(British Medical Journal) -- The risk of suicide for people with a history of attempted suicide or deliberate self harm (parasuicide) persists without decline for two decades, finds a study in this week's BMJ. Providing a high standard of care to these patients could help to reduce this rate.

Researchers traced 140 patients 22 years after they presented to a central London teaching hospital after an episode of parasuicide in the late 1970s.

The rate of suicide plus probable suicide during the period of follow up was 5.9 per 1000 per year in the first five years, rising to 6.8 per 1000 per year in the final three years. The rate did not decline with time.

Clinicians are encouraged to pay particular attention to the management of patients immediately after an episode of parasuicide, say the authors. Previous deliberate self harm remains a potent risk factor for subsequent suicide, even if it occurred many years ago, they conclude.

An accompanying editorial concludes: "To pay attention to previous parasuicide in the assessment of the patient in the emergency department is crucial, because it may indicate a serious risk even if the act was committed several years ago."