Death from natural causes high in patients with schizophrenia
MedWire News: Patients with schizophrenia continue to have a mortality risk that is two to three times that of the general population, findings from a 25-year mortality study show.
Most of these extra deaths are from natural causes, rather than intrinsic to the disease, the researchers report. However, an increase in cardiovascular deaths over this time compared with the general population should be of concern to mental healthcare professionals, they say.
Steve Brown (Hampshire Partnership National Health Service Trust [NHS], Southampton, UK) and colleagues analyzed a cohort of 370 people with schizophrenia, who had been in contact with their local NHS psychiatric services from 1981/1982 until 2006.
In 2006, a total of 199 of the cohort were still alive, seven were untraceable, and 164 had died. Of the 164 deaths, 141 were from natural causes, 21 from unnatural causes, and two were from unknown causes.
The all-cause standardized mortality ratio (SMR) for the patients was 289, which is a three-fold increase compared with population of England and Wales, and there were only small, nonsignificant changes in all-cause SMR between 1981 and 2006. Approximately 81% of the excess mortality was from natural causes and 17% from unnatural causes.
The researchers note in the British Journal of Psychiatry that cardiovascular diseases contributed the most to the overall excess mortality, accounting for 33%, followed-by respiratory diseases, which accounted for a further 19%. Moreover, the SMR for cardiovascular disease increased over the course of the study in patients with schizophrenia, from 129 in 1981–1986 to 350 in 2001–2006.
They add that a large part of the excess mortality can also probably be attributed to the effects of cigarette smoking. Indeed, 73% of the schizophrenia patients were cigarette smokers at the outset of the study, and the SMR among cigarette smokers was significantly higher than that among nonsmokers, at 379 versus 194.
“This study suggests that the natural cause mortality of schizophrenia has been two to three times that of the general population throughout,” say Brown et al.
“Further large-scale long-term follow-up studies are needed to establish the reasons behind the increase and to suggest useful interventions,” they add.
“In the meantime, the most clinically useful intervention is probably to try and help people with schizophrenia to stop smoking, to promote exercise, and to facilitate effective health screening.”
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By Lucy Piper