Cumulative exposure to shift work and sickness absence: associations in a five-year historic cohort.

BACKGROUND: Exposure to shift work has been associated with negative health consequences, although the association between shift work and sickness absence remains unclear. The aim of this study is to investigate associations between cumulative exposure to shift work and sickness absence among ground staff employees of an airline company. METHODS: This study used data from the MORE (Monitoring Occupational Health Risks in Employees) cohort, which is a 5-year historic cohort. The population of the present study consisted of 7562 ground staff employees. For each employee, work schedules and sickness absence days between 2005 and 2009 were obtained from company records. For the exposure to different shift schedule types and to the cumulative number of night shifts, the association with long-term sickness absence (>7 consecutive sickness absence days) and the number of sickness absence episodes during 2009, was calculated using logistic and Poisson regression analyses. Socio-demographic variables, work-related variables, job classification variables, and previous sickness absence days were regarded as confounders. RESULTS: After adjusting for previous sickness absence and job classification variables, only the group of employees that switched into working in a three-shift schedule, showed a significantly increased risk for long-term sickness absence (OR = 1.31, 95%CI 1.02-1.69). Night shift exposure was not significantly associated with long-term sickness absence. Exposure to shift work was negatively associated with more sickness absence episodes. Employees who were exposed to more than 46 night shifts also showed a lower risk for more sickness absence episodes. Subgroup analyses showed that single employees and employees without children had an increased risk for long-term sickness absence when exposed to a three-shift schedule, and when they had changed between shift schedule types. CONCLUSIONS: Cumulative exposure to shift work proved to be negatively associated with more sickness absence episodes, and was not associated with more long-term sickness absence, although selection bias could not be ruled out. Future research should explore the influence of household composition, and take into account both previous sickness absence and psychosocial and physical work factors to obtain a better estimation of the association between shift work and sickness absence.

Risk factors for fatigue among airline pilots.

PURPOSE: The objective of this study is to determine risk factors for fatigue among airline pilots, taking into account person-, work-, health-, sleep-, and lifestyle-related characteristics. METHODS: The study population consisted of 502 pilots who participated in the MORE Energy study. Included risk factors were either measured through an online questionnaire or provided by the company. The outcome of this study, fatigue, was assessed using the Checklist Individual Strength (CIS), and was defined as scoring more than 76 points on this questionnaire. The association of the risk factors with fatigue was determined using univariate and multivariate logistic regression analyses. RESULTS: Of the participating pilots, 29.5 % scored more than 76 points on the CIS and were classified as being fatigued. The fully adjusted regression model showed that person-, work-, health-, and lifestyle-related characteristics were associated with fatigue. Pilots who were aged 31 to 40 (OR 3.36, 95 % CI 1.32-8.53) or 41 to 50 (OR 4.19, 95 % CI 1.40-12.47), an evening type (OR 2.40, 95 % CI 1.38-4.16), scored higher on work-life balance disturbance (OR 1.22, 95 % CI 1.10-1.36), scored higher on need for recovery (OR 1.02, 95 % CI 1.01-1.04), scored lower on general health perception (OR 0.31, 95 % CI 0.20-0.47), were less physically active (OR 0.77, 95 % CI 0.66-0.89), and had a moderate alcohol consumption (OR 3.88, 95 % CI 1.21-12.43), were at higher risk for fatigue. CONCLUSIONS: Higher age, being an evening type, disturbance of the work-life balance, more need for recovery, a lower perceived health, less physical activity, and moderate alcohol consumption were shown to be risk factors for fatigue. Further longitudinal research is needed to elucidate the direction of the associations found and to evaluate the effects of possible countermeasures in airline pilots.

Process evaluation of a tailored mobile health intervention aiming to reduce fatigue in airline pilots.

BACKGROUND: MORE Energy is a mobile health intervention which aims to reduce fatigue and improve health in airline pilots. The primary objective of this process evaluation was to assess the reach, dose delivered, compliance, fidelity, barriers and facilitators, and satisfaction of the intervention. The second objective was to investigate the associations of adherence to the intervention with compliance and with participant satisfaction. Thirdly, we investigated differences between the subgroups within the target population. METHODS: The intervention consisted of a smartphone application, supported by a website. It provided advice on optimal light exposure, sleep, nutrition, and physical activity, tailored to flight and personal characteristics. The reach of the intervention was determined by comparing the intervention group participants and the airline pilots who did not participate. The dose delivered was defined as the total number of participants that was sent an instruction email. Objective compliance was measured through the Control Management System of the application. To determine the fidelity, an extensive log was kept throughout the intervention period. Subjective compliance, satisfaction, barriers, facilitators, and adherence were assessed using online questionnaires. Associations between the extent to which the participants applied the advice in daily life (adherence), compliance, and satisfaction were analysed as well. Finally, outcomes of participants of different age groups and haul types were compared. RESULTS: A total of 2222 pilots were made aware of the study. From this group, 502 pilots met the inclusion criteria and did agree to participate. The reach of the study proved to be 22 % and the dose delivered was 99 %. The included pilots were randomized into the intervention group (n = 251) or the control group (n = 251). Of the intervention group participants, 81 % consulted any advice, while 17 % did this during four weeks or more. Fidelity was 67 %. The participants rated the intervention with a 6.4 (SD 1.6). Adherence was not associated with compliance, but was associated with satisfaction (p ≤ 0.001). Pilots of 35 to 45 year old were significantly more interested in advice regarding physical activity than their colleagues, and short-haul pilots were more interested in advice regarding nutrition compared to long-haul pilots. CONCLUSIONS: The MORE Energy intervention was well received, resulting in an adequate reach and a high dose delivered. The compliance and satisfaction scores indicate that engagement and functionality should be enhanced, and the content and applicability of the advices should be improved to appeal all subgroups of the target population. TRIAL REGISTRATION: Nederlands Trial Register NTR2722 . Registered 27 January 2011.

Evaluation of an mHealth intervention aiming to improve health-related behavior and sleep and reduce fatigue among airline pilots.

OBJECTIVES: The aim of this study was to evaluate the effects of an mHealth intervention (intervention using mobile technology) consisting of tailored advice regarding exposure to daylight, sleep, physical activity, and nutrition, and aiming to improve health-related behavior, thereby reducing sleep problems and fatigue and improving health perception of airline pilots. METHODS: A randomized controlled trial was conducted among 502 airline pilots. The intervention group was given access to both the MORE Energy mobile application (app) with tailored advice and a website with background information. The control group was directed to a website with standard information about fatigue. Health-related behavior, fatigue, sleep, and health perception outcomes were measured through online questionnaires at baseline and at three and six months after baseline. The effectiveness of the intervention was determined using linear and Poisson mixed model analyses. RESULTS: After six months, compared to the control group, the intervention group showed a significant improvement on fatigue (ß= -3.76, P<0.001), sleep quality (ß= -0.59, P=0.007), strenuous physical activity (ß=0.17, P=0.028), and snacking behavior (ß= -0.81, P<0.001). No significant effects were found for other outcome measures. CONCLUSIONS: The MORE Energy mHealth intervention reduced self-reported fatigue compared to a minimal intervention. Some aspects of health-related behavior (physical activity and snacking behavior) and sleep (sleep quality) improved as well, but most did not. The results show offering tailored advice through an mHealth intervention is an effective means to support employees who have to cope with irregular flight schedules and circadian disruption. This kind of intervention might therefore also be beneficial for other working populations with irregular working hours.

Development and evaluation of an intervention aiming to reduce fatigue in airline pilots: design of a randomised controlled trial.

BACKGROUND: A considerable percentage of flight crew reports to be fatigued regularly. This is partly caused by irregular and long working hours and the crossing of time zones. It has been shown that persistent fatigue can lead to health problems, impaired performance during work, and a decreased work-private life balance. It is hypothesized that an intervention consisting of tailored advice regarding exposure to daylight, optimising sleep, physical activity, and nutrition will lead to a reduction of fatigue in airline pilots compared to a control group, which receives a minimal intervention with standard available information. METHODS/DESIGN: The study population will consist of pilots of a large airline company. All pilots who posses a smartphone or tablet, and who are not on sick leave for more than four weeks at the moment of recruitment, will be eligible for participation.In a two-armed randomised controlled trial, participants will be allocated to an intervention group that will receive the tailored advice to optimise exposure to daylight, sleep, physical activity and nutrition, and a control group that will receive standard available information. The intervention will be applied using a smartphone application and a website, and will be tailored on flight- and participant-specific characteristics. The primary outcome of the study is perceived fatigue. Secondary outcomes are need for recovery, duration and quality of sleep, dietary and physical activity behaviours, work-private life balance, general health, and sickness absence. A process evaluation will be conducted as well. Outcomes will be measured at baseline and at three and six months after baseline. DISCUSSION: This paper describes the development of an intervention for airline pilots, consisting of tailored advice (on exposure to daylight and sleep-, physical activity, and nutrition) applied into a smartphone application. Further, the paper describes the design of the randomised controlled trial evaluating the effect of the intervention on fatigue, health and sickness absence. If proven effective, the intervention can be applied as a new and practical tool in fatigue management. Results are expected at the end of 2013. TRIAL REGISTRATION: Netherlands Trial Register: NTR2722.

Flight schedules and occupational accidents among cabin crew: a longitudinal study.

BACKGROUND: Flight schedules of cabin crew involve early starts, long working hours, night flights, and the crossing of time zones, all of which might contribute to the risk of onboard occupational accidents. Because it is unclear if cumulative flight schedule exposure affects the incidence of occupational accidents, the objective of this study is to examine this association among cabin crewmembers. METHODS: Data from the 5-yr historic MORE cohort was used. The study population consisted of 6311 cabin crewmembers. For each employee, all flight schedules from 2005 to 2008 and registered occupational accidents in 2009 were collected. The association between the cumulative exposure to different types of flights and the occurrence of occupational accidents was determined using logistic regression analyses. RESULTS: In 2009, 289 cabin crewmembers reported at least 1 occupational accident. The adjusted logistic regression models showed that the number of short-haul flights during the period 2005-2008 was positively associated with the occurrence of occupational accidents in 2009. Less exposure to long-haul flights was also associated with reporting an occupational accident. DISCUSSION: The results of this study suggest that cumulative exposure to short-haul flights is associated with an increased risk for occupational accidents among cabin crewmembers. This increased risk may be caused by the specific characteristics of short-haul flights. Future research should focus on possible underlying mechanisms, such as fatigue accumulation, and on the influence of adjustments to short-haul schedules. Airline companies can increase their focus on the short-haul operation in order to reduce onboard accidents.

Graded activity for workers with low back pain: who benefits most and how does it work?

OBJECTIVE: To identify subgroups of workers absent from work due to low back pain who are more or less likely to return to work earlier as a result of a graded activity intervention, and to investigate whether this intervention is effective in reducing pain-related fears and if so, whether these reductions in pain-related fears mediate return to work. METHODS: A subgroup analysis was conducted on data from a previous randomized controlled trial of 134 Dutch airline workers, which found that a behaviorally-oriented graded activity intervention was more effective than usual care in stimulating return to work. The subgroup analyses added interaction terms to a Cox regression model that described the relationship between treatment allocation and return to work over 12 months of followup. Furthermore, we studied the effects of graded activity on pain-related fears and added variables indicating a reduction in pain-related fears to the model in order to investigate their influence on return to work. RESULTS: Statistically significant interactions were found for disability, fear-avoidance beliefs about physical activity, and fear-avoidance beliefs about work. No indication was found that the reduction in pain-related fears in the graded activity group mediated more favorable return-to-work results in this group. CONCLUSION: Workers who perceive their disability to be moderate and workers with moderate scores for fear-avoidance beliefs return to work more rapidly as a result of the graded activity intervention than workers with higher scores. The return to work of workers receiving the graded activity intervention is possibly independent from the reductions in pain-related fears caused by this intervention.

Substantial sick-leave costs savings due to a graded activity intervention for workers with non-specific sub-acute low back pain.

The objective of this study is to compare the costs and benefits of a graded activity (GA) intervention to usual care (UC) for sick-listed workers with non-specific low back pain (LBP). The study is a single-blind, randomized controlled trial with 3-year follow-up. A total of 134 (126 men and 8 women) predominantly blue-collar workers, sick-listed due to LBP were recruited and randomly assigned to either GA (N = 67; mean age 39 +/- 9 years) or to UC (N = 67; mean age 37 +/- 8 years). The main outcome measures were the costs of health care utilization during the first follow-up year and the costs of productivity loss during the second and the third follow-up year. At the end of the first follow-up year an average investment for the GA intervention of 475 euros per worker, only 83 euros more than health care utilization costs in UC group, yielded an average savings of at least 999 euros (95% CI: -1,073; 3,115) due to a reduction in productivity loss. The potential cumulative savings were an average of 1,661 euros (95% CI: -4,154; 6,913) per worker over a 3-year follow-up period. It may be concluded that the GA intervention for non-specific LBP is a cost-beneficial return-to-work intervention.

The effects of a graded activity intervention for low back pain in occupational health on sick leave, functional status and pain: 12-month results of a randomized controlled trial.

INTRODUCTION: Behaviorally oriented graded activity interventions have been suggested for sick-listed workers with low back pain on return to work, but have not been extensively evaluated. METHODS: One hundred and thirty-four workers were randomly assigned to either a graded activity intervention (n = 67) or usual care (n = 67) and followed-up for 12 months. RESULTS: The graded activity group returned back to work faster with a median of 54 days compared to 67 days in the usual care group. The graded activity intervention was more effective after approximately 50 days post-randomization (HRR = 1.9, CI = 1.2-3.1, p = 0.01). Differences between the groups in number of recurrent episodes, total number of days of sick leave due to low back pain, and total number of days of sick leave due to all diagnoses, were in favor of the graded activity group, although not statistically significant. No effects of the graded activity intervention were found for functional status or pain. CONCLUSION: Graded activity intervention is a valuable strategy to enhance short-term return to work outcomes.

Effectiveness of a return-to-work intervention for subacute low-back pain.

The effectiveness of return-to-work intervention for subacute low-back pain on work absenteeism, pain severity, and functional status was examined by means of a systematic review of randomized controlled trials. Publications in English that met the selection criteria were identified in a computer-aided search and assessed for methodological quality. A best-evidence synthesis was performed instead of statistical data pooling, because of the heterogeneity of the interventions and study populations. Five of nine studies comparing return-to-work intervention with usual care were identified as methodologically high-quality studies. Strong evidence was found for the effectiveness of return to work intervention on the return-to-work rate after 6 months and for the effectiveness of return-to-work intervention on the reduction of days of absence from work after > or = 12 months. It can be concluded that return-to-work interventions are equal or more effective regarding absence from work due to subacute low-back pain than usual care is.

Graded activity for low back pain in occupational health care: a randomized, controlled trial.

BACKGROUND: Low back pain is a common medical and social problem frequently associated with disability and absence from work. However, data on effective return to work after interventions for low back pain are scarce. OBJECTIVE: To determine the effectiveness of a behavior-oriented graded activity program compared with usual care. DESIGN: Randomized, controlled trial. SETTING: Occupational health services department of an airline company in the Netherlands. PATIENTS: 134 workers who were absent from work because of low back pain were randomly assigned to either graded activity (n = 67) or usual care (n = 67). INTERVENTION: Graded activity, a physical exercise program based on operant-conditioning behavioral principles, to stimulate a rapid return to work. MEASUREMENTS: Outcomes were the number of days of absence from work because of low back pain, functional status (Roland Disability Questionnaire), and severity of pain (11-point numerical scale). RESULTS: The median number of days of absence from work over 6 months of follow-up was 58 days in the graded activity group and 87 days in the usual care group. From randomization onward, graded activity was effective after 50 days of absence from work (hazard ratio, 1.9 [95% CI, 1.2 to 3.2]; P = 0.009). The graded activity group was more effective in improving functional status and pain than the usual care group. The effects, however, were small and not statistically significant. CONCLUSIONS: Graded activity was more effective than usual care in reducing the number of days of absence from work because of low back pain.

Return-to-work interventions for low back pain: a descriptive review of contents and concepts of working mechanisms.

Low back pain is a major medical and social problem associated with disability, work absenteeism and high costs. Given the impact of the problem, there is a need for effective treatment interventions in occupational healthcare that aim at the prevention of chronic disability and the realisation of return to work. These so-called return-to-work (RTW) interventions are becoming increasingly popular. As well as questions concerning the effectiveness of RTW interventions, there are also important questions on the actual content and underlying concepts of these multifactorial intervention strategies. The purpose of this review is to examine the literature on the content and underlying concepts of RTW interventions for low back pain. A systematic literature search identified 14 randomised controlled trials (RCTs) evaluating the effects of 19 RTW interventions. The content and concepts of these RTW interventions are described, compared and discussed in this review. Further, the contents of the RTW interventions are classified by the use of predefined components (physical exercises, education, behavioural treatments and ergonomic measures). The identified RTW interventions varied with respect to the disciplines involved, the target population and the number and duration of sessions. The classification showed that physical exercises were a component of most of the selected interventions, followed by education, behavioural treatments and ergonomic measures. The most prevalent combination of components was the combination of physical exercises, behavioural treatment and education. However, the types of physical exercises, behavioural treatment and education varied widely among the RTW interventions. The described concepts for the physical exercises were an increase of muscle strength, coordination, range of motion of the spine and cardiovascular fitness, and a decrease of muscle tension. Education as a part of RTW interventions is believed to increase the understanding of patients regarding their disorder and treatment. Behavioural treatments were mainly based on the gate control theory of pain (psychophysiological processes are involved in pain perception) and/or the operant conditioning hypothesis (pain behaviour is determined by its consequences). No concepts were described for ergonomic measures. Finally, the plausibility of the described concepts is discussed. Future RCTs on this topic should evaluate the underlying concepts of the RTW intervention in addition to its effectiveness.