Intensive Care Unit Safety Culture and Outcomes: a US Multicenter Study
Intensive Care Unit Safety Culture and Outcomes: a US Multicenter Study
Objective. Safety culture may influence patient outcomes, but evidence is limited. We sought to determine if intensive care unit (ICU) safety culture is independently associated with outcomes.
Design. Cohort study combining safety culture survey data with the Project IMPACT Critical Care Medicine (PICCM) clinical database.
Setting. Thirty ICUs participating in the PICCM database.
Participants. A total of 65 978 patients admitted January 2001–March 2005.
Interventions. None.
Main outcome measures. Hospital mortality and length of stay (LOS).
Methods. From December 2003 to April 2004, we surveyed study ICUs using the Safety Attitudes Questionnaire-ICU version, a validated instrument that assesses safety culture across six factors. We calculated factor mean and percent-positive scores (% respondents with mean score ≥75 on a 0–100 scale) for each ICU, and generated case-mix adjusted, patient-level, ICU-clustered regression analyses to determine the independent association of safety culture and outcome.
Results. We achieved a 47.9% response (2103 of 4373 ICU personnel). Culture scores were mostly low to moderate and varied across ICUs (range: 13–88, percent-positive scores). After adjustment for patient, hospital and ICU characteristics, for every 10% decrease in ICU perceptions of management percent-positive score, the odds ratio for hospital mortality was 1.24 (95% CI: 1.07–1.44; P = 0.005). For every 10% decrease in ICU safety climate percent-positive score, LOS increased 15% (95% CI: 1–30%; P = 0.03). Sensitivity analyses for non-response bias consistently associated safety climate with outcome, but also yielded some counterintuitive results.
Conclusion. In a multicenter study conducted in the USA, perceptions of management and safety climate were moderately associated with outcomes. Future work should further develop methods of assessing safety culture and association with outcomes.
Safety culture has been defined as 'the product of individual and group values, attitudes, perceptions, competencies and patterns of behavior that determine the commitment to, and the style and proficiency of, an organization's health and safety management'. Despite high profile calls for enhancing safety culture in medicine, the actual impact on patient outcomes is unclear. Early investigations in critical care showed conflicting results. A 1986 study examined the role of organizational factors in 13 hospitals and found that intensive care unit (ICU) personnel coordination and interaction appeared to relate to severity-adjusted mortality. However, two follow-up studies only found an association between organizational culture and length of stay (LOS), but not mortality. A possible reason for these disparate results is that the first study relied on site visits and ICU directors' assessments, although the subsequent studies directly surveyed personnel. Studies by our group and others have shown that ICU directors may not accurately estimate their units' culture. Other studies also suggested a potential relationship between ICU culture and patient outcomes, but a recent review concluded that, whereas some evidence existed, articulating the nature of that relationship was difficult. In particular, stronger methodologic definitions and operationalizations of both culture and outcomes were recommended.
We therefore conducted a multicenter cohort study of ICU safety culture and outcomes: ICUTEAMS—Intensive Care Unit Teamwork, Error, and Attitudes towards Management Survey. We directly surveyed personnel in a large network of ICUs located in the USA, using a validated, aviation safety research based survey instrument designed to measure ICU safety culture. We then linked safety culture data with contemporaneous ICU outcome and administrative data, and adjusted for differences in severity of illness using a well-established clinical and physiologic risk adjustment tool. Our primary objective was to determine if ICU safety culture is independently associated with patient hospital mortality and LOS.
Abstract and Introduction
Abstract
Objective. Safety culture may influence patient outcomes, but evidence is limited. We sought to determine if intensive care unit (ICU) safety culture is independently associated with outcomes.
Design. Cohort study combining safety culture survey data with the Project IMPACT Critical Care Medicine (PICCM) clinical database.
Setting. Thirty ICUs participating in the PICCM database.
Participants. A total of 65 978 patients admitted January 2001–March 2005.
Interventions. None.
Main outcome measures. Hospital mortality and length of stay (LOS).
Methods. From December 2003 to April 2004, we surveyed study ICUs using the Safety Attitudes Questionnaire-ICU version, a validated instrument that assesses safety culture across six factors. We calculated factor mean and percent-positive scores (% respondents with mean score ≥75 on a 0–100 scale) for each ICU, and generated case-mix adjusted, patient-level, ICU-clustered regression analyses to determine the independent association of safety culture and outcome.
Results. We achieved a 47.9% response (2103 of 4373 ICU personnel). Culture scores were mostly low to moderate and varied across ICUs (range: 13–88, percent-positive scores). After adjustment for patient, hospital and ICU characteristics, for every 10% decrease in ICU perceptions of management percent-positive score, the odds ratio for hospital mortality was 1.24 (95% CI: 1.07–1.44; P = 0.005). For every 10% decrease in ICU safety climate percent-positive score, LOS increased 15% (95% CI: 1–30%; P = 0.03). Sensitivity analyses for non-response bias consistently associated safety climate with outcome, but also yielded some counterintuitive results.
Conclusion. In a multicenter study conducted in the USA, perceptions of management and safety climate were moderately associated with outcomes. Future work should further develop methods of assessing safety culture and association with outcomes.
Introduction
Safety culture has been defined as 'the product of individual and group values, attitudes, perceptions, competencies and patterns of behavior that determine the commitment to, and the style and proficiency of, an organization's health and safety management'. Despite high profile calls for enhancing safety culture in medicine, the actual impact on patient outcomes is unclear. Early investigations in critical care showed conflicting results. A 1986 study examined the role of organizational factors in 13 hospitals and found that intensive care unit (ICU) personnel coordination and interaction appeared to relate to severity-adjusted mortality. However, two follow-up studies only found an association between organizational culture and length of stay (LOS), but not mortality. A possible reason for these disparate results is that the first study relied on site visits and ICU directors' assessments, although the subsequent studies directly surveyed personnel. Studies by our group and others have shown that ICU directors may not accurately estimate their units' culture. Other studies also suggested a potential relationship between ICU culture and patient outcomes, but a recent review concluded that, whereas some evidence existed, articulating the nature of that relationship was difficult. In particular, stronger methodologic definitions and operationalizations of both culture and outcomes were recommended.
We therefore conducted a multicenter cohort study of ICU safety culture and outcomes: ICUTEAMS—Intensive Care Unit Teamwork, Error, and Attitudes towards Management Survey. We directly surveyed personnel in a large network of ICUs located in the USA, using a validated, aviation safety research based survey instrument designed to measure ICU safety culture. We then linked safety culture data with contemporaneous ICU outcome and administrative data, and adjusted for differences in severity of illness using a well-established clinical and physiologic risk adjustment tool. Our primary objective was to determine if ICU safety culture is independently associated with patient hospital mortality and LOS.
