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30-Day Readmission for Mental Health and Substance Use

This indicator measures the risk-adjusted rate of readmission following discharge for mental health and substance use disorders.

Lower rates are desirable.

Data updated:
Data availability: to (fiscal years)
Geographic coverage
All provinces/territories
Reporting level
National, Province/Territory, Region
Calculation

Risk-adjusted rate for each region = Observed number of readmissions in each region ÷ Expected number of readmissions in the region × Canadian average readmission rate

Unit of Analysis: Episode of care

An episode of care refers to all contiguous inpatient hospitalizations in general and psychiatric hospitals and all day surgery visits regardless of diagnoses. To construct an episode of care, a transfer is assumed to have occurred if the following condition is met:

  • Admission to a general/psychiatric hospital or day surgery facility occurs on the same day as discharge from another general/psychiatric hospital or day surgery facility
Denominator

Number of episodes of care for an MHSU disorder discharged between April 1 and March 1 of the fiscal year

Numerator

Cases within the denominator with a readmission for MHSU disorders within 30 days of discharge after the index episode of care

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Both crude rate and risk-adjusted rate are calculated as a percentage. Please refer to the Methodology tab for details.

For significance, the value yes refers to a rate that is statistically different from the average rate (p <0.05).

The dash (—) indicates that no data is available. Select different parameters or reset the chart.

Disparity Rate Ratio and Potential Rate Reduction metrics are available only for Canada and provinces. Potential Rate Reduction (PRR), and the associated confidence levels (UCL, LCL) are expressed as a percentage where available. Please refer to the General Methodology Notes (PDF) for details.

Hospitalization data for 2016–2017, 2019–2020 and 2020–2021 for Qikiqtani General Hospital in Nunavut was incomplete; thus results for Nunavut are not reported.

Results from 2020–2021 onward should be interpreted in the context of the COVID-19 pandemic. To learn more, see the Impact of COVID-19 on Canada’s health care systems.

Sources

Discharge Abstract Database, Hospital Morbidity Database, National Ambulatory Care Reporting System and Ontario Mental Health Reporting System, Canadian Institute for Health Information.

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Note: This table displays only 25 rows of data. To view all data for your selections, please export the CSV file.

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Notes

Both crude rate and risk-adjusted rate are calculated as a percentage. Please refer to the Methodology tab for details.

For significance, the value yes refers to a rate that is statistically different from the average rate (p <0.05).

The dash (—) indicates that no data is available.

Disparity Rate Ratio and Potential Rate Reduction metrics are available only for Canada and provinces. Potential Rate Reduction (PRR) and the associated confidence levels (UCL, LCL) are expressed as a percentage where available. Please refer to the General Methodology Notes (PDF) for details.

Breakdowns are not available at the region level except by mental health category. 

Hospitalization data for 2016–2017, 2019–2020 and 2020–2021 for Qikiqtani General Hospital in Nunavut was incomplete; thus results for Nunavut are not reported

Results from 2020–2021 onward should be interpreted in the context of the COVID-19 pandemic. To learn more, see the Impact of COVID-19 on Canada’s health care systems.

Sources

Discharge Abstract Database, Hospital Morbidity Database, National Ambulatory Care Reporting System and Ontario Mental Health Reporting System, Canadian Institute for Health Information.

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Name

30-Day Readmission for Mental Health and Substance Use

Short/Other Names

Not applicable

Description

This indicator measures the risk-adjusted rate of readmission following discharge for mental health and substance use (MHSU) disorders.

Note
For further details, please see the General Methodology Notes (PDF)

Rationale

Readmission to inpatient care may be an indicator of relapse or complications after an inpatient stay. Inpatient care for a person living with an MHSU disorder aims to stabilize acute symptoms. Once stabilized, the individual is discharged, and subsequent care and support are ideally provided through outpatient and community programs in order to prevent relapse or complications. High rates of 30-day readmission could be interpreted as a direct outcome of poor coordination of services and/or an indirect outcome of poor continuity of services after discharge.

Interpretation

Lower rates are desirable.

HSP Framework Dimension

Health system outputs: Person-centred

Areas of Need

Living With Illness, Disability or Reduced Function

Targets/Benchmarks

Not applicable

Available Data Years

to (fiscal years)

Geographic Coverage

  • All provinces/territories

Reporting Level/Disaggregation

  • National
  • Province/Territory
  • Region
  • Age group 
  • Recorded sex or gender
  • Neighbourhood income quintile
  • Urban versus rural/remote 
  • Mental health category

For more information, please refer to CIHI’s Equity stratifiers web page.

Update Frequency

Every year

Latest Results Update Date

Updates

Not applicable

Description

Risk-adjusted rate for each region = Observed number of readmissions in each region ÷ Expected number of readmissions in the region × Canadian average readmission rate

Unit of Analysis: Episode of care

An episode of care refers to all contiguous inpatient hospitalizations in general and psychiatric hospitals and all day surgery visits regardless of diagnoses. To construct an episode of care, a transfer is assumed to have occurred if the following condition is met:

  • Admission to a general/psychiatric hospital or day surgery facility occurs on the same day as discharge from another general/psychiatric hospital or day surgery facility

Type of Measurement

Rate - per 100

Denominator

Description:

Number of episodes of care for an MHSU disorder discharged between April 1 and March 1 of the fiscal year

Inclusions:

  1. An MHSU disorder is identified by DSM-IV/DSM-5 diagnostic category in Ontario Mental Health Reporting System (OMHRS) data or by the most responsible diagnosis (MRDx) ICD-10-CA codes in Discharge Abstract Database (DAD)/Hospital Morbidity Database (HMDB) data
  2. The following MHSU disorders are included (see CIHI Mental Health and Substance Use Diagnosis Code Groupings for Selected Indicators (XLSX)): 
     
    1. Substance-related and addictive disorders
    2. Schizophrenia and other psychotic disorders
    3. Mood disorders
    4. Anxiety disorders
    5. Selected disorders of personality and behaviour: 
    6. Other disorders
       
  3. Discharges between April 1 and March 1 of the following year (period of case selection ends on March 1 to allow for 30 days of follow-up)
  4. Recorded sex or gender coded as male or female
  5. Admission to a general or psychiatric hospital

Exclusions:

  1. Records with an invalid health card number
  2. Records with an invalid code for province issuing health card number
  3. Records with a missing age
  4. Records with an invalid admission date
  5. Records with an invalid discharge date
  6. Episodes with discharge as death (DAD Discharge Disposition Code = 07, 72*, 73*, 74*; NACRS Visit Disposition Code = 10, 11, 71*, 72*, 73*, 74*; Discharge Reason Code = 2 or 3 for OMHRS)
  7. Cadaveric donor or stillbirth records (Admission Category Code = R or S)

Note
*2018–2019 data onward.

Numerator

Description:

Cases within the denominator with a readmission for MHSU disorders within 30 days of discharge after the index episode of care

Inclusions:

  1. An episode of care is considered a readmission if the 2 following conditions are met:
    1. It has occurred within 30 days of discharge of an index episode; and
    2. An MHSU disorder was identified the same way as for the denominator (see Denominator for criteria to select diagnosis).

Exclusions:

  1. 2018–2019 data onward: Medical assistance in dying (MAID) (Discharge Disposition Code = 73)

Method of Adjustment

Logistic regression

Adjustment Applied

Covariates used in risk adjustment:

For a detailed list of covariates used in the model, please refer to the Model Specification (PDF) document.

Geographic Assignment

Place of residence

Data Sources

  • DAD
  • HMDB
  • NACRS
  • OMHRS

Caveats and Limitations

Not applicable

Trending Issues

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) was implemented in the Ontario Mental Health Reporting System as of 2016-2017. Prior to 2016-2017, the fourth edition (DSM-IV-TR) was used. Due to the fact that the DSM-IV-TR and DSM-5 diagnostic categories are not fully comparable, there may be some shift in the distribution of cases across categories. Therefore, trending of 2015-2016 and 2016-2017 rates for Ontario may potentially be affected.

Comments

A 30-day readmission can occur in the same facility as the index episode or in a different facility. A readmission can be a planned or unplanned admission. Planned versus unplanned admissions cannot be distinguished in all available data sources. For jurisdictions where comprehensive information was available, rates including both planned and unplanned readmissions and only unplanned readmissions were compared, and they were not statistically significantly different. Published work has shown that few planned readmissions for MHSU disorders within 30 days are scheduled by practitioners.

References

Hermann R, Mattke S. Selecting Indicators for the Quality of Mental Health Care at the Health System Level in OECD Countries (PDF). 2004.

Leslie DL, Rosenheck RA. Comparing Quality of Mental Health Care for Public-Sector and Privately Insured Populations. Psychiatric Services. 2000.

Lin E, Durbin J, Zaslavska M, et al. Hospital Report 2007: Mental Health. 2008.

How to cite:

Canadian Institute for Health Information. 30-Day Readmission for Mental Health and Substance Use. Accessed April 25, 2025.