Background
Methods
Search strategy and study selection
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Population: employed adults.
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Exposure: biomechanical factors in the occupational context (exclusion: studies on diagnostic testing, treatment or rehabilitation).
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Outcome: CTS as primary outcome (exclusion: CTS as concomitant disease, e.g., in diabetes mellitus).
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Design: SRs and meta-analyses (exclusion: narrative reviews, editorials, commentaries).
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Population: employed adults.
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Exposure: consideration of at least one biomechanical exposure factor, giving degrees of association or raw data.
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Outcome: conservative CTS case definition: (a) abnormal findings in the nerve conduction study (NCS) that indicated dysfunction of the N. medianus in the carpal tunnel and (b) either clinical signs (a positive Phalen’s or Tinel’s sign) or symptoms indicative of CTS such as paraesthesia, numbness or pain.
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Design: peer review article with case control, cross-sectional and cohort studies.
Degree of overlap between the SRs
Author, year | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
---|---|---|---|---|---|---|---|---|---|---|
1. Abbas et al. 1998 [21] |
17
| 0 | 9 | 1 | 7 | 10 | 9 | 8 | 3 | 0 |
2. Sulsky et al. 2005 [44] |
34
| 12 | 3 | 12 | 14 | 6 | 13 | 0 | 3 | |
3. Palmer et al. 2007 [22] |
38
| 5 | 19 | 18 | 16 | 19 | 4 | 2 | ||
4. Thomsen et al. 2008 [45] |
9
| 4 | 4 | 1 | 3 | 1 | 3 | |||
5. Lozano-Calderón et al. 2008a [46] |
66
| 18 | 12 | 16 | 5 | 2 | ||||
6. van Rijn et al. 2009 [35] |
44
| 21 | 21 | 3 | 3 | |||||
7. Barcenilla et al. 2012 [41] |
37
| 22 | 3 | 0 | ||||||
8. Spahn et al. 2012a [31] |
55
| 2 | 1 | |||||||
9. You et al. 2014 [43] |
8
| 0 | ||||||||
10. Mediouni et al. 2014 [42] |
6
|
Quality assessment
Quality of evidence
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High – consistent evidence in very good SRs (at least one grade A review).
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Moderate – consistent evidence in good SRs (at least one grade B review).
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Low – one SR of moderate quality (at least grade C) and significant results and/or good SRs (grade B), with some inconsistent results.
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Poor – none of the above conditions were met (i.e., consistent findings in low-quality SRs (grade D), or inconsistent findings in multiple SRs).
Statistical analyses
Ethics
Results
SRs and meta-analyses
Author, year | Analysis | AMSTAR-R grade | Country | Years included | No. of studies included | Study designs | A priori quality criteria | The study’s aim was to … |
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You et al. 2014 [43] | MA | C | US | 1980–2012 | n = 8 | CC = 2; CS = 6 | Recognition of bias by sensitivity analysis | ... conduct a meta-analysis of existing studies to evaluate the evidence of the relationship between wrist posture at work and CTS |
Mediouni et al. 2014 [42] | MA | B | FR | 1992–2012 | n = 6 | C = 2; CS = 4 | Strengths and limitations acknowledged | ... conduct a systematic review and meta-analysis of the available epidemiological data on the association between computer work exposure and CTS |
Barcenilla et al. 2012 [41] | MA | B | AU | 1980–2009 | n = 37 | C = 3; CC = 5; CS = 28 | Risk of Bias Tool | ... examine the association between workplace exposure and CTS by meta-analysis, with respect to exposure to hand force, repetition, vibration and wrist posture |
Spahn et al. 2012 (in German) [31] | MA | C | DE | ≤2011 | n = 55 | n/a | n/a | ... conduct a systematic review and meta-analysis to identify associated and risk factors for CTS in the occupational setting |
Van Rijn et al. 2009 [35] | SR | B | NL | 1966–2007 | n = 44 | C = 5; CC = 9; CS = 30 | 16-item score | ... provide a quantitative assessment of the exposure-response relationship between work-related physical and psychosocial factors and the occurrence of CTS in occupational populations |
Lozano-Calderón et al. 2008 [46] | SR | D | US | ≤2008 | n = 51a; n = 33b; (total = 66) | C = 7a; CC = 12a; C = 29a; Other = 3a | Bradford Hill criteria for causation | ... evaluate the quality and strength of scientific evidence supporting an aetiological relationship between a disease and a proposed risk factor, using a scoring system based on the Bradford Hill criteria for causal association – example of CTS |
Thomsen et al. 2008 [45] | SR | C | DK | ≤2004 | n = 8 | C = 4; CC = 2; CS = 2 | Selected criteria (4 main domains) | ... conduct a systematic review to examine evidence for an association between computer work and CTS |
Palmer et al. 2007 [22] | SR | C | GB | ≤2004 | n = 38 | n/a | n/a | ... conduct a systematic review to assess occupational risk factors for CTS |
Sulsky et al. 2005 [44] | SR | C | DE | 1997–2003 | n = 34 | C = 10; CC = 2; CS = 22 | Selected criteria (6 main domains) | ... clarify the relationship between CTS and occupation using quality based criteria from the epidemiological literature |
Abbas et al. 1998 [21] | MA | D | US | 1980–1995 | n = 17 | C = 3; CC = 4; CS = 10 | n/a | ... conduct a meta-analysis on work-related CTS and to identify risk estimates and possible biases influencing the risk estimates |
Author, year, ↓quality | Vibration (95 % CI) | Repetition (95 % CI) | Force (95 % CI) | Combined exposure (repetition and force) (95 % CI) | Wrist posture (95 % CI) | Computer exposure (95 % CI) |
---|---|---|---|---|---|---|
Barcenilla et al. 2012 [41] Grade B | NIOSH CTS def.: OR 2.7 (1.9–3.9); n = 12 studies Conservative CTS def.a: OR 5.4 (3.1–9.3); n = 3/3 (100 %) studiesd | NIOSH CTS def.: OR 2.3 (1.8–3.0); n = 25 studies Conservative CTS def.a: OR 2.3 (1.7–2.9); n = 5/11 (45 %) studiesd | NIOSH CTS def.: OR 2.2 (1.5–3.3); n = 13 studies Conservative CTS def.a: OR 4.2 (1.5–11.7); n = 3/5 (60 %) studiesd | NIOSH CTS def.: OR 2.0 (1.4–2.9); n = 4/9 (44 %) studiesd Conservative CTS def.a: OR 1.9 (1.0–3.5); n = 5 studies | NIOSH CTS def.: OR 2.7 (1.3–5.5); n = 7 studies Conservative CTS def.a: OR 4.7 (0.4–53.3); n = 1/3 (33 %) studiesd | / |
Mediouni et al. 2014 [42] Grade B | / | / | / | / | / | Computer use: OR 1.7 (0.8-3.6); n = 5 studies; Keyboard/mouse use: OR 1.1 (0.6–2.0); OR 1.9 (0.9–4.2) |
Van Rijn et al. 2009 [35] Grade B | OR 2.5–4.8; n = 3/5 (60 %) studiesd | OR 0.5–9.4; n = 5/8 (62 %) studiesd | OR 2.1–9.0; n = 3/7 (43 %) studiesd | OR 3.2–8.4; n = 3/4 (80 %) studiesd | OR 1.3–8.7; n = 4/5 (80 %) studiesd | OR 2.1–4.4; n = 2/7 (29 %) studiesd |
You et al. 2014 [43] Grade C | / | / | / | / | Non-neutral wrist postures: RR 2.0 (1.7–2.4); n = 4/8 (50 %) studiesd | / |
Spahn et al. 2012 [31] Grade C | OR 2.6 (1.7–4.0); n = 6/9 (67 %) studiesd | OR 2.7 (1.8–3.9); n = 11/13 (85 %) studiesd OR 2.1 (0.4–11.8); n = 3 cohort studies | OR 4.4 (1.4–13.6); n = 4/4 (100 %) studiesd | OR 8.4 (7.8–8.9)b; n = 2/2 (100 %) studiesd OR 1.8 (1.4–2.2)b; n = 2/3 (67 %) cohort studiesd | Flexion: OR 1.7 (1.0–2.6); n = 2/5 (40 %) studiesd | Computer use: OR 1.8 (0.8–4.1); n = n/a studies |
Sulsky et al. 2005 [44]c Grade C | Insufficient evidence; n = 1 study | Consistent small positive association; n = 6 studies | Weak positive association of questionable validity; n = 3 studies | / | Insufficient evidence; n = 1 study | Insufficient evidence; n = 2 studies |
Thomsen et al. 2008 [45] Grade C | / | / | / | / | / | Inconsistent evidence: OR < 1; n = 1 studies; OR > 1; n = 3 studies and n = 4 studies with no effect calculation or n.s. |
Palmer et al. 2007 [22] Grade C | ≥2 OR elevated risk (e.g., exposure ≥8 years); n = 7 studies | ≥2 OR elevated risk (e.g., exposure <10 s. cycle time); n = 5 studies | Elevated risk for high-force jobs and activities (e.g., exposure >4 kg); n = n/a studies | Elevated risk for jobs with combined exposure; n = 1 study | ≥2 OR elevated risk (e.g., exposure >17 or 20 h/week); n = 4 studies | Inconsistent results; n = 4 studies |
Abbas et al. 1998 [21] Grade D | / | Significant predictor | Significant predictor | / | / | / |
Lozano-Calderón et al. 2008 [46] Grade D | Ø OR 5.5; qBHs 6.3/21 points (range 5–8); n = 14/20 (70 %) studiesd | Ø OR 4.0; qBHs 6.5/21 points (range 5–10); n = 30/45 (67 %) studiesd | Ø OR n/a; qBHs 4.5/21 points (range 3–6); n = 15/31 (48 %) studiesd | / | Flexion: Ø OR n/a; qBHs 5.4/21 points (range 4–8); n = 7/17 (41 %) studiesd Extension: Ø OR n/a; qBHs 3.6/21 points (range 3–4); n = 3/7 (43 %) studiesd | / |
Current primary studies
Author, year | Design | Country | Study population | Outcome | Exposition | Main results from multivariate analyses (95 % Confidence Interval) | Confounder | Quality |
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Burt et al. 2011 [48] | CS (baseline) | US | n = 464 workers from hospital servicea, engine and bus plant workplaces | Abnormal NCS + symptoms (hand diagram) | ACGIH TLV for HAL; Exertion/min. or time in %)b; Peak force (% time)c; Flexion/Extension (% time)d; Vibration (observed yes/no) | Peak force ≥20 % vs. <20 %: OR 1.3 (0.6–3.0); peak force ≥70 % vs. <20 %: OR 2.7 (1.3–5.7); exertion ≥15/min vs. <10/min if BMI ≥30: OR 3.4 (1.1–9.9); perceived exertion (unit increase): OR 1.14 (1.0-1.3); ≥AL- < TLV vs. <AL: OR 2.3 (0.6-8.9); ≥TLV vs. <AL: OR 3.0 (1.5–5.8); HAL (unit increase) if male: OR 1.4 (1.1–1.8) | Sex; BMI ≥ 30; arthritis; high blood pressure | High (16/20) |
Burt et al. 2013 [47] | Cohort (2-years) | US | n = 347 workers from hospital servicea, engine and bus plant workplaces | Abnormal NCS + symptoms (hand diagram) | ACGIH TLV for HAL; TLR; Exertion/min. or time in %)b; Peak force (% time)c; Flexion/Extension (% time)d; Vibration (observed yes/no) | Exertion/min. ≥20 % vs <20 %: HR 2.8 (1.2-6.8); exertion/min. ≥60 % vs. <20 %: HR 19.6 (6.0–64.2); TLR (unit increase): HR 1.4 (1.1-1.8) | BMI ≥ 30; job strain | High (19/20) |
Garg et al. 2012 [49] | Cohort (6-years) | US | n = 551 workers from processing, assembly, manufacturing workplaces | Abnormal NCS + symptoms (intensity ≥25 %/d + duration ≥2 month) | ACGIH TLV for HAL; SI score | ≥AL- < TLV vs. <AL: HR 1.4 (0.6-3.8); ≥TLV vs. <AL: HR 2.0 (0.8-5.0); SI score >6.1 vs. <6.1: HR 2.5 (1.0-6.1); | Age; BMI ≥ 30; gardening; depression; co-morbidity (other MSDs; arthritis) | High (18/20) |
Evanoff et al. 2014 [51] | Cohort (3-years) | US | n = 1107 newly hired workers from construction, technical, laboratory, clerical and hospital service workplaces | Abnormal NCS + symptoms (hand diagram) | Job title based exposure on data from O*NET (job title and requirements): repetitive motion (5-point); static/ dynamic strength (7-point) | Results for most recent jobs (≤6 months): repetitive motion: OR 3.3 (1.4–7.8); static strength: OR 4.4 (1.4–13.9); dynamic strength: OR 3.6 (1.04-12.4); | Age; sex; BMI | Moderate (13/20) |
Bonfiglioli et al. 2013 [50] | Cohort (2-years) | IT | n = 2194 workers from factories producing domestic appliances and nursery school | Abnormal NCS + symptoms (hand diagram) | ACGIH TLV for HAL; vibration (observed yes/no) | ≥AL- < TLV vs. <AL: IRR 2.0 (1.2–3.2); ≥TLV vs. <AL: IRR 2.7 (1.5–4.9); HAL (unit increase): IRR 1.4 (1.2–1.6); peak force (unit increase): IRR 1.3 (1.1–1.6) | Age; sex; BMI; predisposing diseases (0 vs. ≥1) | High (17/20) |
Coggon et al. 2013 [53] | CC | GB | n = 475 patients; n = 799 controls | Abnormal NCS + symptoms (duration ≥1 month) | Repeated movements of wrist >4 h/day; repeated bending of elbow >1 h/day; keyboard/ mouse use >4 h/day; vibration >1 h/day | Repeated movements: OR 1.5 (1.1–1.9); vibration: OR 2.4 (1.6–3.8) | Age; sex; BMI; ethnicity; smoking; other diseases, somatic symptoms; mental health; psychosocial factors | Moderate (9/20) |
Goodson et al. 2014 [52] | CC | US | n = 87 patients; n = 74 controls | Abnormal NCS + symptoms | Repetition; force; repetition + force combined; vibration; total occupational exposure | Repetition: OR 1.8 (1.5–2.2) | Age, BMI, job satisfaction, vigorous exercise; exercise strain; physical activities | Moderate (12/20) |