Readmission rate is calculated as the number of patients readmitted within 30 days of discharge divided by the number of patients discharged during the study period.

OMHRS and CIHI/DAD databases are used to identify index as well as subsequent hospitalizations for mental health and addictions.

Number of individuals with any MH&A hospital readmissions* within (≤) 30 days following the incident hospital discharge in the reporting period.

For any MHA hospital discharge (denominator), calculate the following readmissions (numerator):

1. Any MHA Admission during follow-up period:
   • DAD ICD-10-CA Dx10Code1: F04 to F99,
   • or OMHRS DSM-IV: Any hospital admission (including missing diagnosis except for DSM-IV 290.x. 294.x in AXIS1_DSM4CODE_DISCH1)

Exclusions:

• Patients without a valid health insurance number 
• Patients without an Ontario residence 
• Gender not recorded as male or female 
• Age < 15 or Age > 105
• Invalid date of birth, admission date/time, discharge date/time 

• Individuals who die within 30 days of discharge (based on RPDB) before a follow-up or outcome occurs (i.e. a person dies before they have been readmitted or is readmitted but dies before they are discharged)
• Any non-MH&A hospital readmissions*

Notes:

• Separately report the number of individuals who died and re-admitted during the follow-up period overall in all years.
• Calculate within (≤) 30 days acute care re-admission proportion following the index MH&A hospital discharge date (i.e. Count only one visit per IKN per 30 day follow-up period).
• *Reason for re-admission can be for a different MH&A reason than the initial MH&A diagnosis.

Total number of incident MH&A hospital discharges in the reporting period.

Incident = 1st event in a calendar period without any look-back for past events (If multiple hospital visits in CY, use first). Keep only one discharge person per year.

MH&A Hospital Discharges:

From DAD var DX10CODE1 with any of the following ICD-10-CA codes: F04 to F99

From OMHRS:

• If var AXIS1_DSM4CODE_DISCH1 complete* use AXIS1_DSM4CODE_DISCH1
• No, use PROVDX1

*Complete = listed diagnosis from below present

Exclude OMHRS admissions if AXIS1_DSM4CODE_DISCH1 in: (290.x OR 294.x)

Include visits with suspect diagnoses (suspect = T).

With any of the following DSM-IV codes/provisional diagnoses:

• Overall MHA
  • ICD-10-CA: F04 to F99
  • DSM-IV: Any (including missing diagnoses, excluding 290.x. 294.x in AXIS1_DSM4CODE_DISCH1 which are dementia codes)

** MH&A diagnostic categories represent reason for the incident hospital discharge.

Disposition of hospital discharge:

• From DAD where var DISCHDISP = 2,3,4,5,6,12
• From OMHRS where var DISCHREASON = 1,5,6,7,8
• Exclude discharges with a DAD/OMHRS record within 1 day (i.e. are not a true discharge and are a transfer).

Note: re-hospitalizations (numerator) do not have to result in discharge home

Hospitalizations should be constructed as episodes using the following steps:

1. i) Pull all DAD and OMHRS records between the specified calendar years (CY) being examined for this indicator with an ICD-10-CA primary discharge diagnosis of F04 to F99 or DSM-IV codes, excluding 290.x and 294.x
   • Identify the IKNs found for these records
2. For only the IKNs identified in the previous step, pull all DAD records from 1988 onwards and all OMHRS records for all diagnoses, i.e. not only mental health diagnoses, and create episodes by adjoining OMHRS/DAD records that overlap within (+/-) 1 day. These will be considered part of a single episode.
3. Use discharge diagnoses and other variables from the final discharge of the episode
   • Note, if 2 or more records have the same discharge date as the discharge date of the episode, use an OMHRS discharge diagnoses, if applicable (i.e. if one record is DAD and one is OMHRS, take the OMHRS diagnoses)

Inclusions:

• 15 - 105 years i.e. Age >=15 and Age <=105 (other stratifications)

Exclusions: 

• Patients without a valid health insurance number 
• Patients without an Ontario residence 
• Gender not recorded as male or female 
• Age < 15 or Age > 105
• Invalid date of birth, admission date/time, discharge date/time 

• Individuals who die within 30 days of discharge (based on RPDB) before a follow-up or outcome occurs (i.e. a person dies before they have been readmitted or is readmitted but dies before they are discharged)

None