A multisite randomized controlled trial on time to self-support among sickness absence beneficiaries. The Danish national return-to-work programme.

BACKGROUND: In 2010, the Danish Government launched the Danish national return-to-work (RTW) programme to reduce sickness absence and promote labour market attainment. Multidisciplinary teams delivered the RTW programme, which comprised a coordinated, tailored and multidisciplinary effort (CTM) for sickness absence beneficiaries at high risk for exclusion from the labour market. The aim of this article was to evaluate the effectiveness of the RTW programme on self-support. METHODS: Beneficiaries from three municipalities (denoted M1, M2 and M3) participated in a randomized controlled trial. We randomly assigned beneficiaries to CTM (M1: n = 598; M2: n = 459; M3: n = 331) or to ordinary sickness absence management (OSM) (M1: n = 393; M2: n = 324; M3: n = 95). We used the Cox proportional hazards model to estimate hazard ratios (HR) comparing rates of becoming self-supporting between beneficiaries receiving CTM and OSM. RESULTS: In M2, beneficiaries from employment receiving CTM became self-supporting faster compared with beneficiaries receiving OSM (HR = 1.32, 95% CI: 1.08-1.61). In M3, beneficiaries receiving CTM became self-supporting slower than beneficiaries receiving OSM (HR = 0.72, 95% CI: 0.54-0.95). In M1, we found no difference between the two groups (HR = 0.99, 95% CI: 0.84-1.17). CONCLUSION: The effect of the CTM programme on return to self-support differed substantially across the three participating municipalities. Thus, generalizing the study results to other Danish municipalities is not warranted. TRIAL REGISTRATION: ISRCTN43004323.

Month-to-month variation in sleep among healthy, Scandinavian daytime workers.

BACKGROUND: The overall purpose of the present study was to attain more insight in month-to-month variation of sleep duration and quality in order to improve design and interpretation of, e.g. epidemiological studies using sleep as outcome. METHODS: The study design entailed monthly self-reports from 38 (26 women/12 men) daytime workers, who completed the Karolinska Sleep Diary (KSD) once a month during one year. A subgroup (n = 16) also wore actigraphs on one day every month during a year. Self-reports of bedtime, time of awakening, sleep duration, individual sleep characteristics, disturbed sleep index (DSI, 4 items) and awakening index (AWI, 3 items) were analyzed together with actigraphy-derived measures. Hours of daylight were used to test for circa-annual variation in statistical models adjusted for intake of hypnotics and alcohol, gender, age and within-person variability. RESULTS: Hours of daylight were found to be associated to self-reported bedtime (p = 0.032) and DSI (p = 0.030), thereby indicating a circa-annual variation. Bedtime was delayed by 1.8 min (95% CI: 0.6-2.9 min) per 1 hour increase in length of daylight. Sleep was slightly more disturbed during the winter. CONCLUSION: Only circa-annual variation in self-reports of bedtime and DSI were observed in a healthy daytime working population, and the effects were small. Therefore potential bias due to circa-annuality in the studied parameters appears to be of limited concern in adult daytime working populations.

Distribution of subjective health complaints, and their association with register based sickness absence in the Danish working population.

AIMS: To describe the distribution of subjective health complaints (SHCs) in a Danish working population and the associations between SHC and register based sickness absence. METHODS: The study entailed 2876 men and 3574 women aged 18-59 years that constituted the 2005 panel in the Danish Work Environment Cohort Study (DWECS). All had completed a subjective health complaints inventory and the Nordic Musculoskeletal Questionnaire (NMQ). Seven SHC/NMQ indices were constructed and merged with subsequently collected data on prolonged sickness absence periods (each period > 14 days) that was registered in the national Danish register on social transfer payments: the DREAM register. Ordinal logistic regression was used to model the cumulative odds for sickness absence as a function of strata. RESULTS: The majority of participants reported at least one SHC during a 30-day period (circa 89% of the men and 95% of the women). The reports of severe SHC, defined as recurring SHC within the 30-day period, were less common. About 55% of the men and 68% of the women reported at least one severe SHC during a 30-day period. The odds ratios of sickness absence increased with the number of SHC a participant acknowledged. The odds ratios were slightly reduced after adjusting for age, disease history and social class. CONCLUSIONS: The majority of the working population in Denmark report at least one SHC during a 30-day period. Roughly half of the population report having at least one recurrent (often to very often) SHC during the last 30-days (severe SHC). Reporting the presence of several SHCs increases the likelihood of having more prospectively registered periods of sickness absence above two weeks.

Can the job content questionnaire be used to assess structural and organizational properties of the work environment?

OBJECTIVE: The theory behind the Job Content Questionnaire (JCQ) presumes that the "objective" social environment is measurable via self-report inventories such as the JCQ. Hence, it is expected that workers in identical work will respond highly similar. However, since no studies have evaluated this basic assumption, we decided to investigate whether workers performing highly similar work also responded similarly to the JCQ. METHODS: JCQ data from a rubber-manufacturing (RM: n = 95) and a mechanical assembly company (MA: n = 119) were examined. On each worksite, men and women performed identical machine-paced job tasks. A population sample (n = 8,542) served as a reference group. RESULTS: In both the RM and MA groups, the job support questions were rated most similar. Yet, there was a substantial variation as regards choosing to agree or disagree with single JCQ items. The variation was also reflected in the scale scores. In the RM and MA groups, the variance of job demand and job control scores was 64-87% of that of the population sample. For job support scores, the corresponding variation was 42-87%. CONCLUSION: Conducting highly similar work does not lead to highly similar reports in the JCQ. In view of the large response variation, it seems that the attempt to avoid personal influence by minimizing the self-reflexive component in the questions asked, and using response alternative that indicates degree of agreement, does not seem to work as intended.

Heart rate variability changes in physicians working on night call.

PURPOSE: Adverse effects by night-call duty have become an important occupational health issue. The aim of this study was to investigate whether the heart rate variability (HRV) differed during recovery from day work and night-call duty between distinct physician specialities. METHODS: We studied the impact of a 16-h night-call duty on autonomic balance, measured by HRV, among two physician groups differing with respect to having to deal with life-threatening conditions while on call. Nineteen anaesthesiologists (ANEST) and 16 paediatricians and ear, nose and throat surgeons (PENT) were monitored by ambulatory digital Holter electrocardiogram (ECG). Heart rate variability was analysed between 21:00 and 22:00 after an ordinary workday, on night call and in the evening post-call. Absolute and normalized high-frequency power (HF, HFnu) were the main outcome variables, expressing parasympathetic influence on the heart. RESULTS: ANEST had lower HF power than PENT while on night call and post-daytime work (p < 0.05), but not at post-night call. In the whole group of physicians, HFnu was lower on call and post-daytime work compared with post-night-call duty (p < 0.05). CONCLUSIONS: The physiological recovery after night duty seemed sufficient in terms of HRV patterns for HFnu, reflecting autonomic balance and did not differ between specialities. However, the less dynamic HRV after daytime work and during night-call duty in the ANEST group may indicate a higher physiological stress level. These results may contribute to the improvement of night-call schedules within the health care sector.

Sleep and recovery in physicians on night call: a longitudinal field study.

BACKGROUND: It is well known that physicians' night-call duty may cause impaired performance and adverse effects on subjective health, but there is limited knowledge about effects on sleep duration and recovery time. In recent years occupational stress and impaired well-being among anaesthesiologists have been frequently reported for in the scientific literature. Given their main focus on handling patients with life-threatening conditions, when on call, one might expect sleep and recovery to be negatively affected by work, especially in this specialist group. The aim of the present study was to examine whether a 16-hour night-call schedule allowed for sufficient recovery in anaesthesiologists compared with other physician specialists handling less life-threatening conditions, when on call. METHODS: Sleep, monitored by actigraphy and Karolinska Sleep Diary/Sleepiness Scale on one night after daytime work, one night call, the following first and second nights post-call, and a Saturday night, was compared between 15 anaesthesiologists and 17 paediatricians and ear, nose, and throat surgeons. RESULTS: Recovery patterns over the days after night call did not differ between groups, but between days. Mean night sleep for all physicians was 3 hours when on call, 7 h both nights post-call and Saturday, and 6 h after daytime work (p < 0.001). Scores for mental fatigue and feeling well rested were poorer post-call, but returned to Sunday morning levels after two nights' sleep. CONCLUSIONS: Despite considerable sleep loss during work on night call, and unexpectedly short sleep after ordinary day work, the physicians' self-reports indicate full recovery after two nights' sleep. We conclude that these 16-hour night duties were compatible with a short-term recovery in both physician groups, but the limited sleep duration in general still implies a long-term health concern. These results may contribute to the establishment of safe working hours for night-call duty in physicians and other health-care workers.

Seasonal variation in self-reported arousal and subjective health complaints.

Many aspects of human physiology and behavior are seasonally related. Although there are many studies using self-ratings of, for example, subjective health and stress, few involve adjusting effects for seasonal differences. To estimate the need of adjusting for season in field studies, 24 healthy men and women were studied in a design that required them to fill in questionnaires on one workday every month, for 12 consecutive months. The results showed that ratings of stress were higher during winter and early spring, but only in the early afternoon and not in the morning or the evening. While some subjective health complaints were rated higher during winter, the ratings of energy and self-rated health did not vary throughout seasons. This concludes that seasonal variations may be a source of bias in questionnaire studies. Yet, further studies are needed to more definitely sort out which phenomena and self-rating measures that co-vary with season.

Physiological and psychological reactions to work in men and women with identical job tasks.

Differences in physiological functioning in the hypothalamus-pituitary-adrenal cortex axis and the autonomic nervous system have been suggested to contribute to many of the health differences that may be observed between men and women as well as being relevant for the development of musculoskeletal pain. To clarify whether men and women with identical work tasks reacted differently when doing work known to induce musculoskeletal pain, ratings and physiological measurements were obtained at work start (15:30) and at the end of the workshift (22:30) on 17 men and 20 women. Men showed a larger decrease in perceived energy levels during the workshift but there were no differences between men and women as regards cortisol, adrenaline, noradrenaline, heart-rate activation, perceived stress, pain and physical exertion. In conclusion, differential physiological activation during the workshift seem to be an unlikely mechanism for explaining gender differences in pain associated with exposure to awkward and repetitive movements.

Effects on sleep-related problems and self-reported health after a change of shift schedule.

This study prospectively examined the effects of a change of shift schedule from a fast forward-rotating schedule to a slowly backward-rotating one. The initial schedule had a forward rotation from mornings to afternoons to nights over 6 consecutive days, with 2 days on each shift followed by 4 days off before the next iteration of the cycle, whereas the new schedule had a slower backward rotation from mornings to nights to afternoons, with 3 days on a given shift followed by 3 days off before the next shift. Shift workers (n = 118) were compared with a reference group of daytime workers (n = 67) from the same manufacturing plant by means of questionnaires covering subjective health, sleep and fatigue, recovery ability, satisfaction with work hours, work-family interface, and job demands, control, and support. Data were collected 6 months before implementing the new schedule and at a follow-up 15 months later. As predicted, on most dimensions measured the shift workers displayed clear improvements from initially poorer scores than daytime workers, and the daytime workers displayed no improvements.

High cost-benefit of early team-based biomedical and cognitive-behaviour intervention for long-term pain-related sickness absence.

OBJECTIVE: To report the results from a prospective, cognitive-behavioural team-based, individually geared, low-intensity, rehabilitation programme, randomly assigned to care-seekers in primary care physiotherapy with new pain-related sick leave, and to examine a possible reduction in social security expenditure. METHODS: A total of 194 care-seekers were included in a stepwise procedure from November 2000 to February 2002. Control group n = 381. RESULTS: The median number of days of sick leave in the intervention group was 22 during the first 6-month period. After 180 days 5.2% were still on sick leave and after 360 days 4.2%. The comparable figures in the control group were 30 days, 9.7% and 7.2%, respectively. Reductions in social security expenditure were statistically significant from the fourth month. As predicted, clinically relevant subgroups contributed differently to this reduction, both early and later on. The overall problem for one-third of the subgroups was insufficient co-ordination from the employer and the social security executive. CONCLUSION: It was possible to reduce the social security expenditure in this setting. The intervention costs were balanced out during the first year. A large potential for further cost reductions was identified in increased implementation of workplace-based return-to-work interventions.

Bullying at work, health outcomes, and physiological stress response.

The relationships among bullying or witnessing bullying at work, self-reported health symptoms, and physiological stress reactivity were analysed in a sample of 437 employees (294 women and 143 men). Physiological stress reactivity was measured as cortisol in the saliva. Of the respondents, 5% of the women (n=15) and 5% of the men (n=7) reported bullying, whereas 9% of the women (n=25) and 11% of the men (n=15) had witnessed bullying at work. The results indicated that the bullied respondents had lower social support from coworkers and supervisors, and they reported more symptoms of somatisation, depression, anxiety, and negative affectivity (NA) than did the nonbullied respondents. Witnesses reported more symptoms of anxiety and lower support from supervisor than did the nonbullied employees. Concentrations of cortisol in the saliva were lower at awakening in bullied respondents compared with nonbullied respondents. Previous studies have reported lower diurnal concentration of cortisol for people with posttraumatic stress disorder (PTSD) and chronic fatigue. To our knowledge, this is the first full study on the associations among being subjected to bullying, health outcomes, and physiological stress response.

Building-site camps and extended work hours: A two-week monitoring of self-reported physical exertion, fatigue, and daytime sleepiness.

Large-scale construction work often requires people to work longer daily hours and more than the ordinary five days in a row. In order to minimize transportation times and optimize the use of personnel, workers are sometimes asked to live in temporary building-site camps in the proximity of the work site. However, little is known about the biological and psychological effects of this experience. The objective of the present study was to investigate whether exposure to long work hours and extended workweeks while living in building-site camps in between work shifts was associated with a build-up of increased complaints of poor sleep, daytime sleepiness, physical exertion, and fatigue across a two-week work cycle. Two groups of construction workers were examined. The camp group of 13 participants (mean age: 42+/-11 S.D. yrs) lived in building-site camps and worked extended hours (between 07:00 and 18:00 h) and extended workweeks (six days in a row, one day off, five days in a row, nine days off). The home group of 16 participants (mean age 40+/-9 yrs) worked ordinary hours between 07:00 and 15:00 h and returned home after each workday. Self-ratings of daytime sleepiness (Karolinska Sleepiness Scale), physical exertion (Borg CR-10), and mood were obtained six or seven times daily during two workweeks. Fatigue ratings were obtained once daily in the evening, and ratings of sleep disturbances were obtained once daily in the morning with the Karolinska Sleep Diary. Data were evaluated in a repeated measures design. The results showed that both groups reported a similar level of daytime sleepiness, physical exertion, and mood across workdays and time points within a workday (all three-way interactions had p>0.898). Although the home group reported earlier wake-up times, the pattern of sleep disturbance ratings across the workdays did not differ between the groups. Both groups reported few sleep disturbances and good mood. However, the camp group reported higher physical exertion already at the start of work and showed a more gentle increase in ratings during the work shift and a smaller decline between the end of work and bedtime. The camp group also reported higher fatigue scores than the home group. However, none of the groups showed signs of increasing ratings in the progress of the two workweeks. For both groups, the ratings of daytime sleepiness formed a U-shaped pattern, with the highest scores at awakening and at bedtime. Yet, the camp group reported higher daytime sleepiness than the home group at lunch break and at the second break in the afternoon. In conclusion, there were no signs of fatigue build-up or accumulation of daytime sleepiness, physical exertion, or sleep disturbances in either group. Despite the fact that the camp group showed some signs of having trouble in recuperating in between work shifts, as indicated by the higher physical exertion ratings at the start of work, higher fatigue scores, and higher daytime sleepiness, the results constitute no real foundation for altering the camp group's current work schedule and living arrangements.

Impact of an 84-hour workweek on biomarkers for stress, metabolic processes and diurnal rhythm.

OBJECTIVES: This study examined the degree to which long workhours in combination with an extended workweek (12 hours/7 days) with permanent day shifts (0700-1900), as requested by the workers, influenced biomarkers for stress, metabolic processes, and diurnal rhythm. METHODS: Construction workers (N=50) working 84 hours a week, with alternate weeks off, were compared with construction workers (N=25) having a traditional 40-hour work schedule. The participants were all male and between the ages of 21 to 65 years. Blood samples were obtained in the morning immediately prior to the start of work on workday 1, 5, and 7 to assess cholesterol, cortisol, dehydroepiandrosterone, melatonin, prolactin, testosterone, and uric acid. Psychosocial circumstances were assessed with a questionnaire. RESULTS: The 84-hour group had higher melatonin concentrations and reported higher job-control scores than the 40-hour group. For both groups, the melatonin, cortisol, and cholesterol concentrations were lower on workday 5 than on workday 1. In the 84-hour group, most of the biomarkers were significantly lower in concentrations on workday 7 than on workday 1. Only testosterone showed a significant decrease between workdays 5 and 7. The concentrations of dehydroepiandrosterone and uric acid remained stable across all of the days, as did the melatonin concentrations between workdays 5 and 7. CONCLUSIONS: Working of one's own free will on an 84-hour regimen is not, in the short-term, necessarily more harmful for health than working on a 40-hour regimen with a similar type of heavy worktasks. However, working on an 84-hour schedule beyond the ordinary 40-hour week results in signs of a functional shift in hormonal regulation.

Salivary cortisol and self-reported stress among persons with environmental annoyance.

OBJECTIVES: Increased vulnerability to stress has been suggested as a possible mechanism behind medically unexplained conditions such as sensitivity to electricity and common smells. This study examined whether subjective environmental annoyance among the general population is associated with increased physiological reactivity or subjective stress scores. METHODS: Four groups were studied (N=141): an electrically annoyed (N=17), a smell-annoyed (N=29), and a generally annoyed group (N=39) and a reference group matched for age, gender, and socioeconomic status (N=56). Over 5 days, the participants collected saliva for cortisol determination at awakening, 30 minutes after awakening, 8 hours after awakening, and at 9 o'clock in the evening. On the evening preceding the fifth day, the participants ingested a 0.5-mg dexamethasone tablet so that possible differential suppression of the hypothalamic-pituitary-adrenal (HPA) axis could be assessed. Each day, the participants also rated their subjective stress and health complaints. RESULTS: No significant differences were found between the groups regarding cortisol secretion over 5 days. The dexamethasone suppression test showed inhibited cortisol secretion in all four groups. No associations were found between the cortisol concentrations and the self-reported stress scores or subjective health complaints. CONCLUSIONS: Although the environmentally annoyed groups showed no signs of increased HPA-axis activation, being annoyed by both electrical devices and smells seems to be related to increased psychological activation in terms of self-reported stress. Because the participants were otherwise healthy and recruited from the general population, the results imply that subtle psychological stress processes may be important in the early development of environmental annoyance.

Incidence of shoulder and neck pain in a working population: effect modification between mechanical and psychosocial exposures at work? Results from a one year follow up of the Malmö shoulder and neck study cohort.

STUDY OBJECTIVE: To assess the impact of mechanical exposure and work related psychosocial factors on shoulder and neck pain. DESIGN: A prospective cohort study. PARTICIPANTS: 4919 randomly chosen, vocationally active men and women ages 45-65 residing in a Swedish city. Neck and shoulder pain were determined by the standardised Nordic questionnaire. Mechanical exposure was assessed by an index based on 11 items designed and evaluated for shoulder and neck disorders. Work related psychosocial factors were measured by the Karasek and Theorell demand-control instrument. MAIN RESULTS: High mechanical exposure was associated with heightened risk for shoulder and neck pain among men and women during follow up. Age adjusted odds ratios (OR) were 2.17 (95% confidence intervals (CI): 1.65, 2.85) and 1.59 (95% CI: 1.22, 2.06), respectively. In women, job strain (high psychological job demands and low job decision latitude) correlated with heightened risk (OR = 1.73, 95% CI: 1.29, 2.31). These risk estimates remained statistically significant when controlled for high mechanical exposure regarding job strain (and vice versa), and for sociodemographic factors. Testing for effect modification between high mechanical exposure and job strain showed them acting synergistically only in women. CONCLUSION: Job related mechanical exposure in both sexes, and psychosocial factors in women, seem independently of each other to play a part for development of shoulder and neck pain in vocationally active people. The effect of psychosocial factors was more prominent in women, which could be the result of biological factors as well as gender issues. These results suggest that interventions aiming at reducing the occurrence of shoulder and neck pain should include both mechanical and psychosocial factors.

Education for men with solvent-induced chronic toxic encephalopathy and their spouses.

In this study an education, and a series of group sessions for patients with solvent-induced chronic toxic encephalopathy (TE) and their spouses are evaluated. Thirty-eight patients and 21 family members participated in a 1-day education scheduled with short lectures on the clinical examination of chronic toxic encephalopathy and the prognosis. A specialist in occupational medicine, a psychologist and a social worker gave the lectures. Small discussion groups were also arranged. Of the participants from the educational days, 16 TE patients and 14 wives attended a 10-week counselling and coping improvement program with separate group sessions once a week, for patients and spouses. Questionnaires were used to assess symptoms, social network, mastery and family climate, and the participants' satisfaction with the education and the group sessions. The majority of the participants experienced the 1-day information as useful and relevant. The 10-week group sessions were rated as meaningful and the design, number, duration and frequency of the sessions equally good. Self-reported symptoms, social network and mastery were measured before the group sessions, and 3 and 9 months after breaking up the group sessions. In most measurements, there were no statistically significant differences between the three points in time. However, the wives improved more than did the patients but the effect was not lasting the whole follow-up period. Considering the patients' dependence on their wives, it might be most important that the wives experienced some relief from their own symptoms.

Impact of trait anxiety and social conformity on responses to experimental chemical challenge.

The study examined the impact of trait anxiety and social conformity on ratings and test performance during controlled solvent challenge. Healthy women (n=20) and men (n=18) were exposed to increasing levels of toluene and n-butyl acetate in a challenge chamber, during which they repeatedly rated smell intensity and annoyance, and completed neurobehavioral tests. Trait anxiety was measured by the Psychasthenia scale of the Karolinska Scales of Personality (KSP), and social conformity by the KSP Social Desirability scale. Among women, high Psychasthenia was related to higher increase in ratings of mucous membrane irritation, fatigue, and annoyance from other aspects of the environment than smell during challenges, and was related to a higher increase in reaction time variability. Among men, Psychasthenia was unrelated to annoyance ratings, and was inversely related to the increase in smell intensity ratings. Social desirability was unrelated to any rating or performance dimension for either gender.

Implementation of the Danish return-to-work program: process evaluation of a trial in 21 Danish municipalities.

OBJECTIVES: The aim of this study was to evaluate the implementation of the Danish national return-to-work (RTW) program in 21 Danish municipalities. METHODS: We conducted a structured process evaluation on (i) reach and recruitment, (ii) fidelity, (iii) dose-delivered, (iv) dose-received, and (v) context by formulating 29 implementation criteria and analyzing qualitative and quantitative data from administrative records, interviews, field notes, and questionnaires. RESULTS: All municipalities integrated the basic features of the RTW program into the existing framework of the sickness benefit management system to an acceptable degree, ie, establishment of RTW teams, participation of RTW team members in the training courses, and following the general procedures of the program. However, the level of implementation varied considerably between the municipalities, particularly with respect to fidelity (defined as implementation consistent with the principles of the interdisciplinary RTW process). Five municipalities had high and eight had low fidelity scores. Similar large differences were found with regard to dose-delivered, particularly in the quality of cooperation with beneficiaries, employers, and general practitioners. Only 50% of the first consultations with the RTW coordinator were conducted in time. Among participants who were employed when their sickness absence period started, only 9% had at least one meeting with their workplace. CONCLUSION: It was feasible to implement the basic features of the Danish RTW program, however, large variations existed between municipalities. Establishment of well-functioning interdisciplinary RTW teams might require more time and resources, while ensuring early assessment and more frequent cooperation with employers might need more general adjustments in the Danish sickness benefit system.

The experience of pain from the shoulder-neck area related to the total body pain, self-experienced health and mental distress. The Malmö Shoulder-Neck Study group.

The present paper presents the relationship between the total body-pain (TBP) score, defined as the total number of areas shaded on a pain drawing, and the pain from one area, the Shoulder-Neck (SN), among subjects in or out of full-time gainful work respectively. Furthermore, relationships between pain-score, self-experienced health (SEH) and level of mental distress, measured with the General Health Questionnaire (GHQ) were investigated. The analyses is based on a general population sample of 8,116 men and women, 45-60 years of age, completing a questionnaire in the Malmö Shoulder Neck Study. The TBP-score was higher with increasing pain from the SN area, being out of full-time work and among women. Independently of working status, the SEH decreased with increasing pain in the SN area, which was enhanced, by increasing TBP-score. The proportion of women out of full-time gainful work was twice as high as for men. Women showed the same SEH levels with regard to their pain status, independently of their working status while men working full-time scored higher than women did. Oppositely, men out of full-time work had the lowest SEH in relation to their pain status. The GHQ scores of mental distress varied essentially in the same way as the SEH did. The results emphasize the need for an assessment of the number of pain locations and which one that first gave symptoms when studying possible causal relationships between low force musculoskeletal load and development of localized pain. If such data are not collected in epidemiological studies on causes for musculoskeletal pain it will at best lead to unnoticed effect modifications. At worst a potential confounding situation may occur. The relationship between the self-experienced health, mental distress and chronic pain identifies chronic pain as a major public-health problem and suggests a multidisciplinary approach in the treatment and rehabilitation already before work capacity is lost.

Determination of cortisol in human saliva using liquid chromatography-electrospray tandem mass spectrometry.

The aim of this work was to develop a method for determination of cortisol in saliva by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Saliva was sampled on Salivette tubes. These were centrifuged, deuterium-labeled cortisol was added as internal standard and the proteins precipitated by acetonitrile. The supernatant was evaporated, dissolved in methanol acidified with acetic acid and analyzed by LC-MS-MS. The with-in run precision, tested by pooling saliva samples from volunteers and then analyzing these in a single run, was found to be 7% at 0.7 microgram l(-1). The between-run precision was tested by analysis of the same samples at different days and found to be 11% at 2.5 microgram l(-1). The limit of quantification was 0.5 microgram l(-1). The method was applied for analysis of saliva samples from three volunteers during their last week before vacation and the first and second week on vacation. In addition, the method was compared to analysis by an immunological method. The values from the immunological method were 2.7 times higher than the LC-MS-MS results.