Exposure–response relationship between work-related hand–arm vibration exposure and musculoskeletal disorders of the upper extremities: the German hand–arm vibration study

Figures & data

Figure 1. Sampling of cases and controls.

Table 1. Description of study population (n = 823).

Parameter		Cases	Controls
N	–	209	614
Age (years)	Mean (standard deviation)	53 (9)	52 (9)
	Median (range)	53 (22–84)	52 (22–83)
BMI (%)	≤25	17.2	22.0
	25–30	50.7	51.0
	>30	32.1	27.0
Comorbidity (%)	Gout*	14.4	9.0
	Pseudogout	0.5	0.5
	Finger/hand injury^†	39.7	25.7
	Elbow injury**	11.5	5.9
	Shoulder injury*	13.9	8.5
	Arm fracture	10.1	7.2
	Inflammatory disorder:
	Hand^†	26.3	5.7
	Elbow^†	23.9	5.5
	Shoulder^†	17.2	8.8
	Osteoporosis	2.4	1.6
	Knee osteoarthritis^†	28.7	15.0
	Hip osteoarthritis^†	10.1	3.6
	Spinal osteoarthritis^†	19.1	8.6
	Generalized osteoarthritis^†	23.0	4.1
	Rheumatism	6.2	4.4

*Test of difference (χ² test), p < 0.05.

**Test of difference (χ² test), p < 0.01.

^† Test of difference (χ² test), p < 0.001.

Note: BMI = body mass index.

Table 2. Quality of the historical exposure data.

Quality parameter	Cases	Controls
Total number of exposure sections	1863	3252
Exposure values based on direct measurements	1777 (95.4%)	3193 (98.2%)
Exposure values based on comparable devices^a	84 (4.5%)	56 (1.7%)
Exposure values based on similar devices^b	2 (0.01%)	3 (0.001%)

^a Technical power tools with the same designation, use, working material and in the same category of weight, power and rotational speed.

^b Technical power tools with the same designation, use and working material.

Figure 2. Comparability of vibration values of technical power tools used among cases and controls in a total of 5115 exposure sections: (a) a_hv and (b) a_hw. Note: a_hv = vibration exposure in a total of three measuring directions; a_hw = vibration exposure in the direction along the forearm.

Figure 3. Distribution of cumulative vibration exposures among cases and controls (n = 823): (a) D_hv and (b) D_h. Note: D_hv = cumulative vibration doses in three measuring directions; D_hw = cumulative vibration doses in the direction along the forearm.

Table 3. Hand–arm vibration exposure among cases and controls.

Exposure parameter	Cases	Controls
N	209	614
Employment duration (years)
Mean (SD)	24.95 (9.46)	23.86 (11.31)
Median (range)	26.33 (1.12–44.07)	25.49 (0.49–49.43)
Cumulative working hours^a
Mean (SD)	5,127 (4,234)	3,976 (5,202)
Median (range)	3,894 (40–24,169)	2,023 (18–35,576)
Daily vibration exposure values
ahv(8) (m/s^2)
n^b	1863	3252
Mean (SD)	8.91 (5.46)	7.24 (4.97)
Median (range)	8.36 (0.22–29.35)	6.48 (0.26–34.43)
ahw(8) (m/s^2)
n^b	1863	3252
Mean (SD)	5.28 (3.33)	4.15 (2.87)
Median (range)	5.00 (0.12–22.18)	3.83 (0.08–20.10)
Cumulative exposure doses
Dhv (m^2/s^4 •day)
Mean (SD)	355,093 (361,991)	239,227 (363,068)
Median (range)	241,152 (976–2,114,916)	121,995 (23–3,374,370)
Dhw (m^2/s^4 •day)
Mean (SD)	105,303 (99,962)	69,437 (116,440)
Median (range)	82,346 (398–716,980)	37,517 (3–1,703,120)

^a Cumulative working hours with technical power tools related to vibration exposure.

^b Number of exposure sections.

Note: a_hv(8) =daily vibration exposure in a total of three measuring directions; a_hw(8) = daily vibration exposure in the direction along the forearm; D_hv =cumulative vibration doses in a total of three measuring directions; D_hw = cumulative vibration doses in the direction along the forearm.

Table 4. Exposure–response relationship between cumulative vibration exposure (D_hv) and musculoskeletal disorders in the sense of occupational disease No. 2103.

		Unadjusted		Adjusted^a
Determinant	Cases/N	OR	95% CI	OR	95% CI
Joint injury^b	–	1.84	1.38–2.46	1.32	0.98–1.79
Joint inflammatory disorders^c	–	3.24	2.40–4.36	2.57	1.85–3.58
Generalized osteoarthritis	–	3.45	2.44–4.89	2.18	1.49–3.18
Dhv (m^2/s^4 •day)^d
1st quintile	20/165	1	–	1	–
2nd quintile	35/164	2.14	1.17–3.90	2.08	1.12–3.85
3rd quintile	46/165	3.10	1.72–5.59	2.66	1.45–4.88
4th quintile	40/164	2.77	1.52–5.06	3.31	1.78–6.13
5th quintile	68/165	5.03	2.83–8.93	5.65	3.06–10.42
Trend test	–	p < 0.0001		p < 0.001
100 m^2/s^4 •year increase		1.015	1.008–1.023	1.013	1.006–1.021

^a Adjusted for study centres and all variables in this table.

^b Injury of hand, elbow or shoulder joints.

^c Inflammatory disorder of hand, elbow or shoulder joints.

^d Cumulative vibration dose in a total of three measuring directions: 1st quintile, 23 to <29,000; 2nd quintile, 29,000 to <91,700; 3rd quintile, 91,700 to <222,800; 4th quintile, 222,800 to <418,000; 5th quintile, 418,000–3,374,370.

Note: CI = confidence interval; D_hv =cumulative vibration doses in a total of three measuring directions; OR = odds ratio.

Table 5. Exposure–response relationship between cumulative vibration exposure (D_hw) and musculoskeletal disorders in the sense of occupational disease No. 2103.

		Unadjusted		Adjusted^a
Determinants	Cases/N	OR	95% CI	OR	95% CI
Joint injury^b	–	1.84	1.38–2.46	1.33	0.98–1.80
Joint inflammatory disorders^c	–	3.24	2.40–4.36	2.53	1.81–3.53
Generalized osteoarthritis	–	3.45	2.44–4.89	2.20	1.51–3.20
Dhw (m^2/s^4 •day)^d
1st quintile	16/165	1	–	1	–
2nd quintile	27/164	1.93	1.02–3.67	1.73	0.89–3.33
3rd quintile	44/165	3.57	1.92–6.62	3.19	1.70–6.01
4th quintile	58/164	4.91	2.68–8.99	3.92	2.10–7.32
5th quintile	64/165	5.08	2.80–9.22	4.43	2.39–8.21
Trend test	–	p < 0.0001		p < 0.0001
100 m^2/s^4 •year increase		1.036	1.015–1.058	1.028	1.006–1.050

^a Adjusted for study centres and all variables in this table.

^b Injury of hand, elbow or shoulder joints.

^c Inflammatory disorder of hand, elbow or shoulder joints.

^d Cumulative vibration dose in the direction along the forearm: 1st quintile, 3 to <9880; 2nd quintile, 9880 to <30,900; 3rd quintile, 30,900 to <64,000; 4th quintile, 64,000 to <116,690; 5th quintile, 116,690–1,703,120.

Note: CI = confidence interval; D_hw = cumulative vibration doses in the direction along the forearm; OR = odds ratio.

Figure 4. Estimated exposure–response curves for (a) D_hv and (b) D_hw values. Note: CI = confidence interval; D_hv = cumulative vibration doses in three measuring directions; D_hw = cumulative vibration doses in the direction along the forearm.

Table 6. Expected excess risk of musculoskeletal disorders in the sense of occupational disease No. 2103 by cumulative hand–arm vibration exposure.

Expected excess risk	Dhv [95% CI] (m^2/s^4 •day)	Dhw [95% CI] (m^2/s^4 •day)
10% increase	≥19,600 [12,500–45,800]	≥5,300 [3500–11,100]
30% increase	≥53,900 [34,300–126,100]	≥14,700 [9600–30,600]
Doubling increase	≥142,300 [90,600–333,200]	≥38,724 [25,400–80,900]

Note: CI = confidence interval; D_hv =cumulative vibration doses in a total of three measuring directions; D_hw = cumulative vibration doses in the direction along the forearm.

Data availability

Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data are not available.