, 0.41), meaning of work (1.08; 0.36, 1.80), and supervisor social support (1.00; 0.46, 1.55) was associated with an increase in work functioning, while an increase in quantitative demands (− 2.65; − 3.33, − 1.97) was associated with a decrease in work functioning. Changes in work pace, influence at work, and social support from colleagues did not affect the course of work functioning over time. After adding both health status and work-related factors (model 5), the associations remained similar, except for meaning of work; this was no longer associated with the course of work functioning over time.
When including interaction terms between health and work-related factors with time (model 6, n = 1106 person-measurement observations, 72%), the interaction terms between cognitive symptoms and time 3 (i.e., 12 months) and depressive symptoms and time 3 were statistically significant. When adding both interaction terms together to the subsequent and final model, both interaction terms remained not significant.
Discussion
Cancer patients showed an increase in work functioning and a decrease in fatigue and depressive symptoms during the first 12 months and stability between 12 and 18 months after RTW. Cognitive symptoms were stable during the first 18 months after RTW. Working hours increased and social support from supervisor and colleagues decreased in the first 6 months and were stable between 6 and 18 months after RTW. Fatigue, depressive symptoms, and cognitive symptoms were negatively associated with work functioning over time, and working hours and supervisor social support were positively associated with work functioning over time. The effects were the same over time for all variables.
When returned to work, cancer patients experienced difficulties in meeting their job demands due to (physical or emotional) health problems for 22% of their time at work. During the first 12 months after RTW, the amount of time experiencing difficulties decreased to 15% and remained stable between 12 and 18 months. Due to this reduction in experienced difficulties, cancer patients’ level of work functioning 1 year after RTW is similar to the level of work functioning in the general working population [
8].
Fatigue and depressive symptoms were decreasing during the first 12 months after RTW and were stable between 12 and 18 months. Even though cancer patients were already below clinical cut-offs for fatigue and depressive symptoms [
10,
12], their level of fatigue and depressive symptoms decreased after RTW. Work-specific cognitive symptoms were stable during the first 18 months after RTW. Previous research in cancer patients showed that cognitive impairments are typically subtle, with symptoms across various domains of cognition, i.e., working memory, executive function, and processing speed [
18‐
20]. While acute cognitive changes during chemotherapy are common [
19,
20], long-term post-treatment cognitive changes only persist in a subgroup (17–34%) of cancer patients [
21]. To gain more knowledge about subgroups of cancer patients with different courses of work-specific cognitive symptoms and their determinants, more research is needed.
The current longitudinal study identified negative associations between fatigue, depressive symptoms, and cognitive symptoms with work functioning over time. A recent systematic review on physical and psychosocial problems associated with difficulties at work in cancer patients beyond RTW showed similar associations, although mainly based on cross-sectional research [
22]. The negative associations over time can be interpreted in two ways (i.e., both as a between and a within person effect) [
17]. First, cancer patients with fewer health problems (i.e., lower fatigue, depressive symptoms scores, and/or cognitive symptoms) had higher work functioning scores compared to cancer patients with more health problems. Second, a decline in health problems within one cancer patient (i.e., an improvement in health) was associated with an increase in work functioning over time, indicating that an improvement in health can be beneficial for work functioning.
Cancer patients reported an increase in working hours during the first 6 months after RTW, but their working hours were stable between 6 and 18 months after RTW even though they did not reach their contracted working hours (data not shown). The positive association found in this study might be explained by an improvement in health, which allows for better scores on work functioning and for a possibility to work more hours per week. Further research is needed to elaborate this in more detail.
In line with previous research [
23,
24], workplace social support decreased over time, especially in the first 6 months after RTW. When examining the association between social support and work functioning over time, higher supervisor support was related to better work functioning over time. Therefore, the observed decrease of workplace social support might negatively affect cancer patients’ work functioning over time. Continuous supervisor social support might be important when guiding and accommodating cancer patients at work. The fact that social support was not associated with work functioning in the general working population [
25] suggests that workplace social support is more important for work functioning in vulnerable populations, as has previously been shown [
26‐
28].
Several strengths and limitations have to be addressed. A strength of this study is the longitudinal design with repeated measurements of work functioning, health status, and work-related factors at baseline, 6, 12, and 18 months after RTW. Data were available from all four measurement points for the majority of participants. Another strength is the heterogeneous sample of cancer patients with different cancer diagnoses and treatments. In this study, work functioning scores were positively skewed to the right, both at baseline and at follow-up. Therefore, we used GEE analyses instead of mixed models, which allowed for weaker distributional assumptions [
29]. The lack of information about cancer patients who were not asked to participate or were asked but not willing to participate is a study limitation. Consequently, it is not possible to state that the study sample is representative of all cancer patients who resumed work after cancer diagnosis and treatment. Furthermore, this study includes no comparison group of healthy workers or workers with other chronic conditions. In future studies, adding a comparison group could provide additional valuable information to interpret our findings. It is also important to note that both the independent and dependent variables were measured with self-reported measures, which might have resulted in an overestimation of the associations due to shared method variance or shared response biases [
30].
In the future, interventions to improve work functioning might be successful when reducing fatigue, depressive symptoms, and cognitive symptoms of cancer patients, because a reduction of these symptoms is related to an increase in work functioning over time. For interventions to reduce cognitive symptoms, it is important to take the specific work situation into account, since cancer patients indicate these cognitive symptoms in relation to work. Furthermore, we have to inform employers and (occupational) physicians about the importance of continuing supervisor social support on a regular basis. To improve work functioning, it is important to monitor cancer patients not only in the period directly after RTW but up to 18 months after RTW, allowing for timely interventions when needed.