1. Is the relation between physical work exposure and
self-reported work ability dependent on age?
1st PEROSH Research Exchange in Warsaw
Thursday 22. October 2015
Bo Veiersted
Lars-Kristian Lunde
Markus Koch
Morten Wærsted
Stein Knardahl
Stami, Oslo, Norway

2. Outline:
Background
Methods
Preliminary results
Discussion

3. Background

4. Background The elderly part of the population increases
Many countries have increased the retirement age - or are planning to do so
These trends will increase demands on the working life, either by reducing harmful work exposures for all (to improve general work-related health) - or to make work places better fit to include elderly workers with reduced health
This concern may particularly be directed towards physically demanding work, as in the construction and health sector
The aim of this presentation is to evaluate if physical work exposure related to perceived work ability changes by age

6. Methods

7. Material/ methods Subjects Methods:
293 construction workers (93% male)
technical measurements of 64 subjects
301 health care workers (21% male)
technical measurements of 63 subjects
Methods:
Questionnaire at baseline and every 6 months
Technical measurements during work
Ground reaction force by force insoles
Muscle activity in neck and back by electromyography
Activity and work postures by accelerometers
Heart rate by «Actiheart»

8. Material/ methods Subjects Methods:
293 construction workers (93% male)
technical measurements of 64 subjects
301 health care workers (21% male)
technical measurements of 63 subjects
Methods:
Questionnaire at baseline and every 6 months
Technical measurements during work
Ground reaction force by force insoles
Muscle activity in neck and back by electromyography
Activity and work postures by accelerometers
Heart rate by «Actiheart»

9. Questionnaire Mechanical work exposure (sum index, 0-13)
Relative duration of work causing faster breathing
Relative duration in awkward postures
Both have grading; never or short time, proxy ¼, ½, ¾ and most of working day (5 cat.) (SN, 2013)
Lifting 20 kg daily
Grading; never, 1-4, 5-19 and ≥20 times (4 cat.) (SN, 2013)
Perceived heavy work
How physical demanding do you perceive your usual work (grading; 0, 0.5, … 10, >10; anchors, 13 cat.) (RPE10, Borg 1978)

10. Work ability and heart rate
Perceived work ability at present compared to your all time best
single question (graded; 0-10, 10 as best) (Nygård 2005)
Heart rate (HR) measured by «Actiheart»
Heart rate reserve (HRR) was calculated using minimum HR (during night), HR at work and age predicted maximal HR
(Åstrand 2003, Tanaka 2001)
%𝐻𝑅𝑅𝑤𝑜𝑟𝑘= (HRwork−HRmin) (HRmax−HRmin) x 100

11. Measurement setup Individual capacity:
Cycle ergometer test (Åstrand, 2003)
Isometric strength:
Arm abduction
Back extension
Hand grip
After finished work day most equipment is removed
- except 5 actigraphs to be kept on continuously for the next 4-5 days
Actiheart
These pictures shows the application of all systems. Like one can see the chosen measurement systems are very suitable for every day use on the work place. The hole equipment can be worn under the clothes and has to initiated and synchonized once in the beginning of the working shift. The data of all systems is getting collected on data loggers. This allows us to analyze and compare the data of each system over 8 hours.
Force
insoles

12. Preliminary results

13. Correlation between work load, work ability and age – all participants
Table 1 1 2 3 4
Age
N=590
N=593
N=105
N=569
1. Mechanical work exposure (Index, 0-13)
0.56**
0.28**
- 0.2**
- 0.05
2. Perceived heavy work (0-12)
0.31**
-0.25**
- 0.01
3. Heart Rate Reserve during work (%)
- 0.17
- 0.18
4. Work ability compared to best (0-10, 10 best)
0.01
Spearman’s rho; ** p<0.01

14. Mean work load and work ability - stratified by age group (SD, range)
Table 2
16-24
25-34
35-44
45-54
55-
N=33
N=132
N=154
N=164
N=103
Mechanical work exposure (Index, 0-13)
4.1
(2.7, 0-10)
2.8
(2.8, 0-11)
2.9
(2.8, 0-10)
3.1
2.6
(2.7, 0-9)
N=156
N=104
Perceived heavy work (0-12)
5.5
(1.3, 3-10)
4.8
(2.4, 1-11) 5
(2.4, 1-12)
5.2
(2.3, 1-12)
4.7
(2.1, 1-9)
N=9
N=20
N=31
N=27
N=18
Heart Rate Reserve during work (%) 38
(7, 25-45) 29
(8, 14-43)
(7, 17-47) 28
(6, 14-41)
(8, 14-44)
N=32
N=128
N=146
N=158
N=102
Work ability compared to best (0-10, 10 best)
8.7
(1.3, 5-10)
8.4
(1.7, 0-10)
8.2
8.6
(1.5, 2-10)
8.5
(1.5, 3-10)
60-
N=54
2.2
(2.5, 0-9)
N=55
4.5
(2, 1-9)
N=8 23
(7, 14-34)
N=56
8.7
(1.2, 5-10)

15. Work load and work ability Correlation between Perceived Work Ability (0-10) and work load measures
Table 3
16-24
25-34
35-44
45-54
55-
Mechanical work exp.
- 0.19
- 0.14
- 0.21**
- 0.18*
- 0.3**
Perceived heavy work
- 0.06
- 0.32**
- 0.22**
- 0.27**
Heart Rate Reserve during work
0.08
- 0.44
- 0.13
- 0.29
- 0.02
Spearman’s rho; * p<0.05, ** p<0.01

16. Conclusions
Reduced heavy work by age - indicated by both self-reports and a lower heart rate reserve during work
A weak but significant negative correlation between self-reported mechanical work exposures / perceived heavy work - and work ability, (except for the youngest age group?)
No consistent difference dependent on age

17. Discussion… Acknowledgement to external colleagues: Andreas Holtermann
Mikael Forsman
Svend Erik Mathiassen
Discussion…