Factors related to seat belt use : A Turkish case

Seat belts are effective safety devices used to protect car occupants from severe injuries and fatalities during road vehicle accidents. Despite the proven effectiveness of seat belts, seat belt use rates are quite low, especially in developing countries, such as Turkey. The general aim of the present study was to investigate a large variety of factors related to seat belt use among Turkish car occupants using different perspectives and methods and therefore, to contribute to the design of effective seat belt use interventions for increasing seat belt use rates in Turkey. Five sub-studies were conducted within the present study. In the first sub-study, environmental (e.g., road type) and psycho-social factors (e.g., belt use by other car occupants) related to the seat belt use of front-seat occupants were investigated using observation techniques. Being male, of a young age, and traveling on city roads were the main factors negatively related to seat belt use. Furthermore, seat belt use by the drivers and front-seat passengers was highly correlated and a significant predictors of each other. In the second sub-study, the motivations of the car occupants for seat belt use and non-use were investigated using interview techniques. Situational conditions, such as traveling on city roads and for short distances, and not believing in the effectiveness and relevance of seat belt use for safety, were the most frequently reported reasons for not using a seat belt. Safety, habit and avoiding punishment were among the most frequently reported reasons for using a seat belt. In the third sub-study, the Theory of Planned Behavior (TPB) and the Health Belief Model (HBM) were applied to seat belt use using Structural Equation Modeling techniques. The TPB model showed a good fit to the data, whereas the HBM showed a poor fit to the data. Within the TPB model, attitude and subjective norm were significant predictors of intentions to use a seat belt on both urban and rural roads. In the fourth sub-study, seat belt use frequency and motivations for seat belt use among taxi drivers were investigated and compared between free-time and work-time driving using a survey. The results showed that taxi drivers used seat belts more when driving a private car in their free-times compared to when driving a taxi during their work-times. The lack of a legal obligation to use a seat belt in city traffic and fear of being attacked or robbed by the passengers were found as two specific reasons for not using a seat belt when driving a taxi. Lastly, in the fifth sub-study, the relationship of seat belt use to driver and health behaviors was investigated using a survey. Although seat belt use was related both to health and driver behaviors, factor analysis results showed that it grouped with driver behaviors. Based on the results of the sub-studies, a tentative empirical model showing different predictors of seat belt use was proposed. According to the model, safety and normative motivations and perceived physical barriers related to seat belt use are the three important predictors of seat belt use. Keywords: Seat belt use; environmental factors; psycho-social factors; safety and normative motivations; the Theory of Planned Behavior; the Health Belief Model; health behaviors; driver behaviors; front-seat occupants; taxi drivers; Turkey.

Fatigued driving : prevalence, risk factors and groups, and the law

Fatigue and sleepiness are major causes of road traffic accidents. However, precise data is often lacking because a validated and reliable device for detecting the level of sleepiness (cf. the breathalyzer for alcohol levels) does not exist, nor does criteria for the unambiguous detection of fatigue/sleepiness as a contributing factor in accident causation. Therefore, identification of risk factors and groups might not always be easy. Furthermore, it is extremely difficult to incorporate fatigue in operationalized terms into either traffic or criminal law. The main aims of this thesis were to estimate the prevalence of fatigue problems while driving among the Finnish driving population, to explore how VALT multidisciplinary investigation teams, Finnish police, and courts recognize (and prosecute) fatigue in traffic, to identify risk factors and groups, and finally to explore the application of the Finnish Road Traffic Act (RTA), which explicitly forbids driving while tired in Article 63. Several different sources of data were used: a computerized database and the original folders of multidisciplinary teams investigating fatal accidents (VALT), the driver records database (AKE), prosecutor and court decisions, a survey of young male military conscripts, and a survey of a representative sample of the Finnish active driving population. The results show that 8-15% of fatal accidents during 1991-2001 were fatigue related, that every fifth Finnish driver has fallen asleep while driving at some point during his/her driving career, and that the Finnish police and courts punish on average one driver per day on the basis of fatigued driving (based on the data from the years 2004-2005). The main finding regarding risk factors and risk groups is that during the summer months, especially in the afternoon, the risk of falling asleep while driving is increased. Furthermore, the results indicate that those with a higher risk of falling asleep while driving are men in general, but especially young male drivers including military conscripts and the elderly during the afternoon hours and the summer in particular; professional drivers breaking the rules about duty and rest hours; and drivers with a tendency to fall asleep easily. A time-of-day pattern of sleep-related incidents was repeatedly found. It was found that VALT teams can be considered relatively reliable when assessing the role of fatigue and sleepiness in accident causation; thus, similar experts might be valuable in the court process as expert witnesses when fatigue or sleepiness are suspected to have a role in an accident’s origins. However, the application of Article 63 of the RTA that forbids, among other things, fatigued driving will continue to be an issue that deserves further attention. This should be done in the context of a needed attitude change towards driving while in a state of extreme tiredness (e.g., after being awake for more than 24 hours), which produces performance deterioration comparable to illegal intoxication (BAC around 0.1%). Regarding the well-known interactive effect of increased sleepiness and even small alcohol levels, the relatively high proportion (up to 14.5%) of Finnish drivers owning and using a breathalyzer raises some concern. This concern exists because these drivers are obviously more focused on not breaking the “magic” line of 0.05% BAC than being concerned about driving impairment, which might be much worse than they realize because of the interactive effects of increased sleepiness and even low alcohol consumption. In conclusion, there is no doubt that fatigue and sleepiness problems while driving are common among the Finnish driving population. While we wait for the invention of reliable devices for fatigue/sleepiness detection, we should invest more effort in raising public awareness about the dangerousness of fatigued driving and educate drivers about how to recognize and deal with fatigue and sleepiness when they ultimately occur.

Work Stress and Early Atherosclerosis: Do Genetic Background and Pre-Employment Risk Factors Explain Conflicting Findings?

According to the models conceptualizing work stress, increased risk of health problems arise when high job demands co-occur with low job control (the demand-control model) or the efforts invested by the employee are disproportionately high compared to the rewards received (effort-reward imbalance model). This study examined the association between work stress and early atherosclerosis with particular attention to the role of pre-employment risk factors and genetic background in this association. The subjects were young healthy adults aged 24-39 who were participating in the 21-year follow-up of the ongoing prospective "Cardiovascular Risk in Young Finns" study in 2001-2002. Work stress was evaluated with questionnaires on demand-control model and on effort-reward model. Atherosclerosis was assessed with ultrasound of carotid artery intima-media thickness (IMT). In addition, risk for enhanced atherosclerotic process was assessed by measuring with heart rate variability and heart rate. Pre-employment risk factors, measured at age 12 to 18, included such as body mass index, blood lipids, family history of coronary heart disease, and parental socioeconomic position. Variants of the neuregulin-1 were determined using genomic DNA. The results showed that higher work stress was associated with higher IMT in men. This association was not attenuated by traditional risk factors of atherosclerosis and coronary heart disease or by pre-employment risk factors measured in adolescence. Neuregulin-1 gene moderated the association between work stress and IMT in men. A significant association between work stress and IMT was found only for the T/T genotype of the neuregulin-1 gene but not for other genotypes. Among women an association was found between higher work stress and lower heart rate variability, suggesting higher risk for developing atherosclerosis. These associations could not be explained by demographic characteristics or coronary risk factors. The present findings provide evidence for an association between work stress and atherosclerosis in relatively young population. This association seems to be modified by genetic influences but it does not appear to be confounded by pre-employment adolescent risk factors.

Developmental origins of psychological vulnerability factors for mental disorders

Premature birth and associated small body size are known to affect health over the life course. Moreover, compelling evidence suggests that birth size throughout its whole range of variation is inversely associated with risk for cardiovascular disease and type 2 diabetes in subsequent life. To explain these findings, the Developmental Origins of Health and Disease (DOHaD) model has been introduced. Within this framework, restricted physical growth is, to a large extent, considered either a product of harmful environmental influences, such as suboptimal nutrition and alterations in the foetal hormonal milieu, or an adaptive reaction to the environment. Whether inverse associations exist between body size at birth and psychological vulnerability factors for mental disorders is poorly known. Thus, the aim of this thesis was to study in three large prospective cohorts whether prenatal and postnatal physical growth, across the whole range of variation, is associated with subsequent temperament/personality traits and psychological symptoms that are considered vulnerability factors for mental disorders. Weight and length at birth in full term infants showed quadratic associations with the temperamental trait of harm avoidance (Study I). The highest scores were characteristic of the smallest individuals, followed by the heaviest/longest. Linear associations between birth size and psychological outcomes were found such that lower weight and thinness at birth predicted more pronounced trait anxiety in late adulthood (Study II); lower birth weight, placental size, and head circumference at 12 months predicted a more pronounced positive schitzotypal trait in women (Study III); and thinness and smaller head circumference at birth associated with symptoms of attention-deficit hyperactivity disorder (ADHD) in children who were born at term (Study IV). These associations occured across the whole variation in birth size and after adjusting for several confounders. With respect to growth after birth, individuals with high trait anxiety scores in late adulthood were lighter in weight and thinner in infancy, and gained weight more rapidly between 7 and 11 years of age, but weighed less and were shorter in late adulthood in relation to weight and height measured at 11 years of age (Study II). These results suggest that a suboptimal prenatal environment reflected in smaller birth size may affect a variety of psychological vulnerability factors for mental disorders, such as the temperamental trait of harm avoidance, trait anxiety, schizotypal traits, and symptoms of ADHD. The smaller the birth size across the whole range of variation, the more pronounced were these psychological vulnerability factors. Moreover, some of these outcomes, such as trait anxiety, were also predicted by patterns of growth after birth. The findings are concordant with the DOHaD model, and emphasise the importance of prenatal factors in the aetiology of not only mental disorders but also their psychological vulnerability factors.

Pathophysiological factors of irritable bowel syndrome, and the effects of probiotic supplementation

Gastrointestinal symptoms and impaired quality of life caused by irritable bowel syndrome (IBS) affect up to 20% of the adult population worldwide. The exact aetiology and pathophysiology of IBS are incompletely understood. Clinical studies suggest that supplementation with certain probiotics may be beneficial in IBS, but there is not enough evidence to make general recommendations. The aim of this thesis was to investigate microbiota- and mucosa-associated pathophysiological factors of IBS, and to evaluate the long-term effects of multispecies probiotic supplementation on symptoms, quality of life, intestinal microbiota and systemic inflammatory markers in IBS. The intestinal microbiota composition in IBS patients and healthy control subjects was analysed by quantitative polymerase chain reaction (qPCR). Significantly lower counts for the Clostridium coccoides and the Bifidobacterium catenulatum groups were found in IBS compared to controls. Quantitative differences also appeared in subgroup analysis based on the predominant bowel habit: diarrhoea patients harboured significantly lower numbers of Lactobacillus spp. than the constipation-predominant patients, while higher counts for Veillonella spp. were detected in constipation-predominant patients compared to healthy controls. Analysis of mucosal biopsies by a metabolomic approach revealed multiple differences between patients and controls. The most prominent finding was an upregulation of specific lipid species, principally lysophosphatidylcholines and ceramides, in IBS. The effects of multispecies probiotic supplementation with Lactobacillus rhamnosus GG, Lactobacillus rhamnosus Lc705, Propionibacterium freudenreichii subsp. shermanii JS, and Bifidobacterium breve Bb99 or Bifidobacterium animalis subsp. lactis Bb12 was evaluated in two, randomised, double-blind, placebo-controlled trials. Compared to placebo, the probiotic supplementation significantly reduced the total symptoms of IBS. No effects on bowel habit were seen. Health-related quality of life (HRQOL) is reduced in patients with IBS in comparison with the Finnish population on the whole. The probiotic supplementation improved one IBS-specific domain of quality of life (bowel symptoms), whereas no other effects on HRQOL were seen. The probiotics had no major effects on the predominant microbiota as measured by qPCR, but a microarray-based analysis suggested that the probiotic consumption stabilised the microbiota. No effects on serum sensitive-CRP or cytokines were detected. In conclusion, alterations in the microbiota composition and in the mucosal metabolite profile are potential pathophysiological factors of IBS. Multispecies probiotic supplementation alleviates the gastrointestinal symptoms of IBS, and improves the bowel symptoms domain of HRQOL. Probiotic supplementation in IBS is associated with a stabilisation of microbiota, but it does not influence systemic inflammatory markers.

Self-reported bruxism : Associated factors among media personnel with or without irregular shift work

Tutkimuksen kohderyhmänä oli mediatyöntekijöitä, joiden toimenkuva on viime vuosina muuttunut yhä kuormittavammaksi epäsäännöllisen vuorotyön sekä jatkuvien teknisten, organisatoristen ja taloudellisten tekijöiden ristipaineessa. Väitöskirjatutkimus on osa laajempaa tutkimushanketta, joka suunniteltiin selvittämään epäsäännöllisen vuorotyön mahdollisia haittoja. Tutkimusta tukivat taloudellisesti Työsuojelurahasto ja Suomen Hammaslääkäriseura Apollonia sekä resurssipanostuksin Hammaslääketieteen laitos (HY), Työterveyslaitos ja Yleisradio Oy. Bruksismi on tahdosta riippumatonta hampaiden narskuttelua tai yhteenpuristamista. Hampaiden narskuttelu on rytmistä jaksoittain toistuvaa puremalihasten toimintaa, joka esiintyy nukkuessa -tavallisimmin kevyen unen ja havahtumisjaksojen yhteydessä. Valveilla ollessa bruksismi on terveillä ihmisillä lähinnä hampaiden yhteenpuristamista. Yleisen käsityksen mukaan toistuvaa unibruksismia esiintyy noin 10 %:lla ja valveilla tapahtuvaa hampaiden yhteenpuristamista noin 20 %:lla. Aiemmin bruksismi kuului kansainvälisen unihäiriöluokituksen (ICSD 1997) mukaan unen erityishäiriöihin, mutta tuorein luokitus (ICSD 2005) listaa sen unen liikehäiriöihin. Väitöstutkimuksen yleisenä tavoitteena oli kartoittaa koetun bruksismin ja uni- valvehäiriöiden yhteyttä. Tutkimus oli poikittainen vertailututkimus epäsäännöllistä vuorotyötä ja säännöllisiä päivävuoroja tekevien välillä. Mielenkiinto kohdistui myös bruksismin ja kasvojen alueen kivun mahdolliseen yhteyteen. Lisäksi tutkimuksessa selvitettiin joidenkin tunnetusti unen laatua huonontavien psykososiaalisten, neurologisten ja fysiologisten tekijöiden yhteyttä koettuun bruksismiin. Tutkimuksen kohderyhmän muodosti 750 Yleisradion epäsäännöllistä vuorotyötä tekevää työntekijää. Vertailuryhmänä käytettiin samansuuruista satunnaistetusti valittua kaltaistettua Yleisradion työntekijäjoukkoa, joka tekee samankaltaista työtä, mutta säännöllisenä päivätyönä. Kohderyhmälle lähetettiin kyselylomakkeet, jotka kartoittivat koetun bruksismin lisäksi mm. tutkittavien taustatiedot, yleisen terveydentilan, yleisiä koettuja stressioireita ja tuntemuksia, kipuoireita, sekä unen laatua. Lisäksi esitettiin jaksamista ja työympäristöä koskevia kysymyksiä. Kyselyyn vastasi kaikkiaan 874 henkilöä. Kokonaisvastausprosentti oli 58,3 % (53,7 % miehiä). Epäsäännöllistä vuorotyötä tekevien vastausprosentti oli 82,3 % ja säännöllistä päivätyötä tekevien ryhmässä 34,3 %. Työtehtävät sisälsivät ohjelmien toimitus- ja tuottamistyötä, teknistä tuotanto- ja tukityötä, sekä esimies- ja hallintotyötä. Miesten keski-ikä vuorotyöryhmässä oli 45,0 (± 10,6) vuotta ja naisten keski-ikä 42,6 (± 10,7) vuotta, vastaavat luvut päivätyötä tekeville olivat 47,4 (± 9,7) ja 45,5 (± 10,1) vuotta. Vuorotyötä tekevistä oli miehiä 56,6 %, päivätyöryhmässä miehien osuus oli 46,7 %. Usein koettua bruksismia havaittiin koko tutkimusjoukossa 10,6 %:lla. Bruksismin esiintyvyydessä ei ollut merkitsevää eroa epäsäännöllistä vuorotyötä ja päivätyötä tekevien välillä. Kun bruksismia ja stressiä arvioitiin suhteessa tyytyväisyyteen nykyiseen työaikamuotoon, molemmat olivat merkitsevästi vallitsevimpia niillä, jotka halusivat vaihtaa nykyistä työaikamuotoaan. Epäsäännöllistä vuorotyötä tekevät lisäksi ilmoittivat kokevansa enemmän stressiä kuin päivätyötä tekevät sekä olivat tyytymättömämpiä työaikamuotoonsa. Tutkittavista henkilöistä katkonaista unta esiintyi 43,6 %:lla sekä 36,2 % koki unensa virkistämättömäksi. Kasvokipua esiintyi 19,6 %:lla. Usein toistuva bruksaus sekä tyytymättömyys työaikamuotoon olivat erittäin merkitsevästi yhteydessä unihäiriöiden sekä riittämättömän unen oireiden kanssa. Bruksismi ja katkonainen uni osoittautuivat myös kasvokivun taustatekijöiksi. Tutkimus osoitti, että koetulla bruksismilla oli merkitsevä yhteys unihäiriöihin, kasvokipuun, koettuun stressiin ja ahdistuneisuuteen, nuorempaan ikään, runsaampiin hammaslääkäri- ja lääkärikäynteihin sekä siihen että oli tyytymätön työaikamuotoonsa (itse työaikamuoto ei ollut merkitsevä tekijä). Tutkimuksen yhtenä johtopäätöksenä todettiin, että koettu bruksismi voi terveillä työikäisillä henkilöillä olla osa stressaavaa tilannetta ja siihen liittyvää käyttäytymistä. Tämän tiedostaminen terveydenhuollossa voisi olla hyödyllistä.

Temporomandibular disorders and related psychosocial factors in non-patients : A survey and a clinical follow-up study based on the RDC/TMD

Temporomandibular disorders (TMD) and psychosocial factors reportedly associate. The underlying factors remain partially obscure, however, and further studies are required to clarify the relationships. The aims of this study were thus to assess in a non-patient working population the prevalence of TMD and related symptoms, and to clinically diagnose and follow the natural courses of TMD over a one-year period. In addition, possible comorbidity of temporomandibular and/or neck muscle pain and perceived stress and their impact on work performance were investigated, as well as how various psychosocial aspects relate to TMD. A questionnaire was mailed to all 30- to 55-year-old employees of the Finnish Broadcasting Company Ltd. whose employment in the Helsinki area had lasted at least five years (n = 1784). Of the 1339 subjects, who returned the questionnaire, 241 were examined according to the RDC/TMD and standard neck muscle palpation methods. Clinical signs of temporomandibular and/or neck muscle pain were found in 118 subjects. One-year follow-up TMD examinations were conducted on 211 subjects. The prevalence of frequent painless TMJ-related symptoms was 10%, orofacial pain 7%, neck pain 38%, and headache 15%. TMD diagnoses were: myofascial pain (13%), disc displacements (16%), and arthralgia, osteoarthritis, osteoarthrosis (4%). Chronic myofascial pain was present in 7% and chronic disc displacement with reduction in 11% of the subjects. Symptoms were significantly associated with almost all the studied psychosocial symptoms. Reduced work performance was significantly positively associated with continuous pain, severity of pain, and health stress perception, and according to logistic regression, somatization with the probability of having chronic myofascial pain. It could be concluded based on the results of this study among a non-patient working population that TMD and related symptoms are common and associated with psychosocial factors. Moreover, myofascial pain and disc displacement with reduction are the most common diagnoses of TMD. In addition, self-reported health related stress, and continuous pain in temporomandibular and/or neck muscles are associated with reduced work performance, and somatization is significantly associated with chronic myofascial pain.

Restorative treatment practices and dentist-related factors

This study aimed at elucidating real-life aspects of restorative treatment practices. In addition, dentists' views and perceptions of and variation in restorative treatment practices with respect to dentist-related factors were evaluated. Reasons for placement and replacement of restoration, material selection, posterior restoration longevity, and the use of local anesthesia were assessed on two cross-sectional data sets. Data from the Helsinki Public Dental Service (PDS) included details on 3057 restorations performed by dentists (n=134) during routine clinical work in 2001. The other PDS data from Vantaa were based on 205 patient records of young adults containing information on 1969 restorations investigated retrospectively from 1994-1996 backwards; 51 dentists performed the restorations. In addition, dentists’ self-reported use of local anesthesia and estimates of restoration longevity were investigated by means of a nationwide questionnaire sent to 592 general dental practitioners selected by systematic sampling from the membership list of the Finnish Dental Association in 2004. All data sets included some background information on dentists such as gender, year of birth or graduation, and working sector. In PDS in 2001, primary caries was the reason for placement of restoration more often among patients aged under 19 years than among older patients (p<0.001). Among patients over 36 years of age, replacements represented the majority. Regarding dentist-related factors, replacements of restorations were made by younger dentists more frequently than by older dentists (p<0.001). In PDS in 1994-1996, the replacement rate of posterior restorations was greater among female dentists than among male dentists (p=0.01), especially for amalgams (p=0.008). The mean age of replaced posterior restoration among young adults was 8.9 (SD 5.2) years for amalgam and 2.4 (SD 1.4) years for tooth-colored restorations, the actual replacement rate for all existing posterior restorations being 7% in PDS in 1994-1996. Of all restorative materials used, a clear majority (69%) were composites in PDS in 2001. Local anesthesia was used in 48% of cases and more frequently for older patients (55%) than for patients aged under 13 years (35%) (p<0.001). Younger dentists more often used local anesthesia for primary restoration than did the older dentists (p<0.001), especially for primary teeth (p=0.005). Working sector had an impact on dentists’ self-reported use of local anesthesia and estimates of restoration longevity; public sector dentists reported using local anesthesia more frequently than private sector dentists for Class II (p=0.04) and for Class III restorations (p=0.01). Private sector dentists gave longer estimates of posterior composite longevity than public sector dentists (p=0.001). In conclusion, restorative treatment practices seem to vary according to patient age and also dentist-related factors. Replacements of restorations are common for adults. For children, clear underuse of local anesthesia prevails.

Pain among employees : risk factors and consequences

The overall objective of this study was to gain epidemiological knowledge about pain among employee populations. More specifically, the aims were to assess the prevalence of pain, to identify socio-economic risk groups and work-related psychosocial risk factors, and to assess the consequences in terms of health-related functioning and sickness absence. The study was carried out among the municipal employees of the City of Helsinki. Data comprised questionnaire survey conducted in years 2000-2002 and register data on sickness absence. Altogether 8960 40-60 year old employees participated to the survey (response rate 67%). Pain is common among ageing employees. Approximately 29 per cent of employees reported chronic pain and 15 per cent acute pain, and about seven per cent reported moderately or severely limiting disabling chronic pain. Pain was more common among those with lower level of education or in a low occupational class. -- Psychosocial work environment was associated with pain reports. Job strain, bullying at workplace, and problems in combining work and home duties were associated with pain among women. Among men combining work and home duties was not associated with pain, whereas organizational injustice showed associations. Pain affects functional capacity and predicts sickness absence. Those with pain reported lower level of both mental and physical functioning than those with no pain, physical functioning being more strongly affected than mental. Bodily location of pain or whether pain was acute or chronic had only minor impact on the variation in functioning, whereas the simple count of painful locations was associated with widest variation. Pain accounted for eight per cent of short term (1-3 day) sickness absence spells among men and 13 per cent among women. Of absence spells lasting between four and 14 days pain accounted for 23 per cent among women and 25 per cent among men, corresponding figures for over 14 day absence spells being 37 and 30 per cent. The association between pain and sickness absence was relatively independent of physical and psychosocial work factors, especially among women. The results of this study provide a picture of the epidemiology of pain among employees. Pain is a significant problem that seriously affects work ability. Information on risk groups can be utilized to make prevention measures more effective among those at high risk, and to decrease pain rates and thereby narrow the differences between socio-economic groups. Furthermore, the work-related psychosocial risk factors identified in this study are potentially modifiable, and it should be possible to target interventions on decreasing pain rates among employees.

Socioeconomic Status, Occupational Factors and Lifestyle as Predictors of Hospitalisation for Back Disorders

The aim of this dissertation was to examine the determinants of severe back disorders leading to hospital admission in Finland. First, back-related hospitalisations were considered from the perspective of socioeconomic status, occupation, and industry. Secondly, the significance of psychosocial factors at work, sleep disturbances, and such lifestyle factors as smoking and overweight was studied as predictors of hospitalisation due to back disorders. Two sets of data were used: 1) the population-based data comprised all occupationally active Finns aged 25-64, and included hospitalisations due to back disorders in 1996 and 2) a cohort of employees followed up from 1973 to 2000 having been hospitalised due to back disorders. The results of the population-based study showed that people in physically strenuous industries and occupations, such as agriculture and manufacturing, were at an increased risk of being hospitalised for back disorders. The lowest hospitalisation rates were found in sedentary occupations. Occupational class and the level of formal education were independently associated with hospitalisation for back disorders. This stratification was fairly consistent across age-groups and genders. Men had a slightly higher risk of becoming hospitalised compared with women, and the risk increased with age among both genders. The results of the prospective cohort study showed that psychosocial factors at work such as low job control and low supervisor support predicted subsequent hospitalisation for back disorders even when adjustments were made for occupational class and physical workload history. However, psychosocial factors did not predict hospital admissions due to intervertebral disc disorders; only admissions due to other back disorders. Smoking and overweight predicted, instead, only hospitalisation for intervertebral disc disorders. These results suggest that the etiological factors of disc disorders and other back disorders differ from each other. The study concerning the association of sleep disturbances and other distress symptoms with hospitalisation for back disorders revealed that sleep disturbances predicted subsequent hospitalisation for all back disorders after adjustment for chronic back disorders and recurrent back symptoms at baseline, as well as for work-related load and lifestyle factors. Other distress symptoms were not predictive of hospitalisation.

Associations among working conditions and behavioral risk factors : The Helsinki Health Study with International Comparisons

Adverse health behaviors as well as obesity are key risk factors for chronic diseases. Working conditions also contribute to health outcomes. It is possible that the effects of psychosocially strenuous working conditions and other work-related factors on health are, to some extent, explained by adverse behaviors. Previous studies about the associations between several working conditions and behavioral outcomes are, however, inconclusive. Moreover, the results are derived mostly from male populations, one national setting only, and with limited information about working conditions and behavioral risk factors. Thus, with an interest in employee health, this study was set to focus on behavioral risk factors among middle-aged employees. More specifically, the main aim was to shed light on the associations of various working conditions with health behaviors, weight gain, obesity, and symptoms of angina pectoris. In addition to national focus, international comparisons were included to test the associations across countries thereby aiming to produce a more comprehensive picture. Furthermore, a special emphasis was on gaining new evidence in these areas among women. The data derived from the Helsinki Health Study, and from collaborative partners at the Whitehall II Study, University College London, UK, and the Toyama University, Japan. In Helsinki, the postal questionnaires were mailed in 2000-2002 to employees of the City of Helsinki, aged 40 60 years (n=8960). The questionnaire data covered e.g., socio-economic indicators and working conditions such as Karasek s job demands and job control, work fatigue, working overtime, work-home interface, and social support. The outcome measures consisted of smoking, drinking, physical activity, food habits, weight gain, obesity, and symptoms of angina pectoris. The international cohorts included comparable data. Logistic regression analysis was used. The models were adjusted for potential confounders such as age, education, occupational class, and marital status subject to specific aims. The results showed that working conditions were mostly unassociated with health behaviors, albeit some associations were found. Low job strain was associated with healthy food habits and non-smoking among women in Helsinki. Work fatigue, in turn, was related to drinking among men and physical inactivity among women. Work fatigue and working overtime were associated with weight gain in Helsinki among both women and men. Finally, work fatigue, low job control, working overtime, and physically strenuous work were associated with symptoms of angina pectoris among women in Helsinki. Cross-country comparisons confirmed mostly non-existent associations. High job strain was associated with physical inactivity and smoking, and passive work with physical inactivity and less drinking. Working overtime, in turn, related to non-smoking and obesity. All these associations were, however, inconsistent between cohorts and genders. In conclusion, the associations of the studied working conditions with the behavioral risk factors lacked general patters, and were, overall, weak considering the prevalence of psychosocially strenuous work and overtime hours. Thus, based on this study, the health effects of working conditions are likely to be mediated by adverse behaviors only to a minor extent. The associations of work fatigue and working overtime with weight gain and symptoms of angina pectoris are, however, of potential importance to the subsequent health and work ability of employees.