Tjabe Smid

A systematic review of controlled clinical trials on the prevention of back pain in industry.

OBJECTIVE: To assess the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry. METHODS: A computerised search for controlled clinical trials was conducted. A criteria list was used to assess the methodological quality of the studies. The available evidence for the effectiveness of the interventions was graded with a rating system for the level of evidence. Effect sizes of individual studies were combined if the studies were sufficiently similar. RESULTS: 11 studies were identified for the review. The methodological quality of all studies was low, with a maximum score of three out of seven for internal validity. There was no evidence for the effectiveness of lumbar supports due to contradictory outcomes of the studies. Five of the six studies on education reported no effect. Thus there is limited evidence that education does not help to prevent back pain. All three studies on exercise reported a positive result, indicating limited evidence for the effectiveness of exercise. The combined effect size for exercise was 0.53, which is a medium sized effect. CONCLUSIONS: Although widely used, there is little evaluative research on the preventive measures studied here. The review showed that there is limited evidence that exercise has some effect in the prevention of back pain and that education is not effective. No conclusive evidence was found for or against the effectiveness of lumbar supports. Research of higher methodological quality is needed before firm conclusions on the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry can be drawn.

Phone and e-mail counselling are effective for weight management in an overweight working population: a randomized controlled trial

BackgroundThe work setting provides an opportunity to introduce overweight (i.e., Body Mass Index ≥ 25 kg/m2) adults to a weight management programme, but new approaches are needed in this setting. The main purpose of this study was to investigate the effectiveness of lifestyle counselling by phone or e-mail on body weight, in an overweight working population. Secondary purposes were to establish effects on waist circumference and lifestyle behaviours, and to assess which communication method is the most effective.MethodsA randomized controlled trial with three treatments: intervention materials with phone counselling (phone group); a web-based intervention with e-mail counselling (internet group); and usual care, i.e. lifestyle brochures (control group). The interventions used lifestyle modification and lasted a maximum of six months. Subjects were 1386 employees, recruited from seven companies (67% male; mean age 43 (SD 8.6) y; mean BMI 29.6 (SD 3.5) kg/m2). Body weight was measured by research personnel and by questionnaire. Secondary outcomes fat, fruit and vegetable intake, physical activity and waist circumference were assessed by questionnaire. Measurements were done at baseline and after six months. Missing body weight was multiply imputed.ResultsBody weight reduced 1.5 kg (95% CI -2.2;-0.8, p < 0.001) in the phone group and 0.6 kg (95% CI -1.3; -0.01, p = 0.045) in the internet group, compared with controls. In completers analyses, weight and waist circumference in the phone group were reduced with 1.6 kg (95% CI -2.2;-1.0, p < 0.001) and 1.9 cm (95% CI -2.7;-1.0, p < 0.001) respectively, fat intake decreased with 1 fatpoint (1 to 4 grams)/day (95% CI -1.7;-0.2, p = 0.01) and physical activity increased with 866 METminutes/week (95% CI 203;1530, p = 0.01), compared with controls. The internet intervention resulted in a weight loss of 1.1 kg (95% CI -1.7;-0.5, p < 0.001) and a reduction in waist circumference of 1.2 cm (95% CI -2.1;-0.4, p = 0.01), in comparison with usual care. The phone group appeared to have more and larger changes than the internet group, but comparisons revealed no significant differences.ConclusionLifestyle counselling by phone and e-mail is effective for weight management in overweight employees and shows potential for use in the work setting.Trial registrationISCRTN04265725.

The effects of shift work on body weight change - a systematic review of longitudinal studies.

OBJECTIVE This systematic review aims to summarize the available evidence to elucidate the effects of shift work, which includes night work, on body weight change. METHODS A systematic search strategy using longitudinal studies was performed. Articles were included based on strict inclusion criteria; methodological quality was assessed by a standardized quality checklist. The results were summarized using a levels of evidence synthesis. RESULTS The search strategy resulted in eight articles that met the inclusion criteria. Five of them were considered to be high- and three of them low-quality studies. Seven studies presented crude results for an association between shift work exposure and change in body weight: five high- and two low-quality studies. There was strong evidence for a crude relationship between shift work and body weight increase. Five studies presented weight-related outcomes adjusted for potentially relevant confounders (age, gender, bodyweight at baseline, and physical activity). Two studies found a significant difference between groups in the same direction. Consequently, the evidence for a confounders-adjusted relationship between shift work exposure and body weight was considered to be insufficient. CONCLUSIONS Strong evidence for a crude association between shift work exposure and body weight increase was found. In order to further clarify the underlying mechanisms, more and better high quality studies about this subject are necessary.

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

AbstractLow 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. Asystematic 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.

Mechanisms of action of lumbar supports : A systematic review

Study Design. A systematic review and meta-analysis of studies on the putative mechanisms of action of lumbar supports in lifting activities. Objective. To summarize the evidence bearing on the putative mechanisms of action of lumbar supports. Summary of Background Data. A restriction of trunk motion and a reduction in required back muscle forces in lifting are two proposed mechanisms of action of lumbar supports. Available studies on these putative mechanisms of action of lumbar supports have reported contradictory results. Methods. A literature search for controlled studies on mechanisms of action of lumbar supports was conducted. The methodologic quality of the studies was assessed. The evidence for the two proposed mechanisms of action of lumbar supports was determined in meta-analyses. Results. Thirty-three studies were selected for the review. There was evidence that lumbar supports reduce trunk motion for flexion–extension and lateral bending, with overall effect sizes of 0.70 (95% confidence interval [CI] 0.39–1.01) and 1.13 (95% CI 0.17–2.08), respectively. The overall effect size for rotation was not statistically significant (0.69; 95% CI −0.40–4.31). There was no evidence that lumbar supports reduce the electromyogram activity of erector spinae muscles (effect size of 0.09; 95% CI −0.41–0.59) or increase the intra-abdominal pressure (effect size of 0.26; 95% CI −0.07–0.59). Conclusion. There is evidence that lumbar supports reduce trunk motion for flexion–extension and lateral bending. More research is needed on the separate outcome measures for trunk motion before definite conclusions can be drawn about the work conditions in which lumbar supports may be most effective. Studies of trunk motion at the workplace or during specified lifting tasks would be especially useful in this regard.

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.

Long term health complaints following the Amsterdam Air Disaster in police officers and fire‐fighters

Background: On 4 October 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, the Netherlands. Fire-fighters and police officers assisted with the rescue work. Objectives: To examine the long term health complaints in rescue workers exposed to a disaster. Methods: A historical cohort study was performed among police officers (n = 834) and fire-fighters (n = 334) who performed at least one disaster related task and reference groups of their non-exposed colleagues (n = 634 and n = 194, respectively). The main outcome measures included digestive, cardiovascular, musculoskeletal, nervous system, airway, skin, post-traumatic stress, fatigue, and general mental health complaints; haematological and biochemical laboratory values; and urinalysis outcomes. Results: Police officers and fire-fighters who were professionally exposed to a disaster reported more physical and mental health complaints, compared to the reference groups. No clinically relevant statistically significant differences in laboratory outcomes were found. Conclusions: This study is the first to examine long term health complaints in a large sample of rescue workers exposed to a disaster in comparison to reference groups of non-exposed colleagues. Findings show that even in the long term, and in the absence of laboratory abnormalities, rescue workers report more health complaints.

ALIFE@Work: a randomised controlled trial of a distance counselling lifestyle programme for weight control among an overweight working population (ISRCTN04265725)

BackgroundThe prevalence of overweight is increasing and its consequences will cause a major public health burden in the near future. Cost-effective interventions for weight control among the general population are therefore needed. The ALIFE@Work study is investigating a novel lifestyle intervention, aimed at the working population, with individual counselling through either phone or e-mail. This article describes the design of the study and the participant flow up to and including randomisation.Methods/DesignALIFE@Work is a controlled trial, with randomisation to three arms: a control group, a phone based intervention group and an internet based intervention group. The intervention takes six months and is based on a cognitive behavioural approach, addressing physical activity and diet. It consists of 10 lessons with feedback from a personal counsellor, either by phone or e-mail, between each lesson. Lessons contain educational content combined with behaviour change strategies. Assignments in each lesson teach the participant to apply these strategies to every day life.The study population consists of employees from seven Dutch companies. The most important inclusion criteria are having a body mass index (BMI) ≥ 25 kg/m2 and being an employed adult.Primary outcomes of the study are body weight and BMI, diet and physical activity. Other outcomes are: perceived health; empowerment; stage of change and self-efficacy concerning weight control, physical activity and eating habits; work performance/productivity; waist circumference, sum of skin folds, blood pressure, total blood cholesterol level and aerobic fitness. A cost-utility- and a cost-effectiveness analysis will be performed as well.Physiological outcomes are measured at baseline and after six and 24 months. Other outcomes are measured by questionnaire at baseline and after six, 12, 18 and 24 months.Statistical analyses for short term (six month) results are performed with multiple linear regression. Analyses for long term (two year) results are performed with multiple longitudinal regression. Analyses for cost-effectiveness and cost-utility are done at one and two years, using bootstrapping techniques.DiscussionALIFE@Work will make a substantial contribution to the development of cost-effective weight control- and lifestyle interventions that are applicable to and attractive for the large population at risk.

Comparative effectiveness of lifestyle interventions on cardiovascular risk factors among a Dutch overweight working population: A randomized controlled trial

BackgroundOverweight (Body Mass Index [BMI] ≥ 25 kg/m2) and obesity (BMI≥ 30 kg/m2) are associated with increased cardiovascular risk, posing a considerable burden to public health. The main aim of this study was to investigate lifestyle intervention effects on cardiovascular risk factors in healthy overweight employees.MethodsParticipants were 276 healthy overweight employees (69.2% male; mean age 44.0 years [SD 9.2]; mean BMI 29.7 kg/m2 [SD 3.1]). They were randomized to one of two intervention groups receiving a six month lifestyle intervention with behavior counseling by phone (phone group) or e-mail (Internet group), or to a control group receiving usual care. Body weight, height, waist circumference, sum of skinfolds, blood pressure, total cholesterol level and predicted aerobic fitness were measured at baseline, at 6 and at 24 months. Regression analyses included the 141 participants with complete data.ResultsAt 6 months a significant favorable effect on total cholesterol level (-0.2 mmol/l, 95%CI -0.5 to -0.0) was observed in the phone group and a trend for improved aerobic fitness (1.9 ml/kg/min, 95%CI -0.2 to 3.9) in the Internet group. At two years, favorable trends for body weight (-2.1 kg, 95%CI -4.4 to 0.2) and aerobic fitness (2.3 ml/kg/min, 95%CI -0.2 to 4.8) were observed in the Internet group.ConclusionsThe intervention effects were independent of the used communication mode. However short-term results were in favor of the phone group and long-term results in favor of the internet group. Thus, we found limited evidence for our lifestyle intervention to be effective in reducing cardiovascular risk in a group of apparently healthy overweight workers.Trial registrationISRCTN04265725

Associations of cortisol with posttraumatic stress symptoms and negative life events: a study of police officers and firefighters

Given the inconsistent associations of cortisol with posttraumatic stress disorder (PTSD), analysis of basal functioning of the hypothalamic-pituitary-adrenal (HPA) axis in subjects frequently exposed to trauma and critical incidents with a range of PTSD symptomatology, may be valuable. In an epidemiological sample of 1880 police officers and firefighters, associations of salivary cortisol with PTSD, negative life events (NLE) and exposure to a major air disaster more than 8 years earlier, was explored. Probable PTSD was unrelated to cortisol level while past (>8 years earlier) and more recently experienced NLE were associated with lower cortisol levels even after adjustment for confounders. Disaster exposure interacted significantly with PTSD symptoms on cortisol level. In the disaster-exposed subgroup, PTSD symptomclusters of intrusion and hyperarousal (in particular sleep disturbances), were associated with lower and higher cortisol levels, respectively. A final model using backward elimination strategy, retained time of saliva sampling, smoking, gender, and NLE>8 years earlier in the total sample, and additionally symptomclusters of intrusion and hyperarousal in the disaster-exposed subgroup. The final model explained 10% of the variance in cortisol. The findings are discussed in relation to literature on posttraumatic stress and basal functioning of the HPA-axis.