The high prevalence of hospital errors in the U.S. accounts for $19.5 billion in costs and results in 2,500 excess deaths and more than 10 million excess days missed from work due to disability, according to a June report conducted by the consulting firm Milliman.

The researchers evaluated the economic impact of medical errors, which they defined as a “preventable adverse outcome of medical care that is a result of improper medical management (a mistake of commission) rather than a progression of an illness due to lack of care (a mistake of omission).”

The researchers identified errors, calculated injury and error rates and measured the medical costs per injury and inpatient mortality and short-term disability costs per injury through medical claims data.

The researchers found that a total of 6.3 million injuries occurred in 2008, and 1.5 million were medical errors that soaked up an estimated $19.5 billion.

Eighty-seven percent of this $19.5 billion, or $17 billion, was directly related to inpatient, outpatient and prescription drug services to patients who experienced a medical error.

The 10 most common errors were: pressure ulcers; post-op infections; device complications; postlaminectomy syndrome; hemorrhages; infections following an infusion, injection, transfusion or vaccination; pneumothorax; infections from central venous catheter; other complications of internal device, implant and graft nature; and ventral hernias. According to the researchers, these 10 errors accounted for 69 percent of the total medical errors.

Pressure ulcer events soaked up the most costs and accounted for the most errors, $3.9 billion and 374,964 per year, respectively.

The researchers estimated that 10 percent to 35 percent of post-operative shock incidents are errors, which soak up $93,682 per incident. Additionally, central venous catheter-related medical errors cost $83,364 per incident.

Indirect costs associated with mortality rates of patients who experienced medical errors were estimated to be $1.4 billion, and the costs for the loss of productivity from short-term disability claims were estimated at $1.1 million.

Post-op infections accounted for the most days missed in 2008 (2.7 million), but the highest disability costs per case were related to complications of prosthetic joints ($2,293 per error). Post-op infection cases cost $1,246 in disabilities per case.

Mechanical complications of a cardiac device, implant, and grafts accounted for 30,973 errors in 2008 and cost an estimated $5,946 cost per error, almost $1.1 billion total, according to the report.

While total costs related to measurable mortality were estimated to be $1.4 billion—$1.1 million for inpatient errors and $302.85 million for outpatient—researchers warned that these estimations were based on limited data and could have been underestimated.

The Society of Actuaries Health Section funded the study.