Table 1 Papers selected in the final round

Bennnet 1982

United Kingdom

Cross sectional

Physical examination (inspection, scheme and chart)

Job title and precise questionnaire

216 workers in PVC bagging and 84 others

17 (16 in bagging -1 in the control group)

Manual work

14*

Bagging plant vs non-bagging plant

5.5

0.8

36.7

Confounders

Exposure imprecise

Gudmundsson 2000 (1)

Iceland

Cohort

Physical examination (two stages of severity)

Self-administered questionnaire, checked with specially trained secretary (Reykjavik Study)

1297 men including 128 manual workers and 126 tradesmen

249 (including 38 in manual labor, 36 tradesmen)

16*

Manual labor (seamen. farmers) vs controls

1,75

1,14

2,7

Cohort, confounders

Exposure assessment

Gudmundsson 2000 (2)

Iceland

Cohort

Physical examination (two stages of severity)

Self-administered questionnaire, checked with specially trained secretary (Reykjavik Study)

1297 men including 128 manual workers and 126 tradesmen

249 (including 38 in manual labor, 36 tradesmen)

16*

Skilled trades (masons. carpenters, blacksmith) vs controls

1,91

1,24

2,96

Cohort, confounders

Exposure assessment

Godtfredsen 2004

Denmark

Cohort

Physical examination (trained nurses or MD student)

Self-administered questionnaire in a large study (Copenhagen City Heart Study)

7254 participants, 2923 low education ** (280 highly physical job)

772

14*

Low education ** level (considered as a proxy for manual labor) vs high

1.6

1.22

2.1

Cohort, confounders

Exposure assessment considered as a proxy for manual work

Lucas 2008 (1)

France

Cross sectional

Physical examination (occupational physician)

Detailed interview

2406 men working for the equipment ministry (643 highly exposed to force, and 350 highly exposed to vibrations)

212 (including 106 in high exposure group and 47 in high vibration group)

14*

High cumulative work exposure vs low ***

3.1

1.99

4.84

Exposure, dose -response relationship, confounders and study of interactions

Cross sectional, smoking missing, included manual work

Herzog 1951 (1)

United Kingdom

Cross sectional

Physical examination (by the author only)

Job title but individual visit to works and offices

503 steelworkers (men over 40 years), 451 miners (men over 40 years), and 480 clerks (men over 40 years, controls)

61 (22 steelworkers and 21 miners)

6

Steelworkers vs clerical

1.2

0.6

2.3

First large published epidemiological study

Exposure assessment, confounders

Herzog 1951 (2)

United Kingdom

Cross sectional

Physical examination (by the author only)

Job title but individual visit to works and offices

503 steelworkers (men over 40 years), 451 miners (men over 40 years), and 480 clerks (men over 40 years, controls)

61 (22 steelworkers and 21 miners)

6

Miners vs clerical

1.3

0.6

2.5

First large published epidemiological study

Exposure assessment, confounders

Early 1962

United Kingdom

Cross sectional

Physical examination (inspection, palpation, system of staging described)

Job title in similar workplace (office vs locomotive works)

4454 manual workers at locomotive works and 423 male office workers (<65 years)

151 (134 in Crewe locomotive works with manual work, 17 in office)

7

Manual vs clerical

0.98

0.6

1.7

Large sample

Exposure assessment, confounders

Mikkelsen 1978

Norway

Population survey

Physical examination with a staging scheme

From records of occupation, different levels of exposure assessed by interview

6888 men (including 477 with heavy manual work) and 4120 women (including 6 with heavy manual work)

647 men with DC (including 70 in heavy manual work) and 254 women with DC (including 1 in heavy manual group)

11

Heavy work vs light**** (men and women)

3.1

2.2

4.4

Dose -response relationship (severity and exposure)

Except for age, no confounders taken into account, and no duration of exposure

Attali 1987

France

Cross sectional

Physical examination by gastroenterologist (three stages of severity)

Detailed interview

432 patients- 258 with liver disorders and 174 controls, 42.1% of these being manual workers

78 (56 with liver disease and 22 controls)

10

Manual workers

2.46

1.49

4.06

Large number of cases

Exposure assessment, confounders

Niezborala 1995 (1)

France

Case-control

Physical examination

Precise questionnaire

227 patients including 43 with high forceful work in their longest job

121 (including 29 in the high exposure group)

12

Case control study (masons and lumberjacks vs others, longest job)

2.41

1.18

4.92

Information on length of exposure, confounders

Statistical analyses used for confounders

Niezborala 1995 (2)

France

Cross sectional

Physical examination (and severity score)

Precise questionnaire

324 workers, with 191 builders or farmers and 133 non-manual work

31 (including 28 in the exposed group)

11

Cross sectional study (exposed = builders and farmers vs others)

7.5

2.21

24.7

Information on length of exposure, confounders

Statistical analyses used for confounders

Cocco 1987

Italy

Case-control

Physical examination (definite contracture only)

Detailed interview

14557 patients from Occupational health institute, 80 workers with >20 years of vibration exposure; 150 non-exposed

180 (paired with 180 controls on sex, age, date of hospitalization)

Vibration exposure

14*

>20 years of exposure vs controls

3

1.3

6.7

Case control study, dose -response relationship, exposure information

Confounder analysis

Bovenzi 1994 (1)

Italy

Cross sectional

Physical examination (no detail)

Detailed interview and measurement of vibration levels

145 quarry-drillers and 425 stone carvers, 258 controls

66 (57 in workers group, 9 controls)

14*

Quarry-drillers vs controls

2.58

1.07

6.2

Dose -response relationship, exposure information, confounder analysis

Cross sectional design

Bovenzi 1994 (2)

Italy

Cross sectional

Physical examination (no detail)

Detailed interview and measurement of vibration levels

145 quarry-drillers and 425 stone-carvers, 258 controls

66 (57 in workers group, 9 controls)

14*

Masons and stone-carvers vs controls

2.6

1.24

5.49

Dose -response relationship, exposure information, confounder analysis

Cross sectional design

Lucas 2008 (2)

France

Cross sectional

Physical examination (occupational physician)

Detailed interview

2406 men working for the equipment ministry (643 highly exposed to force, and 350 highly exposed to vibrations)

212 (including 106 in high exposure group and 47 in high vibration group)

14*

High cumulative vibration exposure vs low***

1.82

1.24

2.68

Exposure, dose -response relationship, confounders and study of interaction

Cross sectional, lack of blindness, smoking missing

Chanut 1963

France

Cross sectional

Physical examination (inspection, palpation, system of staging described)

Detailed interview

180 stonemasons, 13500 clerks

378 (25 stonemasons, 130 clerks and 223 others)

10

Stone masons vs others

14.57

9.53

22.51

Clinical details

Exposure assessment, confounders

Thomas 1992

United Kingdom

Cross sectional

Physical examination (no detail)

Detailed interview

311 claimants considered to have Vibration white fingers and aged from 50-85 years (and considered as exposed to vibration) and 150 hospital control group

78 (62 in the exposed group)

6

Vibration-exposed vs hospital admission

2.1

1.1

3.9

Dose -response relationship, duration of exposure)

Confounders analysis and selected case for dose-response relationship

Seidler 2001

Germany

Case-control

Physical examination (hand surgery center)

Detailed interview

Cases from two clinics, with 33 males exposed to vibration (over 20 h/week and over 20 years)

317 (including 17 exposed to vibration > 20 h/week and over 20 years)

12

>20 h/week over 20 years of vibration

1.3

0.6

2.7

Confounders and different job exposure

Selection bias, exposure assessment