Impacts of differences in epidemiological case definitions on prevalence for upper-extremity musculoskeletal disorders

Musculoskeletal disorders and its associated factors among hospital cleaners in Addis Ababa, Ethiopia

There is a paucity of published evidence about musculoskeletal disorders among hospital cleaners in Ethiopia. Therefore, this study was conducted to assess the prevalence of musculoskeletal disorders and its associated factors among hospital cleaners in Addis Ababa, Ethiopia. A total of 437 hospital cleaners participated in the study. A standardized questionnaire adapted from the Nordic musculoskeletal questionnaire was used for data collection. Bivariate and multivariable logistic regression analyses were used to determine factors associated with musculoskeletal disorders. The prevalence of work-related musculoskeletal disorders among hospital cleaners was 57.2% with 95% CI (52.6-62.0). Occupational safety training [AOR: 2.34, 95% CI (1.47-3.73)], repetitive tasks [AOR: 3.09, 95% CI (1.61-5.94)], heavy lifting [AOR: 5.21, 95% CI (3.20-8.48)], work-related stress [AOR: 2.42, 95% CI (1.48-3.97) and work-related dissatisfaction [AOR: 1.97, 95% CI (1.23-3.13)] were identified as associated factors for the development of musculoskeletal disorders. In conclusion the study revealed a high prevalence of musculoskeletal disorder. Notably, work related and organizational factors emerged as key contributing factors to the development of disorders. The identified associations underscore the importance of targeted interventions promoting organizational change involving managers to mitigate the risk of musculoskeletal disorders and enhance overall occupational health and well-being.

Work-Related Risk Factors for Rotator Cuff Syndrome in a Prospective Study of Manufacturing and Healthcare Workers

OBJECTIVE

This prospective study assessed the risk of developing rotator cuff syndrome (RCS) with separate or specific combinations of biomechanical exposures measures, controlling for individual confounders.

BACKGROUND

Compared with other musculoskeletal disorders, rates of work-related shoulder musculoskeletal disorders have been declining more slowly.

METHOD

We conducted up to 2 years of individual, annual assessments of covariates, exposures, and health outcomes for 393 U.S. manufacturing and healthcare workers without RCS at baseline. Task-level biomechanical exposures assessed exposure to forceful exertions (level, exertion rates, duty cycles), vibration, and upper arm postures (flexion, abduction). Hazard ratios (HRs) were calculated with Cox proportional hazard models.

RESULTS

We observed 39 incident RCS cases in 694 person-years (incidence rate = 5.62 per 100 person-years). Adjusting for confounders, we found increased risk of incident RCS associated with forceful hand exertions per minute for three upper arm posture tertiles: flexion ≥45° (≥28.2% time, HR = 1.11, CI [1.01, 1.22]), abduction ≥30° (11.9-21.2%-time, HR = 1.18, CI [1.04, 1.34]), and abduction >60° (≥4.8% time, HR = 1.16, CI [1.04, 1.29]). We failed to observe statistically significant effects for other interactions or any separate measures of biomechanical exposure.

CONCLUSION

This study highlights the importance of assessing combinations of exposure to forceful repetition and upper arm elevation when developing interventions for preventing RCS.

APPLICATION

Based on these results, interventions that reduce exposure to forceful repetition (i.e., lower force levels and/or slower exertion rates) may reduce the risk of RCS, especially when upper arm elevation cannot be avoided.

The Test-Retest Reliability of the Pieterse Protocol Return to Flight Assessment for Cabin Crew

INTRODUCTION: The purpose of this study was to assess test-retest reliability of the Pieterse return to flight duty protocol for cabin crew to return to flight duties.METHOD: Flight attendants between 20–50 yr old were included if they underwent rehabilitation at the musculoskeletal rehabilitation unit for a musculoskeletal injury, surgical treatment for orthopedic trauma or industrial injuries, and were assessed by the treating physical therapist and aviation medical examiner to be ready for return to work. Test-retest reliability was calculated with the Fleiss kappa coefficient.RESULTS: Included were 18 flight attendants (10 men, 34.9 ± 6.3 yr; 8 women, 34.2 ± 3.4 yr). Eight participants were rehabilitated following upper extremity injury, eight following lower extremity, and two following both upper and lower extremity injury. Perfect test-retest reliability was observed for nine items; kappa values above 0.9 were observed for three items; one item had a kappa value above 0.8 and two items had a kappa value of 0.78. The results for all 15 items were highly significant, demonstrating that the Fleiss kappa coefficients were significantly different from zero. The kappa coefficient strength of agreement was almost perfect for 13 and substantial for the remaining 3 items. Overall test-retest reliability was 0.95.DISCUSSION: This study demonstrated almost perfect test-retest reliability for 13 items and substantial reliability for two items, with an overall test-retest reliability of 0.95 for a return to flight assessment for flight attendants. The Pieterse protocol is a reliable tool to establish return to work for cabin crew.Hohmann E, Tetsworth K, Pieterse R. The test-retest reliability of the Pieterse protocol return to flight assessment for cabin crew. Aerosp Med Hum Perform. 2022; 93(7):551–556.

Physio- und sporttherapeutische Interventionen zur Behandlung eines Karpaltunnelsyndroms

Hintergrund

Die Behandlung des Karpaltunnelsyndroms (KTS) besteht in der Regel in einer operativen Dekompression des Nervs oder Schienung und einer zusätzlichen medikamentösen Therapie. Physio- und Sporttherapie können eine nichtinvasive und gleichzeitig nebenwirkungsarme Alternative darstellen.

Ziel

Die vorliegende Übersichtsarbeit fasst aktuelle Studien zur Wirksamkeit von physio- und sporttherapeutischen Interventionen für die Therapie des KTS systematisch zusammen und fokussiert auf die Reduktion der Symptome sowie als sekundäres Outcome auf die Verbesserung der Funktionalität der Hand.

Material und Methoden

Das systematische Review integriert randomisierte, kontrollierte Studien mit physio- oder sporttherapeutischen Interventionen, die in den elektronischen Datenbanken PubMed, CINAHL und Web of Science bis Februar 2021 publiziert wurden. Den Richtlinien von Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) und der Cochrane Collaboration folgend wurden eine systematische Suche der Literatur, eine Datenextraktion und eine Bewertung des „risk of bias“ anhand des Cochrane Risk of Bias Tool von zwei unabhängigen Reviewern durchgeführt.

Ergebnisse

Von 461 identifizierten Studien konnten n = 26 in die qualitative Analyse einbezogen werden. Das Biasrisiko über die einzelnen Studien ist als moderat bis gering einzustufen. Verzerrungspotenzial ergibt sich teilweise durch eine unzureichende Verblindung der Patient:innen und des Studienpersonals sowie durch eine selektive Berichterstattung der Studienergebnisse und der Durchführung. Die manuelle Therapie erwies sich im Vergleich zu einem operativen Eingriff als schneller und langfristig gleichermaßen zielführend in Bezug auf Schmerzreduktion und Funktionsverbesserung. Auch Mobilisationstechniken, Massagetechniken und das Kinesiotaping sowie Yoga als therapeutische Interventionen zeigten positive Effekte.

Schlussfolgerung

In der Therapie eines leichten bis mittelschweren KTS zeichnen sich physio- und sporttherapeutische Interventionen vor allem durch Erfolge bereits nach 2‑wöchiger Behandlung aus, zudem durch vergleichbare Erfolge wie nach operativem Eingriff und 3‑monatiger postoperativer Behandlung. Zudem sind Patient:innen keinen Operationsrisiken ausgesetzt. Das Review ist im International Prospective Register of Systematic Reviews (PROSPERO) mit der Nr. 42017073839 registriert.

Towards harmonisation of case definitions for eight work-related musculoskeletal disorders - an international multi-disciplinary Delphi study

Background

International consensus is needed on case definitions of work-related musculoskeletal disorders and diseases (MSDs) for use in epidemiological research. We aim to: 1) study what information is needed for the case definition of work-related low back pain (LBP), lumbosacral radicular syndrome (LRS), subacromial pain syndrome (SAPS), carpal tunnel syndrome (CTS), lateral and medial elbow tendinopathy, and knee and hip osteoarthritis, and to 2) seek consensus among occupational health professionals/researchers regarding the case definitions of these work-related MSDs.

Methods

A two-round Delphi study was conducted with occupational health professionals/researchers from 24 countries. Definition of work-related MSDs were composed of a case definition with work exposures. Round 1 included 32 case definitions and round 2, 60 case definitions. After two rounds, consensus required 75% of the panellists to rate a case definition including work exposures ≥7 points on a 9-point rating scale (completely disagree/completely agree).

Results

Fifty-eight panellists completed both rounds (response rate 90%). Forty-five (70%) panellists thought that for LBP a case definition can be based on symptoms only. Consensus was only reached for work-related medial elbow tendinopathy, while the lowest agreement was found for knee osteoarthritis. Where consensus was not reached, this was – except for LBP - related to physical examination and imaging rather than disagreement on key symptoms.

Conclusion

Consensus on case definitions was reached only for work-related medial elbow tendinopathy. Epidemiological research would benefit from harmonized case definitions for all MSDs including imaging and physical examination for LRS, SAPS, CTS, lateral elbow tendinopathy and hip and knee osteoarthritis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04871-9.

Criteria for diagnosis and attribution of an occupational musculoskeletal disease

BACKGROUND

Criteria for diagnosis and compensation of occupational musculoskeletal diseases varies widely between countries as demonstrated by the large differences between countries with comparable economics and social systems (for example, within the European Union). Several countries have a list of occupational diseases and sometimes these lists include diagnostic and attribution criteria, but these criteria are usually not very specific, and they may also be very different.

OBJECTIVES

The aim of this paper is to explicitly define what are the information needed for an evidence-based diagnosis and attribution of an occupational musculoskeletal disease.

METHODS

Based on the general framework of evidence-based medicine, a review is presented of the information required to define: - when a musculoskeletal disease is present, according to the best available techniques; - how to define a relevant exposure to biomechanical risk factors, according to the best available techniques.

RESULTS

Criteria are presented to combine information regarding the diagnosis of a musculoskeletal disease and exposure to biomechanical risk factors for an evidence-based attribution of the disease to the occupational exposure. The criteria use a probabilistic model that combine epidemiologic and medical findings, workplace exposure assessment, and non-occupational factors evaluation.

DISCUSSION

The use of the proposed criteria may improve the process of diagnosis and attribution of an occupational musculoskeletal disease. In addition, it makes possible to associate a probability rank to the attribution and, ultimately, it may improve the overall quality of the decisional process of the occupational physician.

Disability and functioning assessment of women with RSI/WRMSDs: the use of the ICF checklist

Background:

Comprehensive approaches using the International Classification of Functioning, Disability and Health (ICF) Checklist have been adopted to give more visibility to demands related to specific health situations.

Objective:

To analyze the incapacity and functioning associated with activity/participation and environmental factors of female workers with repetitive strain injury/work-related musculoskeletal disorders (RSI/WRMSDs) using workers’ narratives, ICF codes and the RSI/WRMSDs Checklist developed as a part of the present research project.

Methods:

A qualitative analysis of in-depth interviews with 15 female workers diagnosed with RSI/WRMSDs was completed. Functioning and disability were assessed by linking ICF codes identified in the participants’ narratives to those included in the RSI/WRMSDs Checklist.

Results:

Fifty-three of 60 ICF codes included in the RSI/WRMSDs Checklist were detected in the participants’ narratives. Related to activity/participation, 26 codes were identified and 27 related to environmental factors.

Conclusion:

These results highlight the significance of the RSI/WMSDs Checklist to detect clinical and social problems experienced by workers during the rehabilitation and return-to-work process. They also reinforce the relevance of expanding the application of the checklist to male and female workers with RSI/WRMSDs undergoing rehabilitation to attain other levels of validation.

Musculoskeletal Disorders and Associated Factors among Vehicle Repair Workers in Hawassa City, Southern Ethiopia

Background

Vehicle repair work is one of the highest risk professions for work-related musculoskeletal disorders. Globally, only a few published studies have examined the prevalence and determinants of work-related musculoskeletal disorders among vehicle repair workers. Related studies in Ethiopia are even fewer. This study aimed to determine the prevalence of self-reported work-related musculoskeletal disorders and associated factors among vehicle repair workers in Hawassa city, South Ethiopia, 2019.

Methods

An institution-based cross-sectional study was conducted among 344 vehicle repair workers in the Hawassa city. The Nordic Musculoskeletal Questionnaire-Extended (NMQ-E) was used to assess work-related musculoskeletal disorders on nine body regions. Descriptive statistics and multivariable analyses were used to characterize the data and identify factors associated with work-related musculoskeletal disorders.

Result

The twelve-month prevalence of work-related musculoskeletal disorders among this working group was 47.7% with 95% CI (42.7-53.2). Jobs continuously requiring repetitive motions (AOR: 4.29, 95% CI (1.78-10.2)), not having professional training (AOR: 2.04, 95% CI (1.09-3.81)), force exertion when using tools (AOR: 2.40, 95% CI (1.24-4.62)), job stress (AOR:4.54, 95% CI (2.44-8.46)), and regularly lifting, pushing, and pulling loads greater than 20 kg (AOR:4.85, 95% CI (2.65-8.87)) were identified as associated factors.

Conclusion

This study showed a 47.7% prevalence of work-related musculoskeletal disorders. Force exertion, repetitive tasks, manual handling of heavy loads, stress, and lack of training were the identified factors. Ergonomic awareness among workers should be increased through training. In addition, owners should investigate methods to reduce or eliminate risk factors leading to musculoskeletal disorders found among these workers. Automation of high-risk tasks should also be investigated.

Reorganized Force Control in Elbow Pain Patients During Isometric Wrist Extension

INTRODUCTION

Reorganized force control may be an important adaptation following painful traumas. In this study, force control adaptations were assessed in elbow pain patients. Increasing the contraction demand may overcome pain interference on the motor control and as such act as an internal control. It was hypothesized that elbow pain patients compared with controls would present greater change in the direction of force when increasing the demand of the motor task.

METHODS

Elbow pain patients (n=19) and asymptomatic participants (n=21) performed isometric wrist extensions at 5% to 70% of maximum voluntary contraction. Pressure pain thresholds were recorded at the lateral epicondyle and tibialis anterior muscle. Contraction force was recorded using a 3-directional force transducer. Participants performed contractions according to visual feedback of the task-related force intensity (main direction of wrist extension) and another set of contractions with feedback of the 3 force directions. Going from the simple to the detailed force feedback will increase the demand of the motor task. Force steadiness in all 3 dimensions and force directions were extracted.

RESULTS

Compared with controls, elbow pain patients presented lower pressure pain thresholds at both sites (P<0.05). Force steadiness was not significantly different between groups or feedback methods. The change in force direction when providing simple visual feedback in contrast with feedback of all force components at all contraction levels was greater for patients compared with controls (P<0.05).

CONCLUSION

The larger change in force direction in pain patients implies redistribution of loads across the arm as an associated effect of pain.

Work-related upper extremity musculoskeletal disorders in the United States: 2006, 2009, and 2014 National Health Interview Survey

BACKGROUND

The annual incidence rate of work-related upper extremity musculoskeletal disorders (WUEMSDs) is increasing in US workers according to the United States Bureau of Labor Statistics (BLS). However, the prevalence of WUEMSDs among US total workers has not been estimated.

OBJECTIVE

We aimed to estimate the prevalence of WUEMSDs among US total workers and among each of major occupations and industries.

METHODS

We analyzed data from the National Health Interview Survey Arthritis supplements (2006, 2009, and 2014) among 50,218 current workers (age ≥18 years) to estimate the 30-day prevalence of WUEMSDs and of WUEMSDs affecting work using the SAS-callable SUDAAN software.

RESULTS

About 11.2 million workers reported WUEMSDs based on three surveys (2006, 2009, and 2014). The 30-day prevalence of WUEMSDs was 8.23% the prevalence of WUEMSDs affecting work was 1.24%. The Construction occupation and industry had the highest age- and sex-adjusted 30-day prevalence of WUEMSDs (10.98% for Construction occupation; 9.94% for Construction industry) and WUEMSDs affecting work (3.32% for Construction occupation; 2.31% Construction industry).

CONCLUSIONS

Our results show that construction workers had the highest prevalence of both WUEMSDs and WUEMSDs affecting work. They may be a priority group for interventions to reduce upper extremity musculoskeletal disorders.

The Role of Elbow Tender Point Examination in the Diagnosis of Lateral Epicondylitis

OBJECTIVE

To quantify sensitivity and specificity of the tender points and demonstrate how variability in case definition impacts prevalence of lateral epicondylitis (LE).

METHODS

Baseline data analyzed from 1216 workers from the WISTAH study, a multicenter prospective cohort study of upper extremity musculoskeletal disorders. All workers completed computerized questionnaires, structured interviews, and two independent physical examinations in accordance with an established protocol.

RESULTS

The prevalence of LE differed based on case definition ranging from 4.7% to 12.1%. Sensitivity was low for tender points 1 to 4 ranging from 6.8% to 34.6%. Specificity was high for tender points 1 to 4 ranging from 95.2% to 97.9%.

CONCLUSIONS

The prevalence of lateral epicondylitis differs markedly based on case definition used, ranging more than two-fold. Standardization of a case definition is essential to allow for comparisons across studies.

Common Upper Extremity Disorders and Function Affect Upper Extremity-Related Quality of Life: A Community-Based Sample from Rural Areas

PURPOSE

Upper extremity musculoskeletal disorders (UEMDs), such as rotator cuff tear, epicondylitis, and hand osteoarthritis, have a negative impact on quality of life (QOL). In this study, we evaluated the prevalence of rotator cuff tear, lateral and medial epicondylitis, and hand osteoarthritis in the dominant side and the impact of these UEMDs on the disabilities of the arm, shoulder, and hand (DASH) outcome measure, which assesses upper extremity-related QOL.

MATERIALS AND METHODS

In 2013-2015, 987 participants from rural areas completed a questionnaire and underwent physical examinations, laboratory tests, simple radiographic evaluations of bilateral upper extremities, and magnetic resonance imaging studies of bilateral shoulders. Based on data from these participants, researchers evaluated DASH and performed a functional assessment of each region of the dominant side and related UEMDs.

RESULTS

The prevalences of epicondylitis, rotator cuff tear, and hand osteoarthritis were 33.7%, 53.4%, and 44.6%, respectively. Univariate regression analysis results revealed that epicondylitis, epicondylitis+rotator cuff tear, epicondylitis+hand osteoarthritis, and epicondylitis+rotator cuff tear+hand osteoarthritis were significantly associated with DASH score. Multiple regression analysis, including DASH, UEMD, and regional functional assessments, showed that only epicondylitis and epicondylitis+rotator cuff tear were associated with DASH score.

CONCLUSION

Epicondylitis significantly affected QOL, while other UEMDs, such as hand osteoarthritis and rotator cuff tear, had no significant impact. When a patient's QOL is affected by a UEMD, there is an increased possibility of the simultaneous presence of other UEMDs.

Workplace-Based Interventions for Neck Pain in Office Workers: Systematic Review and Meta-Analysis

Background

At present, there is no consolidated evidence for workplace-based interventions for the prevention and reduction of neck pain in office workers.

Purpose

The purpose of this review was to investigate the effectiveness of workplace-based interventions for neck pain in office workers.

Data Sources

MEDLINE, PEDro, CINAHL, and CENTRAL were searched for trials published since inception and before May 31, 2016.

Study Selection

Randomized controlled trials (RCTs) were considered when they met the following criteria: population consisted of office workers, intervention(s) was performed at the workplace, outcome measures included neck and/or neck/shoulder pain intensity and incidence/prevalence, and comparator groups included no/other intervention.

Data Extraction

Data were extracted by 1 reviewer using predefined data fields and checked by a second reviewer. Risk of bias was assessed by 2 independent reviewers using the 2015 Cochrane Back and Neck Group guidelines. Evidence quality was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system.

Data Synthesis

Twenty-seven RCTs were included. There was moderate-quality evidence that neck/shoulder strengthening exercises and general fitness training were effective in reducing neck pain in office workers who were symptomatic, although the effect size was larger for strengthening exercises. Greater effects were observed with greater participation in exercise. Ergonomic interventions were supported by low-quality evidence.

Limitations

Data could not be obtained from some studies for meta-analysis and assessment of risk of bias. Reporting bias might have been present because only studies in the English language were included.

Conclusions

Workplace-based strengthening exercises were effective in reducing neck pain in office workers who were symptomatic, and the effect size was larger when the exercises were targeted to the neck/shoulder. Future RCTs of ergonomic interventions targeted at office workers who are symptomatic are required. More research on neck pain prevention is warranted.

The prevalence of musculoskeletal symptoms in the construction industry: a systematic review and meta-analysis

PURPOSE

Although individual studies have reported high prevalence of musculoskeletal symptoms (MSS) among construction workers, no systematic review has summarized their prevalence rates. Accordingly, this systematic review/meta-analysis aimed to synthesize MSS prevalence in different construction trades, gender and age groups, which may help develop specific ergonomic interventions.

METHODS

Nine databases were searched for articles related to the research objective. Two reviewers independently screened citations, extracted information and conducted quality assessment of the included studies. Meta-analyses were conducted on clinical and statistical homogenous data.

RESULTS

Thirty-five out of 1130 potential citations were included reporting diverse types of period prevalence and case definitions. Only the 1-year prevalence rates of MSS (defined as at least one episode of pain/MSS in the last year) at nine anatomical regions had sufficient homogeneous data for meta-analysis. Specifically, the 1-year prevalence of MSS was 51.1% for lower back, 37.2% for knee, 32.4% for shoulder, 30.4% for wrist, 24.4% for neck, 24.0% for ankle/foot, 20.3% for elbow, 19.8% for upper back, and 15.1% for hip/thigh. Female workers demonstrated a higher prevalence of MSS while there was insufficient information on the prevalence of trade-specific or age-related MSS. The quality assessments revealed that many included studies estimated prevalence solely based on self-reported data, and did not report non-respondents' characteristics.

CONCLUSIONS

Lumbar, knee, shoulder, and wrist MSS are the most common symptoms among construction workers. Future studies should standardize the reporting of period prevalence of MSS in different construction trades to allow meta-analyses and to develop relevant MSS prevention program.

Effectiveness of Nerve Gliding Exercises on Carpal Tunnel Syndrome: A Systematic Review

OBJECTIVE

The objective of this study was to review the literature regarding the effectiveness of neural gliding exercises for the management of carpal tunnel syndrome (CTS).

METHODS

A computer-based search was completed through May 2014 in PubMed, Physiotherapy Evidence Database (PEDro), Web of Knowledge, Cochrane Plus, and CINAHL. The following key words were included: nerve tissue, gliding, exercises, carpal tunnel syndrome, neural mobilization, and neurodynamic mobilization. Thirteen clinical trials met the inclusion/exclusion criteria, which were: nerve gliding exercise management of participants aged 18 years or older; clinical or electrophysiological diagnostics of CTS; no prior surgical treatment; and absence of systemic diseases, degenerative joint diseases, musculoskeletal affectations in upper limbs or spine, or pregnancy. All studies were independently appraised using the PEDro scale.

RESULTS

The majority of studies reported improvements in pain, pressure pain threshold, and function of CTS patients after nerve gliding, combined or not with additional therapies. When comparing nerve gliding with other therapies, 2 studies reported better results from standard care and 1 from use of a wrist splint, whereas 3 studies reported greater and earlier pain relief and function after nerve gliding in comparison with conservative techniques, such as ultrasound and wrist splint. However, 6 of the 13 studies had a quality of 5 of 11 or less according to the PEDro scale.

CONCLUSION

Limited evidence is available on the effectiveness of neural gliding. Standard conservative care seems to be the most appropriate option for pain relief, although neural gliding might be a complementary option to accelerate recovery of function. More high-quality research is still necessary to determine its effectiveness and the subgroups of patients who may respond better to this treatment.

Exploring Methods to Measure the Prevalence of Ménière's Disease in the US Clinformatics™ Database, 2010-2012

Recent studies on the epidemiology of the inner-ear disorder Ménière's disease (MD) use disparate methods for sample selection, case identification and length of observation. Prevalence estimates vary geographically from 17 to 513 cases per 100,000 people. We explored the impact of case detection strategies and observation periods in estimating the prevalence of MD in the USA, using data from a large insurance claims database. Using case detection strategies of ≥1, ≥2 and ≥3 ICD-9 claim codes for MD within a 1-year period, the 2012 prevalence estimates were 66, 27 and 14 cases per 100,000 people, respectively. For ≥1, ≥2 and ≥3 insurance claims within a 3-year observation period, the prevalence estimates were 200, 104 and 66 cases per 100,000 people, respectively. Estimates based on a single claim are likely to overestimate prevalence; this conclusion is aligned with the American Academy of Otolaryngology-Head and Neck Foundation criteria requiring ≥2 definitive episodes for a definite diagnosis, and it has implications for future epidemiologic research. We believe estimates for ≥2 claims may be a more conservative estimate of the prevalence of MD, and multiyear estimates may be needed to allow for adequate follow-up time.

Association between work-related biomechanical risk factors and the occurrence of carpal tunnel syndrome: an overview of systematic reviews and a meta-analysis of current research

BACKGROUND

Occupational risks for carpal tunnel syndrome (CTS) have been examined in various occupations, and several systematic reviews (SRs) have been published on this topic. There has been no critical appraisal or synthesis of the evidence in the SRs. The aims of this study are (1) to synthesise the observational evidence and evaluate the methodological quality of SRs that assess the effect of biomechanical risk factors on the development of CTS in workers, (2) to provide an update of current primary research on this association, (3) to assess a potential dose-response relationship.

METHODS

We searched MEDLINE, EMBASE, CINAHL, the Cochrane Library and the reference lists of articles. The first step covered SRs (1998-2014), and the second step covered current primary studies (2011-2014). The methodological quality of the SRs was evaluated by using the AMSTAR-R tool; primary studies were assessed using a list of 20 items. A qualitative approach was used for synthesising evidence. In addition, we undertook a meta-analysis of the primary studies to determine risk ratios in the dose-response relationship.

RESULTS

We identified ten SRs that covered a total of 143 original studies. Seven primary studies met the criteria for inclusion, of which four provided longitudinal data. We found high quality of evidence for risk factors such as repetition, force and combined exposures. Moderate quality of evidence was observed for vibration, and low quality of evidence was found for wrist postures. An association between computer use and CTS could not be established. Recent primary studies supported the existence of a significant relationship between CTS and repetition, force and combined exposure. The meta-analysis of current research revealed a dose-response relationship between CTS and the American Conference of Governmental Industrial Hygienists' (ACGIH) threshold limit value (TLV) for hand-activity level (HAL). Those between the action limit and TLV and above TLV had RR of 1.5 (95% CI 1.02-2.31) and RR 2.0 (95% CI 1.46-2.82), respectively.

CONCLUSIONS

Occupational biomechanical factors play a substantial role in the causation of CTS. Data from current primary studies on dose-response suggest that the risk of CTS increases with the ACGIH TLV levels.

Effects of varying case definition on carpal tunnel syndrome prevalence estimates in a pooled cohort

OBJECTIVE

To analyze differences in carpal tunnel syndrome (CTS) prevalence using a combination of electrodiagnostic studies (EDSs) and symptoms using EDS criteria varied across a range of cutpoints and compared with symptoms in both ≥1 and ≥2 median nerve-served digits.

DESIGN

Pooled data from 5 prospective cohorts.

SETTING

Hand-intensive industrial settings, including manufacturing, assembly, production, service, construction, and health care.

PARTICIPANTS

Employed, working-age participants who are able to provide consent and undergo EDS testing (N=3130).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

CTS prevalence was estimated while varying the thresholds for median sensory latency, median motor latency, and transcarpal delta latency difference. EDS criteria examined included the following: median sensory latency of 3.3 to 4.1 milliseconds, median motor latency of 4.1 to 4.9 milliseconds, and median-ulnar sensory difference of 0.4 to 1.2 milliseconds. EDS criteria were combined with symptoms in ≥1 or ≥2 median nerve-served digits. EDS criteria from other published studies were applied to allow for comparison.

RESULTS

CTS prevalence ranged from 6.3% to 11.7%. CTS prevalence estimates changed most per millisecond of sensory latency compared with motor latency or transcarpal delta. CTS prevalence decreased by 0.9% to 2.0% if the criteria required symptoms in 2 digits instead of 1.

CONCLUSIONS

There are meaningful differences in CTS prevalence when different EDS criteria are applied. The digital sensory latency criteria result in the largest variance in prevalence.

Prevalence of low back pain by anatomic location and intensity in an occupational population

Background

Low Back Pain (LBP) is a common and costly problem, with variation in prevalence. Epidemiological reports of rating of pain intensity and location within the low back area are rare. The objective is to describe LBP in a large, multi-center, occupational cohort detailing both point and 1-month period prevalence of LBP by location and intensity measures at baseline.

Methods

In this cross-sectional report from a prospective cohort study, 828 participants were workers enrolled from 30 facilities performing a variety of manual material handling tasks. All participants underwent a structured interview detailing pain rating and location. Symptoms in the lower extremities, demographic and other data were collected. Body mass indices were measured. Outcomes are pain rating (0–10) in five defined lumbar back areas (i) LBP in the past month and (ii) LBP on the day of enrollment. Pain ratings were reported on a 0–10 scale and subsequently collapsed with ratings of 1–3, 4–6 and 7–10 classified as low, medium and high respectively.

Results

172 (20.8%) and 364 (44.0%) of the 828 participants reported pain on the day of enrollment or within the past month, respectively. The most common area of LBP was in the immediate paraspinal area with 130 (75.6%) participants with point prevalence LBP and 278 (77.4%) with 1-month period prevalence reported having LBP in the immediate paraspinal area. Among those 364 reporting 1-month period prevalence pain, ratings varied widely with 116 (31.9%) reporting ratings classified as low, 170 (46.7%) medium and 78 (21.4%) providing high pain ratings in any location. Among the 278 reporting 1-month period prevalence pain in the immediate paraspinal area, 89 (32.0%) reported ratings classified as low, 129 (46.4%), medium and 60 (21.6%) high pain ratings.

Conclusions

Pain ratings varied widely, however less variability was seen in pain location, with immediate paraspinal region being the most common. Variations may suggest different etiological factors related to LBP. Aggregation of different locations of pain or different intensities of pain into one binary classification of LBP may result in loss of information which may potentially be useful in prevention or treatment of LBP.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-283) contains supplementary material, which is available to authorized users.