# Presentation: 453368

## Population-based injury data in Ontario

- Presentation for ICE meeting
- Washington, September 7, 2006
- Alison K. Macpherson, PhD
- Assistant Professor
- School of Kinesiology and Health Science
- York University

## Sources of data

**National ambulatory care reporting system (NACRS) database**
**Includes all patients reporting to ED in Ontario **
**Reporting required by government in the context of a one-party payment system (universal healthcare)**
**Coded by nosologists using a standardized process**
**Uses international classification system (ICD-10-CA)**
**Includes unique identifier (scrambled OHIP number)**

## Sources of data (2)

**Discharge Abstract Database (DAD)**
**Includes all patients hospitalized in Ontario **
**Can be linked to NACRS by unique identifier**
**Uses international classification system (ICD-10)**
**Both datasets include: **
**mechanism of injury **
**geographic indicators**
**Diagnoses (ICD-10)**
**sociodemographic information**

## Injuries in Ontario: An ICES Research Atlas

**Objective: To describe the injury problem in Ontario, paying special attention to variation by:**
**Age**
**Gender**
**SES**
**Geographic location**
**Mechanism of injury**

## Methods

**National ambulatory care reporting system (NACRS) database linked with Discharge Abstract Database (DAD)**
**One year (2002-2003)**
**All patients reporting to ED in Ontario **
**Grouped by **
**county (49 in Ontario)**
**SES based on average family income in the residential census tract**

## Variable definition

**Injury variable****- Diagnosis (ICD-10 codes)****- ****Visits with an e-code **_**and**_** a trauma diagnosis included**
** ****Grouped according to ICE categories for  cause:**
**Falls **
**Motor vehicle crashes**
**Bicycle-related injuries**
**Pedestrian injuries**
**Overexertion**
**Drowning**
**-etc....**

## 12,068,300

- 4,921,085

- 1,211,550

- Population of Ontario

- Number of ED visits

- ED visits for injury (25% of ED visits)

## Results

**1.2 million ED visits for an injury in one year**
**13,678/100,000 injury rate**
**62,377 (2.6%) admitted to hospital**
**2700 (0.02%) died in hospital**

## Slide 9

**Notes:**
Exhibit 1.2 Rate of injury-related emergency department visits and hospitalizations per 100,000 population, by age group and sex, in Ontario, 2002/03

## Slide 10

**Notes:**
Exhibit 1.9 Percent of total emergency department visits and hospitalizations caused by injury, by age group, in Ontario, 2002/03

## Slide 11

**Notes:**
Exhibit 1.12 Rate of injury-related emergency department visits per 100,000 population, by age group and income quintile, in Ontario, 2002/03

## Slide 12

**Notes:**
Exhibit 1.6 Rate of injury-related emergency department visits per 100,000 population, by county, in Ontario 2002/03 (Part 2)

## How do NACRS and DAD  compare for all injury admissions?

|  | Agree perfectly
(same code for ED and hospitalization)
N (%) | Do not agree perfectly
N (%) |
| --- | --- | --- |
| Primary diagnosis | 25216 (40%) | 37161 (60%) |
| Cause of injury | 32947 (53%) | 29430 (47%) |
| Intent (unintentional/unknown, self inflicted, assault) | 51106 (82%) | 11271 (18%) |

## How do NACRS and DAD  compare for injury admissions > 3 days?

|  | Agree perfectly
(same code for ED and hospitalization)
N (%) | Do not agree perfectly
N (%) |
| --- | --- | --- |
| Primary diagnosis | 13478 (37%) | 23385 (63%) |
| Cause of injury | 18636 (51%) | 18227 (49%) |
| Intent (unintentional/unknown, self inflicted, assault) | 29682 (81%) | 7181 (19%) |

## Strengths and Limitations of Ontario injury data

**Strengths**
**Population-based study **
**Linked data**
**Coded using standardized practices**
**Limitations**
**Administrative data **
**Possibility of coding errors**
**Variation in injury rates may partially reflect variation in ED visits**

## Conclusions

**Ontario has rich sources of injury data**** **
**Can be used for local planning and international comparisons**
**Linkable data can help with validation for ICE injury projects**
**Atlas exhibits available at **_[www.ices.on.ca](http://www.ices.on.ca/)__ under publications_