February/March 2017 Research Plus

Research Plus - an online resource signposting the latest research in occupational health - published bi-monthly in Occupational Health [at Work] and funded by BOHRF.

Archived editions can be viewed here.

PTSD therapy

Cognitive processing therapy (CPT) is an evidence-based treatment for post-traumatic stress disorder (PTSD). CPT helps individuals process traumatic incidents and recognise and challenge dysfunctional cognitions and thoughts. This randomised controlled trial compared individual versus group CPT for active-duty US soldiers (91% male, mean age 33 years) seeking treatment for PTSD after deployment in Afghanistan or Iraq. Participants were randomised to group CPT (133 participants in 15 groups) or individual CPT (n = 135), twice a week for 12 weeks. Group sessions lasted 90 minutes, individual ones lasted an hour. PTSD was assessed using the Posttraumatic Symptom Scale–Interview Version (PSS-I) and the stressor-specific Posttraumatic Stress Disorder Checklist (PCL-S). Both groups had lower PTSD severity after the interventions, but those receiving individual CPT showed greater and more rapid improvement (p = 0.05). Effect sizes were rated as ‘very large’ for individual CPT and ‘medium’ for group CPT. The improvements remained significant at six months’ follow-up in both groups. Depression scores on the Beck Depression Inventory improved significantly in both groups.

Exercise for chronic fatigue syndrome

Exercise therapy can be an effective treatment for chronic fatigue syndrome (CFS), this Cochrane systematic review concludes. Eight studies were included, covering 1,518 participants diagnosed with CFS, with mean ages between 33 and 45 years. The exercise therapy regimes lasted between 12 and 26 weeks and were variously compared with passive controls (eg medical assessment and advice, waiting list, or relaxation/flexibility), cognitive behavioural therapy (CBT), cognitive therapy, supportive listening, ‘adaptive pacing therapy’ (a self-help intervention in which the individual monitors and stays within their own energy levels), pharmacological and combination treatments. Exercise therapy reduced fatigue compared with passive or no treatment (moderate quality evidence), and improved sleep (low quality evidence), physical functioning (low) and self-rated health (moderate). There was no statistically significant difference between exercise therapy and CBT, which both improved fatigue. Exercise was superior to pacing and supportive listening, but there was insufficient evidence regarding drug-based interventions. There was no evidence that exercise worsens outcomes.

Preventing burnout in mental health workers

Interventions to prevent burnout in mental health professionals were effective and sustainable, according to this meta-analysis of 27 studies; however, the effects were relatively small. Most studies used the Maslach Burnout Inventory, the most widely used instrument for assessing burnout. Organisational interventions included: job training and education; co-worker support groups; clinical supervision; job redesign and restructuring; and improved team communication. Person-directed interventions included stress management workshops, mindfulness, and rational emotive therapy. There were statistically significant positive effects on burnout – immediately after the intervention and (depending on the trial) at one to six months’ follow-up – but the effects were small. There were similar small, but positive effects on the emotional exhaustion and de-personalisation/cynicism subscales. Person-directed interventions were more effective than organisational interventions at reducing emotional exhaustion, but there were no differences in their reduction of overall burnout. Job training and education interventions were more effective than the other organisational interventions for lowering burnout and feelings of reduced personal accomplishment/efficacy, but there was no difference in respect of emotional exhaustion.

Medical students’ emotional wellbeing

A systematic review and meta-analysis of 167 cross-sectional and 16 longitudinal studies found a 27.2% prevalence of depression or depressive symptoms among medical students (95% confidence interval (CI) 24.7%–29.9%)1. The included papers covered 129,123 individuals in 47 countries. Analysis of 24 studies from 15 countries identified an 11.1% prevalence of suicidal ideation (CI 9.0%–13.7%). Seven papers reported information on 954 medical students who had screened positive for depression – just 15.7% of them said they had sought treatment for the condition (CI 10.2%–23.4%).

A second systematic review of 28 papers covering 8,224 participants, found limited, low-quality evidence, that various interventions to improve the emotional wellbeing of medical students can be effective2. Interventions included: mental health programmes; ‘mind-body’ or mindfulness-type training; wellbeing; mentoring; using simple pass/fail grading (rather than traditional A–F or honours/pass/fail grades) to avoid the stress associated with competing for higher grades; changing the curriculum structure (eg more clinical contact time); and multicomponent programmes. Three studies on pass/fail grading had the highest methodological quality and all demonstrated improvements in various measures of mental health and wellbeing.

Pre-placement carpal tunnel screening

Post-offer pre-placement (POPP) screening was ineffective at predicting future cases of carpal tunnel syndrome (CTS), this retrospective cohort study concluded. Researchers examined data provided by a US manufacturing company where production workers carried out hand-intensive work on assembly lines. When the manufacturing facility was opened all workers were given POPP screening, which involved a physical examination, functional assessment and nerve conduction velocity (NCV) study. A total of 1,777 employees were hired for production jobs in the 21 months after the opening. Screening and other relevant data was collected over the following five years. Physical exposures and frequencies relevant to CTS risk were estimated from job-demand scores. Confirmed and possible CTS cases were established from company medical records. Data were available for 1,648 production workers (77% male, mean age 35 years, mean BMI 28.7 kg/m2) – job exposure information was available for 1,335 workers, of whom 23.1% were classified as working in ‘high’ hand/wrist exposure jobs. At POPP screening, 17.3% of workers were found to have ‘abnormal’ POPP NCV tests (median nerve distal motor latencies of at least 4.5 ms in one or both hands) – though this was not taken into account in the hiring decision. Subsequently, 42 workers were identified with confirmed CTS (incidence rate = 8.02 cases per 1,000 person-years) while 10 had possible CTS. There was no association between abnormal POPP NCV results and subsequent CTS (relative risk (RR) 0.96; CI 0.43–2.18). Working in a high-exposure job was associated with an increased risk of CTS compared with working in a low exposure job (RR = 2.82; 95% CI 1.52 to 5.22).

Respiratory protective equipment training

There is very low-quality evidence that training and education does not improve the correct use and wearing of respiratory protective equipment (RPE) this Cochrane systematic review found. It included 14 randomised controlled trials, controlled before-and-after studies and interrupted time series. For example, one study found no difference in the rate of correct use of RPE between workers who had been given training and fit testing with those who had received no such support. And in another, interactive computerised training was no more effective than passive training, where participants simply read the information in a book or on a computer. Larger, high-quality studies are needed to assess different types of interventions to promote the correct use of RPE.

Interventions for common mental health problems

Interventions for workers with common mental health conditions did not improve their return-to-work (RTW) rate but did reduce their mean absence, from 165 to 151 days, this systematic review of 16 randomised controlled trials found. The studies included 3,345 workers with depression, anxiety disorder, obsessive-compulsive disorder, post-traumatic stress disorder or other common conditions. Interventions included cognitive behavioural therapy, problem solving, developing and restoring coping strategies, exposure therapy and psychoeducation – none involved medication. A meta-analysis found no significant change in RTW rate for the intervention group compared to controls (risk ratio = 1.05; CI 0.97–1.12) but significantly lower days lost to sickness absence (mean improvement per employee = 13.38 days; CI 2.69–24.07).

Night nurses’ increased mortality risk

Older nurses working night or evening shiftwork had an increased risk of all-cause mortality and death from cardiovascular disease (CVD) and diabetes, but not cancer, this nationwide Danish cohort study found. More than 23,000 nurses aged over 44 years were recruited in 1993 and 1999 to the Danish Nurse Cohort study. They provided information on current working patterns, lifestyle, health and use of hormone therapy and oral contraceptives. Mortality data was obtained from the national death register. The analysis included 18,015 nurses, with a mean follow-up of 17.6 years (316,644 person-years). A total of 1,616 nurses died during the follow-up period: 945 from cancer; 217 from CVD; 67 from psychiatric diseases; 33 from Alzheimer’s or dementia; and 20 from diabetes. After adjusting for lifestyle and other factors, working nights (hazard ratio (HR) = 1.26, CI 1.05–1.51) or evenings (HR = 1.29; CI 1.11–1.49) were associated with increased all-cause mortality when compared to working days. Nightshift work was associated with deaths from CVD (HR = 1.71; CI 1.09–2.69) and diabetes (HR = 12.0; CI 3.17–45.2) but not with all-cancer or psychiatric disease mortality. There were strong associations between evening (HR = 4.28; CI 1.62–11.3) and rotating (HR = 5.39; CI 2.35–12.3) shiftwork and mortality from Alzheimer’s disease and dementia, but no association between rotating shiftwork and all-cause or all-cancer mortality. No associations were found for breast cancer mortality – 90% of nurses in Denmark have worked night shifts at some point in their careers, and exposure to night or shiftwork when younger may be more important for this disease. This research looked at working patterns only at the time of recruitment to the study cohort (ie when aged over 44 years).

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