Work-related amputations in Washington state, 1997-2005

Work-related amputations are infrequent but devastating injuries. Attempts to more accurately estimate the burden of amputations and industries at risk have led the Washington State occupational surveillance program to explore new methods for case identification in Washington State workers' compensation data.

Two methods were utilized for case identification of work-related amputations. The first method used the ANSI Z16 nature code for amputation. An alternative method utilized medical, hospital, and claim administration coding of medical bills and bill payment systems. After identifying suspected amputation claims, a sample of the medical records associated with different case identification methods were reviewed to verify that an amputation likely occurred.

From 1997 to 2005, 2,528 amputations were identified using the ANSI Z16 code for amputation (Nature = 100) and an additional 3,912 amputations were identified using the alternative method. There was an increasing trend of amputation injuries over the time period using the ANSI amputation definition; however, the trend in amputation injuries captured by the alternative method was decreasing. This may indicate a bias in estimating a trend due to misclassification of amputation injuries. The sectors with the highest amputation claims rates were Manufacturing; Construction; Agriculture, Forestry, Fishing and Hunting; Accommodation and Food Services; and Wholesale and Retail Trade.

Current methods to identify work-related amputations in the workers' compensation data system underestimate the burden of amputations in Washington State. By utilizing alternative case identification methods, we estimate that there were about 150% more amputations in Washington State over the time period.