Preplacement Nerve Testing for Carpal Tunnel Syndrome: Is it Cost Effective?

Movements of the wrist and the risk of carpal tunnel syndrome: a nationwide cohort study using objective exposure measurements

OBJECTIVES

We conducted a large cohort study to investigate the association between work-related wrist movements and carpal tunnel syndrome (CTS).

METHODS

Electro-goniometric measurements of wrist movements were performed for 30 jobs (eg, office work, child care, laundry work and slaughterhouse work). We measured wrist angular velocity, mean power frequency (MPF) and range of motion (ROM). We established a cohort of Danish citizens born 1940-1979 who held one of these jobs from age 18-80 years, using Danish national registers with annual employment information from 1992 to 2014. We updated the cohort by calendar year with job-specific and sex-specific means of measured exposures. Dates of a first diagnosis or operation because of CTS were retrieved from the Danish National Patient Register. The risk of CTS by quintiles of preceding exposure levels was assessed by adjusted incidence rate ratios (IRR^adj) using Poisson regression models.

RESULTS

We found a clear exposure-response association between wrist angular velocity and CTS with an IRR^adj of 2.31 (95% CI 2.09 to 2.56) when exposed to the highest level compared with the lowest. MPF also showed an exposure-response pattern, although less clear, with an IRR^adj of 1.83 (1.68 to 1.98) for the highest compared with the lowest exposure level. ROM showed no clear pattern. Exposure-response patterns were different for men and women.

CONCLUSIONS

High levels of wrist movement were associated with an increased risk of CTS. Preventive strategies should be aimed at jobs with high levels of wrist movements such as cleaning, laundry work and slaughterhouse work.

Reducing Disability Durations and Medical Costs for Patients With a Carpal Tunnel Release Surgery Through the Use of Opioid Prescribing Guidelines

OBJECTIVE

The impacts of compliance with opioid prescribing guidelines on disability durations and medical costs for carpal tunnel release (CTR) were examined.

METHODS

Using a dataset of insured US employees, opioid prescriptions for 7840 short-term disability cases with a CTR procedure were identified. Opioids prescriptions were compared with the American College of Occupational and Environmental Medicine (ACOEM)'s opioid prescribing guidelines for postoperative, acute pain, which recommends no more than a 5-day supply, a maximum morphine equivalent dose of 50 mg/day, and only short-acting opioids.

RESULTS

Most cases (70%) were prescribed an opioid and 29% were prescribed an opioid contrary to ACOEM's guidelines. Cases prescribed an opioid contrary to guidelines had disability durations 1.9 days longer and medical costs $422 higher than cases prescribed an opioid according to guidelines.

CONCLUSIONS

The use of opioid prescribing guidelines may reduce CTR disability durations and medical costs.

Postoffer Pre-Placement Screening for Carpal Tunnel Syndrome in Newly Hired Manufacturing Workers

OBJECTIVE

We determined the predictive validity of a postoffer pre-placement (POPP) screen using nerve conduction velocity studies (NCV) to identify future cases of carpal tunnel syndrome (CTS).

METHODS

A cohort of 1648 newly hired manufacturing production workers underwent baseline NCS, and were followed for 5 years.

RESULTS

There was no association between abnormal POPP NCV results and incident CTS. Varying NCV diagnostic cut-offs did not improve predictive validity. Workers in jobs with high hand/wrist exposure showed greater risk of CTS than those in low exposed jobs (relative risk 2.82; 95% confidence interval 1.52 to 5.22).

CONCLUSIONS

POPP screening seems ineffective as a preventive strategy for CTS.

Pre-employment examinations for preventing injury, disease and sick leave in workers

BACKGROUND

Many employers and other stakeholders believe that health examinations of job applicants prevent occupational diseases and sickness absence. This is an update of the original Cochrane review (Mahmud 2010).

OBJECTIVES

To evaluate the effectiveness of pre-employment examinations of job applicants in preventing occupational injury, disease and sick leave compared to no intervention or alternative interventions.

SEARCH METHODS

We searched CENTRAL (the Cochrane Library), MEDLINE, EMBASE, CINAHL, PsycINFO and PEDro (up to 31 March 2015). We did not impose any restrictions on date, language or publication type.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled before-after (CBA) studies, and interrupted time-series (ITS) studies of health examinations to prevent occupational diseases and injuries in job applicants in comparison to no intervention or alternative interventions.

DATA COLLECTION AND ANALYSIS

All five review authors independently selected studies from the updated search for inclusion. We retrieved two new studies with the updated search from 1 April 2008 to 31 March 2015, resulting in a total of eleven studies.

MAIN RESULTS

We included two RCTs, seven CBA studies and two ITS studies. Nine studies with 7820 participants evaluated the screening process of pre-employment examinations as a whole, and two studies with 2164 participants evaluated the measures to mitigate the risks found following the screening process. The studies were too heterogeneous for statistical pooling of results. We rated the quality of the evidence for all outcomes as very low quality. The two new CBA studies both used historical controls and both had a high risk of bias.Of those studies that evaluated the screening process, there is very low quality evidence based on one RCT that a general examination for light duty work may not reduce the risk for sick leave (mean difference (MD) -0.09, 95% confidence interval (CI) -0.47 to 0.29). For army recruits, there is very low quality evidence based on one CBA study that there is a positive effect on fitness for duty after 12 months follow-up (odds ratio (OR) 0.40, 95% CI 0.19 to 0.85).We found inconsistent evidence of an effect of job-focused pre-employment examinations on the risk of musculoskeletal injuries in comparison with general or no pre-employment examination based on one RCT with high risk of bias, and four CBA studies. There is very low quality evidence based on one ITS study that incorporation of a bronchial challenge test may decrease occupational asthma (trend change -2.6, 95% CI -3.6 to -1.5) compared to a general pre-employment examination with lung function tests.Pre-employment examinations may also result in a rejection of the applicant for the new job. In six studies, the rates of rejecting job applicants increased because of the studied examinations , on average, from 2% to 35%, but not in one study.There is very low quality evidence based on two CBA studies that risk mitigation among applicants considered not fit for work at the pre-employment examination may result in a similar risk of work-related musculoskeletal injury during follow-up compared to workers considered fit for work at the health examination.

AUTHORS' CONCLUSIONS

There is very low quality evidence that a general examination for light duty work may not reduce the risk for sick leave, but may have a positive effect on fitness for duty for army recruits after 12 months follow-up.There is inconsistent evidence of an effect of job-focused pre-employment examinations on the risk of musculoskeletal injuries in comparison with general or no pre-employment examination. There is very low quality evidence that incorporation of a bronchial challenge test may decrease occupational asthma compared to a general pre-employment examination with lung function tests. Pre-employment examinations may result in an increase of rejecting job applicants in six out of seven studies. Risk mitigation based on the result of pre-employment examinations may be effective in reducing an increased risk for occupational injuries based on very low quality evidence. This evidence supports the current policy to restrict pre-employment examinations to only job-specific examinations. Better quality evaluation studies on pre-employment examinations are necessary, including the evaluation of the benefits of risk mitigation, given the effect on health and on the financial situation for those employees who do not pass the pre-employment examination.

Comparison of automated versus traditional nerve conduction study methods for median nerve testing in a general worker population

OBJECTIVE

To investigate the validity of automated nerve conduction studies compared to traditional electrodiagnostic studies (EDS) for testing median nerve abnormalities in a working population.

DESIGN

Agreement study and sensitivity investigation from 2 devices.

SETTING

Field research testing laboratory.

PARTICIPANTS

Active workers from several industries participating in a longitudinal study of carpal tunnel syndrome.

METHODS

Sixty-two subjects received bilateral median and ulnar nerve conduction testing across the wrist with a traditional device and the NC-stat automated device. We compared the intermethod agreement of analogous measurements.

MAIN OUTCOME MEASUREMENT

Nerve conduction study parameters.

RESULTS

Median motor and sensory latency comparisons showed excellent agreement (intraclass correlation coefficients 0.85 and 0.80, respectively). Areas under the receiver operating characteristic curves were 0.97 and 0.96, respectively, using the optimal thresholds of 4.4-millisecond median motor latency (sensitivity 100%, specificity 86%) and 3.9-millisecond median sensory latency (sensitivity 100%, specificity 87%). Ulnar nerve testing results were less favorable.

CONCLUSION

The automated NC-stat device showed excellent agreement with traditional EDS for detecting median nerve conduction abnormalities in a general population of workers, suggesting that this automated nerve conduction device can be used to ascertain research case definitions of carpal tunnel syndrome in population health studies. Further study is needed to determine optimal thresholds for defining median conduction abnormalities in populations that are not seeking clinical care.

The effectiveness of post-offer pre-placement nerve conduction screening for carpal tunnel syndrome

OBJECTIVE

We evaluated post-offer pre-placement (POPP) nerve conduction studies (NCS) for carpal tunnel syndrome (CTS), testing diagnostic yield and cost-effectiveness.

METHODS

A total of 1027 newly hired workers underwent baseline NCS and were followed for an average of 3.7 years for diagnosed CTS. Measures of diagnostic yield included sensitivity, specificity, and positive predictive value (PPV). Cost-effectiveness of POPP screening was evaluated using a range of inputs.

RESULTS

Abnormal NCS was strongly associated with future CTS with univariate hazard ratios ranging from 2.95 to 11.25, depending on test parameters used. Nevertheless, PPV was poor, 6.4% to 18.5%. Cost-effectiveness of POPP varied with CTS case costs, screening costs, and NCS thresholds.

CONCLUSIONS

Although abnormal NCS at hire increases risk of future CTS, the PPV is low, and POPP screening is not cost-effective to employers in most scenarios tested.

Economic evaluations of occupational health interventions from a company's perspective: a systematic review of methods to estimate the cost of health-related productivity loss

OBJECTIVES

To investigate the methods used to estimate the indirect costs of health-related productivity in economic evaluations from a company's perspective.

METHODS

The primary literature search was conducted in Medline and Embase. Supplemental searches were conducted in the Cochrane NHS Economic Evaluation Database, the National Institute for Occupational Safety and Health database, the Ryerson International Labour, Occupational Safety and Health Index database, scans of reference lists and researcher's own literature database. Article selection was conducted independently by two researchers based on title, keywords, and abstract, and if needed, full text. Differences were resolved by a consensus procedure. Articles were selected based on seven criteria addressing study population, type of intervention, comparative intervention, outcome, costs, language and perspective, respectively. Characteristics of the measurement and valuation of health-related productivity were extracted and analyzed descriptively.

RESULTS

A total of 34 studies were included. Costs of health-related productivity were estimated using (a combination of) data related to sick leave, compensated sick leave, light or modified duty or work presenteeism. Data were collected from different sources (e.g. administrative databases, worker self-report, supervisors) and by different methods (e.g. questionnaires, interviews). Valuation varied in terms of reported time units, composition and source of the corresponding price weights, and whether additional elements, such as replacement costs, were included.

CONCLUSIONS

Methods for measuring and valuing health-related productivity vary widely, hindering comparability of results and decision-making. We provide suggestions for improvement.

Physical examination has a low yield in screening for carpal tunnel syndrome

BACKGROUND

physical examination is often used to screen workers for carpal tunnel syndrome (CTS). In a population of newly hired workers, we evaluated the yield of such screening.

METHODS

our study population included 1,108 newly hired workers in diverse industries. Baseline data included a symptom questionnaire, physical exam, and bilateral nerve conduction testing of the median and ulnar nerves; individual results were not shared with the employer. We tested three outcomes: symptoms of CTS, abnormal median nerve conduction, and a case definition of CTS that required both symptoms and median neuropathy.

RESULTS

of the exam measures used, only Semmes-Weinstein sensory testing had a sensitivity value above 31%. Positive predictive values were low, and likelihood ratios were all under 5.0 for positive testing and over 0.2 for negative testing.

CONCLUSION

physical examination maneuvers have a low yield for the diagnosis of CTS in workplace surveillance programs and in post-offer, pre-placement screening programs.

Pre-employment examinations for preventing occupational injury and disease in workers

BACKGROUND

Many employers and other stakeholders believe that health examinations of job applicants prevent occupational diseases and sickness absence.

OBJECTIVES

To evaluate the effectiveness of pre-employment examinations of job applicants in preventing occupational injury, disease and sickness absence compared to no intervention or alternative interventions.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library), MEDLINE, EMBASE, CINAHL, PsycINFO and PEDro (to December 2009) not restricted by date, language or publication type.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled before-after studies (CBA), and interrupted time-series (ITS) of health examinations to prevent occupational diseases and injuries in job applicants.

DATA COLLECTION AND ANALYSIS

Four review authors (NM, ML, JV, ES) independently selected studies, extracted data, and determined study quality. The studies were too heterogeneous for statistical pooling of results.

MAIN RESULTS

We included two RCTs, five CBA studies and two ITS. Seven studies with 5872 participants evaluated the screening process of pre-employment examinations and two studies with 2164 participants evaluated the measures to mitigate the risks found following the screening process.Of those studies that evaluated the screening process, one study found that a general examination did not reduce sick leave (Mean Difference -0.1 95% CI -0.5 to 0.3) but another study found that a more task focused examination did (MD -36 95% CI -68.3 to -3.8). One study found that incorporation of a bronchial challenge test decreased occupational asthma (trend change -2.6 95% CI -3.6 to -1.5). Three studies that included functional capacity evaluation found contradictory effects on injury rates and number of medical visits. The rates of rejecting job applicants varied from 2% to 35%.Neither of the two studies that evaluated risk mitigation found an increased injury rate after training or work accommodations had been implemented.We rated the evidence for all outcomes as very low quality.

AUTHORS' CONCLUSIONS

There is very low quality evidence that pre-employment examinations that are specific to certain jobs or health problems could reduce occupational disease, injury, or sickness absence. This supports the current policy to restrict pre-employment examinations to job-specific examinations. More studies are needed that take into account the harms of rejecting job applicants.

Modeling the cost-benefit of nerve conduction studies in pre-employment screening for carpal tunnel syndrome

OBJECTIVE

The aim of this study was to evaluate the costs associated with pre-employment nerve conduction testing as a screening tool for carpal tunnel syndrome (CTS) in the workplace.

METHODS

We used a Markov decision analysis model to compare the costs associated with a strategy of screening all prospective employees for CTS and not hiring those with abnormal nerve conduction, versus a strategy of not screening for CTS. The variables included in our model included employee turnover rate, the incidence of CTS, the prevalence of median nerve conduction abnormalities, the relative risk of developing CTS conferred by abnormal nerve conduction screening, the costs of pre-employment screening, and the worker's compensation costs to the employer for each case of CTS.

RESULTS

In our base case, total employer costs for CTS from the perspective of the employer (cost of screening plus costs for workers' compensation associated with CTS) were higher when screening was used. Median costs per employee position over five years were US$503 for the screening strategy versus US$200 for a no-screening strategy. A sensitivity analysis showed that a strategy of screening was cost-beneficial from the perspective of the employer only under a few circumstances. Using Monte Carlo simulation varying all parameters, we found a 30% probability that screening would be cost-beneficial.

CONCLUSIONS

A strategy of pre-employment screening for CTS should be carefully evaluated for yield and social consequences before being implemented. Our model suggests such screening is not appropriate for most employers.

Clinical quality measures for electrodiagnosis in suspected carpal tunnel syndrome

Extensive research has documented that medical care in the United States is not of optimal quality, meaning that well-established care processes are not consistently provided to the patients who would benefit from them. To assess and improve quality of care, specific measures are needed. The objective of this study was to develop quality measures for electrodiagnostic testing in suspected carpal tunnel syndrome (CTS). We used a variation of the well-established RAND/UCLA Appropriateness Method to develop the measures. A physiatrist and quality measurement experts developed draft measures based on guidelines and literature. Subsequently, in a two-round, modified-Delphi process, a multidisciplinary panel of 11 national experts in CTS reviewed a summary of the evidence and then rated the measures for validity and feasibility. Seven draft measures were developed. The expert panel combined two, modified the others, and then judged all resulting measures to be valid and feasible. The measures cover compelling indications for testing, essential test components when CTS is suspected, skin temperature measurement and normalization, and the appropriate interpretation of test results. These measures define a minimum standard of care for the use of electrodiagnostic tests in suspected CTS and are consistent with recent guidelines developed by the American Association of Neuromuscular and Electrodiagnostic Medicine. Provider organizations, insurance companies, and professional societies can use these measures in efforts to monitor and improve quality of care for this common and disabling condition.