The purposes of occupational medical surveillance in US industry and related health findings

Cannabis Use in Physicians: A Systematic Review and Meta-Analysis

Background: Cannabis use by physicians can be detrimental for them and their patients. We conducted a systematic review and meta-analysis on the prevalence of cannabis use by medical doctors (MDs)/students. Method: PubMed, Cochrane, Embase, PsycInfo and ScienceDirect were searched for studies reporting cannabis use in MDs/students. For each frequency of use (lifetime/past year/past month/daily), we stratified a random effect meta-analysis depending on specialties, education level, continents, and periods of time, which were further compared using meta-regressions. Results: We included 54 studies with a total of 42,936 MDs/students: 20,267 MDs, 20,063 medical students, and 1976 residents. Overall, 37% had used cannabis at least once over their lifetime, 14% over the past year, 8% over the past month and 1.1 per thousand (‱) had a daily use. Medical students had a greater cannabis use than MDs over their lifetime (38% vs. 35%, p < 0.001), the past year (24% vs. 5%, p < 0.001), and the past month (10% vs. 2%, p < 0.05), without significance for daily use (0.5% vs. 0.05%, NS). Insufficient data precluded comparisons among medical specialties. MDs/students from Asian countries seemed to have the lowest cannabis use: 16% over their lifetime, 10% in the past year, 1% in the past month, and 0.4% daily. Regarding periods of time, cannabis use seems to follow a U-shape, with a high use before 1990, followed by a decrease between 1990 and 2005, and a rebound after 2005. Younger and male MDs/students had the highest cannabis use. Conclusions: If more than a third of MDs tried cannabis at least once in their lifetime, this means its daily use is low but not uncommon (1.1‱). Medical students are the biggest cannabis users. Despite being common worldwide, cannabis use is predominant in the West, with a rebound since 2005 making salient those public health interventions during the early stage of medical studies.

Integrating pharmacogenomics into clinical trials of hearing disorders

In 2019, the U.S. Food and Drug Administration issued guidance to increase the efficiency of drug development and support precision medicine, including tailoring treatments to those patients who will benefit based on genetic variation even in the absence of a documented mechanism of action. Although multiple advancements have been made in the field of pharmacogenetics (PGx) for other disease conditions, there are no approved PGx guidelines in the treatment of hearing disorders. In studies of noise-induced hearing loss (NIHL), some progress has been made in the last several years associating genomic loci with susceptibility to noise damage. However, the power of such studies is limited as the underlying physiological responses may vary considerably among the patient populations. Here, we have summarized previous animal studies to argue that NIHL subtyping is a promising strategy to increase the granularity of audiological assessments. By coupling this enhanced phenotyping capability with genetic association studies, we suggest that drug efficacy will be better predicted, increasing the likelihood of success in clinical trials when populations are stratified based on genetic variation or designed with multidrug combinations to reach a broader segment of individuals suffering or at risk from NIHL.

The Genetic Architecture of Noise-Induced Hearing Loss: Evidence for a Gene-by-Environment Interaction

The discovery of environmentally specific genetic effects is crucial to the understanding of complex traits, such as susceptibility to noise-induced hearing loss (NIHL). We describe the first genome-wide association study (GWAS) for NIHL in a large and well-characterized population of inbred mouse strains, known as the Hybrid Mouse Diversity Panel (HMDP). We recorded auditory brainstem response (ABR) thresholds both pre and post 2-hr exposure to 10-kHz octave band noise at 108 dB sound pressure level in 5–6-wk-old female mice from the HMDP (4–5 mice/strain). From the observation that NIHL susceptibility varied among the strains, we performed a GWAS with correction for population structure and mapped a locus on chromosome 6 that was statistically significantly associated with two adjacent frequencies. We then used a “genetical genomics” approach that included the analysis of cochlear eQTLs to identify candidate genes within the GWAS QTL. In order to validate the gene-by-environment interaction, we compared the effects of the postnoise exposure locus with that from the same unexposed strains. The most significant SNP at chromosome 6 (rs37517079) was associated with noise susceptibility, but was not significant at the same frequencies in our unexposed study. These findings demonstrate that the genetic architecture of NIHL is distinct from that of unexposed hearing levels and provide strong evidence for gene-by-environment interactions in NIHL.

Effects of interventions on use of hearing protectors among farm operators: A randomized controlled trial

OBJECTIVE

The purpose of this study was to compare the effectiveness of three interventions designed to promote hearing protector device (HPD) use.

DESIGN

Randomized controlled trial.

STUDY SAMPLE

Farm operators (n = 491) were randomly assigned to one of five intervention groups: (1) interactive web-based information with mailed assortment of HPDs; (2) Interactive web-based information only; (3) static web-based information with mailed assortment of HPDs; (4) Static web-based information only; or (5) mailed assortment of HPDs only. Data were analysed using a mixed model approach.

RESULTS

HPD use increased among all participants, and increased more among participants receiving the mailed HPDs (with or without information) compared to participants receiving other interventions. Participants receiving the interactive web-based information had comparable increased use of HPDs to those receiving the static web-based information. Participants receiving the mailed HPDs had more positive situational influences scale scores than other participants. Program satisfaction was highest among mailed and web-based information groups.

CONCLUSIONS

A mailed assortment of hearing protectors was more effective than information. Interactive and static information delivered via web were similarly effective. Programs interested in increasing HPD use among farmers should consider making hearing protectors more available to farmers.

Protocol of a randomized controlled trial of hearing protection interventions for farm operators

Background

Hearing loss and tinnitus are prevalent in America, and noise-induced hearing loss is a leading cause of hearing loss. Noise-induced hearing loss has negative impact on quality of life, physical and emotional functioning, social life, and employment. In addition, noise-induced hearing loss results in heavy social and economic burdens on families and communities from all ethnic and socioeconomic groups. Farmers are a group that is particularly high risk for noise-induced hearing loss, and is underserved by programs designed to limit that risk. They are among the most noise-exposed group of workers, and experience the second highest prevalence of noise-induced hearing loss among all occupational categories. In agriculture, 1.5 million workers (43.3%) report exposure to hazardous noise. Although use of hearing protection devices (HPDs) would protect them from noise-induced hearing loss, use among farmers is low.

Methods/Design

The purpose of this project is to compare the effectiveness of several approaches to influencing hearing protector use. Approaches include: a) an interactive, predictors-based intervention delivered via the Internet; b) a static informational web site; and c) a mailed sampler of hearing protectors. The goals are to further develop an intervention to promote farmers’ use of HPDs, and compare the effectiveness of the interventions delivered in various combinations. Participants will include 701 farmers. Sites will be affiliates of a major farmer organization. Data will be collected at baseline, 6, and 12 months. A random intercept mixed model will be used to explore the fixed effects of the three NIHL prevention interventions over time while adjusting for age and gender. This project will involve a partnership between the University of Michigan and a major farmer organization to accomplish project aims.

Discussion

Results of this study will be used to inform future research-to-practice studies to increase hearing protector use. Increased use of hearing protectors is expected to reduce rates of noise-induced hearing loss and other negative effects of high noise exposure, and improve quality of life in this high-risk and underserved group.

Trial registration

Clinicaltrials.gov NCT01454895 Registered 14 October, 2011.

Validation of a questionnaire to identify hearing loss among farm operators

Workers in certain industries (e.g., agriculture) do not participate in a hearing conservation program and rarely receive this important preventive care. The National Institute for Deafness and Communication Disorders (NIDCD) has published a questionnaire to assess a person's need for medical examination of their hearing. The use of a self-administered questionnaire may pose a simple, low cost opportunity to assess the hearing health of workers not included in a hearing conservation program. However, the validity of the NIDCD questionnaire has not been tested. A study was conducted to compare the results of audiometric screening and the NIDCD questionnaire in identifying persons at risk for hearing impairment who may benefit from a medical referral. Data were collected from 103 farm operators at a regional farm show. Receiver-operator characteristic curves, measuring the ability of the questionnaire to correctly classify those with and without the disease suggested that the level of performance of the questionnaire as a whole, ranged from 0.74 to 0.69 (fair to poor). However, selected questionnaire items (e.g., Do you have to strain to understand conversations?) had moderate agreement (0.38 to 0.41) with screening audiogram results. Overall, the 10-item instrument did not perform as well as instruments with fewer items reported in separate studies. These findings suggest that, while less desirable than audiometry, alternative self-administered instruments might perform the better in this group. This approach may be useful as an alternative screening method to detect risk of hearing loss and identifying the need for medical evaluation of hearing sensitivity, particularly among farm operators.

Effects of a low intensity intervention to increase hearing protector use among noise-exposed workers

BACKGROUND

Farm operators experience exposure to high noise and high prevalence of noise-induced hearing loss, but use of hearing protection in this worker group is low. The purpose of this study was to test a brief intervention to increase farm operators' use of hearing protection.

METHODS

In this one-group pre- and post-test study, a random sample of 32 members of a farmers' organization was supplied a variety of hearing protectors. Participants received an assortment of hearing protectors by mail with manufacturer's instructions for use.

RESULTS

Mean pre-intervention hearing protector use when in high noise in this group was 23% (SD 29). Of the 32 participants, 27 (84%) were exposed to hazardous noise during the study period. Post-intervention mean use of HPDs was 64%, an increase of 41% (t = 5.26, P < 000).

CONCLUSION

Results of this study suggest that overall, hearing protectors were acceptable to farm operators, and that a brief mailed intervention is feasible.

[Morbidity among job applicants in the Metropolitan Region of Salvador, Bahia, Brazil]

This cross-sectional study evaluates the pre-employment health status of job applicants, based on prevalence estimates of abnormal laboratory test results, clinical diagnosis, and a physician-signed fit-for-work assessment, which is mandatory in Brazil. The study population was a random sample of 1,237 male workers selected from medical records (1988-1996) from an Occupational Medical Center located in Salvador, the capital of Bahia State, Brazil. The data were from a single pre-employment medical assessment for each individual. The most common diseases were intestinal parasites (51.7%), anemia (12.8%), and hypertension (12.7%). Drivers showed a high prevalence of overweight (38.2%) and hypertension (16.2%). In addition to work-related risks and diseases, occupational hygiene and safety programs need to address prevailing illnesses and risk factors, which in this population are typical of poor living conditions. Special attention should to be given to drivers, who are at increased risk of cardiovascular disease.

Evaluation research in occupational health services: general principles and a systematic review of empirical studies

OBJECTIVES

To study the nature and extent of evaluation research in occupational health services (OHSs).

METHODS

Literature review of evaluation research in OHSs. On the basis of a conceptual model of OHS evaluation, empirical studies are categorised into aspects of input, process, output, outcome, and OHS core activities.

RESULTS

Many methods to evaluate OHSs or OHS activities exist, depending on the objective and object of evaluation. The amount of empirical studies on evaluation of OHSs or OHS activities that met the non-restrictive inclusion criteria, was remarkably limited. Most of the 52 studies were more descriptive than evaluative. The methodological quality of most studies was not high. A differentiated picture of the evidence of effectiveness of OHSs arises. Occupational health consultations and occupational rehabilitation are hardly studied despite much time spent on the consultation by occupational physicians in most countries. The lack of effectiveness and efficiency of the pre-employment examination should lead to its abandonment as a means of selection of personnel by OHSs. Periodic health monitoring or surveillance, and education on occupational health hazards can be carried out with reasonable process quality. Identification and evaluation of occupational health hazards by a workplace survey can be done with a high output quality, which, however, does not guarantee a favourable outcome.

CONCLUSIONS

Although rigorous study designs are not always applicable or feasible in daily practice, much more effort should be directed at the scientific evaluation of OHSs and OHS instruments. To develop evidence-based occupational health care the quality of evaluation studies should be improved. In particular, process and outcome of consultation and rehabilitation activities of occupational physicians need to be studied more.

Decision model for optimizing respirator protection

Respirators are widely used for protection against inhaled toxins. The emphasis of research and implementation effort has evolved through several stages: the respirator device itself, use situation, respirator program factors under employer control, individual worker factors not under employer control, and occupational health systems. For this study, a computer-simulation decision assistance model was developed to assess the impact of various factors on the number of workers receiving adequate protection. Factors include the respirator protection factor, identification of sites needing respirator protection, selection of proper device, availability when needed, frequency of ever use, regularity of use among users, and variability in personal susceptibility or other factors. This analysis demonstrates that for both moderate-risk and high-risk (i.e., IDLH, immediately dangerous to life and health) exposures under current circumstances, the actual protection afforded depends upon the optimization of program factors and detection of atypical outlier persons and worksites. Therefore, programs and research must focus on these areas. Occupational medicine specialists should help optimize these areas and, in addition, use each case of respiratory protection failure as an index case to improve the overall programs.

Medical surveillance for ethylene oxide exposure: practices and clinical findings in Massachusetts hospitals

The medical surveillance requirements of the Occupational Safety and Health Administration's (OSHA) ethylene oxide (EtO) standard became effective in 1985. However, little is known about the nature of the response of EtO users to this regulatory requirement. In an effort to begin to understand this, we conducted a survey of EtO health and safety in Massachusetts hospitals (n = 92). We determined the cumulative incidence of provision of EtO medical surveillance, the characteristics of the surveillance interventions provided, and the clinical findings of EtO medical surveillance efforts in Massachusetts hospitals. From 1985 to 1993, medical surveillance for EtO exposure was provided one or more times in 62% of EtO-using hospitals. Sixty-five percent of EtO medical surveillance providers reported performance of all five medical surveillance procedures required by OSHA's EtO standard. Medical surveillance provider certification in occupational medicine or nursing, and a greater extent of coverage of written medical surveillance policies, were related to higher likelihoods of fulfillment of OSHA-required procedures. Twenty-seven percent of medical surveillance providers reported detection of EtO-related symptoms or conditions, ranging from mucous membrane irritation to peripheral neuropathy. These findings reveal wide-spread implementation of OSHA-mandated EtO medical surveillance, with concomitant incomplete fulfillment of OSHA-specified procedures. From the provider-based survey, we estimate that one or more workers at 19% of EtO-using Massachusetts hospitals have experienced EtO-related health effects.

Company characteristics and workplace medical testing

OBJECTIVES

This study measures the relative impact of company economic characteristics and workplace hazards on the prevalence of several types of medical testing. It uses the results to assess likely public health impacts of testing.

METHODS

We used data on potential exposure to workplace hazards, medical testing, unionization, firm size, and turnover from the National Occupational Hazards Survey and the National Occupational Exposure Survey. Other sources provided industry-specific data on wages and turnover. Logistic regression analysis estimated the relationship of economic variables and workplace health risks to the prevalence of medical testing.

RESULTS

Economic variables were related to the prevalence of testing. However, consistent positive relationships were not found between health hazards and testing.

CONCLUSIONS

Employers' testing decisions may not be beneficial to the health of workers and may shift the costs of illness to workers or other employers. Safer firms may provide too much medical testing, and firms that are less safe may provide too little.