2.0 Health System Performance 2011

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2.0 Health System Performance

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2.1 Wait Time for Hip Fracture Surgery

Definitions

Proportion with surgery within 48 hours: Risk-adjusted proportion of hip fracture patients age 65 and older who underwent hip fracture surgery within 48 hours of admission to hospital.

Proportion with surgery same or next day: Risk-adjusted proportion of hip fracture patients age 65 and older who underwent hip fracture surgery on the day of admission or the next day.

Proportion with surgery same, next day or day after: Risk-adjusted proportion of hip fracture patients age 65 and older who underwent hip fracture surgery on the day of admission, the next day or the day after that.

Method of Calculation

Denominator:

The number of hip fracture patients age 65 and older who underwent hip fracture surgery in an acute care hospital.

Numerator:
A subset of the denominator according to one of the three available definitions. Wait time is measured from the date/time of the first admission with hip fracture (index admission) to the date/time when hip surgery was received.

Refer to the Technical Note for the case selection and inclusion/exclusion criteria.

Separate logistic regression models were fitted with age, sex and selected pre-admission comorbid diagnoses (heart failure, ischemic heart disease, hypertension, chronic obstructive pulmonary disease, diabetes with complications and cardiac dysrhythmia) as independent variables, modelling the probability of having hip fracture surgery within each specified time frame. Coefficients derived from the logistic models were used to calculate the probability for each case. The expected number of patients in a region is the sum of these case probabilities for that region. The risk-adjusted proportion was calculated by dividing the observed number by the expected number of cases and multiplying by the Canadian average. A 95% confidence interval was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
Operative delay in older patients with hip fracture is associated with a higher risk of post-operative complications and mortality. Wait time for surgery following hip fracture provides a measure of access to care. The wait time may be influenced by comorbid conditions, hospital transfers and practice differences related to certain types of medications, like blood thinners. However, longer waits may indicate lack of resources, physician unavailability and/or other issues related to access to care.

Standards/Benchmarks
A benchmark of hip fracture fixation within 48 hours was set by federal, provincial and territorial governments in December 2005.

Data Source
Discharge Abstract Database (DAD), CIHI

Reference Period

April 1, 2009, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
Beginning with 2009–2010 data, information on procedure start time is available in the DAD; therefore, the proportion of hip fracture patients receiving surgery within 48 hours can be calculated. Prior to that, the indicator was calculated in days rather than hours.

Note: due to differences in methodology, this indicator may differ from similar indicators developed and reported by jurisdictions.

Bibliography
Bergeron, E. et al. “Is the Delay to Surgery for Isolated Hip Fracture Predictive of Outcome in Efficient Systems?” The Journal of Trauma 60 (2006): pp. 753–757.

Canadian Institute for Health Information. Health Indicators 2007. Ottawa, Ont.: CIHI, 2007.

Canadian Institute for Health Information. Waiting for Heath Care in Canada: What We Know and What We Don’t Know. Ottawa, Ont.: CIHI, 2006.

Health Canada. Final Report of the Federal Advisor on Wait Times. Ottawa, Ont.: Health Canada, 2006.

Ministry of Health and Long-Term Care. First Common Benchmarks Will Allow Canadians to Measure Progress in Reducing Wait Times (press release). Toronto, Ont.: MOHLTC, December 12, 2005. Accessed from <http://www.health.gov.on.ca/english/media/news_releases/archives/nr_05/n....

Vidal, E. I. et al. “Hip Fracture in the Elderly: Does Counting Time From Fracture to Surgery or From Hospital Admission to Surgery Matter When Studying In-Hospital Mortality?” Osteoporosis International 20 (2009): pp. 723–729.

Weller, I. et al. “The Effect of Hospital Type and Surgical Delay on Mortality After Surgery for Hip Fracture.” Journal of Bone and Joint Surgery. British Volume 87 (2005): pp. 361–366.

Appropriateness

2.2 Caesarean Section Rate

Definition
Proportion of women delivering babies in acute care hospitals by Caesarean section.

Method of Calculation
(Number of Caesarean sections / number of deliveries ) x 100

Denominator (Delivery):

Inclusion:
Delivery coded in any diagnosis field:

ICD-9
641–676 with a fifth digit of 1 or 2; 650 or V27

ICD-10-CA
O10–O16, O21–O29, O30–O37, O40–O46, O48, O60–O69, O70–O75, O85–O89, O90–O92, O95, O98, O99 with a sixth digit of 1 or 2; or Z37

Exclusion:
Delivery in which an abortive procedure* was recorded:

CCP
78.52, 86.3, 86.4, 87.0, 87.1 or 87.2

CCI
5.CA.88^^, 5.CA.89^^ or 5.CA.93^^

Numerator (Caesarean section):

The numerator is a subset of the denominator. Caesarean section is identified as any of the following procedure codes*:

CCP
86.0–86.2, 86.8 or 86.9

CCI
5.MD.60^^

(* Code may be recorded in any position. Procedures coded as cancelled, previous, out of hospital and abandoned after onset are excluded.)

Interpretation

Caesarean section rates provide information on the frequency of surgical birth delivery relative to all modes of birth delivery. Since Caesarean section delivery increases maternal morbidity/mortality and is associated with higher costs, Caesarean section rates are often used to monitor clinical practices, with an implicit assumption that lower rates indicate more appropriate, as well as more efficient, care.

Standards/Benchmarks
Guidelines defining the appropriate indications for Caesarean section are available.

Data Sources
Discharge Abstract Database (DAD), CIHI
Fichier des hospitalisations MED-ÉCHO, ministère de la Santé et des Services sociaux du Québec

Reference Period
April 1, 2009, to March 31, 2010

Comprehensiveness
Available for all provinces and territories.

Comments
Prior to the 2001–2002 rate, deliveries were based on adjusted newborn counts. Beginning with the 2002–2003 rate, stillbirths are included in the delivery count. Prior to that, stillbirths were excluded.

Bibliography
Canadian Institute for Health Information. Giving Birth in Canada: A Regional Profile. Ottawa, Ont.: CIHI, 2004.

Canadian Institute for Health Information. Giving Birth in Canada: Regional Trends From 2001–2002 to 2005–2006. Ottawa, Ont.: CIHI, 2007.

Joseph, K. S. et al. “Determinants of Pre-Term Birth Rates in Canada From 1981 Through 1983 and From 1992 Through 1994.” New England Journal of Medicine 339 (1998): pp. 1434–1439.

Liu, S. et al. “Recent Trends in Caesarean Delivery Rates and Indications for Caesarean Delivery in Canada.” Journal of Obstetrics and Gynaecology Canada 26 (2004): pp. 735–742.

Liu, S. et al. “Risk of Maternal Postpartum Readmission Associated With Mode of Delivery.” Obstetrics and Gynecology 105 (2005): pp. 836–842.

National Collaborating Centre for Women’s and Children’s Health. Caesarean Section (clinical guidelines). London, U.K.: RCOG Press, 2004. Accessed December 14, 2010, from <http://www.rcog.org.uk/resources/public/pdf/cs_section_full.pdf>.

Shearer, E. L. “Cesarean Section: Medical Benefits and Costs.Social Science & Medicine 37 (1993): pp. 1223–1231.

2.3 Percentage of Patients With Repeat Hospitalizations for a Mental Illness

Definition
Risk-adjusted percentage of individuals that had three or more episodes of care for a selected mental illness* over all those who had at least one episode of care for a selected mental illness in general hospitals** within a given year. An episode of care refers to all contiguous hospitalizations and same-day surgery visits in general hospitals.

(* The mental illnesses selected for this indicator are substance-related disorders; schizophrenia, delusional and non-organic psychotic disorders; mood/affective disorders; anxiety disorders; and selected disorders of adult personality and behaviour.)

(** Refer to the General Methodology Notes section for more information.)

Method of Calculation

Total number of individuals who had at least three episodes of care for a selected mental illness over a year

× 100

Total number of individuals with at least one episode of care for a selected mental illness over a year

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age, sex, type of mental illness and discharged against medical advice (yes/no) as independent variables. These factors were captured on the index episode of care. Coefficients derived from the logistic model were used to calculate the probability of repeat hospitalizations for each patient. The expected number of repeat hospitalizations for a region is the sum of these probabilities in that region. The risk-adjusted percentage was calculated by dividing the observed number of repeat hospitalizations in each region by the expected number of repeat hospitalizations in the region and multiplying by the Canadian average repeat hospitalizations percentage. A 95% confidence interval was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
This indicator is considered an indirect measure of appropriateness of care, since the need for frequent admission to hospital depends on the person and the type of illness. Challenges in getting appropriate care/support in the community and/or the appropriate medication often lead to frequent hospitalizations. Variations in this indicator across jurisdictions may reflect differences in the services that help individuals with mental illness remain in the community for a longer period of time without the need for hospitalization.1

This indicator may help to identify a population of frequent users, and further investigations could provide a description of the characteristics of this group. Understanding this population can aid in developing/enhancing programs that may prevent the need for frequent rehospitalization.

Standard/Benchmark
Benchmarks have not been identified for this indicator.

Data Sources
Discharge Abstract Database (DAD), CIHI
Ontario Mental Health Reporting System (OMHRS), CIHI
Fichier des hospitalisations MED-ÉCHO, ministère de la Santé et des Services sociaux du Québec

Reference Period
April 1, 2008, to March 31, 2010

Comprehensiveness
Available for all provinces and territories.

Comments
Each individual has a 12-month follow-up after his or her first episode of care in a given year. Repeat hospitalizations over a 12-month period can occur at more than one facility.

When building episodes of care, the exclusion of psychiatric hospitals might introduce a bias. It is possible that the wrong discharge date might be used to track repeat hospitalizations, or two hospitalizations that belong to the same episode might be erroneously attributed to two different episodes. Further analyses demonstrated that this bias is minimal and does not affect the indicator results.

References
1. E. Lin et al., Hospital Report Card: Mental Health 2007 Briefing Pages, accessed from <www.hospitalreport.ca/downloads/2007/MH/2007_MH_techbrief.pdf>.

Continuity

2.4 30-Day Mental Illness Readmission Rate

Definition

Risk-adjusted rate of readmission following discharge for a mental illness. A case is counted as a readmission if it is for a selected mental illness diagnosis* and if it occurs within 30 days of the index episode of inpatient care. An episode of care refers to all contiguous hospitalizations and same-day surgery visits in general hospitals**.

(* The mental illnesses selected for this indicator are substance-related disorders; schizophrenia, delusional and non-organic psychotic disorders; mood/affective disorders; anxiety disorders; and selected disorders of adult personality and behavior.)

(**Refer to the General Methodology Notes section for more information.)

Method of Calculation

Total number of episodes with a 30-day readmission for a selected mental illness in a given fiscal year

× 100

Total number of episodes with a selected mental illness in the first 11 months of the same fiscal year

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age, sex, type of mental illness, discharged against medical advice (yes/no) and multiple previous admissions for a selected mental illness (two and more) during the past 12 months as independent variables. These factors were captured on the index episode of care. Coefficients derived from the logistic model were used to calculate the probability of readmission for each episode. The expected number of readmissions for a region is the sum of these probabilities in that region. The risk-adjusted readmission rate was calculated by dividing the observed number of readmissions in each region by the expected number of readmissions in the region and multiplying by the Canadian average readmission rate. A 95% confidence interval for the risk-adjusted readmission rate was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
Readmission to inpatient care may be an indicator of relapse or complications after an inpatient stay. Inpatient care for people living with a mental illness 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.

Standard/Benchmark
Benchmarks have not been identified for this indicator.

The following results were found in the literature. According to the Hospital Mental Health Services in Canada 2005–2006 report, the 30-day readmission rate, including general hospitals only, was 9.2%.1 According to the National Association of State Mental Health Program Directors, in 1995, the 30-day readmission rate for psychiatric hospitals in America was between 8.1% and 10.2%.2 For patients from Department of Veterans Affairs medical centres in the United States, the percentage of patients readmitted within 30 days was between 13.1% and 15.3%.3

Data Sources
Discharge Abstract Database (DAD), CIHI
Ontario Mental Health Reporting System (OMHRS), CIHI
National Ambulatory Care Reporting System (NACRS), CIHI
Fichier des hospitalisations MED-ÉCHO, ministère de la Santé et des Services sociaux du Québec

Reference Period
April 1, 2009, to March 31, 2010

Comprehensiveness
Available for all provinces and territories.

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, results including all readmissions and only unplanned readmissions were compared; the findings were not statistically different. Published work has shown that few planned readmissions for mental illness within 30 days are scheduled by practitioners.4

When building episodes of care, the exclusion of psychiatric hospitals might introduce a bias. It is possible that the wrong discharge date might be used to track readmissions, or two hospitalizations that belong to the same episode might be erroneously attributed to two different episodes. Further analyses demonstrated that this bias is minimal and does not affect the indicator results.

References

1. Canadian Institute for Health Information, Hospital Mental Health Services in Canada 2005–2006 (Ottawa, Ont.: CIHI, 2008).

2. R. Hermann and S. Mattke, Selecting Indicators for the Quality of Mental Health Care at the Health System Level in OECD Countries (Paris, France: OCED, 2004).

3. D. L. Leslie and R. A. Rosenheck, “Comparing Quality of Mental Health Care for Public-Sector and Privately Insured Populations,” Psychiatric Services 51, 5 (2000): pp. 650–655.

4. E. Lin et al., Hospital Report Card: Mental Health 2007 Briefing Pages, accessed from <www.hospitalreport.ca/downloads/2007/MH/2007_MH_techbrief.pdf>.

Effectiveness

2.5 Ambulatory Care Sensitive Conditions Hospitalization Rate

Definition
Age-standardized acute care hospitalization rate for conditions where appropriate ambulatory care prevents or reduces the need for admission to hospital, per 100,000 population younger than age 75.

Method of Calculation
(Total number of acute care hospitalizations for ambulatory care sensitive conditions younger than age 75 / total mid-year population younger than age 75) x 100,000 (age adjusted)

Inclusion criteria:

Based on a list of conditions developed by Billings et al., any one most responsible diagnosis code of

  • Grand mal status and other epileptic convulsions;
  • Chronic obstructive pulmonary diseases;
  • Asthma;
  • Heart failure and pulmonary edema;
  • Hypertension;
  • Angina; or
  • Diabetes.

See the Technical Note for codes used.

Exclusion criteria:

  1. Individuals age 75 and older
  2. Death before discharge

Interpretation
Hospitalization for an ambulatory care sensitive condition is considered to be a measure of access to appropriate primary health care. While not all admissions for these conditions are avoidable, it is assumed that appropriate ambulatory care could prevent the onset of this type of illness or condition, control an acute episodic illness or condition, or manage a chronic disease or condition. A disproportionately high rate is presumed to reflect problems in obtaining access to appropriate primary care.

Standards/Benchmarks
The right level of utilization is not known, and large regional variations in the rate of hospitalization for these conditions exist.

Data Sources
Discharge Abstract Database (DAD), CIHI
Fichier des hospitalisations MED-ÉCHO, ministère de la Santé et des Services sociaux du Québec

Reference Period
April 1, 2009, to March 31, 2010

Comprehensiveness
Available for all provinces and territories.

Comments

Beginning with the 2006–2007 rate, the definition of the ambulatory care sensitive conditions indicator was refined to better align it as a measure of primary health care. In the revised definition, the diabetes component includes diabetes with short-term complications and diabetes without mention of complication; angina, hypertension and heart failure components exclude records where cardiac procedures were also coded. Rates based on the new definition were calculated for the previous years to allow for comparisons over time.

Bibliography
Anderson, G. M. “Common Conditions Considered Sensitive to Ambulatory Care.” In Goel, V. et al. (Eds.), Patterns of Health Care in Ontario, 2nd Ed. Ottawa, Ont.: Canadian Medical Association, 1996, pp. 104–110.

Billings, J., G. M. Anderson and L. S. Newman. “Recent Findings on Preventable Hospitalizations.” Health Affairs 15 (1996): pp. 239–249.

Billings, J. et al. “Impact of Socio-Economic Status on Hospital Use in New York City.” Health Affairs 12 (1993): pp. 162–173.

Manitoba Centre for Health Policy and Evaluation. Concept: Ambulatory Care Sensitive (ACS) Conditions. Accessed December 14, 2010, from <http://www.umanitoba.ca/centres/mchp/concept/dict/ACS_conditions.htm>.

2.6 30-Day Acute Myocardial Infarction In-Hospital Mortality Rate

Definition
The risk-adjusted rate of all-cause in-hospital death occurring within 30 days of first admission to an acute care hospital with a diagnosis of acute myocardial infarction (AMI).

Method of Calculation

Numerator:
Number of deaths from all causes occurring in hospital within 30 days of admission for AMI

Denominator:
Total number of AMI episodes in an 11-month period

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age, sex and select preadmission comorbid diagnoses as independent variables. Coefficients derived from the logistic model were used to calculate the probability of in-hospital death following AMI for each case (episode). The expected number of in-hospital deaths in a region is the sum of the case probabilities of that region. The risk-adjusted mortality rate (RAMR) was calculated by dividing the observed number of in-hospital deaths for each region by the expected number of in-hospital deaths for the region and multiplying by the Canadian average in-hospital death rate. A 95% confidence interval for the RAMR was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
A lower risk-adjusted mortality rate following AMI may be related to quality of care or other factors. It has been shown that the 30-day in-hospital mortality rate is highly correlated (r = 0.9) with total mortality (death in and out of hospital) following AMI.1 Inter-regional variations in 30-day in-hospital mortality rates may be due to jurisdictional and institutional differences in standards of care, as well as other factors that were not included in the adjustment.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Source
Discharge Abstract Database (DAD), CIHI

Reference Period
Rates are based on three years of pooled data: April 1, 2007, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
Beginning with the rates based on 2003–2004 to 2005–2006 data, AMI case selection criteria were revised to account for the fact that an increasing number of AMI patients are undergoing a revascularization procedure (percutaneous coronary intervention or coronary artery bypass) at their index admission. In the case of revascularization procedures, AMI may not be coded as the most responsible diagnosis; these cases were previously excluded from the indicator. In addition, exclusion criteria were revised so patients with a length of stay of less than three days who are discharged alive are no longer excluded. Comparison of rates with those of previous years should be made with caution.

These rates should be interpreted with caution due to potential differences in the coding of comorbid conditions across provinces and territories.

Reference
1. J. V. Tu et al., “Acute Myocardial Infarction Outcomes in Ontario,” in C. D. Naylor and P. M. Slaughter (Eds.), Cardiovascular Health & Services in Ontario: An ICES Atlas (Toronto, Ont.: Institute for Clinical Evaluative Sciences, 1999): pp. 84–100.

Bibliography
Hosmer, D. W. and S. Lemeshow. “Confidence Interval Estimates of an Index of Quality Performance Based on Logistic Regression Models.” Statistics in Medicine 14 (1995): pp. 2161–2172.

Tu, J. V. et al. “Acute Myocardial Infarction Outcomes in Ontario (Methods Appendix).” In Naylor, C. D. and P. M. Slaughter (Eds.), Cardiovascular Health & Services in Ontario: An ICES Atlas (Technical and Methods Appendices). Toronto, Ont.: Institute for Clinical Evaluative Sciences, 1999.

2.7 30-Day Stroke In-Hospital Mortality Rate

Definition
The risk-adjusted rate of all-cause in-hospital death occurring within 30 days of first admission to an acute care hospital with a diagnosis of stroke.

Method of Calculation

Numerator:
Number of deaths from all causes occurring in hospital within 30 days of admission for stroke

Denominator:
Total number of stroke episodes in an 11-month period

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age, sex, type of stroke and select preadmission comorbid diagnoses as independent variables. Coefficients derived from the logistic model were used to calculate the probability of in-hospital death following stroke for each case (episode). The expected number of in-hospital deaths for a region is the sum of these case probabilities in that region. The risk-adjusted mortality rate (RAMR) was calculated by dividing the observed number of in-hospital deaths for each region by the expected number of in-hospital deaths for the region and multiplying by the Canadian average in-hospital death rate. A 95% confidence interval for the RAMR was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
Stroke is a leading cause of death and long-term disability. Adjusted mortality rates following stroke may reflect the underlying effectiveness of treatment and quality of care. Inter-regional variations in stroke mortality rates may be due to jurisdictional and institutional differences in standards of care, as well as other factors that are not included in the adjustment.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Source
Discharge Abstract Database (DAD), CIHI

Reference Period
Rates are based on three years of pooled data: April 1, 2007, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
Beginning with rates based on 2003–2004 to 2005–2006 data, case selection criteria for stroke were revised to include patients transferred to rehabilitation during their index admission. In this case, stroke may not be coded as the most responsible diagnosis; these cases were previously excluded from the indicator. In addition, stroke resulting from occlusion of pre-cerebral arteries is now included in the indicator. These cases were previously excluded because their identification was not possible in the ICD-9 coding system. Comparison of rates with those of previous years should be made with caution.

This indicator is based on the methodology used to calculate the 30-day acute myocardial infarction in-hospital mortality rate. Rates should be interpreted with caution due to potential differences in the coding of comorbid conditions across provinces and territories.

Bibliography
Hosmer, D. W. and S. Lemeshow. “Confidence Interval Estimates of an Index of Quality Performance Based on Logistic Regression Models.” Statistics in Medicine 14 (1995): pp. 2161–2172.

Mayo, N. E. et al. “Changing Rates of Stroke in the Province of Quebec, Canada: 1981–1988.” Stroke 22 (1991): pp. 590–595.

Mayo, N. E. et al. “Hospitalization and Case-Fatality Rates for Stroke in Canada From 1982 Through 1991: The Canadian Collaborative Study Group of Stroke Hospitalizations.” Stroke 27 (1996): pp. 1215–1220.

Weir, N. and M. S. Dennis. “Towards a National System for Monitoring the Quality of Hospital-Based Stroke Services.” Stroke 32 (2001): pp. 1415–1421.

2.8 Acute Myocardial Infarction Readmission Rate

Definition
Risk-adjusted rate of unplanned readmission following discharge for acute myocardial infarction (AMI). A case is counted as a readmission if it is for a relevant diagnosis and occurs within 28 days after the index AMI episode of care. An episode of care refers to all contiguous inpatient hospitalizations and same-day surgery visits.

Relevant diagnoses for assigning readmission cases:

  • Acute myocardial infarction
  • Other acute and subacute forms of ischemic heart disease
  • Old myocardial infarction
  • Angina pectoris
  • Other forms of chronic ischemic heart disease
  • Conduction disorders
  • Cardiac dysrhythmias
  • Functional disturbances following cardiac surgery
  • Pneumococcal pneumonia
  • Other bacterial pneumonia
  • Bronchopneumonia, organism unspecified
  • Pneumonia, organism unspecified
  • Urinary tract infection

Method of Calculation

Numerator: Number of AMI episodes with a readmission for a given year

Denominator: Total number of AMI episodes in an 11-month period

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age, sex and multiple previous AMI admissions (two and more) as independent variables. Coefficients derived from the logistic model were used to calculate the probability of readmission for each case (episode). The expected number of readmissions in a region is the sum of the case probabilities of that region. The risk-adjusted readmission rate (RARR) was calculated by dividing the observed number of readmissions for each region by the expected number of readmissions for the region and multiplying by the Canadian average readmission rate. A 95% confidence interval for the RARR was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
Readmission rates provide one measure of quality of care. The risk of readmission following an AMI may be related to the type of drugs prescribed at discharge, patient compliance with post-discharge therapy, the quality of follow-up care in the community or the availability of appropriate diagnostic or therapeutic technologies during the initial hospital stay. Although readmission for medical conditions may involve factors outside the direct control of the hospital, high rates of readmission act as a signal to hospitals to look more carefully at their practices, including the risk of discharging patients too early and the relationship with community physicians and community-based care.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Sources
Discharge Abstract Database (DAD), CIHI
National Ambulatory Care Reporting System (NACRS), CIHI
Alberta Ambulatory Care Database, Alberta Health and Wellness

Reference Period
Rates are based on three years of pooled data: April 1, 2007, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
Beginning with rates based on 2003–2004 to 2005–2006 data, AMI case selection criteria were revised to account for the fact that an increasing number of AMI patients are undergoing a revascularization procedure (percutaneous coronary intervention or coronary artery bypass) at their index admissions. In the case of revascularization procedures, AMI diagnosis may not be coded as most responsible; these cases were previously excluded from the indicator. In addition, exclusion criteria were revised so patients with a length of stay less than three days and who are discharged alive are no longer excluded. Comparison of rates with those of previous years should be made with caution.

All jurisdictions are now coding to the ICD-10-CA/CCI standard. Therefore, an adjustment that was made to this indicator to enable comparison of rates between ICD-9/ICD-9-CM and ICD-10-CA jurisdictions for data years 2000–2001 to 2002–2003 and 2001–2002 to 2003–2004 has been discontinued. This adjustment was to exclude AMI cases that occurred between four and eight weeks following an earlier AMI (ICD-9/ICD-9-CM labels these as acute AMI, while ICD-10-CA considers such cases to be chronic). Effective with the rates based on 2002–2003 to 2005–2006 data, this exclusion was no longer applied, and only AMI occurring within four weeks of a previous AMI is considered acute. Comparisons with the rates for the previous years should be made with caution.

A new combination code for acute lower respiratory infections in patients with chronic obstructive pulmonary disease, or COPD, (J44.0) was introduced with ICD-10-CA. According to the Canadian Coding Standards, if COPD patients present with pneumonia, only J44.0 should be used, not the other codes from the J44 rubric. This code should be assigned as most responsible diagnosis (MRDx), with pneumonia assigned as a secondary diagnosis. To correct the evident erroneous applications of this coding standard, pneumonia cases coded as MRDx will be removed if J44 was also recorded in any of the secondary diagnosis positions.

Effective with the rates based on 2001–2002 to 2003–2004 data, the methodology for this indicator no longer excludes readmissions associated with a transfer for catheterization, angiography, angioplasty, insertion of pacemaker or coronary artery bypass graft surgery. This change may affect the comparability of rates with those appearing in previous releases.

Bibliography
Brown, A. D. and G. M. Anderson. “Methods for Measuring Clinical Utilization and Outcomes.” In Baker, G. R. et al. (Eds.), The Hospital Report 99. Toronto, Ont.: Health Care Performance Measurement Group, University of Toronto, 1999.

Canadian Institute for Health Information and University of Toronto. Hospital Report Acute Care 2001. Technical Notes, Clinical Utilization and Outcomes. Toronto, Ont.: Ontario Hospital Association and Government of Ontario, 2001.

Hosmer, D. W. and S. Lemeshow. “Confidence Interval Estimates of an Index of Quality Performance Based on Logistic Regression Models.” Statistics in Medicine 14 (1995): pp. 2161–2172.

2.9 Asthma Readmission Rate

Definition
Risk-adjusted rate of unplanned readmission following discharge for asthma. A case is counted as a readmission if it is for a relevant diagnosis and occurs within 28 days after the index episode of care. An episode of care refers to all contiguous inpatient hospitalizations and same-day surgery visits.

Relevant diagnoses for assigning readmission cases:

  • Pneumococcal pneumonia
  • Other bacterial pneumonia
  • Bronchopneumonia, organism unspecified
  • Pneumonia, organism unspecified
  • Asthma
  • Empyema
  • Pulmonary collapse
  • Respiratory arrest
  • Respiratory complications during or resulting from a procedure

Method of Calculation

Numerator: Number of asthma episodes with a readmission for a given year

Denominator: Total number of asthma episodes in an 11-month period

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age, sex and multiple previous admissions for asthma (two and more) as independent variables. Coefficients derived from the logistic model were used to calculate the probability of readmission for each case (episode). The expected number of readmissions for a region is the sum of these case probabilities in that region. The risk-adjusted readmission rate (RARR) was calculated by dividing the observed number of readmissions for each region by the expected number of readmissions for the region and multiplying by the Canadian average readmission rate. A 95% confidence interval for the RARR was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
Readmission rates provide one measure of quality of care. Although readmission for medical conditions may involve factors outside the direct control of the hospital, high rates of readmission act as a signal to hospitals to look more carefully at their practices, including the risk of discharging patients too early and the relationship with community physicians and community-based care.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Sources
Discharge Abstract Database (DAD), CIHI
National Ambulatory Care Reporting System (NACRS), CIHI
Alberta Ambulatory Care Database, Alberta Health and Wellness

Reference Period
Rates are based on three years of pooled data: April 1, 2007, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
A new combination code for acute lower respiratory infections in patients with chronic obstructive pulmonary disease, or COPD, (J44.0) was introduced with ICD-10-CA. According to the Canadian Coding Standards, if COPD patients present with pneumonia, only J44.0 should be used, not the other codes from the J44 rubric. This code should be assigned as most responsible diagnosis (MRDx), with pneumonia assigned as a secondary diagnosis. To correct the evident erroneous applications of this coding standard, pneumonia cases coded as MRDx will be removed if J44 was also recorded in any of the secondary diagnosis positions.

Bibliography
Brown, A. D. and G. M. Anderson. “Methods for Measuring Clinical Utilization and Outcomes.” In Baker, G. R. et al. (Eds.), The Hospital Report 99. Toronto, Ont.: Health Care Performance Measurement Group, University of Toronto, 1999.

Canadian Institute for Health Information and University of Toronto. Hospital Report Acute Care 2001. Technical Notes, Clinical Utilization and Outcomes. Toronto, Ont.: Ontario Hospital Association and Government of Ontario, 2001.

Hosmer, D. W. and S. Lemeshow. “Confidence Interval Estimates of an Index of Quality Performance Based on Logistic Regression Models.” Statistics in Medicine 14 (1995): pp. 2161–2172.

2.10 Hysterectomy Readmission Rate

Definition
Risk-adjusted rate of unplanned readmission following discharge for hysterectomy. A case is counted as a readmission if it is for a relevant diagnosis and occurs within 7 or 28 days (depending on condition) after the index episode of care. An episode of care refers to all contiguous inpatient hospitalizations and same-day surgery visits.

Relevant diagnoses for assigning readmission cases:

  • Acute post-hemorrhagic anemia: 28 days
  • Paralytic ileus: 28 days
  • Cardiac complications during or resulting from a procedure: 28 days
  • Respiratory complications resulting from a procedure: 28 days
  • Post-operative infection: 28 days
  • Urinary tract infection, site not specified: 7 days
  • Retention of urine: 7 days

Method of Calculation

Numerator: Number of hysterectomy episodes with a readmission for a given year

Denominator: Total number of hysterectomy episodes in an 11-month period

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age as an independent variable. Coefficients derived from the logistic model were used to calculate the probability of readmission for each case (episode). The expected number of readmissions for a region is the sum of these case probabilities for that region. The risk-adjusted readmission rate (RARR) was calculated by dividing the observed number of readmissions for each region by the expected number of readmissions for the region and multiplying by the Canadian average readmission rate. A 95% confidence interval for the RARR was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
Readmission rates provide one measure of quality of care. Although readmission following surgery may involve factors outside the direct control of the hospital, high rates of readmission act as a signal to hospitals to look more carefully at their practices, including the risk of discharging patients too early and the relationship with community physicians and community-based care.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Sources
Discharge Abstract Database (DAD), CIHI
National Ambulatory Care Reporting System (NACRS), CIHI
Alberta Ambulatory Care Database, Alberta Health and Wellness

Reference Period
Rates are based on three years of pooled data: April 1, 2007, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
Effective with the rates based on 2006–2007 to 2008–2009 data, hysterectomy cases include both total and subtotal hysterectomies. Subtotal hysterectomy was not uniquely identified in the Canadian Classification of Health Interventions (CCI) versions 2001 and 2003; therefore, rates based on 2001–2002 to 2005–2006 data included only total hysterectomies. Identification of subtotal hysterectomies became possible with version 2006 of CCI. For jurisdictions with higher volumes of subtotal hysterectomies, comparability with the previous years might be affected.

Bibliography
Benbassat, J. and M. Taragin. “Hospital Readmissions as a Measure of Quality of Health Care. Advantages and Limitations.” Archives of Internal Medicine 160 (2000): pp. 1074–1081.

Brown, A. D. and G. M. Anderson. “Methods for Measuring Clinical Utilization and Outcomes.” In Baker, G. R. et al. (Eds.), The Hospital Report 99. Toronto, Ont.: Health Care Performance Measurement Group, University of Toronto, 1999.

Canadian Institute for Health Information and University of Toronto. Hospital Report Acute Care 2001. Technical Notes, Clinical Utilization and Outcomes. Toronto, Ont.: Ontario Hospital Association and Government of Ontario, 2001.

Hosmer, D. W. and S. Lemeshow. “Confidence Interval Estimates of an Index of Quality Performance Based on Logistic Regression Models.” Statistics in Medicine 14 (1995): pp. 2161–2172.

Makinen, J. et al. “Morbidity of 10,110 Hysterectomies by Type of Approach.” Human Reproduction 16 (2001): pp. 1473–1478.

Pennsylvania Health Care Cost Containment Council. Measuring the Quality of Pennsylvania’s HMOs. A Managed Care Performance Report (fiscal year 1999 technical report). Harrisburg, Pennsylvania: Pennsylvania Health Care Cost Containment Council, July 2000.

2.11 Prostatectomy Readmission Rate

Definition
Risk-adjusted rate of unplanned readmission following discharge for prostatectomy. A case is counted as a readmission if it is for a relevant diagnosis or procedure and occurs within 28 days after the index episode of care. An episode of care refers to all contiguous inpatient hospitalizations and same-day surgery visits.

Relevant procedures for assigning readmission cases:

  • Operations on the ureter
  • Operations on the urinary bladder
  • Operations on the urethra
  • Other operations on the urinary tract
  • Operations on the prostate and seminal vesicles

Relevant diagnoses for assigning readmission cases:

  • Intestinal infections, other specified bacteria
  • Pneumonia, organism unspecified
  • Urinary tract infection, site not specified
  • Hematuria
  • Prostatic hypertrophy
  • Retention of urine
  • Pneumococcal pneumonia
  • Other bacterial pneumonia
  • Bronchopneumonia, organism unspecified
  • Cardiac complications during or resulting from a procedure
  • Respiratory complications resulting from a procedure
  • Post-operative infection

Method of Calculation

Numerator: Number of prostatectomy episodes with a readmission for a given year

Denominator: Total number of prostatectomy episodes in an 11-month period

Refer to the Technical Note for the episode building and case selection criteria.

A logistic regression model was fitted with age and select preadmission comorbid diagnoses as independent variables. Coefficients derived from the logistic model were used to calculate the probability of readmission for each case (episode). The expected number of readmissions for a region is the sum of these case probabilities for that region. The risk-adjusted readmission rate (RARR) was calculated by dividing the observed number of readmissions for each region by the expected number of readmissions for the region and multiplying by the Canadian average readmission rate. A 95% confidence interval for the RARR was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Model Specifications for a list of variables entered in the model and coefficient values.

Interpretation
Readmission rates provide one measure of quality of care. Although readmission following surgery may involve factors outside the direct control of the hospital, high rates of readmission act as a signal to hospitals to look more carefully at their practices, including the risk of discharging patients too early and the relationship with community physicians and community-based care.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Sources
Discharge Abstract Database (DAD), CIHI
National Ambulatory Care Reporting System (NACRS), CIHI
Alberta Ambulatory Care Database, Alberta Health and Wellness

Reference Period
Rates are based on three years of pooled data: April 1, 2007, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
A new combination code for acute lower respiratory infections in patients with chronic obstructive pulmonary disease, or COPD, (J44.0) was introduced with ICD-10-CA. According to the Canadian Coding Standards, if COPD patients present with pneumonia, only J44.0 should be used, not the other codes from the J44 rubric. This code should be assigned as most responsible diagnosis (MRDx), with pneumonia assigned as a secondary diagnosis. To correct the evident erroneous applications of this coding standard, pneumonia cases coded as MRDx will be removed if J44 was also recorded in any of the secondary diagnosis positions.

These rates should be interpreted with caution due to potential differences in the coding of comorbid conditions across provinces and territories.

Bibliography
Brown, A. D. and G. M. Anderson. “Methods for Measuring Clinical Utilization and Outcomes.” In Baker, G. R. et al. (Eds.), The Hospital Report 99. Toronto, Ont.: Health Care Performance Measurement Group, University of Toronto, 1999.

Canadian Institute for Health Information and University of Toronto. Hospital Report Acute Care 2001. Technical Notes, Clinical Utilization and Outcomes. Toronto, Ont.: Ontario Hospital Association and Government of Ontario, 2001.

Hosmer, D. W. and S. Lemeshow. “Confidence Interval Estimates of an Index of Quality Performance Based on Logistic Regression Models.” Statistics in Medicine 14 (1995): pp. 2161–2172.

Lu-Yao, G. L. et al. “Effect of Age and Surgical Approach on Complications and Short Term Mortality After Radical Prostatectomy—A Population Based Study.” Urology 54 (1999): pp. 301–307.

2.12 Self-Injury Hospitalization Rate

Definition
Age-standardized rate of hospitalization in a general hospital* due to self-injury per 100,000 population.

(* Refer to the General Methodology Notes section for more information.)

Method of Calculation

Total number of discharges for a self-injury for patients age 15 and older

× 100,000 (age adjusted)

Total mid-year population age 15 and older

Self-injury is identified by an external cause of injury code:

ICD-10-CA

X60 to X84

To select all the cases hospitalized in Ontario, individuals identified in emergency departments with a self-injury code as the main reason for the visit and then transferred to a designated mental health bed were counted.*

(* More information is available upon request)

Interpretation
Self-injury is defined as a deliberate bodily injury that may or may not result in death. This type of injury is the result of either suicidal or self-harming behaviours, or both. Self-injury can be prevented, in many cases, by early recognition, intervention and treatment of mental illnesses. While some risk factors for self-injury are beyond the control of the health system, high rates of self-injury hospitalization can be interpreted as the result of a failure of the system to prevent self-injuries that are severe enough to require hospitalizations.

Standard/Benchmark
Benchmarks have not been identified for this indicator.

The following results were found in the literature. In Canada, in 2001–2002, the age-adjusted hospitalization rate due to self-injuries was 7.6 per 10,000.1

Data Sources
Discharge Abstract Database (DAD), CIHI
Ontario Mental Health Reporting System (OMHRS), CIHI
National Ambulatory Care Reporting System (NACRS), CIHI
Fichier des hospitalisations MED-ÉCHO, ministère de la Santé et des Services sociaux du Québec

Reference Period
April 1, 2009, to March 31, 2010

Comprehensiveness
Available for all provinces and territories.

Comments
This indicator does not include cases of self-injury involving outpatient treatment in hospital emergency rooms or other medical facilities or completed suicide prior to hospital admission. Thus, this indicator cannot be used to estimate the prevalence of self-injury in the general population. Also not included are patients who were institutionalized in psychiatric hospitals and were self-injured during their stay but did not require admission to a general hospital. For a broader estimate of self-injury, please refer to the In Focus section of Health Indicators 2011.

Using the available data sources, capturing intention is difficult. This indicator cannot distinguish whether or not the self-injury was intended to result in death (self-harming or suicidal behaviour). In addition, this indicator might provide biased estimates of the true number of hospitalizations for self-injury, due to the manner in which intent is captured in the data sources available. For example, poisoning can be coded as “unintentional”—an overdose—or “undetermined”—reflecting an uncertainty between unintentional and intentional motives. Both unintentional and undetermined injuries were not included in this indicator, even though it is assumed that a small number of these cases were, in fact, intentional.

References
1. Canadian Institute for Health Information, National Trauma Registry Analytic Bulletin: Hospitalizations Due to Suicide Attempts and Self-Inflicted Injury in Canada, 2001–2002 (Ottawa, Ont.: CIHI, 2004).

Safety

2.13 Hospitalized Hip Fracture Event Rate

Definition
Age-standardized rate of new hip fractures admitted to an acute care hospital, per 100,000 population age 65 and older. A new event is defined as a first-ever hospitalization for hip fracture or a subsequent hip fracture occurring more than 28 days after the admission for the previous event in the reference period.

Method of Calculation

(Total number of new hip fracture events for persons age 65 and older / total mid-year population age 65 and older) x 100,000 (age adjusted)

Numerator Inclusion Criteria:

  1. Hip fracture present on admission
    ICD-10-CA: S72.0, S72.1 or S72.2; ICD-9/ICD-9-CM: 820.0–820.3, 820.8 or 820.9 coded as diagnosis type (1) or
  2. Age at admission 65 and older
  3. Sex recorded as male or female
  4. Admission to an acute care institution
  5. Canadian resident

Numerator Exclusion Criteria:

  1. Records with an invalid health card number or date of birth
  2. Records with an invalid admission date
  3. Hip fracture admissions within 28 days after the admission date of the previous hip
  4. fracture hospitalization
  5. Transfers*

(* If a subsequent hip fracture admission occurs on the same day as or prior to the discharge date of a previous hip fracture admission, it is considered a transfer.)

Interpretation
Hip fractures represent a significant health burden for seniors and for the health system. As well as causing disability or death, hip fracture may have a major effect on independence and quality of life. Measuring occurrence of hip fractures in the population is important for planning and evaluating preventive strategies, allocating health resources and estimating costs.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Sources
Discharge Abstract Database (DAD), CIHI
Fichier des hospitalisations MED-ÉCHO, ministère de la Santé et des Services sociaux du Québec

Reference Period
April 1, 2009, to March 31, 2010

Comprehensiveness
Available for all provinces and territories.

Comments
This indicator includes all new hospitalized hip fractures in the reference period, encompassing first-ever and recurrent events. A person may have more than one hip fracture event in the reference period. Hip fractures not admitted to an acute care hospital and in-hospital hip fractures are not included in this indicator. Hip fractures occurring in a hospital are reported separately in the in-hospital hip fracture indicator.

Bibliography
Chevalley, T. et al. “Incidence of Hip Fracture Over a 10-Year Period (1991–2000): Reversal of a Secular Trend.” Bone 40 (2007): pp. 1284–1289.

Marks, R. et al. “Hip Fractures Among the Elderly: Causes, Consequences and Control.” Ageing Research Reviews 2 (2003): pp. 57–93.

2.14 In-Hospital Hip Fracture Rate

Definition
Risk-adjusted rate of in-hospital hip fracture among acute care inpatients age 65 and older, per 1,000 discharges.

Method of Calculation

Numerator:
Total number of discharges coded with in-hospital hip fracture for patients age 65 and older

Denominator:
Total number of discharges among inpatients age 65 and older

Refer to the Technical Note for the case selection criteria.

A logistic regression model was fitted with age, sex, select preadmission comorbid conditions and whether a surgical procedure was provided as independent variables. Coefficients derived from the logistic model were used to calculate the probability of in-hospital hip fracture for each case. The expected number of in-hospital hip fractures for a region is the sum of these case probabilities for that region. The risk-adjusted in-hospital hip fracture rate (RAR) was calculated by dividing the observed number of in-hospital hip fractures for each region by the expected number of in-hospital hip fractures for the region and multiplying by the Canadian average rate. A 95% confidence interval for the RAR was also calculated; the method used to calculate confidence intervals is available upon request. Refer to the Technical Note for a list of variables entered in the model and to the Model Specifications for the coefficient values.

Interpretation
Proposed by the Agency for Healthcare Research and Quality (AHRQ) and based on the Complications Screening Program, this indicator represents a potentially preventable complication resulting from an inpatient stay in an acute care facility. Variation in the rates may be attributed to numerous factors, including hospital processes, environmental safety and availability of nursing care. High rates may prompt investigation of potential quality of care deficiencies.

Standards/Benchmarks
Benchmarks have not been identified for this indicator.

Data Source
Discharge Abstract Database (DAD), CIHI

Reference Period
Rates are based on three years of pooled data: April 1, 2007, to March 31, 2010

Comprehensiveness
Available for all provinces and territories, except Quebec. Rates for Quebec are not available due to differences in data collection.

Comments
Effective with the rates based on 2004–2005 to 2006–2007 data, the in-hospital hip fracture rate is reported by the jurisdiction where hospitalization occurred rather than by the jurisdiction of patient residence. With this change the indicator better reflects the concept of patient safety in hospitals. This change may affect comparability with rates for the previous years.

ICD-10-CA code M96.6 Fracture of bone following insertion of orthopaedic implant, joint prosthesis, or bone plate and in-hospital hip fracture coded in conjunction with ICD-10-CA external cause of injury code Y65.8 Misadventure during surgical or medical care have been excluded because these events do not reflect patient safety in the context in which it is currently understood. These exclusions are applicable as of the rate based on 2001–2002 to 2003–2004 data.

These rates should be interpreted with caution due to potential differences in the coding of comorbid conditions across provinces and territories.

Bibliography
Agency for Healthcare Research and Quality. AHRQ Quality Indicators—Guide to Patient Safety Indicators. Rockville, Maryland: AHRQ, 2003.

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