Background. The extent to which clusters of attempted suicides occur i
s a significant problem that is complementary to the current available
research on the clustering of completed suicide. However, little syst
ematic research on clusters of attempted suicides exists. The present
study examines the extent and nature of clustering of suicide attempts
. Method. The occurrence of clustering of attempted suicide was examin
ed in nationwide data for all New Zealand hospitals, obtained from the
New Zealand Health Statistics Services for the years 1988-1990. The S
can statistic and Knox procedure were employed for testing the signifi
cance of clusters in time and time-space, respectively. Results. The a
nalyses indicated that significant time clustering occurred in younger
age groups, specifically among 15-19 and 20-24 year olds. The results
could not be accounted for by seasonal variations in admissions. Age
specificity of time-space clusters emerged, exhibiting a similar patte
rn to that reported for completed suicides in the US. Conclusions. The
results suggest a similar underlying mechanism for the clustering of
parasuicide and completed suicides and provide support for the existen
ce of contagion of suicidal behaviour. The implications for prevention
are discussed.