Applying the capture-recapture method to estimate road traffic deaths and injuries in three non-contiguous cities in the Philippines

In establishing goals for the Philippine road safety plan, police data were used. Police reports are likely underreporting. We apply capture-recapture analysis to determine expansion factors and estimate the true incidence. Three cities were visited where data on deaths (2014) and injury (January–March 2014) from hospitals, police and civil registry were collected. Matching was done to generate a final list of injured and dead individuals. The Chapman method was used for estimating the true number of cases. Police data exhibited underreporting in all site. Expansion factors of the police data range from 5.4 to 29× for deaths and 3.2 to 47× for non-fatal injuries. Expansion factors are likely useful to estimate the true incidence of road traffic injuries in areas with weak injury surveillance systems such as the Philippines.