Use of geographic information systems to assess the error associated with the use of place of residence in injury research

Table 2 Driving time between place of injury and place of residence

	T_rh-T_ih: Difference in driving time between place of residence and hospital and place of injury and hospital (minutes)
T_ir: Driving time between place of injury and place of residence (minutes)	Mean	Median
0–10	0.9	0.1
10.1–20	8.7	9.4
20up	70.8	42.0

Shows that as the driving time between place of injury and place of residence increases, the error in driving time to the hospital also increases. The sharp difference in error indicates that the use of place of residence as a proxy for place of injury is reliable only with case populations where the distance between place of residence and place of injury is minimal (eg elderly, falls)

ISSN: 2197-1714