Epidemiological analysis of injury in Shandong Province, China

BMC Public Health

Table 1 Health economic indexes and calculation*

Abbreviation	Name	Formula and calculation
YPLL	Years of potential life lost	$Y P L L = \sum_{i = 1}^{N - 1} d_{i} (N - i)$
WYPLL	Working years of potential life lost	$W Y P L L = \sum_{i = 1}^{W - 1} d_{i} (N - W) + \sum_{i = w}^{N} d_{i} (N - i)$
VYPLL**	Valued years of potential life lost	$V Y P L L = \sum_{i = 1}^{N - 1} [(I_{1} + C_{1} - P_{1}) + (P_{0} - I_{0} - C_{0})]$
IEL***	Indirect economic loss	$I E L = \sum_{i = W}^{N - 1} (T_{L} I_{A})$

Variables: i=age at death; di=number of deaths at age i; N= upper cut-off age, 70 was used here; W= lower cut-off age of working, 20 was used here; I₁ = invested years; Io = uninvested years; P₁ = produced years; P₀ = unproduced years; C₁ = consumed years; C₀ = un-consumed years; T_L = Lost Time caused by injury (years for fatal injury and days for nonfatal injury; I_A = Average income per lost time (per year for fatal injury and per day for nonfatal injury)
* Cited from [6].
** Lifetime is divided into three segments, as investment (0–19), producer (20–59), and consumer (60–70). Invested years, produced years and consumed years were years one have been invested during investment period, years one have made contribution during producer period and years one have consumed during consumer period.
*** Indirect economic loss is classified into indirect economic loss 1(IEL1) and indirect economic loss 2 (IEL2), which is the value of lost labour caused by nonfatal and fatal injuries, respectively. It was calculated according to loss of work days/years caused by injury and per capita income of per day/year. Per capita income was average social dominatable income for urban dwellers and average pure earnings for rural dwellers according to local statistics in 2003.

ISSN: 1471-2458