Stability and prediction of physical activity in 5-, 10-, and 28-year follow-up studies among industrial employees.

The aim of the study was to examine the stability of voluntary and household physical activity (PA) and to compare it with that of the use of the most common stimulants. The prospective cohort study comprised of follow-ups at 5, 10, and 28 years at baseline in 1973 in four plants of an industrial corporation in Finland. A systematic, non-proportional sample (n=902, age range 18-64 years) stratified for age, gender, and occupational status was drawn from the employees. Scores of PA were based on a questionnaire and interviews. Logistic regression models with proportional odds assumptions were counted. The 5-year stability (Spearman's rho) of PA time was 0.44 (PA intensity 0.44), the respective 10-year coefficient was 0.26 (0.32), and that in the 28-year follow-up was 0.18 (0.20). The stability of PA decreased rapidly from 1973 to 1983 and more slowly thereafter. Changes along the follow-up reflect a polarization of the distributions of PA within the sample. Age and an initially low level of activity were the strongest predictors of inactivity. The stability coefficient of smoking and alcohol consumption was twice as high as that of PA. Stimulant use was a greater factor in the individual's lifestyle than PA.

Leisure time physical activity and strenuousness of work as predictors of physical functioning: a 28 year follow up of a cohort of industrial employees.

AIMS: To examine associations of leisure time physical activity and physical strenuousness of work with physical functioning 28 years later. METHODS: A cohort (n = 902) of metal industry employees was studied for exercise and housework activity in 1973 and 1978, and for BMI, current smoking, strenuousness of work, grip strength, and chronic diseases in 1973. Of the 670 survivors in 2000, 529 (79%) responded to all studied items in a follow up questionnaire including the SF-36 Physical Functioning (PF) scale. Belonging to the lower quartile of the PF scale denoted poor functioning. RESULTS: Vigorous exercise and housework activity were inversely associated with poor PF 28 years later in both white-collar and blue-collar workers. Engaging in activities of any intensity was similarly associated among the blue-collar workers. In a multiple logistic regression model including as independent variables age, sex, occupational class, the number of chronic diseases, vigorous leisure time physical activity, BMI, physical work strenuousness, and smoking (all measured at baseline), the risk of poor PF at follow up was decreased by vigorous leisure time physical activity and increased by high physical strenuousness of work, high BMI, and smoking. The effect of work strenuousness was mainly due to that among the blue-collar group. Allowing for baseline grip strength did not materially alter the results. CONCLUSION: Vigorous leisure time physical activity decreased the risk of poor physical functioning as perceived considerably later in life, while high work strenuousness, smoking, and overweight increased it. Among blue-collar workers a beneficial association was observed with all leisure time activity, including that of lower intensity.

Need for near vision in daily work in different occupational groups.

To evaluate the need, characteristics and proportion of occupational accurate close work in different socio-economic groups we sent a questionnaire to all 26- and 46-year-old people in the Jyväskylä district. 1,503 (75%) of the 26-year-old subjects and 1,035 (78%) of the 46-year-old subjects returned the questionnaire. 71% of the 26-year-old subjects and 68% of the 46-year-old subjects reported that they need accurate near vision in their daily work. Accurate near vision was needed for reading and writing in 61% in the younger and 55% in the older age group, industrial quality control in 14% in the younger and in 26% in the older age group, Visual Display Unit work in 7% in both age groups, and other accurate close work in 19% in the younger and in 12% in the older age group. The results show that there is a need for accurate near vision in most occupations and indicate that the visual acuity and refraction of the employee requiring occupational accurate near vision should be examined when newly employed and when having problems with near work.

Wearing of spectacles and occurrence of ocular symptoms in close work in different occupations.

To study the wearing of spectacles in different occupations we sent a questionnaire to all 26- and 46-year-old people (altogether 3,337 subjects) in the Jyväskylä district. 69% in the older age group and 42% in the younger age group had spectacles. Women wore spectacles more often than men. There was a correlation between the use of spectacles and accurate occupational close work. The proportion of those wearing spectacles was highest in subjects working, at least partly, with Visual Display Units (VDU). Farmers, industrial workers and service personnel wore spectacles less often than those in other occupations. In the older age group 70% and in the younger age group 11% of the subjects considered that they do not have good near vision without spectacles. Of those who used spectacles, 90% in the older and 52% in the younger age group reported that their near vision is better with spectacles than without them. In both age groups there was a positive correlation between the use of spectacles and the duration of daily close work. Subjective ocular symptoms occurred equally in different close work categories in the younger age group. In the older age group, those doing VDU work and reading and writing work had less symptoms of eye problems than those in other job categories.

Effects of job change on job satisfaction and mental strain.

The effect of improved work conditions on symptoms of mental strain was examined in a longitudinal study of metal industry employees. The aim was to study the changes in work conditions, job satisfaction, and indices of mental strain among the employees who were promoted or who changed employer in comparison to those who had stayed in the same job during the five-year follow-up period (matched groups, N 136). During the study period, work content and physical work environment had significantly improved in the job-change group compared to the reference group. Job dissatisfaction, life dissatisfaction, and stress symptoms had decreased significantly in the job-change group. The most powerful predictors of changes in job stress or general mental strain were changes in work content and changes in the quality of the physical work environment. However, the multiple correlations obtained in the regression analyses were not high.