Kelly B. Zarnke

Derivation and validation of an index to predict early death or unplanned readmission after discharge from hospital to the community

Background: Readmissions to hospital are common, costly and often preventable. An easy-to-use index to quantify the risk of readmission or death after discharge from hospital would help clinicians identify patients who might benefit from more intensive post-discharge care. We sought to derive and validate an index to predict the risk of death or unplanned readmission within 30 days after discharge from hospital to the community. Methods: In a prospective cohort study, 48 patient-level and admission-level variables were collected for 4812 medical and surgical patients who were discharged to the community from 11 hospitals in Ontario. We used a split-sample design to derive and validate an index to predict the risk of death or nonelective readmission within 30 days after discharge. This index was externally validated using administrative data in a random selection of 1 000 000 Ontarians discharged from hospital between 2004 and 2008. Results: Of the 4812 participating patients, 385 (8.0%) died or were readmitted on an unplanned basis within 30 days after discharge. Variables independently associated with this outcome (from which we derived the nmemonic “LACE”) included length of stay (“L”); acuity of the admission (“A”); comorbidity of the patient (measured with the Charlson comorbidity index score) (“C”); and emergency department use (measured as the number of visits in the six months before admission) (“E”). Scores using the LACE index ranged from 0 (2.0% expected risk of death or urgent readmission within 30 days) to 19 (43.7% expected risk). The LACE index was discriminative (C statistic 0.684) and very accurate (Hosmer–Lemeshow goodness-of-fit statistic 14.1, p = 0.59) at predicting outcome risk. Interpretation: The LACE index can be used to quantify risk of death or unplanned readmission within 30 days after discharge from hospital. This index can be used with both primary and administrative data. Further research is required to determine whether such quantification changes patient care or outcomes.

A Randomized Study Comparing a Patient-Directed Hypertension Management Strategy With Usual Office-Based Care

This study aimed to compare the efficacy of a patient-directed management strategy with office-based management in maintaining blood pressure control in patients with chronic stable hypertension using a randomized trial of two months duration. The subjects had chronic stable essential hypertension without secondary causes or unstable cardiovascular disease and were selected through the offices of 11 family physicians and a tertiary care hypertension research unit. Patients were randomly assigned (2:1 ratio) to either a patient-directed management strategy using home blood pressure monitoring to adjust drug therapy if readings consistently exceeded defined limits, or office-based management through physician visits. The primary endpoint was the change from baseline in mean arterial pressure as determined by automatic ambulatory blood pressure monitoring. Secondary endpoints were changes in compliance, quality of life, and health care resource use. Ninety-one potential subjects were screened and 31 were randomized. Subjects in the patient-directed management group employed the drug adjustment protocols appropriately without complications. A significant difference in change in mean blood pressure was observed, favoring the patient-directed management (-0.95 mm Hg and +1.90 mm Hg, respectively, for patient-directed management and office-based management, P = .039). Compliance rates and quality of life scores were not significantly different between groups. Physician visits were more frequent in the patient-directed management group (1.05 v 0.20 visits/8 weeks, respectively, for patient-directed management and office-based management groups, P = .045). A patient-directed hypertensive management strategy may be feasible for patients with chronic stable hypertension. Such a strategy may improve blood pressure control compared with usual office-based care. However, physician visits may be increased using this strategy, at least in the short term.

The independent association of provider and information continuity on outcomes after hospital discharge: implications for hospitalists.

BACKGROUND Since hospitalist physicians do not frequently see patients in follow-up after discharge from the hospital, patient continuity of care will decrease. To determine how this influenced patient outcomes, we examined the independent association of several physician continuity and information continuity measures on death or urgent readmission after discharge from hospital. DESIGN Multicenter, prospective cohort study of patients discharged to the community after elective or emergency hospitalization. We measured three physician continuity scores (preadmission; hospital; and postdischarge) and two information continuity scores (discharge summary; postdischarge visit information) as time-dependent covariates. Continuity scores ranged from 0 (perfect discontinuity) to 1 (perfect continuity). The primary outcomes were time to all-cause death or urgent readmission. RESULTS A total of 3876 people were followed for a median of 175 days. Death rate was 2.6 events per 100 patient-years observation (pys) (95% confidence interval [CI], 2.0-3.4) and urgent readmission rate was 19.6 events per 100 pys (95% CI, 15.9-24.3). After adjusting for important covariates and other continuity scores, increased preadmission physician continuity was independently associated with a decreased risk of urgent readmission (adjusted hazard ratio 0.94 [95% CI, 0.91-0.98] for each absolute increase in continuity of 0.1). Other continuity measures-including hospital physician continuity-were not associated with either outcome. CONCLUSIONS After discharge from the hospital, increased continuity with physicians who routinely treated the patient prior to the admission was significantly and independently associated with a decreased risk of urgent readmission. These data suggest that continuity with the hospital physician after discharge did not independently influence the risk of patient death or urgent readmission.

A prospective cohort study found that provider and information continuity was low after patient discharge from hospital

OBJECTIVE Continuity of care is composed of provider and information continuity and can change value over time. Most studies that have quantitatively associated continuity of care and outcomes have ignored these characteristics. This study is a detailed examination of continuity of care in patients discharged from hospital that simultaneously measured separate components of continuity over time or determined the factors with which they are associated. DESIGN SETTING Multicenter, prospective cohort study of patients discharged to the community after elective or emergent hospitalization. For all physician visits during 6 months after discharge, we identified the physician and the availability of particular information (including hospital discharge summary and any information from previous physician visits). Four physician continuity scores (preadmission; hospital admitting; hospital consultant; and postdischarge) and two information continuity scores (discharge summary and postdischarge visit information) were calculated for all patients (range: 0-1, where 0 is perfect discontinuity and 1 is perfect continuity). RESULTS Four thousand five hundred fifty-three people were followed for a median of 175 days. Both provider (range of median values: 0-0.410) and information (range: 0.220-0.427) continuity scores were low and varied extensively over time. With a few exceptions, continuity measures were independent of each other. The influence of patient factors on continuity varied extensively between the continuity measures with the most influential factors being admission urgency, admitting service, and the number of physicians who regularly treated the patient. CONCLUSION Both provider and information continuity was low in patients discharged from hospital. Continuity measures can change extensively over time, which are usually independent of each other, and are associated with patient and admission characteristics. Future studies should measure multiple components of provider and information continuity over time to completely capture continuity of care.

Dietary sodium and cardiovascular outcomes: A rational approach

Hypertension, the leading risk factor for mortality in the world, affects nearly one in four Canadians. There is substantive evidence that high dietary sodium contributes to hypertension. Animal studies consistently demonstrate increased blood pressure and cardiovascular morbidity and mortality with high dietary sodium intake. Evidence of the adverse health effects in humans associated with increased sodium intake is accumulating rapidly. Previously, limitations on sodium consumption were recommended only for those identifiable groups of people shown to be at higher risk. With the lifetime risk of developing hypertension being more than 90% in an average lifespan, the need for a population-based approach to reducing hypertension is clear. The present paper reviews the evidence of sodium and cardiovascular disease, resulting in the 2007 Canadian Hypertension Education Program recommendation of daily intake of less than 100 mmol of sodium in both normotensive and hypertensive adults.

Patient-directed intelligent and interactive computer medical history-gathering systems: a utility and feasibility study in the emergency department.

INTRODUCTION Patients can be used as a resource to enter their own pertinent medical information. This study will evaluate the feasibility of an intelligent computer medical history-taking device directed at patients in the emergency department (ED). METHODS Two of the authors (MB, RE) developed an expert system that can take patient-directed medical histories. Patients interacted with the computer in the ED waiting room while it gathered a medical history based on chief complaint (CC). A survey was completed post history. A sub-study assessed the computers ability to take an adequate history for an index CC. We compared the computer and emergency physician histories for the presence or absence of important historical elements. RESULTS Sixty-seven patients used the interactive computer system. The mean time to complete the history was 5 min and 32s +/- 1 min and 21s. The patient response rate was 97%. Over 83% felt that the computer was very easy to use and over 92% would very much use the computer again. A total of 15 patients with abdominal pain (index CC) were evaluated for the sub-study. The computer history asked 90+/-7%, and the emergency physician asked 55+/-18%, of the important historical elements. These groups were statistically different with a p-value of <0.00001. CONCLUSION This feasibility study has shown that the computer history-taking device is well accepted by patients and that such a system can be integrated into the normal process of patient triage without delaying patient care. Such a system can serve as an initial mode for documentation and data acquisition directly from the patient.

Diagnosing technical competence in six bedside procedures: comparing checklists and a global rating scale in the assessment of resident performance.

Purpose To compare procedure-specific checklists and a global rating scale in assessing technical competence. Method Two trained raters used procedure-specific checklists and a global rating scale to independently evaluate 218 video-recorded performances of six bedside procedures of varying complexity for technical competence. The procedures were completed by 47 residents participating in a formative simulation-based objective structured clinical examination at the University of Calgary in 2011. Pass/fail (competent/not competent) decisions were based on an overall global assessment item on the global rating scale. Raters provided written comments on performances they deemed not competent. Checklist minimum passing levels were set using traditional standard-setting methods. Results For each procedure, the global rating scale demonstrated higher internal reliability and lower interrater reliability than the checklist. However, interrater reliability was almost perfect for decisions on competence using the overall global assessment (Kappa range: 0.84–1.00). Clinically significant procedural errors were most often cited as reasons for ratings of not competent. Using checklist scores to diagnose competence demonstrated acceptable discrimination: The area under the curve ranged from 0.84 (95% CI 0.72–0.97) to 0.93 (95% CI 0.82–1.00). Checklist minimum passing levels demonstrated high sensitivity but low specificity for diagnosing competence. Conclusions Assessment using a global rating scale may be superior to assessment using a checklist for evaluation of technical competence. Traditional standard-setting methods may establish checklist cut scores with too-low specificity: High checklist scores did not rule out incompetence. The role of clinically significant errors in determining procedural competence should be further evaluated.

Risk prediction models for acute kidney injury following major noncardiac surgery: systematic review

BACKGROUND Acute kidney injury (AKI) is a serious complication of major noncardiac surgery. Risk prediction models for AKI following noncardiac surgery may be useful for identifying high-risk patients to target with prevention strategies. METHODS We conducted a systematic review of risk prediction models for AKI following major noncardiac surgery. MEDLINE, EMBASE, BIOSIS Previews and Web of Science were searched for articles that (i) developed or validated a prediction model for AKI following major noncardiac surgery or (ii) assessed the impact of a model for predicting AKI following major noncardiac surgery that has been implemented in a clinical setting. RESULTS We identified seven models from six articles that described a risk prediction model for AKI following major noncardiac surgeries. Three studies developed prediction models for AKI requiring renal replacement therapy following liver transplantation, three derived prediction models for AKI based on the Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease (RIFLE) criteria following liver resection and one study developed a prediction model for AKI following major noncardiac surgical procedures. The final models included between 4 and 11 independent variables, and c-statistics ranged from 0.79 to 0.90. None of the models were externally validated. CONCLUSIONS Risk prediction models for AKI after major noncardiac surgery are available; however, these models lack validation, studies of clinical implementation and impact analyses. Further research is needed to develop, validate and study the clinical impact of such models before broad clinical uptake.

Identification of factors driving differences in cost effectiveness of first-line pharmacological therapy for uncomplicated hypertension.

BACKGROUND Published practice guidelines and economic evaluations have come to different conclusions regarding optimal pharmacotherapy for the treatment of uncomplicated hypertension. The drivers of these disparities are not clear. Greater understanding is needed for clinicians, researchers and policy makers to determine the most effective and sustainable strategies. OBJECTIVES To identify how cost and cost-effectiveness considerations are used to generate recommendations by major hypertension guidelines, and determine key drivers of cost-effectiveness conclusions in available economic evaluations. METHODS A systematic search and narrative review of major hypertension guidelines and health technology assessments of first-line antihypertensive therapy were performed. RESULTS Of the eight guidelines identified, formal cost-effectiveness analysis was rarely integrated in the formulation of recommendations. When guidelines considered costs, recommendations remained incongruent. Two economic evaluations were identified (United Kingdom and Canada); however, these differed in their conclusion of the most cost-effective agent and attractiveness of calcium channel blockers. Review of these economic evaluations suggests that cost-effectiveness conclusions are strongly influenced by relative costs of drug classes; when relative differences in drug costs are lower, the impact on associated conditions such as heart failure and diabetes influences cost-effectiveness conclusions. CONCLUSION In the setting of finite health care resources and significant budget impact due to high population prevalence, cost effectiveness is an important consideration in the treatment of uncomplicated hypertension. Identification of key drivers of cost effectiveness will assist interpretation and conduct of current and future economic evaluations.

Direct angiotensin converting enzyme inhibitor—mediated venodilation

The vasodilator effects of angiotensin converting enzyme inhibitors have been ascribed to systemic inhibition of the angiotensin II generation. However, local mechanisms of vasodilation also have been suggested. We tested whether the angiotensin converting enzyme inhibitor enalaprilat mediated local vasodilation in human dorsal hand veins.