Objective: To identify cause-of-death categories in which suicides might be misclassified in Taiwan.
Methods: We plotted secular trends (1971-2007) in sex- and method-specific rates of deaths classified as suicide, undetermined intent and accident for the Taiwanese population aged 15+ and compared the sex, age and marital status profiles of deaths in these three categories by method of death.
Results: The demographic profiles of registered suicides generally resembled those for deaths of undetermined intent and accidents by pesticide poisoning/suffocation but differed from those for accidents from non-pesticide poisoning/drowning/falling/poisoning by non-domestic gas. For the period 1990-2007, suicide rates based on suicides alone (14.8 per 100,000) would increase by 23, 7 and 1%, respectively, when including deaths of undetermined intent, accidental pesticide poisonings and accidental suffocations.
Conclusions: Suicide rates may be underestimated by more than 30% in Taiwan because some suicides are 'hidden' amongst deaths certified as due to other causes.