injuries are much more costly than injuries to the lower extremities or abdomen, holding AIS constant. This suggests that estimates of injuries may need to distinguish type and location of injury as well AIS as threat-to-life code.

Estimates of lost productivity include temporary work losses associated with an injury, and losses associated with long-term disability. In the United States, estimates of the number of days of work lost immediately following the injury come from populationbased surveys and are valued at the average wage. Estimates of the earnings loss associated with permanent long-term disability are calculated by multiplying the present value of foregone earnings by the probability of permanent disability, for each injury type. For partial disability, the present discounted value of lost earnings associated with partial disability and the probability of partial disability are multiplied to estimate the productivity loss (Corso et al., 2006; Zaloshnja et al., 2004).

It is, in principle, possible to compute medical costs and productivity losses associated with various injuries in developing countries. The World Health Organization (WHO) has recently published estimates of the cost of a hospital day (classified by type of hospital) and a doctor’s visit, for all WHO member countries (see Appendix B.) Estimates of productivity losses could be estimated by multiplying estimates of foregone earnings by the probability of full or partial disability associated with a disease. In the US, detailed estimates of the probability of full or partial disability exist for injuries classified by ICD-9 diagnosis and AIS threat-to-life code (Miller et al., 1995; Spicer and Miller, 2008). Whether these estimates could be transferred to other countries remains an open question.

# C. Estimates of QALYs Lost Due to Injury

One way of capturing the lost quality of life associated with an injury is to estimate the fraction of a healthy life year lost each year, over the remainder of the individual’s life, due to limitations imposed by the injury. Health-Related Quality of the Life (HRQL) indices assign a Quality of Life (QALY) index to various health states, which ranges from 1 (perfect health) to 0 (death). Health states are described by scores assigned to various dimensions of functioning (e.g., mobility, ability to eat or dress oneself, absence of pain). Comparing the QALY index for an injury (e.g., a severed spinal cord) with the QALY index associated with normal (or perfect) health provides an estimate of the utility loss associated with the injury.

Constructing a QALY index for an injury is accomplished in two stages. It is first necessary to select an HRQL index from the literature that will be used to measure the QALYs associated with different health states. Different HRQL indices include different dimensions of functioning, but measures commonly included are the ability to walk, bend and stoop (mobility), the ability to eat, speak, or dress oneself. (Appendix C lists the different domains included in various survey instruments.) In some instruments, the ability to function socially, or cognitively, or the absence of pain, constitute a separate domain. The number of domains times the number of levels within each domain determines the number of possible health states in the survey instrument. For example, 24