Introduction 1997 2007 2000 1991 2007 1997 2001a 2001 2002 2006 The purpose of this study was to explore the associations of psychosocial factors at work, stressful life events, and life style on health and work ability among white-collar workers. Methods Subjects n n Work ability 1998 Functional health status 2002 Psychosocial factors at work 2001 Stressful life events 1967 Life style factors 1985 1995 2006 Physical examination 1975 −1  −1 2  −1 −1 Statistics 2 P The results of the regression analyses are presented by the regression coefficients and associated standard errors. A regression coefficient is an expression of the change in the work ability score due to a change in one unit of measurement of the independent variable of interest. For categorical variables, this reflects the effect on the work ability score of the presence of this determinant. The regression analysis on determinants of work ability was stratified for three age groups. All significant determinants in the multivariate model for one age group were included in the models for other age groups as well in order to provide an appropriate comparison. 1999 Results 1 Table 1 Characteristics of 1,141 commercial workers who participated in a voluntary medical examination Characteristics Cases Median (min–max) Frequency (%) Individual characteristics  Age (year) 1,141 35.7 (18–63) 67.4  Male 769   Work ability  Excellent (44–49) 488 42.1 (9–49) 42.8  Good (37–43) 518  45.4  Moderate (28–36) 111  9.7  Poor (7–27) 24  2.1 Health  Mental health component summary (MCS) (8–74) 1,141 54.2 (10.9–67.9)   Physical health component summary (PCS) (4–73) 1,141 53.4 (18.2–70.6)  Psychosocial factors at work  Teamwork (0–100) 1,136 81.0 (27–100)   Stress-handling (0–100) 1,136 68.0 (11–100)   Self-development (0–100) 1,136 78.0 (9–100)  Stressful life events (0–100) 1,136 5.5 (0−38.4)  Life style −1 798  70.2 −1 886  78.0  Current smoker 145  12.8  Problematic alcohol use 42  4.5 Physical examination −2 371 35.9 (11.4–61.7) 34.6 −2 57 37.0 (8.0–94.0) 5.3 2 −1  −1 1,117    Biceps strength (kg) 1,134   2 Table 2 n  Mental Health (MCS)
 Physical health (PCS) Univariate model Multivariate model Univariate model Multivariate model β SE β SE β SE β SE Individual characteristics  Age (year) 0.09* 0.03 0.07* 0.02 –0.07* 0.02 –0.09* 0.02  Male 2.41* 0.51 1.52* 0.47 1.66* 0.38 1.91* 0.38 Psychosocial factors at work  Low versus high teamwork  –5.90* 0.56 –2.71* 0.66 –0.92* 0.43 n.s.   Intermediate high versus teamwork  –2.39* 0.57 –0.70 0.58 –0.68 0.45 n.s.   Low versus high stress-handling  –6.94* 0.56 –4.71* 0.62 –0.26 0.45 n.s.   Intermediate versus  high stress-handling  –2.39* 0.58 –1.42* 0.59 0.01 0.46 n.s.   Low versus  high self-development  –5.44* 0.60 –2.12* 0.65 –0.73 0.46 n.s.   Intermediate versus  high self-development  –2.19* 0.58 –0.59 0.57 –0.81 0.45 n.s.  Stressful life events  High versus  low stressful life events –3.13* 0.59 –3.13* 0.54 –0.62 0.44 n.s.   Intermediate versus  low stressful life events –1.91* 0.59 –1.98* 0.53 –0.05 0.44 n.s.  Life style  Lack of moderate physical activity –0.14 0.53 n.s.  –0.01 0.39 n.s.   Lack of vigorous physical activity –1.27* 0.58 –1.37* 0.52 –1.79* 0.43 –1.71* 0.42  Current smoker –2.02* 0.72 –1.96* 0.65 –1.14* 0.54 n.s.   Problematic alcohol use –1.76 1.27 n.s.  –1.61 0.92 n.s.  Physical examination  Obesity (BMI ≥ 30) versus normal (BMI < 25) –0.84 1.14 n.s  –1.54 0.83 n.s.   Overweight (BMI 25–30) versus normal  0.34 0.54 n.s  –0.30 0.39 n.s.  2 –0.01 0.03 n.s  0.05* 0.02 n.s.   Biceps strength (kg) 0.03 0.02 n.s  0.04* 0.02 n.s.  n.s P 3 Table 3 n  Work ability Work ability Univariate model Multivariate model β SE β SE Individual characteristics  Age (year) –0.07* 0.02 –0.09* 0.01  Male 2.13* 0.31 2.08* 0.28 Psychosocial factors at work  Low versus high teamwork –4.02* 0.32 –1.32* 0.40  Intermediate versus high  teamwork –1.52* 0.34 –0.20 0.35  Lowversus versus high stress-handling –4.39* 0.34 –2.75* 0.35  Intermediate versus high  stress-handling –1.41* 0.35 –0.79* 0.35  Low versus high  self-development –4.11* 0.35 –2.20* 0.39  Intermediate versus high  self-development  –1.67* 0.34 –0.91* 0.34 Stressful life events  High versus low stressful life  events –1.36* 0.36 –2.01* 0.32  Intermediate versus low stressful  life events –0.97* 0.36 –1.14* 0.32 Life style  Lack of moderate physical  activity 0.49 0.32 n.s 0.31  Lack of vigorous physical  activity –0.71* 0.35 –0.71*   Current smoker –0.68 0.44 n.s.   Problematic alcohol use –0.52 0.74 n.s.  Physical examination  Obesity (BMI ≥ 30) versus  normal (BMI < 25) –2.02* 0.68 –1.21* 0.59  Overweight (BMI 25–30) versus  normal (BMI < 25) –0.49 0.32 –0.32 0.28 2 −1 −1 0.03 0.02 n.s.   Biceps strength (kg) 0.03 0.01 n.s.  n.s P No significant interaction was observed for age, sex, and psychosocial factors at work. 4 Table 4 n   n n n β SE β SE β SE Individual characteristics  Male 1.43* 0.42 1.37* 0.49 3.19* 0.83 Psychosocial factors at work  Low versus high teamwork –0.44 0.61 –1.40* 0.63 –1.07 0.98  ntermediate versus high  teamwork –0.49 0.50 –0.39 0.60 –0.58 0.89  Low versus high  stress-handling –2.85* 0.55 –3.22* 0.63 –2.44* 0.95  Intermediate versus high  stress-handling –0.96 0.52 –1.08 0.61 –0.83 0.86  Low versus high  self-development –2.59* 0.64 –1.64* 0.59 –3.57* 1.01  Intermediate versus high  self-development  –1.27* 0.51 –0.92 0.57 –1.63 0.84 Stressful life events  High versus low stressful life  events –1.25* 0.49 –1.67* 0.51 –2.60* 0.84  Intermediate versus low  stressful life events –0.64 0.53 –1.78* 0.52 –0.34 0.72 Life style  Lack of moderate  physical activity –0.28 0.47 0.02 0.51 1.45* 0.70  Lack of vigorous physical  activity –0.58 0.49 –0.56 0.53 –1.62* 0.79  Problematic alcohol use 1.70 0.93 –0.85 1.19 –2.62* 1.33 P Discussion This study showed that work ability of white-collar workers in commercial services industry was strongly associated with psychosocial factors at work, such as teamwork, stress handling, self-development, and, to a lesser extent, with stressful life events, lack of physical activity, and obesity. Work ability was strongly associated with mental and physical health. Determinants of mental health were very similar to those of work ability, whereas physical health was influenced primarily by lack of life physical activity. Some limitations must be taken into account in this study. First, the cross-sectional design does not permit exploration of causal relationships between the determinants and work ability. Therefore, it remains unknown whether, for example, poor stress handling will decrease work ability or decreased work ability will cause a poorer stress handling. Nevertheless, the results are still of interest as they give a first insight into important factors for interventions among white-collar workers. Second, data were drawn from voluntary participants. Information on non-response for both measures showed that age and sex did not bias response. Non-response differences between questionnaire and physical examination did not show any bias; none of the questionnaire variables were associated with not participating in the physical examination; and also none of the physical examination variables were associated with not participating in the questionnaire. Third, the reliability of the physical examination highly depends on the professional skills of the instructor and the standardization of the examination. The maximum oxygen uptake was indirectly calculated using the heart rate, which can be easily increased by minor distractions, such as room temperature, and talking during the test. 1998 Work ability in this study population was influenced by sex, age, psychosocial factors at work, stressful life events, and life style factors. These factors together explained 29% of the total variance in work ability in this study population. Male sex increased work ability with two points, which means 4% of the maximum score. An increase in age of 40 years decreases the WAI score with four points, which is 7.3% of the maximum score, which indicates a rather modest influence of age on work ability. Psychosocial factors each had an effect on WAI comparable to sex, whereas the combined effect of the psychosocial factors is approximately 1.5-fold the effect of 40 years of aging. Lack of vigorous physical activity decreases the WAI score with only 0.7 points, which is no more than 1.5% of the maximum score. Obesity (5% of the population) compared to normal weight decreases the WAI score with 1.2 points, which is 2.4% of the maximum score. Each psychosocial factor at work was negatively associated with work ability. Univariate results showed comparable strength in associations, while the multivariate model showed lower regression coefficients, especially for teamwork. It seems that the association between teamwork and work ability was more influenced by other determinants included in the multivariate model, than the associations between work ability and stress handling and self-development. 2004 β 2002 2000 2001b OR 1991 1991 2001a Stratification by age showed the importance of lifestyle in the oldest age group, but not among younger workers. This effect may be explained by the fact that health problems due to an unhealthy lifestyle, most notably diabetes mellitus and cardiovascular disease, occur primarily at older age. In the total study population, obesity was significantly associated with lower work ability, whereas no significant associations were found in the stratified analyses. This is partly due to lack of statistical power in these strata with smaller numbers of workers, since the magnitude of the regression coefficients were comparable but the standard errors increased substantially. 2004 The results of the current study outline the importance of work-related factors in white-collar workers, with regard to work ability. The combined impact of psychosocial factors is much stronger than is for individual factors, and is amenable to change, in contrast to individual factors as age, and sex. In conclusion, among white-collar workers in commercial services industry psychosocial factors at work, stressful life events, lack of vigorous physical activity, and obesity were significant with regard to work ability. The strong associations between psychosocial factors at work and mental health and work ability suggest that in this study population health promotion should address working conditions rather than individual life style factors, although the importance of life style factors seems to increase with aging of the worker.