Concept: Schizophrenia - Measuring Prevalence

Introduction

This concept defines schizophrenia and describes how this medical condition has been defined in MCHP research. This includes a list of databases where this information resides, the ICD diagnosis codes that are used to define it, and a list of MCHP research that has investigated schizophrenia, with links to the research results and findings in this research.

Schizophrenia is a severe mental disorder characterized by difficulty in distinguishing between real and unreal experiences (delusions and hallucinations), thinking logically, having normal emotional responses to others, and behaving normally in social situations. To obtain a diagnosis of schizophrenia, the symptoms must have been present for at least one month (American Psychiatric Association, 2013).

There are several related conditions, including several types of schizophrenia, schizotypal and schizoaffective disorder. Schizotypal disorder is defined as having eccentric behaviour and anomalies of thinking and mood, which resemble those seen in schizophrenia. Schizoaffective disorder is characterized by both symptoms of a mood disorder and schizophrenia (American Psychiatric Association, 2013).

Technical Definition of Schizophrenia

The technical definition of schizophrenia using administrative data includes:

• Data Sources:
  
  • Hospital Abstracts data; and
    
  • Medical Services (Physician Claims) data.
  
  
• Code Values and Conditions: - defined as Manitoba residents with:
  
  
  • one or more hospitalization with a diagnosis for schizophrenia:
    
    
    • ICD-9-CM code: 295 (schizophrenic disorders); OR
      
    • ICD-10-CA codes: F20 (schizophrenia), F21 (schizotypal disorder), F23.2 (acute schizophrenia-like psychotic disorder), F25 (schizoaffective disorders); OR
    
    
  • one or more physician visits with a diagnosis for schizophrenia using ICD-9-CM code 295.
  
  NOTE: In most MCHP research, the definition is generally restricted to those aged 10 and older. In Brownell et al. (2015, 2018), the definition is restricted to those aged 12 and older. In Chartier et al. (2015), the definition is restricted to those aged 13 and older. In Chartier et al. (2016) this is restricted to adolescents, aged 13 to 19 years.

MCHP Research Investigating Schizophrenia

The following sections describe how schizophrenia is investigated in several MCHP deliverables and provides links to specific information in each report.

1. Martens et al. (2004)
   
   In the Patterns of Regional Mental Illness Disorder Diagnoses and Service Use in Manitoba: A Population-Based Study deliverable by Martens et al. (2004) they investigated the treatment prevalence of schizophrenia separately and as one of five cumulative disorders. For more information, see:
   
   
   • 2.2 Treatment Prevalence of Cumulative Disorders - information is presented by RHA for 1997/98 to 2001/02;
     
   • 2.8 Treatment Prevalence of Schizophrenia - information is presented by RHA, RHA District, age and sex, and income quintile for 1997/98 to 2001/02.
   
   NOTE 1: Additional information on schizophrenia is provided throughout the report.
   NOTE 2: In addition to using the Hospital Abstracts and Medical Services data, this report also used the Mental Health Management Information System (MHMIS) data.
   
   
2. Doupe et al. (2008)
   
   In the An Initial Analysis of Emergency Departments and Urgent Care in Winnipeg deliverable by Doupe et al. (2008) they investigated the use of emergency departments and Urgent Care by patients with mental illness diagnoses, including schizophrenia. For more information, see:
   
   
   • Table 8.4: Distribution of Emergency Department Users by Previous Diagnosis of Select Mental Illnesses
     
   • Table 8.5: Distribution of Emergency Department Visits at HSC and SBGH by Mental Illness Diagnosed at the Time of the Visit
     
   • Table 9.3: Distribution of Urgent Care Users by Previous Diagnosis of Select Mental Diseases
   
   
3. Fransoo et al. (2009)
   
   In the Manitoba RHA Indicators Atlas 2009 deliverable by Fransoo et al. (2009) they compared the prevalence of schizophrenia between 1996/97-2000/01 and 2001/02-2005/06 separately and as one of five cumulative disorders. For more information, see:
   
   
   • Table 5.1: Comparison of Mental Illness Prevalence Values
     
   • Section 5.1 - Cumulative Mental Illness that contains information on cumulative mental illness prevalence by RHA; and
     
   • Section 5.5 - Schizophrenia that contains information on schizophrenia prevalence by RHA, RHA District and Winnipeg Neighbourhood Clusters
   
   
4. Martens et al. (2010)
   
   In the Profile of Metis Health Status and Healthcare Utilization in Manitoba: A Population-Based Study deliverable by Martens et al. (2010) they compared a cohort of Metis to all other Manitobans on several aspects of health. They investigated and compared the prevalence of schizophrenia as one of five conditions in a cumulative mental illness condition, separately, and as a comorbidity of mental illness diagnoses. The general time frame for this study is from 2002/03 to 2006/07. For more information, see:
   
   
   • Section 4.10 - All Cause Five-Year Mortality Rates for Individuals with Cumulative Mental Illness including information by RHA, Metis Region, and Winnipeg Community Area;
     
   • Table 6.0 - Overall Key Findings of Mental Illness Indicators
     
   • Section 6.1 - Cumulative Mental Illness that contains prevalence information by RHA, Metis Region and Winnipeg Community Area.
     
   • Section 6.5 - Schizophrenia that contains prevalence information by RHA, Metis Region and Winnipeg Community Area.
     
   • Section 6.8 - Comorbidity of Mental Illness Diagnoses that includes information on comorbidities among specified mental illness disorders for the Metis population and all other Manitobans.
   
   
5. Martens et al. (2010)
   
   In the Health Inequities in Manitoba: Is the Socioeconomic Gap in Health Widening or Narrowing Over Time? deliverable by Martens et al. (2010) they investigated schizophrenia as one of five conditions belonging to a condition termed "cumulative mental health illness". Values were calculated for two 5–year periods, 1996/97–2000/01 and 2001/02–2005/06. Within each period, records going back 12 years were examined to ensure inclusion of residents diagnosed earlier, but who have not had the diagnosis attributed to recent service use records. For more information, see:
   
   
   • Chapter 7 - Mental Health - Cumulative Health measuring five-year periods of prevalence over time, including information by RHA, income quintiles, rural and urban areas, and using Lorenz curves
   
   
6. Chartier et al. (2012)
   
   In the Health and Healthcare Utilization of Francophones in Manitoba deliverable by Chartier et al. (2012) they compared the prevalence of schizophrenia between a Francophone cohort and a group of Other Manitobans for 2004/05 - 2008/09, separately and as one of five cumulative mental health disorders. Rate ratios are used to compare the two groups. For more information, see:
   
   
   • section 6.1 Cumulative Mental Health Disorders
     
   • section 6.6 Schizophrenia
   
   
7. Smith et al. (2013)
   
   In the Social Housing in Manitoba. Part II: Social Housing and Health in Manitoba: A First Look deliverable by Smith et al. (2013) they investigated the prevalence of schizophrenia in a social housing cohort compared to all other Manitobans. For more information, see the section titled:
   
   
   • Schizophrenia - measuring prevalence from 2004/05 to 2008/09 including information by RHA and Winnipeg Community Area.
   
   
8. Brownell et al. (2015)
   
   In The Educational Outcomes of Children in Care in Manitoba deliverable by Brownell et al. (2015) they investigated the prevalence of mental disorders, including schizophrenia, for children in care. For more information, see the section titled:
   
   
   • Mental Disorders
   
   
9. Chartier et al. (2015)
   
   In the Care of Manitobans Living with Chronic Kidney Disease deliverable by Chartier et al. (2015) they investigated the prevalence and relative risk of schizophrenia as part of a term called "any mental disorder" in cohorts of patients with end stage kidney disease (ESKD), chronic kidney disease (CKD), and no CKD. For more information, see:
   
   
   • Table 4.2: Mental Disorders in Adults in End Stage Kidney Disease Patient Cohorts
     
   • Table 4.6: Mental Disorders in Adults in Chronic Kidney Disease Patient Cohorts
     
   • Table 5.2: Mental Disorders in Children in Patient Cohorts
   
   
10. Chartier et al. (2016)
    
    In The Mental Health of Manitoba's Children deliverable by Chartier et al. (2016), they investigated the prevalence of psychotic disorders, of which schizophrenia was part of the definition, and schizophrenia separately, for adolescents, aged 13-19 years. The findings are presented by Health Region, Winnipeg Community Area, sex, and income quintile, comparing the prevalence over two different time periods: 2005/06-2008/09 and 2009/10-2012/13. For more information see the section titled Schizophrenia in the on-line deliverable.
    
    
11. Chartier et al. (2018)
    
    In The Mental Illness Among Adult Manitobans deliverable by Chartier et al. (2018), they investigated the prevalence of psychotic disorders, of which schizophrenia was part of the definition, and schizophrenia separately. The findings are presented by Health Region, Health Region District, Winnipeg Neighbourhood Cluster, Age and Sex, and Income Quintile, comparing the prevalence over two time periods: 2010/11 to 2014/15.
    For more information, see the section titled Schizophrenia in the online deliverable.