The National Occupational Exposure Survey is an important national resource for hazard surveillance providing the data to describe the distribution of ergonomic risk factors by industry and occupation. The survey, however, was last carried out almost 20 years ago and is not likely to represent well the distribution of current exposures. It also does not provide exposure characterization of the risk factors present in emerging industrial sectors.
Data from medical care records could be particularly valuable in providing much greater detail about the nature, distribution, time course, and disability associated with musculoskeletal disorders. Such data, however, have important limitations:
1. Medical confidentiality mechanisms need to be developed to allow use of these data for surveillance purposes and to protect the individual identity of those whose records are in the system.
2. Although specific diagnostic information is recorded by ICD-9 coding, algorithms will need to be developed to ensure consistency in diagnostic practice across providers and determine reliability.
3. Systems to match information on occupation or employer will need to be developed so that patterns of musculoskeletal disorders among different working groups can be examined.
Since the estimates of cost are contingent on estimates of incidence, severity, and prevalence rates for musculoskeletal disorders and differentiation of work from nonwork-related cases, all of the above limitations apply to these estimates. In addition, there are issues unique to the economic estimates: (1) other than the direct costs of health services and wage offsets, there is no uniformly agreed-on formula for estimating the additional costs of each case, such as domestic productivity, reduced future occupational productivity, reduced educational opportunities for children, etc.; (2) it appears likely that additional costs, over and above health services and wage replacement, accrue not only to victims of musculoskeletal disorders, but also to their employers and to society. These include administrative costs, training of replacement workers, lost tax revenues, utilization of public replacement benefits or assistance, etc.