New CIHI analysis shows varying rates of adverse events in Canada

August 14, 2007

A new analysis on adverse events released today by the Canadian Institute for Health Information (CIHI) examines the risk of birth trauma in hospital and a range of other adverse events, including medication errors, in-hospital hip fractures and problems related to blood transfusions. Focusing on results from recent surveys, as well as several patient safety indicators, Patient Safety in Canada, shows that some adverse events are comparatively rare, but others occur more frequently. For example, in 2005, 1 in 10 adults with health problems reported receiving the wrong medication or wrong dose in the previous year. Adverse blood transfusion events are reported much less often. They occurred in about 1 in 4,100 cases in 2003.

“While we do not know how to prevent all adverse events, tracking how often they occur and understanding the factors that contribute to them is an important step in improving patient safety,” says Dr. Jennifer Zelmer, CIHI’s Vice-President of Research and Analysis.

One in 141 babies experience birth trauma each year; one in 21 women experience obstetric trauma

There are over one quarter of a million babies born in Canadian hospitals each year (outside of Quebec), one of the leading reasons for hospitalization in Canada. While most deliveries proceed smoothly, adverse events do occur in some cases. For example, the analysis found that between April 2003 and March 2006, on average, one in 141 babies born in hospitals outside of Quebec experienced birth trauma, such as injuries to a baby’s scalp and nervous system or skull fractures. This represents more than 1700 cases yearly.

Likewise, 1 out of 21 mothers giving birth by vaginal delivery (almost 5%) experience obstetrical traumas, such as lacerations of the cervix, vaginal wall or sulcus, or injury to the bladder or urethra. Between April 2003 and March 2006, there were, on average, more than 9,100 reported obstetric traumas in Canadian hospitals outside of Quebec each year. Previous research suggests that risk factors for obstetric trauma include newborns weighing more than 4 kg, long labour, instrumental delivery and a woman’s position during birth.

Risk of post-admission pulmonary embolisms measured for the first time

CIHI’s analysis found that 3.6 out of every 1,000 patients in Canadian hospitals (outside of Quebec and parts of Manitoba) experience a pulmonary embolism (PE), which occurs when
a blood clot or globule of fat or tissue travels through the veins and into the lung. It usually originates in a vein in the leg, when it is known as deep vein thrombosis (DVT).

The risk of post-admission PE or DVT generally increases with age, with patients 60 and over at higher risk than younger patients. However, the rate among children 4 and under is statistically significantly higher compared to that for older children up to 17 years of age.

Reducing the risk of foreign objects left in after surgery

Foreign objects left in after a procedure are less common than many other adverse events, affecting about 1 in 3,000 inpatients in Canadian hospitals outside of Quebec and parts of Manitoba, resulting in more than 200 cases per year between 2003–2004 and 2005–2006.

Previous studies show that obese patients are at higher risk of having a foreign object left behind after surgery. Other higher risk groups include patients who undergo emergency operations, have an unexpected change in operation or have a change in nursing or surgical staff during a procedure. Patients aged 17 and under are at lower risk than adults.

“The consequences of leaving a sponge or other foreign object in after surgery can be significant, but experts suggest that targeted strategies can reduce the risk,” says Dr. Indra Pulcins, CIHI’s Director of Health Reports and Analysis. “Documented prevention strategies include following a strict practice of sponge and instrument counts, as well as vigilant inspection of body cavities when the surgery is complete.”

Improving patient safety

“Health professionals always give their best efforts yet the fact remains that problems or adverse events happen during care delivery,” said Phil Hassen, CEO of the Canadian Patient Safety Institute. “By being vigilant in our focus on patient safety, we hope to see changes in practice that will significantly reduce needless injuries and deaths that result from adverse events.”

For example, many health care providers are focused on reducing the risk of medication errors. In a survey conducted in 2006, 8% of primary care doctors reported that patients had received the wrong drug or dose in the last 12 months. In 2005, 18% of nurses surveyed reported that patients in their care had occasionally or frequently received the wrong medication or dose in the previous year.

Experts have suggested a number of strategies to reduce the risk, including medication reconciliation—the process designed to prevent medication errors at patient transition points—(recently made an accreditation requirement for Canadian health care facilities) and automated drug alerts. In 2006, 10% of Canadian primary care physicians reported routinely receiving computerized alerts about potential drug interactions or dose problems. (Another 31% said that they received this information using a manual system.) Canada’s 10% compares with 23% in the United States, 40% in Germany and 80% or more in Australia, New Zealand, the Netherlands and the United Kingdom.

About CIHI

The Canadian Institute for Health Information (CIHI) collects and analyzes information on health and health care in Canada and makes it publicly available. Canada’s federal, provincial and territorial governments created CIHI as a not-for-profit, independent organization dedicated to forging a common approach to Canadian health information. CIHI’s goal: to provide timely, accurate and comparable information. CIHI’s data and reports inform health policies, support the effective delivery of health services and raise awareness among Canadians of the factors that contribute to good health.