Changes in statistical methods affected the validity of official suicide rates

This study suggests that the decreasing suicide rate in 1988-94 reflects a real change. However, the general quality of mortality statistics has deteriorated since the late 1990s, making it difficult to assess developments since 1994. Such variations in the reliability of official suicide statistics complicate international comparisons. However, shifts in the death rate because of “ill-defined” causes could serve as a warning that data quality is not consistent over time.