Repetition of deliberate self-harm: a study of the characteristics and subsequent deaths in patients presenting to a general hospital according to extent of repetition

Repetition of deliberate self-harm (DSH) is common. Some patients repeat multiple times. We have investigated the characteristics of repeaters, and mortality in three groups of DSH patients by repetition status. Data collected by the Oxford Monitoring System for Attempted Suicide were used to examine the pattern of repetition of DSH patients presenting to a general hospital between 1990 and 1997. Each patient was tracked through the monitoring system with regard to repetition. Patients traceable through National Death Registers were followed up until 2000 with respect to mortality. A total of 4,167 patients were studied of which 1,022 (24.5%) repeated at least once during follow-up. Using multinomial regression, past history of DSH was the variable most strongly associated with frequent (4+) and less frequent (1-3) repetitions. Risk of suicide was significantly increased in females with frequent repetition (7.7% dying by suicide), compared with both those with 1-3 repetitions (2.3%) and those not repeating (1.0%). The analyses were repeated for the 2,167 patients with no past history of DSH at their first presentation. Using multinomial regression, personality disorder was the only variable that was associated with 4+ repetitions compared with no repetitions, although a number of variables distinguished between patients with 1-3 repetitions and no repeat episodes. For clinicians assessing DSH patients, past history of DSH is the best predictor of infrequent and frequent repetition. In patients with no past history of DSH the presence of personality disorder increases the risk of frequent repetition of DSH.