Recognising inaccuracies in Australian suicide and 'hidden suicide' data

To examine the effects of revision of Australian mortality statistics every year since 2007 on numbers and rates of suicide and 'hidden suicide'.

Nine months after the end of each year, the Australian Bureau of Statistics releases preliminary statistics concerning deaths registered in that year, together with revised and finalised data regarding previous years. Numbers and rates of suicide and of deaths coded to selected categories of accidental, undetermined and unknown cause deaths were tabled.

Upward revision of suicide and accidental drug poisoning death numbers, three years after first release, show that true rates are substantially higher than initially released data suggested. Concomitant downward revision of rates of undetermined and unknown cause deaths supports evidence that at first release some suicides are coded to these categories.

Australia's finalised suicide data are likely to be more accurate than equivalent data from nations that do not revise mortality data. More comprehensive investigation (including verbal or psychological autopsy) in doubtful cases in Australia and elsewhere would probably lead to reported suicide rates being higher.