CPSC Identifies Improvements to Injury Cost Model

A CPSC report, made available August 9 outlined a series of improvements for measuring long-term costs associated with lead poisoning, carbon monoxide (CO) poisoning, and pool and spa submersion. The report, prepared by PIRE, notes that the agency’s injury cost model (ICM) is not designed to take into account many long-term neurological consequences that are often associated with these types of incidents. As a result, data on true health costs of these incidents is incomplete. Some factors the group analyzed were quality-of-life losses, associated work losses, and acute medical care costs. The task group charged with updating the cost model looked at 1) lead poisoning for ages zero to four, 2) pool and spa submersions for ages zero to fourteen, and 3) CO poisoning for all ages.

1) The report notes that lead poisoning, while rarely fatal, has been determined to cause large long-term changes in IQ. These decreases are associated with substantial losses in future work productivity as well as quality of life. In addition, the report found that lead poisoning incidents occurring ages of 0 to 4 can lead to increased needs for special education, elevated risk of attention deficit hyperactivity disorder, and increased rates of future criminal behavior.

In addressing the effect of lead poisoning on future work productivity, the report recommends CPSC estimate productivity losses by using the age-earnings model built into the ICM. Using this model, a blood lead level of 2 (?g/dL) would be associated with an IQ loss of 1.9 points, which would translate to a 3.3% decrease in future earnings. In comparison, a blood lead level of 90 (?g/dL) would be associated with an IQ loss of 12.1 points, translating to a 21.4% loss of future earnings.

In addressing quality of life, the group based its findings on existing quality-adjusted life year (QALY) rating scales. Under these models, the group was able to calculate estimates of utility loss for various brain injuries. For example, it calculated utility loss for individuals with habitual irritability and reproductive impacts (at blood lead levels ?60 ?g/dL), ranking them by functional impact such as whether a person learns and remembers more slowly than classmates, requires special education due to learning and remembering very slowly, or cannot learn. On average, the group suggests a 20% QALY loss for childhood exposures.

2) Out of the three injuries addressed by the report, it was estimated that submersion injuries lead to significantly higher acute medical costs than lead or CO poisoning. The report estimates the mean hospital costs for lead poisoning (ages 0-4) at $7,857 with a lifetime medical cost multiplier of 1.73; the mean hospital costs for CO poisoning (all ages) at $15,769 with a lifetime medical cost multiplier of 1.86; and the mean hospital costs for submersions (ages 0-14) at $25,896 with a lifetime medical cost multiplier of 3.36.

The reason for the higher medical costs associated with submersion is that incidents with long-term health consequences, or sequelae, almost always involve the need for tracheotomy and feeding tubes, which means dependence on breathing machines, round-the-clock nursing care, and shorter lifespans. Furthermore, because children with submersion-related sequelae rarely survive into adulthood, their entire lifetime productivity is lost. Regarding quality-of-life loss, the report estimates utility losses in tracheotomy-tube dependent cases to be in the 90 percent range.

3) Concerning CO poisoning, the report estimates a 15% loss in earning capacity for those cases involving enduring cognitive sequelae. Using the age earnings model included in CPSC’s ICM with an average lifetime productivity of $937,815, a 15% decrease in earnings loss would translate to a lifetime earnings loss of $140,672. The report also notes that although CO poisoning does not shorten lifespan, lifestyle factors cause those who experience CO poisoning to have elevated risks of subsequent death from suicide, violence, substance abuse, or unintentional injury.

The report cited a study that found that long-term consequences of CO poisoning can be substantial, especially without hyperbaric oxygen treatment. The report noted that the probability of sequelae at 6 weeks was 53% with no oxygen treatment, 41% with normobaric oxygen, and 24% with hyperbaric oxygen treatment.

At 6 months, probability of sequelae was 30% without hyperbaric oxygen treatment and 17% with treatment; and at 12 months, sequelae drop to 18% without hyperbaric oxygen treatment and 14% with treatment. Six years after exposure, another study found that 37% of patients who were not treated with hyperbaric oxygen have abnormal neurologic evaluations and 19% have cognitive problems.

In terms of quality of life, the report suggests a conservative 15% QALY loss per year for those with long-term health consequences from CO poisoning, with 20% of patients experiencing lifetime sequelae. Using CPSC’s QALY value of $4,062,185, a 15% loss would translate to a quality-of-life loss of $609,328.

The report notes that it was unable to access severity distribution data and therefore was only able to provide average figures by assuming a distribution. It suggests that future research might be conducted if Medicaid claims forms were made available, which would allow one to infer the frequency of moderate to severe sequelae.

The report can be found at www.cpsc.gov/Global/Research-and-Statistics/Injury-Statistics/ Carbon-Monoxide-Posioning/IncidenceandCostofCarbonMonoxidePoisoningPoolandSpaSubmersionandLeadPoisoning%20.pdf.