For example, individuals in a group characterized by substance use disorders (SUDs) had a depression prevalence of about 60% and relatively high death rates from unintentional injury and hepatitis.
American Psychiatric Association
Dr. Alison Hwong
“The health care needs of older adults with schizophrenia can vary widely, so aging persons with schizophrenia can’t be considered a uniform population,” study investigator Alison Hwong, MD, PhD, University of California, San Francisco, National Clinicians Scholars Program and San Francisco Veterans Affairs, told this news organization.
“For patients with multiple chronic conditions, we need to be proactive in coordinating specialty care. At the same time, we need novel models of person-centered care to help aging adults with schizophrenia live longer, healthier lives,” Dr. Hwong added.
The findings were presented as part of the American Association for Geriatric Psychiatry annual meeting.
Widening mortality gap
The life expectancy of patients with schizophrenia is lower by 8-15 years, compared with those without schizophrenia and this “mortality gap” has widened in recent years, Dr. Hwong noted. Those with schizophrenia also have high rates of health care utilization and high direct and indirect health care costs.
Most previous research looking at illness in schizophrenia focused on a single medical condition, “but by midlife, adults with schizophrenia may have multiple medical conditions,” said Dr. Hwong. “Little is known about multimorbidity in aging adults with schizophrenia and how that could be related to mortality outcomes.”
The study included 82,858 U.S. veterans aged 50 years and older who had at least one inpatient or two outpatient encounters associated with a diagnosis of schizophrenia in the previous 2 years. The study period ran from 2012 to 2018.
Using health care records and data linkages, researchers examined 20 common medical and psychiatric conditions other than schizophrenia that required medical attention. The investigators used the “latent class analysis” statistical model to assess differences across classes.
The study included three distinct patient classes: minimal morbidity (43% of the cohort), depression and medical comorbidity (34.2%), and SUDs and related conditions (22.8%).
The SUD group tended to be younger, with a mean age of 57.9 years versus 60.4 years for the minimal comorbidity group and 65.9 years for the depression group.
The SUD group was also less likely to be female (4.8% vs. 6.7% and 6%, respectively), less likely to be White, and more likely to be Black. This group was also less likely to be married and more likely to have a history of homelessness.
Disease prevalence rates
Results showed the minimal morbidity group had prevalence rates of less than 10% for all major conditions, except for tobacco dependence, which had a rate of 11.8%.
The depression and medical comorbidity group had very high prevalence rates (more than 20%) for heart attack, heart failure, stroke, cancer, dementia, arthritis, renal disease, sleep disorders, depression, and tobacco dependence. In addition, the rate was 60% for chronic obstructive pulmonary disease.
Participants in the SUD and related conditions group had rates of more than 70% for alcohol use disorder, other drug use disorders, and tobacco dependence. They also had high rates of COPD, hepatitis C, chronic pain, sleep disorders, depression, and PTSD.
On average, the SUD group was younger and may explain why they were less likely to have heart failure and renal disease, Dr. Hwong noted. These results may help inform treatment approaches, she added.
“For the group with largely substance use–related conditions, perhaps we can better address their needs with, for example, specific addiction and infectious disease services instead of a one-size-fits-all model,” said Dr. Hwong.
The investigators also examined mortality rates. Those in the depression and morbidity group had the highest rate of overall mortality; 47.5% of this class died during the observation period, compared with 27.2% of the SUD group.
More research is needed to understand why the mortality rate is so high in the depression and morbidity group, she said.