The codes and conditions list was developed for use within WorkSafe New Zealand, and to support further research about the classification of work-related musculoskeletal disorders. The development report outlines how we developed the codes and conditions list.

Executive summary

Work-related musculoskeletal disorders (WRMSDs) have significant impact on people all over the world. Musculoskeletal disorders (MSDs) affect 1.71 billion people worldwide and are the main contributor to the global need for rehabilitation. The prevalence of these disorders in specific working populations and/or occupational sectors is significantly higher than in general populations. In New Zealand, MSDs represent over 30% of the overall burden of harm from work-related ill-health and injury.

The Human Factors/Ergonomics (HFE) team at WorkSafe New Zealand are leading work which targets exposure to musculoskeletal health risks in New Zealand workplaces. The HFE team found there was no clear definition of WRMSDs used in New Zealand, or what specific injuries or conditions were included in the musculoskeletal harm data. This is necessary for accurate WRMSDs data, and to understand the high-risk work activities that result in WRMSDs. Good understanding of high-risk work activities will then determine appropriate risk assessment methods and help WorkSafe to prioritise interventions.

The purpose of this project was to develop a WRMSDs codes and conditions list for use within WorkSafe New Zealand, and to support further research. This was achieved in two stages. First, we conducted a literature review of health classification and WRMSDs classifications systems used in New Zealand and abroad. The second stage involved using the findings of the review to develop the WRMSDs codes and conditions list.

Key findings of the review

Our review found there is no internationally recognised classification system or list for WRMSDs. We found:

• there is a lack of consensus on terminology and definitions used for WRMSDs in research and within countries, and the conditions included under the definition
• there are inconsistencies in how health professionals diagnose these conditions
• there is a lack of agreement amongst researchers on case definitions for WRMSDs
• that government health priorities and the role of compensatory bodies within a country influence and determine what conditions are included as WRMSDs, and
• that WRMSDs are difficult to diagnose and classify as both work-related and individual factors contribute to their development.

There were differences in how each country classified or collected WRMSDs data. We were unable to obtain full data sets from any country, which made it difficult to compare musculoskeletal harm data.

New Zealand mainly uses ACC injury claims data to understand work-related musculoskeletal harm. WorkSafe uses the System of Work-related Injury Forecasting and Targeting (SWIFT) tool to further analyse data. The SWIFT tool provides many benefits – it allows more sophisticated analysis of the data, better understanding of injury causation, and may help WorkSafe with prioritising where to target interventions. WorkSafe uses injuries and conditions that fall into the ‘Body Stressing’ mechanism for reporting on musculoskeletal conditions at work. This is not without its limitations, and other mechanisms where WRMSDs occur are overlooked, for example from slips, trips and falls, or from exposure to vibration.

Development of the WRMSDs codes and conditions list

The findings of the review were used to develop a WRMSDs codes and conditions list for use within WorkSafe. The HFE team developed an initial codes and conditions list by:

• reviewing and refining the current diagnostic codes used in New Zealand, including the ACC Read codes and ICD-10-AM codes
• establishing criteria for inclusion of codes and conditions. We used the findings of the literature review and the WorkSafe definition for WRMSDs to inform selection criteria. This ensured that we included conditions based on international research and best practice, and not solely determined by the Accident Compensation framework
• working with WorkSafe stakeholders and subject matter experts to consider and justify why the relevant codes or conditions were included.

Conclusion

This report provides a summary of classification systems and data collection methods for WRMSDs in New Zealand and abroad. While there was no international classification system for WRMSDs we applied the review findings to develop the codes and conditions list. This review also found gaps in New Zealand’s surveillance of WRMSDs.

Recommendations

Based on the main findings, we recommend that:

• WorkSafe adopts and uses the WRMSDs codes and conditions list for reporting of musculoskeletal harm data
• WorkSafe considers opportunities to collect other sources of musculoskeletal harm data. For example, workplace discomfort data, early intervention monitoring information from health organisations, and other health monitoring data
• WorkSafe, other government agencies, and industry bodies conduct or support research that examines workers’ exposure to musculoskeletal risks. Such projects may include nationwide surveys, or applied research within industry
• WorkSafe and ACC (and other relevant organisations) consider how the work by Boocock et al. (2009) on the upper extremity classification framework can be further integrated into practice within New Zealand.