Impact of socio-economic status on unplanned readmission following injury: A multicenter cohort study.

BACKGROUND: Unplanned readmissions cost the US economy approximately $17 billion in 2009 with a 30-day incidence of 19.6%. Despite the recognised impact of socio-economic status (SES) on readmission in diagnostic populations such as cardiovascular patients, its impact in trauma patients is unclear. We examined the effect of SES on unplanned readmission following injury in a setting with universal health insurance. We also evaluated whether additional adjustment for SES influenced risk-adjusted readmission rates, used as a quality indicator (QI). STUDY DESIGN: We conducted a multicenter cohort study in an integrated Canadian trauma system involving 56 adult trauma centres using trauma registry and hospital discharge data collected between 2005 and 2010. The main outcome was unplanned 30-day readmission; all cause, due to complications of injury and due to subsequent injury. SES was determined using ecological indices of material and social deprivation. Odds ratios of readmission and 95% confidence intervals adjusted for covariates were generated using multivariable logistic regression with a correction for hospital clusters. We then compared a readmission QI validated previously (original QI) to a QI with additional adjustment for SES (SES-adjusted QI) using the mean absolute difference. RESULTS: The cohort consisted of 52,122 trauma admissions of which 6.5% were rehospitalised within 30 days of discharge. Compared to patients in the lowest quintile of social deprivation, those in the highest quintile had a 20% increase in the odds of all-cause unplanned readmission (95% CI=1.06-1.36) and a 27% increase in the odds of readmission due to complications of injury (95% CI=1.04-1.54). No association was observed for material deprivation or for readmissions due to subsequent injuries. We observed a strong agreement between the original and SES-adjusted readmission (mean absolute difference= 0.04%). CONCLUSIONS: Patients admitted for traumatic injury who suffer from social deprivation have an increased risk of unplanned rehospitalisation due to complications of injury in the 30 days following discharge. Better discharge planning or follow up for such patients may improve patient outcome and resource use for trauma admissions. Despite observed associations, results suggest that the trauma QI based on unplanned readmission does not require additional adjustment for SES.

Impact of socio-economic status on hospital length of stay following injury: a multicenter cohort study.

BACKGROUND: Injury is second only to cardiovascular disease in terms of acute care costs in North America. One key to improving injury care efficiency is to generate knowledge on the determinants of resource use. Socio-economic status (SES) is a documented risk factor for injury severity and mortality but its impact on length of stay (LOS) for injury admissions is unknown. This study aimed to examine the relationship between SES and LOS following injury. This multicenter retrospective cohort study was based on adults discharged alive from any trauma center (2007-2012; 57 hospitals; 65,486 patients) in a Canadian integrated provincial trauma system. SES was determined using ecological indices of material and social deprivation. Mean differences in LOS adjusted for age, gender, comorbidities, and injury severity were generated using multivariate linear regression. RESULTS: Mean LOS was 13.5 days. Patients in the highest quintile of material/social deprivation had a mean LOS 0.5 days (95 % CI 0.1-0.9)/1.4 days (1.1-1.8) longer than those in the lowest quintile. Patients in the highest quintiles of both social and material deprivation had a mean LOS 2.6 days (1.8-3.5) longer than those in the lowest quintiles. CONCLUSIONS: Results suggest that patients admitted for traumatic injury who suffer from high social and/or material deprivation have longer acute care LOS in a universal-access health care system. The reasons behind observed differences need to be further explored but may indicate that discharge planning should take patient SES into consideration.

Influence of access to an integrated trauma system on in-hospital mortality and length of stay.

BACKGROUND: Few data are available on population-based access to specialised trauma care and its influence on patient outcomes in an integrated trauma system. We aimed to evaluate the influence of access to an integrate trauma system on in-hospital mortality and length of stay (LOS). METHODS: All adults admitted to acute care hospitals for major trauma [International Classification of Diseases Injury Severity Score (ICISS<0.85)] in a Canadian province with an integrated trauma system between 2006 and 2011 were included using an administrative hospital discharge database. The influence of access to an integrated trauma system on in-hospital mortality and LOS was assessed globally and for critically injured patients (ICISS<0.75), according to the type of injury [traumatic brain injury (TBI), abdominal/thoracic, spine, orthopaedic] using logistic and linear multivariable regression models. RESULTS: We identified 22,749 injury admissions. In-hospital mortality was 7% and median LOS was 9 days for all injuries. Overall, 92% of patients were treated within the trauma system. Globally, patients who did not have access had similar mortality and LOS compared to patients who had access. However, we observed a 62% reduction in mortality for critical abdominal/thoracic injuries (odds ratio=0.38; 95% CI, 0.16-0.92) and an 8% increase in LOS for TBI patients (geometric mean ratio=1.08; 95% CI, 1.02-1.14) treated within the trauma system. CONCLUSIONS: Results provides evidence that in a health system with an integrated mature trauma system, access to specialised trauma care is high and the small proportion of patients treated outside the system, have similar mortality and LOS compared to patients treated within the system. This study suggests that the Québec trauma system performs well in its mandate to offer appropriate treatment to victims of injury that require specialised care.

Access to a Canadian provincial integrated trauma system: a population-based cohort study.

BACKGROUND: Access to specialised trauma care is an important measure of trauma system efficiency. However, few data are available on access to integrated trauma systems. We aimed to describe access to trauma centres (TCs) in an integrated Canadian trauma system and identify its determinants. METHODS: We conducted a population-based cohort study including all injured adults admitted to acute care hospitals in the province of Québec between 2006 and 2011. Proportions of injured patients transported directly or transferred to TCs were assessed. Determinants of access were identified through a modified Poisson regression model and a relative importance analysis was used to determine the contribution of each independent variable to predicting access. RESULTS: Of the 135,653 injury admissions selected, 75% were treated within the trauma system. Among 25,522 patients with major injuries [International Classification of diseases Injury Severity Score (ICISS<0.85)], 90% had access to TCs. Access was higher for patients aged under 65, men and among patients living in more remote areas (p-value <0.001). The region of residence followed by injury mechanism, number of trauma diagnoses, injury severity and age were the most important determinants of access to trauma care. CONCLUSIONS: In an integrated, mature trauma system, we observed high access to TCs. However, problems in access were observed for the elderly, women and in urban areas where there are many non-designated hospitals. Access to trauma care should be monitored as part of quality of care improvement activities and pre-hospital guidelines for trauma patients should be applied uniformly throughout the province.