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Biomedical subjects

Jack V Tu

Publications and source records attributed to Jack V Tu.

At least 19 recordsLinked to original sources
PubMed2005

Quality of care and outcomes of older patients with heart failure hospitalized in the United States and Canada.

BACKGROUND: Health care expenditure per person is significantly higher in the United States compared with Canada, but whether there are differences in quality of care of many conditions is unknown. We compared the process of care and outcomes of patients with heart failure, the most common cause of hospitalization for individuals 65 years and older in both countries. METHODS: We compared processes of care and 30-day and 1-year risk-standardized mortality rates among 28,521 US Medicare beneficiaries and 8180 similarly aged patients in Ontario, Canada, hospitalized with heart failure from 1998 to 2001. RESULTS: More US patients underwent left ventricular ejection fraction assessment during hospitalization compared with Canadian patients (61.2% vs 41.7%, P<.001). At discharge, patients in the United States were prescribed beta-blockers more frequently (28.7% vs 25.4%, P<.001) but angiotensin-converting enzyme inhibitors less frequently (54.3% vs 63.4%, P<.001). Among ideal candidates, prescription of beta-blockers (32.5% vs 29.7%, P = .08) or angiotensin-converting enzyme inhibitors (78.3% vs 77.6%, P = .68) was not significantly different between the 2 countries. The US patients had lower risk characteristics on admission and lower crude mortality rates at 30 days and 1 year. Thirty-day risk-standardized mortality was significantly lower for the US patients (8.9% vs 10.7%, P<.001), but 1-year risk-standardized mortality was no longer significantly different (32.2% vs 32.3%, P = .98). CONCLUSION: Patients with heart failure who are hospitalized in the United States had lower short-term mortality at 30 days, but 1-year mortality rates were not significantly different between the United States and Canada.

Aged↗
PubMed2005

Risk-treatment mismatch in the pharmacotherapy of heart failure.

CONTEXT: Patients with heart failure have a wide spectrum of mortality risks. To maximize the benefit of available pharmacotherapies, patients with high mortality risk should receive high rates of drug therapy. OBJECTIVE: To examine patterns of drug therapy and underlying mortality risk in patients with heart failure. DESIGN, SETTING, AND PATIENTS: In the Enhanced Feedback for Effective Cardiac Treatment (EFFECT) population-based cohort (1999-2001) of 9942 patients with heart failure hospitalized in Ontario, Canada, we evaluated 1418 patients with documented left ventricular ejection fraction of 40% or less and aged 79 years or younger with low-, average-, and high-predicted risk of death within 1 year; all patients survived to hospital discharge. Administration of angiotensin-converting enzyme (ACE) inhibitors, ACE inhibitors or angiotensin II receptor blockers (ARBs), and beta-adrenoreceptor antagonists was evaluated according to predicted risk of death. MAIN OUTCOME MEASURE: Heart failure drug administration rates at time of discharge and 90 days after hospital discharge. RESULTS: At hospital discharge, prescription rates for patients in the low-, average-, and high-risk groups were 81%, 73%, 60%, respectively, for ACE inhibitors; 86%, 80%, 65%, respectively, for ACE inhibitors or ARBs; and 40%, 33%, 24%, respectively, for beta-adrenoreceptor antagonists (all P<.001 for trend). Within 90 days following hospital discharge, the rates were 83%, 76%, and 61% for ACE inhibitors; 89%, 83%, and 67% for ACE inhibitors or ARBs; and 43%, 36%, and 28% for beta-adrenoreceptor antagonists for the 3 risk groups, respectively (all P<.001 for trend). The pattern of lower rates of drug administration in those patients at increasing risk was maintained up to 1 year postdischarge (P<.001). After accounting for varying survival time and potential contraindications to therapy, low-risk patients were more likely to receive ACE inhibitors or ARBs (adjusted hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.49-1.74) and beta-adrenoreceptor antagonists (HR, 1.80; 95% CI, 1.60-2.01) compared with high-risk patients (both P<.001). CONCLUSIONS: Patients with heart failure at greatest risk of death are least likely to receive ACE inhibitors, ACE inhibitors or ARBs, and beta-adrenoreceptor antagonists. Understanding the reasons underlying this mismatch may facilitate improvements in care and outcomes for patients with heart failure.

Adrenergic beta-Antagonists↗
PubMed2005

How many patients with heart failure are eligible for cardiac resynchronization? Insights from two prospective cohorts.

AIMS: To determine what proportion of patients with heart failure are eligible for cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Eligibility criteria from the trials establishing the efficacy of CRT were applied to two prospective cohorts: the first enrolled patients with newly diagnosed heart failure discharged from 103 hospitals between April 1999 and March 2001 ('the hospital discharge cohort'); the second enrolled patients seen in a specialized clinic between August 2003 and January 2004 ('the specialty clinic cohort'). In the hospital discharge cohort, 73 patients (3% of the 2640 patients with ischaemic or dilated cardiomyopathy and 1% of all 9096 patients with heart failure discharged alive) met trial eligibility criteria: LVEF< or =0.35, QRS > or =120 ms, sinus rhythm, and NYHA class III or IV symptoms despite the treatment with ACE-inhibitor/angiotensin receptor blocker and beta-blocker. In the specialty clinic cohort, 54 patients (21% of the 263 patients with ischaemic or dilated cardiomyopathy and 17% of all 309 patients with heart failure) met these criteria. If persistent symptoms despite taking spironolactone were required for CRT eligibility, then the proportions qualifying dropped to 1% in the hospital discharge cohort and 18% in the specialty clinic cohort. CONCLUSION: Few heart failure patients meet trial eligibility criteria for CRT.

Adrenergic beta-Antagonists↗
PubMed2005

Administrative Data Feedback for Effective Cardiac Treatment: AFFECT, a cluster randomized trial.

CONTEXT: Hospital report cards are increasingly being implemented for quality improvement despite lack of strong evidence to support their use. OBJECTIVE: To determine whether hospital report cards constructed using linked hospital and prescription administrative databases are effective for improving quality of care for acute myocardial infarction (AMI). DESIGN: The Administrative Data Feedback for Effective Cardiac Treatment (AFFECT) study, a cluster randomized trial. SETTING AND PATIENTS: Patients with AMI who were admitted to 76 acute care hospitals in Quebec that treated at least 30 AMI patients per year between April 1, 1999, and March 31, 2003. INTERVENTION: Hospitals were randomly assigned to receive rapid (immediate; n = 38 hospitals and 2533 patients) or delayed (14 months; n = 38 hospitals and 3142 patients) confidential feedback on quality indicators constructed using administrative data. MAIN OUTCOME MEASURES: Quality indicators pertaining to processes of care and outcomes of patients admitted between 4 and 10 months after randomization. The primary indicator was the proportion of elderly survivors of AMI at each study hospital who filled a prescription for a beta-blocker within 30 days after discharge. RESULTS: At follow-up, adjusted prescription rates within 30 days after discharge were similar in the early vs late groups (for beta-blockers, odds ratio [OR], 1.06; 95% confidence interval [CI], 0.82-1.37; for angiotensin-converting enzyme inhibitors, OR, 1.17; 95% CI, 0.90-1.52; for lipid-lowering drugs, OR, 1.14; 95% CI, 0.86-1.50; and for aspirin, OR, 1.05; 95% CI, 0.84-1.33). In addition, adjusted mortality was similar in both groups, as were length of in-hospital stay, physician visits after discharge, waiting times for invasive cardiac procedures, and readmissions for cardiac complications. CONCLUSIONS: Feedback based on one-time, confidential report cards constructed using administrative data is not an effective strategy for quality improvement regarding care of patients with AMI. A need exists for further studies to rigorously evaluate the effectiveness of more intensive report card interventions.

Adrenergic beta-Antagonists↗
PubMed2005

Population rates of cardiac catheterization and yield of high-risk coronary artery disease.

BACKGROUND: The optimal population rate of cardiac catheterization is unknown. One potential way to determine it would be to examine whether there is a population rate beyond which the yield of high-risk coronary artery disease (CAD) does not rise. METHODS: Using a detailed clinical registry that captures all patients undergoing cardiac catheterization in Alberta, we determined annual population rates of cardiac catheterization and the corresponding yield of cases of high-risk CAD in each of Alberta's 17 health regions from 1995 to 2002. Least squares linear regression analysis and hierarchical modelling methods were then used to assess the linear relation between catheterization rates and rates of high-risk CAD. RESULTS: The age-adjusted average rate of cardiac catheterization among men ranged from 404.9 to 638.1 per 100,000 population aged over 20 years. Among women, the average rate ranged from 171.8 to 314.0 per 100,000. For both sexes, increased regional rates of catheterization were associated with a linearly increasing yield of high-risk CAD, with no evidence of a plateau in yield when more procedures were performed. One additional case of high-risk CAD was identified for every 2.5 additional cardiac catheterization procedures performed among men, and for every 3.7 additional procedures performed among women. INTERPRETATION: The increasing yield of patients with high-risk CAD associated with increased regional population rates of cardiac catheterization, together with the absence of a plateau in yield, suggests that Alberta's population rates of cardiac catheterization are suboptimal to detect people with high-risk CAD.

Adult↗
PubMed2005

The use of the propensity score for estimating treatment effects: administrative versus clinical data.

There is an increasing interest in using administrative data to estimate the treatment effects of interventions. While administrative data are relatively inexpensive to obtain and provide population coverage, they are frequently characterized by lack of clinical detail, often leading to problematic confounding when they are used to conduct observational research. Propensity score methods are increasingly being used to address confounding in estimating the effects of interventions in such studies. Using data on patients discharged from hospital for whom both administrative data and detailed clinical data obtained from chart reviews were available, we examined the degree to which stratifying on the quintiles of propensity scores derived from administrative data was able to balance patient characteristics measured in clinical data. We also determined the extent to which measures of treatment effect obtained using propensity score methods were similar to those obtained using traditional regression methods. As a test case, we examined the treatment effects of ASA and beta-blockers following acute myocardial infarction. We demonstrated that propensity scores developed using administrative data do not necessarily balance patient characteristics contained in clinical data. Furthermore, measures of treatment effectiveness were attenuated when obtained using clinical data compared to when administrative data were used.

Adrenergic beta-Antagonists↗
PubMed2005

Effectiveness of statins for secondary prevention in elderly patients after acute myocardial infarction: an evaluation of class effect.

BACKGROUND: Clinical trials have shown the benefits of statins after acute myocardial infarction (AMI). However, it is unclear whether different statins exert a similar effect in reducing the incidence of recurrent AMI and death when used in clinical practice. METHODS: We conducted a retrospective cohort study (1997-2002) to compare 5 statins using data from medical administrative databases in 3 provinces (Quebec, Ontario and British Columbia). We included patients aged 65 years and over who were discharged alive after their first AMI-related hospital stay and who began statin treatment within 90 days after discharge. The primary end point was the combined outcome of recurrent AMI or death from any cause. The secondary end point was death from any cause. Adjusted hazard ratios (HRs) for each statin compared with atorvastatin as the reference drug were estimated using Cox proportional hazards regression analysis. RESULTS: A total of 18,637 patients were prescribed atorvastatin (n = 6420), pravastatin (n = 4480), simvastatin (n = 5518), lovastatin (n = 1736) or fluvastatin (n = 483). Users of different statins showed similar baseline characteristics and patterns of statin use. The adjusted HRs (and 95% confidence intervals) for the combined outcome of AMI or death showed that each statin had similar effects when compared with atorvastatin: pravastatin 1.00 (0.90-1.11), simvastatin 1.01 (0.91-1.12), lovastatin 1.09 (0.95-1.24) and fluvastatin 1.01 (0.80-1.27). The results did not change when death alone was the end point, nor did they change after adjustment for initial daily dose or after censoring of patients who switched or stopped the initial statin treatment. INTERPRETATION: Our results suggest that, under current usage, statins are equally effective for secondary prevention in elderly patients after AMI.

Aged↗
PubMed2005

The use of quantile regression in health care research: a case study examining gender differences in the timeliness of thrombolytic therapy.

Investigators are frequently interested in determining patient and system characteristics associated with delays in the provision of essential medical treatment. Investigators have typically used either multiple linear regression or Cox proportional hazards models to assess the impact of patient and system characteristics on the timeliness of medical treatment. A drawback to the use of these two methods is that they allow, at best, a partial exploration of how a distribution of delays in treatment or of waiting times changes with patient characteristics. In contrast, quantile regression models allow one to assess how any quantile of a conditional distribution changes with patient characteristics. We illustrate the utility of quantile regression by examining gender differences in the delivery of thrombolysis in patients with an acute myocardial infarction. We demonstrate that richer inferences can be drawn through the use of quantile regression. Females were more likely to experience delays in treatment compared to males. Furthermore, gender had a greater impact upon those patients who had the greatest delays in treatment. Investigators who want to determine how a distribution of delays in treatment or of waiting times changes with patient or system characteristics should consider complementing their analyses with the use of quantile regression.

Aged↗
PubMed2005

Pharmacological treatment of congestive heart failure in Canada: a description of care in five provinces.

INTRODUCTION: Congestive heart failure (CHF) is responsible for significant morbidity, mortality and health resource consumption. There have been major advances in the treatment of this condition over the past two decades, yet little information is currently available regarding the current status of CHF management in Canada. OBJECTIVE: To describe the pharmacological management of patients hospitalized with CHF in five provinces: Alberta, British Columbia, Nova Scotia, Ontario and Quebec. DESIGN AND METHODS: Administrative data sources were used to identify all consecutive patients hospitalized with a principal diagnosis of CHF and discharged alive in the provinces of Alberta, British Columbia, Quebec and Ontario. Rates of use of prespecified medications at 30 days after hospital discharge were obtained for patients 65 years of age and older by linkage of their hospital records with drug benefit plans in these provinces. For Nova Scotia, the disease-specific registry of the Improving Cardiovascular Outcomes in Nova Scotia (ICONS) study was used to obtain discharge medications of individuals consecutively hospitalized with a diagnosis of CHF. Where available, data were acquired from 1997 to 2002. RESULTS: Data were obtained for a total of 115,037 patients in the five provinces over the five-year period. Overall, 54.9% of patients received an angiotensin-converting enzyme inhibitor at or 30 days after hospital discharge, with minimal change in prescription rates over the five-year period. Beta-blocker prescription rates increased steadily during the study, more than doubling from 15.0% in 1997/1998 to 32.0% in 2001/2002. Spironolactone use increased dramatically, with only 2.2% of patients receiving this medication in 1997/1998 compared with 18.7% in 2001/2002. The rates of digoxin prescription decreased each year, while the use of angiotensin receptor blockers increased slightly throughout the observation period. CONCLUSIONS: While the use of evidence-based treatment for CHF in Canada is increasing and is currently at levels similar to those reported in other developed countries, there is still the potential in every province for further improvement.

Adrenergic beta-Antagonists↗
PubMed2005

Quality of care of international and Canadian medical graduates in acute myocardial infarction.

BACKGROUND: International medical graduates (IMGs) make up a substantial proportion of the physician workforce and play an important role in the care of patients with acute myocardial infarction (AMI). There are concerns that IMGs may provide inferior medical care compared with locally trained medical graduates, but that has not been established. METHODS: We performed a retrospective cohort study of linked administrative databases containing health care claims of physicians' service payments, hospital discharge abstracts, and patients' vital status. We included 127,275 AMI patients admitted between April 1, 1992, and March 31, 2000, to acute care hospitals in Ontario. We then compared the risk-adjusted mortality rates and adjusted use of secondary prevention medications and cardiac invasive procedures in patients treated by IMGs vs Canadian medical graduates. RESULTS: Of the 127,275 admitted AMI patients, 28,061 (22.0%) were treated by IMGs and 99,214 (78.0%) by Canadian medical graduates. The risk-adjusted mortality rates of IMG- and Canadian medical graduate-treated patients were not significantly different at 30 days (13.3% vs 13.4%, P = .57) and at 1 year (21.8% vs 21.9%, P = .63). Furthermore, AMI patients treated by both groups had similar adjusted likelihood of receiving secondary prevention medications at 90 days and cardiac invasive procedures at 1 year. CONCLUSIONS: The use of secondary prevention medications and cardiac procedures and the mortality of AMI patients were similar, regardless of the origin of medical education of the admitting physician. This information places the care provided by IMGs into perspective and supports the ability of well-selected IMGs in caring for AMI patients.

Adult↗
PubMed2005

Statin use and survival outcomes in elderly patients with heart failure.

BACKGROUND: Coronary artery disease is a leading cause of heart failure. Statins are efficacious drugs for the primary and secondary prevention of coronary heart disease, but their value in persons with heart failure remains unknown. METHODS: We performed a population-based retrospective cohort study involving the entire province of Ontario, Canada, restricting participants to those aged 66 to 85 years who were free of cancer and who survived at least 90 days following hospitalization for newly diagnosed heart failure. The primary study outcome was the risk of death from all causes, nonfatal acute myocardial infarction, or nonfatal stroke among persons newly dispensed statins (n = 1,146) relative to those who were not (n = 27,682). RESULTS: The mean age of all participants was 76.5 years, and half were women. During the 7-year study period, death, acute myocardial infarction, or stroke occurred in 217 statin recipients (13.6 per 100 person-years) vs 12,299 nonrecipients (21.8 per 100 person-years; adjusted hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.63-0.83). Most of the benefit from statins was related to a reduction in all-cause mortality (adjusted HR, 0.67; 95% CI, 0.57-0.78). No significant reduction was seen for subsequent myocardial infarction (adjusted HR, 0.81; 95% CI, 0.63-1.03) or stroke (adjusted HR, 0.81; 95% CI, 0.53-1.25). CONCLUSIONS: Statin use is associated with a lower risk of death among seniors newly diagnosed as having congestive heart failure. While statin use has been previously shown to be efficacious in patients with coronary heart disease and stroke, we could not control for all prognostic risk factors in the present study, including left ventricular ejection fraction and serum lipid levels. Better evidence can direct clinicians about which patients with heart failure might benefit from these drugs.

Aged↗
PubMed2005

Association between lipid testing and statin therapy in acute myocardial infarction patients.

BACKGROUND: Clinical guidelines recommend lipid testing in all hospitalized acute myocardial infarction (AMI) patients. Inhospital lipid testing has also been proposed as a quality indicator for AMI care, but little is known about its use or importance. We sought to examine rates of inhospital lipid testing and its association with statin therapy at hospital discharge. METHODS: We performed an analysis using medical chart abstraction data that included demographic and comprehensive clinical information for patients hospitalized in Ontario, Canada, with an AMI from 1999 to 2001. RESULTS: Among 11,468 patients, inhospital lipid testing was performed in 6,019 (52.5%) patients and in 4,169 (36.4%) patients within 24 hours of admission. Patients who had lipid testing were significantly more likely to be discharged on statin therapy compared with patients not tested (41.4% vs 23.0%, P < .001). In addition, inhospital lipid testing was strongly associated (odds ratio 3.61, 95% CI 3.15-4.14) with statin therapy prescription at hospital discharge after adjusting for other clinical, physician, and hospital factors. CONCLUSIONS: Despite endorsements from practice guidelines, less than half of all admitted AMI patients received lipid testing within 24 hours of hospital admission. Because inhospital lipid testing was strongly associated with the initiation of statin therapy at discharge, many opportunities to initiate statin therapy were lost. Efforts to increase the use of lipid testing in hospitalized AMI patients may translate into higher rates of lipid-lowering therapy and improved patient outcomes.

Aged↗
PubMed2005

Can the wrong statistic be bad for health? Improving the reporting of door-to-needle time performance in acute myocardial infarction.

BACKGROUND: Current acute myocardial infarction (AMI) guidelines call for reperfusion to be given to all eligible patients within a set time interval after hospital arrival, yet current hospital performance benchmarks are based on the median door-to-intervention time among treated patients. Our objective is to compare hospital performance rankings when door-to-needle time (DNT) is measured at the current benchmark (median < or = 30 minutes) versus those obtained with more stringent benchmarks common for other AMI treatments. METHODS: A secondary analysis of data from the EFFECT study from 52 small, community and teaching hospitals in Ontario. All Ontario hospital corporations that treated > or = 30 patients with AMI from 1999 to 2001 participated. The charts of approximately 125 patients with AMI per hospital were reviewed; median and 85th percentile DNTs were then calculated for patients with ST-elevation AMI given thrombolysis at each site along with the proportion of patients thrombolysed within the recommended time. Hospitals were then ranked according to each indicator. RESULTS: Data were obtained on 1,578 patients given thrombolytic drugs at 52 hospitals. The median and 85th percentile DNTs were 37 and 82 minutes, respectively; the proportion of patients treated in < or = 30 minutes ranged from 8.5% to 60%. Hospitals that achieved a median DNT of < or = 30 minutes treated 40% to 50% of their patients outside that time frame. The ranks of the top 15 median DNT hospitals changed substantially when re-ranked according to the 85th percentile (average change in rank -16, range +6 to -40). If DNT improved such that a 30-minute median target was achieved, the estimated reduction for the average patient would be 13 minutes versus a 43-minute reduction if the 85th percentile target was achieved. CONCLUSION: Hospitals that achieve a 30-minute median DNT benchmark still treat 40% to 50% of their patients outside the recommended time, which is not consistent with current AMI treatment guidelines. Door-to-needle time for the average patient would be up to 43 minutes faster if the DNT target was achieved at the 85th percentile.

Benchmarking↗
PubMed2005

Mitral repair versus replacement for ischemic mitral regurgitation.

BACKGROUND: We compared mitral repair to replacement in patients with chronic ischemic mitral regurgitation (IMR), due to left ventricular dysfunction (LV-IMR) or papillary muscle infarction (PM-IMR). METHODS: Patients with IMR undergoing repair (n = 65) or replacement (n = 137) from 1990 to 2001 were evaluated. There were 87 patients with LV-IMR, and 115 patients with PM-IMR. Patients presenting in cardiogenic shock were excluded. Outcomes were evaluated by Cox survival analysis with propensity score adjustment and bootstrap validation. RESULTS: Survival at 3, 5, and 9 years was, respectively, 0.94, 0.79, and 0.63 in the repair group, and 0.73, 0.67, and 0.59 in the replacement group. The hazard ratio (HR) of death for mitral repair versus replacement was not constant over the period of follow-up. Repair was associated with better early survival in the PM-IMR group, with an adjusted HR of 0.25 (95% confidence interval: 0.09 to 0.71) at 1 year. In the LV-IMR group and in patients with PM-IMR with high acuity and comorbidity, there was no significant survival advantage associated with repair. The beneficial effect of repair was not evident at late follow-up in either group. These findings were independent of the surgeon. Need for reoperation was more common after repair than after replacement (14% versus 3%, p = 0.003). CONCLUSIONS: Patients with PM-IMR benefit from mitral repair with a significantly better early survival. However, the benefit of repair is not evident at longer follow-up. There was a nonsignificant trend toward greater early survival among patients with LV-IMR who underwent repair.

Aged↗
PubMed2005

The identification and development of Canadian coronary artery bypass graft surgery quality indicators.

OBJECTIVE: The study objective was to develop quality indicators for coronary artery bypass graft surgery that relate to quality of care, associate with preventable death, and could be reported on performance reports. METHODS: A comprehensive list of quality indicators was collected from quality improvement organizations including the Society For Thoracic Surgery, Northern New England Cardiovascular Disease Study Group, and Veteran's Affairs System. Indicators were collated from practice guidelines from the American College of Cardiology and the American Heart Association. A MEDLINE search using the keywords "quality indicators" and "coronary bypass" was completed. A 17-member multidisciplinary international expert panel was assembled, who voted using a 2-step Delphi process regarding association with quality of care, risk adjustment, association with preventable death, and inclusion on performance reports. RESULTS: A total of 149 quality indicators were examined. This list was distilled to 33 indicators related to quality of care, 10 indicators that could be adequately risk adjusted, 34 indicators related to preventable death, and 18 indicators to be included on performance reports. These selected indicators consisted of 19 outcome variables, 23 process of care variables, and 4 structure variables. The quality indicators believed to be useful on a Canadian institutional coronary artery bypass graft surgery report card included the following: 30-day mortality, in-hospital mortality, electrocardiographic myocardial infarction, red cell transfusion, allogeneic blood product transfusion, deep sternal wound infection, postoperative stroke, postoperative dialysis, intensive care unit readmission, intensive care unit length of stay, ventilation time, repeat cardiac operation, repeat surgery with cardiopulmonary bypass, repeat revascularization, waiting time to surgery, completion of surgery within a recommended waiting time, use of left internal thoracic artery graft, and institutional volume. CONCLUSIONS: This set of consensus quality indicators can be used as a standard list to be monitored by providers of coronary artery bypass graft surgery in an effort to continuously evaluate and improve their performance.

Canada↗
PubMed2005

Comparison of coding of heart failure and comorbidities in administrative and clinical data for use in outcomes research.

BACKGROUND: Despite the potential usefulness of administrative databases for evaluating outcomes, coding of heart failure and associated comorbidities have not been definitively compared with clinical data. OBJECTIVE: To compare the predictive value of heart failure diagnoses and secondary conditions identified in a large administrative database with chart-based records. METHODS: The authors studied 1808 patient records sampled from 14 acute care hospitals and compared clinically recorded data with administrative records from the Canadian Institute for Health Information. The impact of comorbidity coding in the administrative data set according to the Charlson classification was examined in models of 30-day mortality. RESULTS: The positive predictive value (PPV) of a primary diagnosis ICD-9 428 was 94.3% using the Framingham criteria and 88.6% using criteria previously validated with pulmonary capillary wedge pressure. There was reduced prevalence of secondary comorbid conditions in administrative data in comparison with clinical chart data. The specificities and PPV/negative predictive values of administratively identified index comorbidities were high. The sensitivities of index comorbidities were low, but were enhanced by examination of hospitalizations within 1 year prior to the index heart failure admission. Using information from prior hospitalizations modestly enhanced 30-day mortality model performance; however, the odds ratio point estimates of the index and enhanced administrative data sets were consistent with the clinical model. CONCLUSION: The ICD-9 428 primary diagnosis is highly predictive of heart failure using clinical criteria. Examination of hospitalization data up to 1 year prior to the index admission improves comorbidity detection and may provide enhancements to future studies of heart failure mortality.

Aged↗
PubMed2005

The impact of under coding of cardiac severity and comorbid diseases on the accuracy of hospital report cards.

CONTEXT: Hospital report cards usually are based on administrative discharge abstracts. However, cardiac severity and comorbidities generally are under-reported in administrative data. OBJECTIVE: We sought to determine how undercoding of cardiac severity and comorbidities affects the determination that some hospitals are high-mortality outliers. DESIGN: Simulations using retrospective data on 18,795 patients admitted with an acute myocardial infarction (AMI) to 109 acute care hospitals in Ontario. MAIN OUTCOME MEASURE: Change in the number of hospitals that remained high-mortality outliers after adjusting for potentially increased prevalence of as many as 9 separate measures of cardiac severity and comorbid conditions, individually or together. RESULTS: For most measures of cardiac severity and comorbidities, increasing the prevalence of each factor to the highest observed hospital-specific prevalence seldom altered the status of high-mortality outlier hospitals. Increases in the prevalence of cardiogenic shock or acute renal failure to even the median level led to reclassification of up to 4 of the 12 high-mortality outlier hospitals to nonoutlier status. Most high-mortality outlier hospitals were reclassified if the maximum prevalence was imputed for these 2 factors. Simultaneously increasing the prevalence of all comorbidities to the median level typically converted the status of about half the outlier hospitals. Not until the prevalence of all measures of cardiac severity and comorbidities were simultaneously increased to the maximum observed hospital-specific prevalence, did all hospitals initially classified as high-mortality outliers revert to nonoutlier status. CONCLUSIONS: Undercoding of severity and comorbidities in administrative data in itself is very unlikely to account for the outlier status of most hospitals. However, some potential for misclassification of individual institutions exists if influential factors are variably coded.

Comorbidity↗