Table 1. The characteristics and standardized or reference value of each indicator and the demonstration calculation process of SEWI in Jiangsu province, China.
| First-order indicator (Weight) | Second-order indicator (Weight) | Third-order indicator | The standardized or reference value | Weight a | Value of example point b | SEWI calculation c |
| A: Endemic status (0.366) | A1: Endemic status of human (0.129) | A11: The local infectious case of schistosomiasis within last three years | Whether there exists the local case? Yes = 1; and No = 0 | 0.0431 | 1 | 0.0431×1 |
| A12: The infection rate of schistosomiasis | The true infection rate | 0.0424 | 0.1 | 0.0424×0.1 | ||
| A13: The acute case of schistosomiasis within last three years | Whether there exists the acute case? Yes = 1; and No = 0 | 0.0433 | 1 | 0.0433×1 | ||
| A2: Endemic status of snails (0.127) | A21: The area of snail habitat | The true value divided by the reference value of 70 thousand square meter | 0.0143 | 40,000 | 0.0143×(40,000÷70,000) | |
| A22: The density of live snail | The true value divided by the reference value of 0.5 snail per 0.1 square meter | 0.0144 | 0.2 | 0.0144×(0.2÷0.5) | ||
| A23: The number of snail habitat | For the point evaluation: Whether there exist the distribution of snail? Yes = 1; and No = 0For the regional evaluation: The true value divided by the reference value of 5 which is the average number | 0.0131 | 1 | 0.0131×1 | ||
| A24: The trend of snail area/density within last three years | Whether area/density increases? Yes = 1; and No = 0 | 0.0131 | 0 | 0.0131×0 | ||
| A25: The area of infected snail habitat | The true value divided by the reference value of 10 thousand square meter | 0.0147 | 2 000 | 0.0147×(2 000÷10 000) | ||
| A26: The density of infected snail | The true value divided by the reference value of 0.05 snail per 0.1 square meter | 0.0151 | 0.2 | 0.0151×(0.2÷0.05) | ||
| A27: The number of infected snail habitat | For the point evaluation: Whether there exists the distribution of an infected snail? Yes = 1; and No = 0. For the regional evaluation: The true value divided by the reference value of 2 | 0.0147 | 1 | 0.0147×1 | ||
| A28: The detection of an infected snail within last three years | Whether there exists the infected snail? Yes = 1; and No = 0 | 0.0145 | 1 | 0.0145×1 | ||
| A29: The area of emergence habitat of snail | For the point evaluation: Whether there exists the emergence habitat of snail? Yes = 1; and No = 0. For the regional evaluation: The true value divided by the reference value of 0.1 | 0.0136 | 1 | 0.0136×1 | ||
| A3: Transmission route (0.110) | A31: The result of sentinel mice survey | Whether there exist the infected sentinel mice? Yes = 1; and No = 0 | 0.0546 | 1 | 0.0546×1 | |
| A32: The result of snail detection | Whether there exist the infected snails? | 0.0555 | 1 | 0.0555×1 | ||
| B: Control measures (0.343) | B1: Control measures for human (0.168) | B11:The cover rate of screening and chemotherapy of schistsosomiasis | The true value of cover rate (%) | 0.0329 | 0.1 | 0.0329×(1–0.1) |
| B12: The cover rate of monitoring high risk group | The true value of cover rate (%) | 0.0348 | 0.7 | 0.0348×(1–0.7) | ||
| B13: The storage of prevention material and drug | Whether there exists the storage? Yes = 1; and No = 0 | 0.0321 | 0.5 | 0.0321×0.5 | ||
| B14: The registration rate of the population contacting with the risk water | The true value of cover rate (%) | 0.0306 | 0.2 | 0.0306×(1–0.2) | ||
| B15: The immediacy of the treatment of the acute case | Whether it is immediate? Yes = 0; and No = 1 | 0.0375 | 0 | 0.0375×0 | ||
| B2: Control measures for snail (0.175) | B21: The completion rate of snail detection | The true value of cover rate (%) | 0.0435 | 0.1 | 0.0435×(1–0.1) | |
| B22:The cover rate of snail killing | The true value of cover rate (%) | 0.0451 | 0.3 | 0.0451×(1–0.3) | ||
| B23: The effectives of snail killing | The true value of cover rate (%) | 0.0444 | 0.9 | 0.0444×(1–0.9) | ||
| B24: The cover rate of environmental change | The true value of cover rate (%) | 0.0419 | 0.2 | 0.0419×(1–0.2) | ||
| C: Social and environmental factors (0.291) | C1: Geographical factors (0.147) | C11: The assembly centres of mobile boatmen and fishermen | Whether there exist? Yes = 1; and No = 0 | 0.0477 | 0 | 0.0477×0 |
| C12: The assembly centres of large enterprises, construction projects | Whether there exist? Yes = 1; and No = 0 | 0.0496 | 0 | 0.0496×0 | ||
| C13: The livestock grazing areas and waterways in direct connection with the Yangtze River. | Whether there exist? Yes = 1; and No = 0 | 0.0498 | 0 | 0.0498×0 | ||
| C2: Social factors (0.144) | C21: The popularizing rate of sanitary toilets | The true vale (%) | 0.0275 | 0.8 | 0.0275×(1–0.8) | |
| C22: The cover rate of feces harmless treatment | The true vale (%) | 0.028 | 0.9 | 0.028×(1–0.9) | ||
| C23: The cover rate of individual protection | The true vale (%) | 0.0263 | 0.98 | 0.0263×(1–0.98) | ||
| C24: The local expenditure per capita for schistosomiasis control | The true value divided by the reference value of 1 | 0.0311 | 0.5 | 0.00311×(0.5÷1.0) | ||
| C25: The guarantee of organization management and policy | Whether there exist? Yes = 0; and No = 1 | 0.0309 | 0 | 0.0309×0 |
a
the combination weights of the third-order indicator;
b
it is the just example, and the filed value come example point;
c
the procedure showing the calculation of SEIW.