The ALERT scale: an observational study of early prediction of adverse hospital outcome for medical patients.

OBJECTIVES: Some medical patients are at greater risk of adverse outcomes than others and may benefit from higher observation hospital units. We constructed and validated a model predicting adverse hospital outcome for patients. Study results may be used to admit patients into planned tiered care units. Adverse outcome comprised death or cardiac arrest during the first 30 days of hospitalisation, or transfer to intensive care within the first 48 h of admission. SETTING: The study took place at two tertiary teaching hospitals and two community hospitals in Winnipeg, Manitoba, Canada. PARTICIPANTS: We analysed data from 4883 consecutive admissions at a tertiary teaching hospital to construct the Early Prediction of Adverse Hospital Outcome for Medical Patients (ALERT) model using logistic regression. Robustness of the model was assessed through validation performed across four hospitals over two time periods, including 65,640 consecutive admissions. OUTCOME: Receiver-operating characteristic curves (ROC) and sensitivity and specificity analyses were used to assess the usefulness of the model. RESULTS: 9.3% of admitted patients experienced adverse outcomes. The final model included gender, age, Charlson Comorbidity Index, Activities of Daily Living Score, Glasgow Coma Score, systolic blood pressure, respiratory rate, heart rate and white cell count. The model was discriminative (ROC=0.83) in predicting adverse outcome. ALERT accurately predicted 75% of the adverse outcomes (sensitivity) and 75% of the non-adverse outcomes (specificity). Applying the same model to each validation hospital and time period produced similar accuracy and discrimination to that in the development hospital. CONCLUSIONS: Used during initial assessment of patients admitted to general medical wards, the ALERT scale may complement other assessment measures to better screen patients. Those considered as higher risk by the ALERT scale may then be provided more effective care from action such as planned tiered care units.

The association between geographic proximity to a dialysis facility and use of dialysis catheters.

BACKGROUND: Residing remotely from health care resources appears to impact quality of care delivery. It remains unclear if there are differences in vascular access based on distance of one's residence to dialysis centre at time of dialysis initiation, and whether region or duration of pre-dialysis care are important effect modifiers. METHODS: We studied the association of distance from a patients' residence to the nearest dialysis centre and central venous catheter (CVC) use in an observational study of 26,449 incident adult dialysis patients registered in the Canadian Organ Replacement Registry between 2000-2009. Multivariate logistic regression was used to assess the association between distance in tertiles and CVC use, adjusted for patient demographics and comorbidities. Geographic region and duration of pre-dialysis care were examined as potential effect modifiers. RESULTS: Eighty percent of patients commenced dialysis with a CVC. Incident CVC use was highest among those living > 20 km from the dialysis centre (OR 1.29 (1.24-1.34)) compared to those living < 5 km from centre. The length of pre-dialysis care and geographic region were significant effect modifiers; among patients residing in the furthest tertile (>20 km) from the nearest dialysis centre, incident CVC use was more common with shorter length of pre-dialysis care (< 1 year) and residence in central regions of the country. CONCLUSION: Residing further from a dialysis centre is associated with increased CVC use, an effect modified by shorter pre-dialysis care and the geographic region of the country. Efforts to reduce geographical disparities in pre dialysis care may decrease CVC use.

Mortality risk for women on chronic hemodialysis differs by age.

BACKGROUND: Previous reports have demonstrated similar survival for men and women on hemodialysis, despite women's increased survival in the general population. OBJECTIVES: To examine the effect of age on mortality in women undergoing chronic hemodialysis. DESIGN: A retrospective cohort study using an administrative data registry, the Canadian Organ Replacement Registry (CORR) from Jan. 2001 and Dec. 2009. SETTING: Canada. PATIENTS: 28,971 (Women 11,792 (40.7%), Men 17,179 (59.3%)) incident chronic hemodialysis patients who survived greater than 90 days on dialysis. MEASUREMENTS: All-cause mortality. METHODS: Cox proportional hazards and competing risks models were employed to determine the independent association between sex, age and likelihood of all-cause mortality with renal transplantation as the competing outcome. RESULTS: During the study period, 6060 (51.4%) of women and 8650 (50.4%) of men initiating dialysis died. Younger women experienced higher mortality (Age < 45: Women 22.5%, Men 18.2%, hazard ratio (HR) 1.31 (1.12-1.52)) whereas elderly women experience lower mortality (Age 75-85: Women 65%, Men 67.3%, HR 0.94 95% CI 0.88-0.99, Age > 85: Women 66%, Men 70.2%, HR 0.83 95% CI 0.71-0.97) compared to men. This relationship persisted after accounting for the competing risk of transplantation. LIMITATIONS: The cause of death was unknown. CONCLUSIONS: Women's survival on chronic hemodialysis varies by age compared to men with a significantly higher mortality in women younger than 45 years old and lower mortality in woman older than 75 years of age.

CONTEXTE: Des rapports précédents ont démontré une survie similaire pour les hommes et les femmes en hémodialyse, malgré une meilleure survie pour les femmes dans la population générale. OBJECTIFS: Examiner l'incidence de l'âge sur la mortalité chez les femmes en hémodialyse chronique. TYPE D'ÉTUDE: Une étude de cohorte rétrospective basée sur un registre de données administratives, le Registre canadien des insuffisances et des transplantations d'organes (RCITO), de janvier 2001 à décembre 2009. ÉCHANTILLON: Canada. PARTICIPANTS: 28 971 (femmes 11 792 (40,7%), hommes 17 179 (59,3%)) nouveaux patients souffrant d'insuffisance rénale et traités en hémodialyse, qui ont survécu plus de 90 jours. MESURES: Mortalité toutes causes confondues. MÉTHODES: On a eu recours au modèle des risques proportionnels de Cox et au modèle de probabilités concurrentes pour déterminer l'association indépendante entre le genre, l'âge et les probabilités de mortalité toutes causes confondues, et la transplantation rénale est considérée comme un résultat concurrent. RÉSULTATS: Au cours de la période d'étude, 6 060 (51,4%) des femmes et 8 650 (50,4%) des hommes qui ont entamé la dialyse sont décédés. La mortalité des jeunes femmes a été supérieure (âge < 45: femmes 22,5%, hommes 18,2%, rapport des risques (hazard ratio, HR) 1,31 (1,12-1,52)), alors que la mortalité des femmes âgées a été inférieure (âge 75-85: femmes 65%, hommes 67,3%, HR 0,9495% IC 0,88-0,99; âge >85: femmes 66%, hommes 70,2%, HR 0,83 95% IC 0,71-0,97) que celle des hommes. Ce rapport demeurait, après avoir pris en considération le risque concurrent de la transplantation. LIMITES DE L'ÉTUDE: La cause du décès est inconnue. CONCLUSIONS: La survie des femmes en hémodialyse chronique, comparativement à celle des hommes, varie selon l'âge. En effet, la mortalité des femmes de moins de 45 ans est significativement supérieure à celle des hommes du même âge alors que celle des femmes âgées de plus de 75 ans est inférieure à celle des hommes de plus de 75 ans.

Young aboriginals are less likely to receive a renal transplant: a Canadian national study.

BACKGROUND: Previous studies have demonstrated Aboriginals are less likely to receive a renal transplant in comparison to Caucasians however whether this applies to the entire population or specific subsets remains unclear. We examined the effect of age on renal transplantation in Aboriginals. METHODS: Data on 30,688 dialysis (Aboriginal 2,361, Caucasian 28, 327) patients obtained between Jan. 2000 and Dec. 2009 were included in the final analysis. Racial status was self-reported. Cox proportional hazards, the Fine and Grey sub-distribution method and Poisson regression were used to determine the association between race, age and transplantation. RESULTS: In comparison to Caucasians, Aboriginals were less likely to receive a renal transplant (Adjusted HR 0.66 95% CI 0.57-0.77, P < 0.0001) however after stratification by age and treating death as a competing outcome, the effect was more predominant in younger Aboriginals (Age 18-40: 20.6% aboriginals vs. 48.3% Caucasians transplanted; aHR 0.50(0.39-0.61), p < 0.0001, Age 41-50: 10.2% aboriginals vs. 33.9% Caucasians transplanted; aHR 0.46(0.32-0.64), p = 0.005, Age 51-60: 8.2% aboriginals vs. 19.5% Caucasians transplanted; aHR0.65(0.49-0.88), p = 0.01, Age >60: 2.7% aboriginals vs. 2.6% Caucasians transplanted; aHR 1.21(0.76-1.91), P = 0.4, Age X race interaction p < 0.0001). Both living and deceased donor transplants were lower in Aboriginals under the age of 60 compared to Caucasians. CONCLUSION: Younger Aboriginals are less likely to receive a renal transplant compared to their Caucasian counterparts, even after adjustment for comorbidity. Determination of the reasons behind these discrepancies and interventions specifically targeting the Aboriginal population are warranted.

Association of modality with mortality among Canadian Aboriginals.

BACKGROUND AND OBJECTIVES: Previous studies have shown that Aboriginals and Caucasians experience similar outcome on dialysis in Canada. Using the Canadian Organ Replacement Registry, this study examined whether dialysis modality (peritoneal or hemodialysis) impacted mortality in Aboriginal patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study identified 31,576 adult patients (hemodialysis: Aboriginal=1839, Caucasian=21,430; peritoneal dialysis: Aboriginal=554, Caucasian=6769) who initiated dialysis between January of 2000 and December of 2009. Aboriginal status was identified by self-report. Dialysis modality was determined 90 days after dialysis initiation. Multivariate Cox proportional hazards and competing risk models were constructed to determine the association between race and mortality by dialysis modality. RESULTS: During the study period, 939 (51.1%) Aboriginals and 12,798 (53.3%) Caucasians initiating hemodialysis died, whereas 166 (30.0%) and 2037 (30.1%), respectively, initiating peritoneal dialysis died. Compared with Caucasians, Aboriginals on hemodialysis had a comparable risk of mortality (adjusted hazards ratio=1.04, 95% confidence interval=0.96-1.11, P=0.37). However, on peritoneal dialysis, Aboriginals experienced a higher risk of mortality (adjusted hazards ratio=1.36, 95% confidence interval=1.13-1.62, P=0.001) and technique failure (adjusted hazards ratio=1.29, 95% confidence interval=1.03-1.60, P=0.03) than Caucasians. The risk of technique failure varied by patient age, with younger Aboriginals (<50 years old) more likely to develop technique failure than Caucasians (adjusted hazards ratio=1.76, 95% confidence interval=1.23-2.52, P=0.002). CONCLUSIONS: Aboriginals on peritoneal dialysis experience higher mortality and technique failure relative to Caucasians. Reasons for this race disparity in peritoneal dialysis outcomes are unclear.

High rates of mortality and technique failure in peritoneal dialysis patients after critical illness.

INTRODUCTION: Little is known regarding the causes and outcomes of peritoneal dialysis (PD) patients admitted to the intensive care unit (ICU). We explored the outcomes of technique failure and mortality in a cohort of PD patients admitted to the ICU. METHODS: Using a provincial database of 990 incident PD patients followed from January 1997 to June 2009, we identified 90 (9%) who were admitted to the ICU. Parametric and nonparametric tests were used as appropriate to determine differences in baseline characteristics. The Cox proportional hazards and competing risk methods were used to investigate associations. RESULTS: Compared with other patients, those admitted to the ICU had been on PD longer (p < 0.0001) and were more often on continuous ambulatory PD (74.2% vs 25.8%, p = 0.016). Cardiac problems were the most common admitting diagnosis (50%), followed by sepsis (23%), with peritonitis accounting for 69% of the sepsis admissions. The 1-year mortality was 53.3%, with 12% alive and converted to hemodialysis, and one third remaining alive on PD. In multivariate Cox modeling, age [hazard ratio (HR): 1.01; 95% confidence interval (CI): 0.99 to 1.03], white blood cell count (HR: 1.02; 95% CI: 1.00 to 1.04), temperature (HR: 0.75; 95% CI: 0.61 to 0.92), and peritonitis (1.64; 95% CI: 1.21 to 2.22) at admission to the ICU were associated with the composite outcome of technique failure or death. In a competing risk analysis, the risk for death was 30%, and for technique failure, 36% at 1 year. CONCLUSIONS: Patients on PD have high rates of death and technique failure after admission to the ICU.

The role of functional status in discharge to assisted care facilities and in-hospital death among dialysis patients.

BACKGROUND: Functional status is an important component in the assessment of hospitalized patients. We set out to determine the scope, severity, and prognostic significance of impaired functional status in acutely hospitalized dialysis patients. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 1,286 hospitalized dialysis patients admitted and discharged from 1 of 11 area hospitals in Manitoba, Canada, from September 2003 to September 2010 with an activity of daily living (ADL) assessment within 24 hours of admission. PREDICTOR: The 12-point ADL score assesses 6 domains (bathing, toileting, dressing, incontinence, feeding, and transferring) and scores them as independent or supervision only (score, 0), partial assistance (1), and full assistance (2). Thus, higher score indicates worse functional status. Parametric and nonparametric tests were used as appropriate to determine differences in baseline characteristics. OUTCOMES: Multivariable logistic regression and Cox proportional hazards assessed the association between functional status, in-hospital death, and discharge to an assisted care facility. RESULTS: During the study period, 250 (19.4%) and 72 (5.6%) patients experienced the outcomes of in-hospital death or discharge to an assisted care facility. Abnormalities in functional status were present in >70% of the cohort. ADL score within 24 hours of admission combined with age differentiated risks of death and discharge to an assisted care facility home, ranging from 4.8%-46.6% and 0.6%-17.8%, respectively. After adjustment, ORs of death and discharge to an assisted care facility were 1.16 (95% CI, 1.11-1.22; P < 0.001; C statistic = 0.79) and 1.25 (95% CI, 1.14-1.36; P < 0.001; C statistic = 0.91) per 1-point increase in ADL score, respectively. Findings were consistent after accounting for the competing outcomes of in-hospital death or discharge to an assisted care facility versus discharge to home. LIMITATIONS: A 1-time measurement of ADLs could not differentiate temporary from long-term deterioration in functional status. CONCLUSIONS: Impaired functional status is common at the time of admission in the dialysis population. A single ADL score measurement at admission combined with age is highly predictive of poor outcomes in the hospitalized dialysis population.

Long-term outcomes of end-stage renal disease patients admitted to the ICU.

BACKGROUND: End-stage renal disease (ESRD) patients admitted to the intensive care unit (ICU) have poor survival and high rates of readmission; however, little evidence exists on long-term outcomes. We set out to investigate the long-term (6 and 12 months) survival of ESRD patients admitted to the ICU and whether differential survival could be explained by dialysis modality and vascular access. METHODS: We compared the admission characteristics, outcomes and readmission rates of 619 ESRD [95 peritoneal dialysis (PD), 334 hemodialysis with a catheter (HD CVC), 190 hemodialysis with an AV fistula (HD AVF)] patients admitted to 11 ICU's in Winnipeg, Manitoba, Canada. Parametric and nonparametric tests were used as appropriate to determine differences in baseline characteristics. Multivariable Cox and logistic regression was used to assess outcomes between the groups. RESULTS: The 6- and 12-month crude survival was 62 and 52%, respectively. In a univariate model, modality and vascular access were associated with an increased hazard ratio (HR) of death [PD HR 1.60 95% confidence interval (CI) 1.20-2.13, HD CVC HR 1.55 95% CI 1.25-1.93] compared to patients on HD with an AVF. In three different multivariate adjusted models, this association persisted with HRs for death of 1.63-1.75 for PD and 1.50-1.58 for HD CVC. CONCLUSIONS: Overall long-term survival of ESRD patients after admission to the ICU is poor. Being on PD or being dialyzed with a catheter was independently associated with an increased mortality.

End-stage renal disease status and critical illness in the elderly.

BACKGROUND AND OBJECTIVES: Elderly patients (> 65 years old) are a rapidly growing demographic in the ESRD and intensive care unit (ICU) populations, yet the effect of ESRD status on critical illness in elderly patients remains unknown. Reliable estimates of prognosis would help to inform care and management of this frail and vulnerable population. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The effect of ESRD status on survival and readmission rates was examined in a retrospective cohort of 14,650 elderly patients (>65 years old) admitted to 11 ICUs in Winnipeg, Manitoba, Canada between 2000 and 2006. Logistic regression models were used to adjust odds of mortality and readmission to ICU for baseline case mix and illness severity. RESULTS: Elderly ESRD patients had twofold higher crude in-hospital mortality (22% versus 13%, P < 0.0001) and readmission rate (6.4 versus 2.7%, P = 0.001). After adjustment for illness severity alone or illness severity and case mix, the odds ratio for mortality decreased to 0.85 (95% CI: 0.57 to 1.25) and 0.82 (95% CI: 0.55 to 1.23), respectively. In contrast, ESRD status remained significantly associated with readmission to ICU after adjustment for other risk factors (OR 2.06 [95% CI: 1.32, 3.22]). CONCLUSIONS: Illness severity on admission, rather than ESRD status per se, appears to be the main driver of in-hospital mortality in elderly patients. However, ESRD status is an independent risk factor for early and late readmission, suggesting that this population might benefit from alternative strategies for ICU discharge.

Acute kidney injury in critically ill patients infected with 2009 pandemic influenza A(H1N1): report from a Canadian Province.

BACKGROUND: 2009 pandemic influenza A(H1N1) has led to a global increase in severe respiratory illness. Little is known about kidney outcomes and dialytic requirements in critically ill patients infected with pandemic H1N1. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 50 patients with pandemic H1N1 admitted to any of 7 intensive care units in Manitoba, Canada, were prospectively followed. OUTCOME & MEASUREMENTS: Outcomes were kidney injury and kidney failure defined using RIFLE (risk, injury, failure, loss, end-stage disease) criteria or need for dialysis therapy. RESULTS: The pandemic H1N1 group was composed of 50 critically ill patients with pandemic H1N1 with severe respiratory syndrome (47 confirmed cases, 3 probable). Kidney injury, kidney failure, and need for dialysis occurred in 66.7%, 66%, and 11% of patients, respectively. Mortality was 16%. Kidney failure was associated with increased death (OR, 11.29; 95% CI, 1.29-98.9), whereas the need for dialysis was associated with an increase in length of stay (RR, 2.38; 95% CI, 2.13-25.75). LIMITATIONS: Small population studied from single Canadian province; thus, limited generalizability. CONCLUSIONS: In critically ill patients with pandemic H1N1, kidney injury, kidney failure, and the need for dialysis are common and associated with an increase in mortality and length of intensive care unit stay.

Outcomes of chronic dialysis patients admitted to the intensive care unit.

Admission rates and outcomes of patients who have ESRD and are admitted to an intensive care unit (ICU) are not well defined. We conducted a historical cohort study using a prospective regional ICU database that captured all 11 adult ICUs in Winnipeg, Canada. Between 2000 and 2006, there were 34,965 total admissions to the ICU, 1173 (3.4%) of which were patients with ESRD. The main admission diagnoses among patients with ESRD were cardiac disease (31%), sepsis (15%), and arrest (10%). Compared with other patients in the ICU, those with ESRD were significantly younger but had more diabetes, peripheral arterial disease, and higher APACHE II (Acute Physiology and Chronic Health Evaluation II) scores; mean length of stay in the ICU was similar, however, between these two groups. Restricting the analysis to first admissions to the ICU, unadjusted in-hospital mortality was higher for patients with ESRD (16 versus 11%; P < 0.0001), but this difference did not persist after adjustment for baseline illness severity. In conclusion, although ESRD associates with increased mortality among patients who are admitted to the ICU, this effect is mostly a result of comorbidity.