Documentation of hemoglobin A1c (HbA1c) levels in individuals with SMI and diabetes mellitus (ages 18 years or older)
Individuals who had at least one documentation of HbA1c-levels in the measurement year (numerator) among individuals 18 years or older with SMI and diabetes (denominator)
Severe mental illness (SMI) includes schizophrenia, schizoaffective disorders, and bi-polar disorders. Individuals with SMI are at a higher risk of poor physical health and of premature death. It is estimated that for people with SMI, two out of three deaths are from physical illnesses that can be prevented . Cardiovascular disease and cardiovascular risk factors are more common in people with SMI compared with the general population. For instance, the prevalence of obesity is 1.5-2 fold higher in persons with SMI compared with the general population, and the prevalence of diabetes is 2-3 times higher. Additionally, the age of diabetes onset is earlier in persons with SMI, and the incidence and severity of complications are higher as well, including micro- and macro-vascular complications, acute metabolic dysregulation, and diabetes-associated mortality. The underlying mechanisms relating cardiovascular risk factors and SMI are complex, and include genetic, environmental, and behavioral aspects, as well as aspects related to anti-psychotic drug therapy .
Individuals in the denominator who had at least one documentation of HbA1c-levels in the measurement year
Individuals 18 years or older with SMI and diabetes (see "prevalence of diabetes in persons with SMI" for definition)
 Severe mental illness (SMI) and physical health inequalities: briefing. Public Heath England, September 2018. Available at: https://www.gov.uk/government/publications/severe-mental-illness-smi-physical-health-inequalities/severe-mental-illness-and-physical-health-inequalities-briefing
 Holt RI, Mitchell AJ, Diabetes mellitus and severe mental illness: mechanisms and clinical implications. Nat Rev Endocrinol. 2015 Feb;11(2):79-89