Occupational Medicine

There is substantial evidence to support the positive link between work and health (physical, mental and social health). Both employment and income are separate determinants of health and are used as health status indicators. Absence from work contributes to declining health, slower recovery times, and longer duration of disability. Maintaining and restoring working capacity is an important function of health services which improves function and can also impact upon recovery and prognosis. Supporting unnecessary restrictions or total disability (absence from work) creates disability which in turn negatively impacts upon health. When asked to provide an opinion on functional abilities to employers or insurers, the focus should be on abilities; restrictions should be objective, specific, and listed only when absolutely medically indicated.

Increases in opioid prescribing have been accompanied by simultaneous increases in abuse, serious injuries, and deaths from overdose. Compared to those on no, or lower opiate doses, those prescribed higher opiate doses have increased disability risk and duration. The use of opiates can result in effects such as euphoria, drowsiness or inability to concentrate. Cognitive and psychomotor ability are essential functions for driving a motor vehicle and other complex work tasks. Those who prescribe opiates may be obligated to report a patient’s inability to drive safely.

Acute low back pain is a common health problem affecting between 50-90% of people over the course of a lifetime with less than 2% of cases representing potentially serious conditions requiring surgical or medical intervention. Red flags suggesting additional testing include such things as a history of significant trauma, cauda equina syndrome, symptoms suggestive of tumour or infection (fever, weight loss, history of cancer), steroid use, etc. However, the majority of acute low back pain episodes are benign, self-limited cases that do not warrant any imaging studies. Unnecessary imaging can be harmful due to the potential adverse health effects associated with radiation exposure and due to attribution of symptoms to unrelated incidental findings leading to prolonged disability.

Although clinically significant exposures may still occur in Canada, less than 1% of Canadian adults have total blood mercury concentrations above Health Canada’s guidance value. As such, the large majority of individuals who present with concerns of metal toxicity do not actually have toxicity, and testing results in false positives (values above the reference range but not in the range of toxicity). Occupationally exposed workers and childbearing women are susceptible subgroups therefore testing in these populations is warranted in cases where a careful occupational and/or environmental history suggests a significant exposure. In the absence of clinical presentation and history indicating toxicity risk, testing should be avoided because it may lead to misinterpretation and unnecessary concern or interventions (dietary restriction, chelation) that may cause harm.

Asbestosis generally becomes manifest clinically 15-20 years after the onset of exposure. High resolution CT (HRCT) is more sensitive than both chest radiography and conventional CT for detecting parenchymal fibrosis (asbestosis) but a normal HRCT scan cannot completely exclude asbestosis. Given the long latency between asbestos exposure and asbestosis and given that no effective treatment is available to improve the outcome, screening and early detection of asbestosis is unlikely to allow any remedial action to be taken in the workplace or to confer any health advantage on asbestos-exposed individuals. Repeated imaging exposes the patient to radiation, which is not without risk. Therefore, while it is appropriate to obtain a baseline X-ray at the time of first assessment, for screening purposes, radiation risk outweighs the benefit of frequent chest X-rays. Radiation exposure would also be a concern for repeated CT scans.

Reverse Transcription-Polymerase Chain Reaction (RT-PCR) amplification tests remain positive in some people’s respiratory samples after recovery from coronavirus disease 2019 (COVID-19) infection with prolonged viral RNA shedding demonstrated without direct evidence of there being viable virus capable of replicating or causing infection. Test-based strategies relying on the absence of viral fragments, such as RNA or antigen, for return to work clearance may therefore inappropriately delay return to work. The United States Centres for Disease Control (US-CDC) recommends time-based approaches. A time-based approach based on epidemiologic studies suggests that it is safe to return to work 10 to 20 days after symptom onset depending on the severity of the illness and symptom resolution criteria. Return to work criteria requiring one or more negative RT-PCR or other approved tests may still be considered in high risk occupational settings such as working with high risk persons in a health care setting.