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Occupational Medicine Advance Access originally published online on October 16, 2006
Occupational Medicine 2007 57(2):85-91; doi:10.1093/occmed/kql105
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© The Author 2006. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Activity, functional capacity and well-being in ageing Finnish workers

Jorma Seitsamo, Kaija Tuomi and Rami Martikainen

Finnish Institute of Occupational Health, Helsinki, Finland

Correspondence to: Jorma Seitsamo, Finnish Institute of Occupational Health, Topeliuksenkatu 41 a A, Helsinki FI-00250, Finland. Tel: +358 304742410; fax: +358 304742423; e-mail: jorma.seitsamo{at}ttl.fi


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 Conflicts of interest
 References
 
Background The ageing of the labour force and falling employment rates have forced policy makers in industrialized countries to find means of increasing the well-being of older workers and of lengthening their work careers.

Aims To longitudinally study the relationship between activity and functional capacity and the well-being of ageing workers.

Methods Follow-up study to that carried out by the Finnish Institute of Occupational Health in 1981–97 (n = 3817). Activity level was measured using various free-time activities, and functional capacity was measured through daily-life activities. The measure of well-being included items with both positive and negative affects. The associations between activity, functional capacity and well-being were analysed by general linear models with repeated measures.

Results Activity level and functional capacity had a strong positive effect (the effects of one unit increase were 0.32 and 0.30, respectively) on well-being. They were also interdependent. The impact of activity level in maintaining well-being became 31% greater during the follow-up, whereas the effect of functional capacity diminished by 17%.

Conclusion The results of the study indicate that both involvement in activities and functional capacity have an important, partly compensatory role in maintaining the well-being of ageing workers.

Keywords      Ageing workers; functional capacity; retirement; well-being


   Introduction
Top
 Abstract
 Introduction
Methods
 Results
 Discussion
 Conflicts of interest
 References
 
It has been estimated that in Europe, the proportion of people >65 years will triple, rising to 30% of the population from 1950 to 2050. The proportion of 55- to 64-year olds is also growing steadily in most industrialized countries and the same trend is also anticipated in developing countries [1–3].

Elderly people are now healthier than ever, their functional capacity is better and they have fewer diseases compared to the same aged people some 20 years ago [4]. However, the employment rate of older workers (55- to 64-year olds) has been decreasing since the 1970s. In 2001, for instance, it was 38.5% in the European Union. Not surprisingly then, social policy requires individuals to work longer, retire later, remain active after retirement, engage in health-sustaining activities and be as self-reliant as possible [2,4–7].

There has been a long research tradition in social gerontology concerning the questions of functional capacity [8–10]. One reason for this ‘popularity’ may be that physical functioning declines with age [11,12] which may eventually threaten independent living of the elderly. Functional capacity is also one of the building blocks of work ability and, consequently, an important contributing factor to occupationally active years [13–15].

Functional capacity can mean a person's ability to cope with daily-life activities, but in its widest definition it may mean health status or quality of life [12,16]. Functional capacity has often been studied through measuring daily-life activities (ADL scales) or instrumental daily-life activities (IADL scales) [8,13,17,18]. Chronic diseases, depression, cognitive impairment, low physical and social activity and low socio-economic status are also connected to physical functioning [10,19,20].

Even though functional capacity is based on physical health, they are not synonyms; ageing may have different effects on each of them. Even though diseases increase steadily with the onset of age, the assessments people make of their functioning may actually improve [21].

Well-being may denote all the domains of human life which make up good living [1]. On a personal level, well-being may mean happiness or satisfaction with life, and on a social level the focus may be on economic welfare [22]. There has been ample research on subjective well-being and the focus has often been on personal feelings of positive and negative affects, happiness, satisfaction with life and self-esteem [8,23–25]. It has been suggested that subjective well-being should be defined as a balance between positive and negative affect [23,26,27].

The important role of physical exercise for maintaining well-being is often reported [27–29]. Some studies have demonstrated that it is not only physical activity which contributes to well-being but also activities of a social or intellectual nature [30–32]. In her recent longitudinal study of Canadian older adults [33], Menec found that the level of activity (including components of social, solitary and productive activities) correlated positively with happiness, better functioning and reduced mortality, but not, however, with life satisfaction.

As far as we are aware, there is little or no research where the associations between functional capacity and health have been longitudinally studied in the context of retirement transition. The purpose of this study was to examine the relations between activity, functional capacity and the well-being of workers in different occupational groups over a 16-year period, from occupationally active years until retirement.

The research questions were as follows:

(i) How did the level of activity and functional capacity change during the 11–16 years of follow-up in different occupational groups?
(ii) Were there any changes in the level of well-being in the occupational groups during the follow-up?
(iii) What was the role of activity in maintaining a person's well-being, and how was functional capacity connected to this?


   Methods
Top
 Abstract
 Introduction
 Methods
Results
 Discussion
 Conflicts of interest
 References
 
The study material is comprised of a follow-up questionnaire study of Finnish municipal workers which was conducted at the Finnish Institute of Occupational Health in 1981–97 [34]. In 1981, a postal questionnaire was sent to 7344 municipal workers in different regions of Finland. The respondents were born in 1923–35 and their mean age was 50.5 years. A total of 6257 persons responded to the first questionnaire (response rate 85%). Over the follow-up period, 715 persons died and 1725 dropped out of the study. In the end, a total of 3817 persons had responded to all four (1981, 1985, 1992, 1997) cross-sectional questionnaires (the response rate was 69% of the living participants who responded to the first questionnaire). The baseline characteristics of the participants, those who dropped out, and the deceased are shown in Table 1.


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  		Table 1. Baseline characteristics in 1981 between participants in the follow-up, deceased and other dropouts

 
Well-being
It was defined as a subjective, emotional concept involving positive and negative components. Its measure was based on positive and negative affect, mental symptom and mental resource dimensions from the Occupational Stress Questionnaire [35]. The six questions were ‘Have you recently been able to enjoy your daily activities?’, ‘Have you recently been active and energetic?’, ‘Have you recently felt hopeful about the future?’, ‘Are you strained?’, ‘Are you nervous?’ and ‘Are you depressed?’ (1 = all the time, 2 = often, 3 = every now and then 4 = seldom, 5 = never). From each four sets of cross-sectional data, a summary score was created by adding up total responses. The reliability index (Cronbach's Alpha) of the scale varied from 0.82 (1981) to 0.85 (1992).

Functional capacity
It was defined as a person's ability to perform domestic and self-care activities free of physically related limitations [8]. It was assessed in 1985, 1992 and 1997 by 11 Likert-type questions concerning coping with mainly physically demanding daily activities. The question was ‘How well are you able to do the following tasks/ functions?’ (3 = with no difficulty, 2 = with some difficulty, 1 = with great difficulty, 0 = not at all). The tasks were heavy cleaning work (e.g. carrying and beating carpets, cleaning windows), lifting and carrying heavy weights (>10 kg), climbing three flights of stairs without needing to rest, walking ~2 km without a rest, running a short distance (~100 m) without a rest, sitting still for ~2 h, squatting down on one's heels and getting up, bending over (e.g. to wash one's face or make the bed), bending down (e.g. putting on socks), lifting hands above the head, detailed movements of the arms and fingers (e.g. peeling a potato, using a screwdriver). A summary score was created by adding up all the responses (Table 1). The reliability index (Cronbach's Alpha) of the scale varied between 0.91 and 0.92.

Activities
Identical questions of different activities were included in the questionnaires in 1981, 1992 and 1997. The question was ‘To what extent are you engaged in the following hobbies or activities?’ (3 = daily, 2 = once or twice a week, 1 = less frequently, 0 = not at all). The items covered physical exercise, needlework and handicrafts, studying, reading literature and attending clubs and associations. A summary score was also created for the activity items (Table 1).

Type of work
Altogether 133 different occupation titles were included in the study. These were first classified into 13 occupational groups, based on observations at the workplaces and profile analyses. These analyses were carried out with German ‘ergonomic job analysis procedure’, known as AET (‘Arbeitswissenschaftliche Erhebungsverfahren zur Tätigkeitsanalyse’) which covers the physical, mental, environmental and organizational aspects of work [36]. According to the result of the profile analyses, depending on the physical or mental demands of the occupation, three types of work groups were formed, i.e. physical, mental and mixed (both physically and mentally demanding work) [37]. The physical work category included job titles from auxiliary work, installation work and home care work. The mixed work category group consisted of transport work, dumping groundwork, kitchen supervision, dental work and nursing work. The mental work category covered office work, administrative work, technical supervision, physician's work and teaching work [37].

Morbidity
The questionnaire included a list of 51 diseases [38] from which the participants could choose the appropriate items (1 = yes I have, own opinion; 2 = yes I have, diagnosed by a physician). The measure of diseases included only illnesses which were reported as diagnosed by a physician.

Retirement status
Information on retirement was acquired from the Finnish Centre for Pensions. The classification used was normal retirement (old-age pension) and early retirement (disability pension).

‘Age’ and ‘gender’ were also included in the analysis.

The differences between the time points were analysed by cross-tabulations and means. The adjusted effects of the activity level, functional capacity, age, morbidity, type of work, retirement status and gender on well-being were estimated by general linear models with repeated measures (SAS Mixed Procedure) [39]. In this method, the dependencies between the observations can also be taken into account. One interest is also that the regression coefficients have the same interpretation as those from a traditional cross-sectional analysis. These likelihood-based methods are valid under missing-at-random assumption when missing data might depend on observed data [40]. With this method, it was possible to use all available data from each time point and there was no need to restrict to the follow-up data only. During the analysis, all first-order interactions between independent variables were tested, and only statistically significant interactions were included in the final model. The activity level information from 1985 was replaced with the 1981 activity measure because the questions in the 1985 inquiry were not comparable to other inquiries.


   Results
Top
 Abstract
 Introduction
 Methods
 Results
Discussion
 Conflicts of interest
 References
 
At the beginning of the study, the participants had already been working at the same workplace for a long time and on average 17 years. At the end of the follow-up, almost all (95%) had retired (Figure 1). The main transition to retirement occurred between the second (1985) and the third (1992) inquiry.


Figure 1
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  		Figure 1. The follow-up data by occupational status in 1981–97 (n = 3817).

 
There were some differences between those who participated in the follow-up and those who died or had dropped out (Table 1). Those participants who responded to all four questionnaires were more often women, in the mental work category, and younger. In addition, the follow-up subjects had higher functional capacity; they were more active, had less diseases and better well-being than those who dropped out and those deceased.

During the follow-up, the involvement in activities changed in many respects and these are summarized in Table 2. Most notably, the prevalence of daily physical exercise and outdoor activities nearly doubled in all occupational groups from 1981 to 1992. Attending clubs and associations was equally common in all occupational groups. There was, however, a clear gender difference in the direction of change from 1981 to 1997. Women's interest in this kind of activity increased by ~10% during the follow-up, whereas among men there was a slight decrease. Needlework and handicrafts were most common among women who had previously done physically demanding work.


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  		Table 2. Activities of men and women in 1981–97 by type of work (%)

 
There were changes in the level of activity as well in the time factor. The average activity level increased in all occupational groups from 1981 to 1992 after which involvement in activities remained at the previous level or decreased slightly. Women were more active than men in every occupational group (Table 3).


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  		Table 3. Average levels of activity, functional capacity and well-being in different types of work by gender

 
Functional capacity weakened compared to its baseline in 1992 in all groups except among men in the mixed work category (Table 3). After 1992, functional capacity increased in all groups with the exception of men and women in the mixed work category. Among them, there were no changes from 1992 to 1997. Functional capacity was constantly highest among those men and women who were employed in the mental work category (the mean difference between the physical and mental work categories was about three units).

There was some increase in the level of well-being from 1981 to 1997 in all occupational groups, both in men and in women, except among men in physical work (Table 3). On average, those who had previously done mentally demanding work had the highest level of well-being. The increase in the mean value of well-being from 1981 to 1997 was about one unit among those in the mental and mixed work categories and among women in physical work (Table 3).

To summarize the results of the univariate analysis, it can be said that activity level, functional capacity and well-being were lowest among those who had previously done mainly physically demanding work. The main changes occurred between 1981/85 and 1992 and they were similar in all groups. Activity level was highest in 1992, after which it decreased to its previous level; functional capacity, on the other hand was at the lowest but after 1992 its mean value began to rise again. Well-being increased steadily throughout the period.

The final study question covered the role of activity in maintaining a person's well-being, and how functional capacity might strengthen or weaken this relationship. To solve the problem, general linear models with repeated measurements were used. The final model included time (1985, 1992, 1997), level of activity, functional capacity, occupational status (occupationally active, disability pension and old-age pension) and number of diseases at different time points. Also age, gender and occupational history (physical, mental or mixed work categories) and all significant interactions were included. The estimates in Table 4 show how much each factor contributes to the average level of well-being.


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  		Table 4. The general linear model of well-being 1985–97

 
Activity level and functional capacity both had a strong positive effect on well-being (0.32 and 0.30, P < 0.001, respectively). The significant (negative) interaction between functional capacity and activity level (–0.01, P < 0.001) indicates that these factors depend inversely on each other, which means that an improvement in functional capacity would decrease the positive effect of activity and vice versa. Furthermore, both activity level and functional capacity were dependent on time. These interactions are included in Figure 2. In the case of activity level, the time-related impact was positive: if a person was able to maintain his or her activity level across time, its impact on well-being would be increasingly important. The effect of functional capacity was quite the opposite, meaning that the role of functional capacity in maintaining well-being would decline across time.


Figure 2
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  		Figure 2. The estimated effects of activity level and functional capacity on well-being at different time points.

 
There were some significant effects of background variables on well-being: co-morbidity had a negative effect on well-being; transition to retirement—due to either old age or disability—increased well-being. Age also had a positive effect. On the other hand, gender and the type of work did not have any effect on well-being during the follow-up time.


   Discussion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
Conflicts of interest
 References
 
The results indicate that time-related changes in activity and functional capacity do not inevitably decrease, at least not in the early years of retirement. When people retire, they may try out some new activities, but gradually the activity diminishes to its previous level. This is in concordance with Kelly's idea that at least the most valued personal activities are acquired during one's life course, and they are always long-standing [41], and thus permanent changes do not happen easily. The huge increase in physical activity during the follow-up may be explained partly by the fact that people's physical activities in general have been increasing steadily in Finland [42].

The changes in functional capacity over the follow-up were not clearly as negative as would be expected from research on ageing [43,44]. The decrease in functional capacity before the retirement may reflect the increasing conflict between the requirements of work and the functional capacities of ageing workers [14]. Likewise, the increase in functional capacity after the retirement could reflect the impact of retirement.

Involvement in activities and functional capacity both had a positive effect on well-being. These findings corroborate the activity theory of ageing (e.g. [45]) and the results of recent longitudinal studies [33,46]. The diverging time effects of these factors on well-being add an interesting viewpoint to this discussion. While the importance of activities became stronger as time passed, the effect of functional capacity steadily lost its significance as a contributor to well-being. This connection may mean that well-being is not necessarily completely tied to good physical functioning. The weakening of functional capacity may be compensated by increasing activities and vice versa. These findings are in concordance with research on age-related changes and personal ways of coping with these changes [47–49].

The strength of the statistical method used in this study (general model with repeated measures) becomes evident here. By including several periods of time in the analysis, it is possible to shed light on the period effects. It was also possible to include in the analysis all the variations in the independent and dependent factors at each period of time [50]. The advantages of this method are obvious: in a typical study setting, the end-point factor is explained by the baseline variables and the changes in variables between the follow-up periods are lost.

The proportion of men and those who had been engaged in mainly physically demanding work decreased during the follow-up. Multivariate analysis was done with a method [40] which allows the use of all available data at every time point. In this way, we could minimize the possible bias caused by the missing data. Another methodological fact which needs consideration is the replacement of the 1985 activity measure with 1981 information in the multivariate analysis. This was necessary because the questions were different in 1985. This is not, however, a significant source of bias since the time interval is only 4 years and the time period from 1981 to 1985 was still a steady occupationally active time for the respondents. The measure of well-being is based on two dimensions of the Occupational Stress Questionnaire which has been validated in clinical practice [35]. The items of functional capacity were standard ADL and IADL questions modified for middle-aged respondents which have proved their validity elsewhere [16,51].

To conclude, involvement in activities and functional capacity have an important, partly compensatory role in maintaining well-being. If this result is applied to ageing workers and to early retirement, it means that when functional capacity declines, it should be possible to adjust a person's work environment in such a way that after the day's work is done, they still have the energy and resources to take part in activities which are personally important.


   Conflicts of interest
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Conflicts of interest
References
 
None declared.


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Conflicts of interest
 References
 

  1. WHO. (2002) Active Ageing. A Policy Framework(World Health Organization, Geneva, Switzerland).

  2. Avramov D and Maskova M. (2003) Active Ageing in Europe(Council of Europe Publishing, Strasbourg, France).

  3. Ilmarinen J. (1999) Ageing Workers in the European Union—Status and Promotion of Work Ability, Employability and Employment(Finnish Institute of Occupational Health, Helsinki, Finland).

  4. Reday-Mulvey G. (2005) Working beyond 60. Key Policies and Practices in Europe(Palgrave Macmillan, Hampshire, England).

  5. In Gould R and Laitinen-Kuikka S (Eds.). Current Trends in Disability Pensions in Europe (2003) (Finnish Centre for Pensions, Helsinki, Finland).

  6. Walker A. (2001) Towards Active Ageing in the European Union. Millennium Project Workshop—Towards Active Ageing in the 21st Century(The Japan Institute of Labour, Tokyo, Japan).

  7. Davey JA. (2002) Active ageing and education in mid and later life. Ageing Soc 22:95–113.[CrossRef][Web of Science]

  8. Bowling A. (2005) Measuring Health. A Review of Quality of Life Measurement Scales 3rd edn (Open University Press, Maidenhead, England).

  9. Guralnik J and Ferrucci L. (2003) Assessing the building blocks of function. Utilizing measures of functional limitation. Am J Prev Med 25:Suppl. ii, 112–121.[Web of Science][Medline]

  10. Stuck A, Walthert J, Nikolaus T, Büla C, Hohmann C, Beck J. (1999) Risk factors for functional status decline in community-living elderly people: a systematic literature review. Soc Sci Med 48:445–469.[CrossRef][Web of Science][Medline]

  11. Hillsdon M, Brunner J, Guralnik J, Marmot M. (2005) Prospective study of physical activity and physical function in early old age. Am J Prev Med 28:245–250.[CrossRef][Web of Science][Medline]

  12. Heikkinen E. (1995) Healthy aging. Utopia or a realistic target. In Heikkinen E, Kuusinen J, Ruoppila I (Eds.). Preparing for Aging(Plenum Press, New York) pp. 105–119.

  13. Blaxter M. (2004) Health(Polity Press, Cambridge, UK).

  14. Ilmarinen J. (2001) Functional capacities and work ability as predictors of good 3rd age. In Shiraki K, Sagawa S, Yousef MK (Eds.). Physical Fitness and Health Promotion in Active ging(Backhuys Publishers, Leiden, the Netherlands) pp. 61–80.

  15. Ilmarinen J, Tuomi K, Seitsamo J. (2005) New dimensions of work ability. Int Cong Ser 1280:3–7.[CrossRef]

  16. Wang T-J. (2004) Concept analysis of functional status. Int J Nurs Stud 41:457–462.[CrossRef][Web of Science][Medline]

  17. Blaxter M. (1990) Health and Lifestyles(Tavistock, London).

  18. Jylhä M, Jokela J, Tolvanen E, et al. (1992) The tampere longitudinal study on ageing. Description of the study. Basic results on health and functional ability. Scand J Soc Med Suppl (Suppl. 47).

  19. Rautio N, Heikkinen E, Heikkinen R-L, et al. (2001) The association of socio-economic factors with physical and mental capacity in elderly men and women. Arch Gerontol Geriatr 33:163–178.[Web of Science][Medline]

  20. Rautio N, Heikkinen E, Ebrahim S. (2005) Socio-economic position and its relationship to physical capacity among elderly people living in Jyväskylä, Finland: five- and ten-year follow-up studies. Soc Sci Med 60:2405–2416.[CrossRef][Web of Science][Medline]

  21. Seitsamo J and Martikainen R. (1999) Changes in capability in a sample of Finnish aging workers. Exp Aging Res 25:345–352.[CrossRef][Web of Science][Medline]

  22. Van Praag BMS, Frijters P, Ferrer-i-Carbonell A. (2003) The anatomy of subjective well-being. J Econ Behav Organ 51:29–49.[CrossRef][Web of Science]

  23. Kashdan TB. (2004) The assessment of subjective well-being (issues raised by the Oxford Happiness Questionnaire). Pers Individ Dif 36:1225–1232.[CrossRef]

  24. Ervasti H. (2002) Unemployment, Subjective Well-Being and Job-Search. A Comparison of Denmark and Finland(Department of Social Policy, University of Turku, Turku, Finland).

  25. Goul Andersen J. (2002) Coping with long-term unemployment: economic security, labour market integration and well-being. Results from a Danish panel study, 1994 –1999. Int J Soc Welfare 11:178–190.[CrossRef]

  26. Diener E, Suh EM, Lucas RE, Smith HL. (1999) Subjective well-being: three decades of progress. Psychol Bull 125:276–302.[CrossRef][Web of Science]

  27. McAuley E, Blissmer B, Marquez DX, Jerome GJ, Kramer AF, Katula J. (2000) Social relations, physical activity, and well-being in older adults. Prev Med 31:608–617.[CrossRef][Web of Science][Medline]

  28. Boxtel MPJ, Langerak K, Houx PJ, Jolles J. (1994) Self-reported physical activity, subjective health, and cognitive performance in older adults. Exp Aging Res 22:363–379.[CrossRef]

  29. Gauvin L and Spence J. (1996) Physical activity and psychological well-being: knowledge base, current issues, and caveats. Nutr Rev 54:53–65.

  30. Burr JA, Caro FG, Moorhead J. (2002) Productive aging and civic participation. J Aging Stud 16:87–105.[CrossRef][Web of Science]

  31. Cooper L and Thomas H. (2002) Growing old gracefully: social dance in the third age. Ageing Soc 22:709–728.[CrossRef][Web of Science]

  32. Fisher BJ and Specht DK. (1999) Successful aging and creativity in later life. J Aging Stud 13:457–472.[CrossRef][Web of Science]

  33. Menec VH. (2003) The relation between everyday activities and successful aging. A 6-year longitudinal study. J Gerontol B Psychol Sci Soc Sci 58B:S74–S82.[Abstract/Free Full Text]

  34. Tuomi K, Ilmarinen J, Klockars M, et al. (1997) Finnish research project on aging workers in 1981 –1992. Scand J Work Environ Health 23:(Suppl. 1), 7–11.

  35. Elo A-L, Leppänen A, Ropponen T, et al. (1992) Occupational Stress Questionnaire: User's Instructions(Finnish Institute of Occupational Health, Helsinki, Finland).

  36. Rohmert W and Landau K. (1983) A New Technique for Job Analysis(Taylor & Francis, London).

  37. Ilmarinen J, Suurnäkki T, Nygård C-H, Landau K. (1991) Classification of municipal occupations. Scand J Work Environ Health 17:(Suppl. 1), 12–19.

  38. Tuomi K, Ilmarinen J, Jahkola A, Katajarinne L, Tulkki A. (1998) Work Ability Index(Finnish Institute of Occupational Health, Helsinki, Finland).

  39. Littell RC, Milliken GA, Stroup WW, Wolfinger RD. (1996) SAS System for Mixed Models(SAS Institute, Cary, NC).

  40. Little RJA and Rubin DB. (1987) Statistical Analysis with Missing Data(Wiley, New York).

  41. Kelly JR. (1987) Peoria winter: styles and resources in alter life. (DC Heath, Lexington, MA).

  42. Helakorpi S, Patja K, Prättälä R, Aro A, Uutela A. (2005) Health Behaviour and Health among the Finnish Adult Population, Spring 2004(National Public Health Institute, Helsinki, Finland).

  43. Savinainen M. (2004) Physical Capacity and Workload among Ageing Workers(University of Tampere, Tampere, Finland).

  44. In Sulander T (Ed.). Functional Ability and Health Behaviours (2005) (National Public Health Institute, Helsinki, Finland).

  45. Lemon BW, Bengtson VL, Peterson JA. (1972) An exploration of the activity theory of aging: activity types and life satisfaction among in-movers to a retirement community. J Gerontol 27:511–523.[Free Full Text]

  46. Lampinen P. (2004) Activity and Mobility as Associates and Predictors of Mental Well-Being among Older Adults [In Finnish with an English summary](University of Jyväskylä, Jyväskylä, Finland).

  47. Baltes PB and Baltes MM. (1990) Psychological perspectives on successful aging: the model of selective optimization with compensation. In Baltes PP and Baltes MM (Eds.). Successful Aging: Perspectives from Behavioural Sciences(Cambridge University Press, New York) pp. 1–34.

  48. Duke J, Leventhal H, Brownlee S, Leventhal EA. (2002) Giving up and replacing activities in response to illness. J Gerontol B Psychol Sci Soc Sci 57B:367–376.

  49. Staudinger UM, Marsiske M, Baltes PB. (1993) Resilience and levels of reserve capacity in later adulthood: perspectives from life-span theory. Dev Psychopathol 5:541–566.[Web of Science]

  50. Diggle P, Liang K-Y, Zeger SL. (1994) Analysis of Longitudinal Data(Claredon Press, Oxford).

  51. Malmberg J, Miilunpalo S, Vuori I, Pasanen M, Oja P, Haapanen-Niemi N. (2002) Improved functional status in 16 years of follow up of middle aged and elderly men and women in north eastern Finland. J Epidemiol Community Health 56:905–912.[Abstract/Free Full Text]


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