Hospital characteristics and Adverse event Rate Measurements (HARM) Evaluated over 21 years.

An adverse event, a measure of patient safety defined as an unintended consequence of healthcare that leads to patient harm, is experienced by approximately 9% of hospitalized patients during a hospital stay. Adverse events, which include infections arising in hospital, reactions to drugs, and complications from medical procedures, can increase both the hospital length of stay and the risk of a an in-hospital death. Adverse events result in harm to the individual patient and considerable costs to the healthcare system. Across Canada, substantial expenditures on patient safety have been justified by the goals of reducing healthcare-associated harm and its associated cost, but the available evidence suggests that these programs have not improved overall safety; adverse event rates per hospital stay are unchanged over the past four decades. There is a need for research aimed at identifying better targets for healthcare safety programs. The proposed research will meet that need, using records from the Canadian Institute for Health Information of all in-hospital adverse events occurring between 2002-22 in adults at eligible Canadian hospitals. Three separate objectives will be addressed as part of the overarching objective of describing adverse events affecting adult hospitalized patients in Canada: [1] To estimate rates over-time from 2002-2022, overall and for those receiving ICU, surgical, medical, and obstetric care . [2] To evaluate the effects of factors that put the health system under stress - factors related to epidemic and pandemic conditions (e.g., influenza, COVID-19), time and day of admission, and how close a hospital is to being full. [3] To evaluate effects of factors that may make a patient more susceptible to adverse events. We will investigate socioeconomic status and physiologic factors such has age and co- existing illnesses, and will also assess whether these factors have stronger effects at times the healthcare system is under stress