Adults with schizophrenia were more than 3.5 times as likely to die as adults in the general U.S. population, particularly from cardiovascular and respiratory diseases, and that implicates tobacco as a modifiable risk factor, according to an article published online by JAMA Psychiatry.
Many factors, including economic disadvantage, negative health behaviors, and difficulty accessing and adhering to medical treatments are believed to contribute to premature death among individuals with schizophrenia. Smoking, limited physical activity, obesity, elevated blood glucose level, hypertension and dyslipidemia are more common in individuals with schizophrenia than in the general population.
Mark Olfson, M.D., M.P.H.., of Columbia University, New York, and coauthors describe the overall and cause-specific death rates and standardized mortality ratios (SMRs, which are used to compare death rates in populations) for adults with schizophrenia compared with the U.S. general population. The authors identified a national group of more than 1.1 million Medicaid patients with schizophrenia (between the ages of 20 to 64) and 74,003 deaths, of which 65,553 had a known cause.
Among the 65,553 deaths with a known cause, 55,741 were from natural causes, which include a variety of diseases, and 9,812 were due to unnatural deaths, which included suicide, homicide assault and accidents, both poisoning and nonpoisoning, according to the results.
Cardiovascular disease had the highest mortality rate (403.2 per 100,000 person-years) and accounted for almost one-third of all natural deaths (n=19,381). Cancer accounted for about 1 in 6 deaths. Among the other natural causes of death, chronic obstructive pulmonary disease (COPD), diabetes, influenza and pneumonia had the highest mortality rates, study results indicate.
Unnatural causes of death accounted for about 1 in 7 deaths with known causes (n=9,812), with suicide accounting for about one-quarter of the unnatural deaths (n=2,498). Accidents accounted for more than twice as many deaths (n=5,753) as suicide.
Nonsuicidal substance-induced death, mostly from alcohol or other drugs, also was a leading cause of death (95.2 per 100,000 person-years).
Limitations noted by the authors include not having information about key health risk factors such as smoking status, body mass index and substance abuse.
“The results from this study confirm a marked excess of deaths in schizophrenia, particularly from cardiovascular and respiratory disease, that is evident in early adulthood and persists into later life. Especially high risks of mortality were observed from diseases for which tobacco use is a key risk factor. These findings support efforts to train mental health care professionals in tobacco use prevention and treatment and in implementation of policies that incentivize smoking control interventions in settings treating patients with schizophrenia,” the study concludes.