A comparison of administrative versus clinical data: coronary artery bypass surgery as an example. Ischemic Heart Disease Patient Outcomes Research Team

The impact of comorbidities on outcomes of concomitant mitral valve intervention with ascending aortic surgery

INTRODUCTION

The Charlson Comorbidity Index (CCI) is widely utilized for risk stratification for non-cardiac surgical patients, yet it has not been broadly validated in patients undergoing cardiac surgery. We aim to assess its ability to predict early and late outcomes of concomitant mitral valve intervention with ascending aortic surgery.

METHODS

Patients who underwent surgery between 1997 and 2022 were reviewed. Age-adjusted CCI scores were calculated based on clinical status at a time of index operation. The primary endpoint was all causes mortality while secondary outcomes were major adverse events (MAE) that included combined perioperative mortality, dialysis, myocardial infarction, and stroke in addition to the individual outcomes and take back for bleeding and tracheostomy. Chi-square test, Logistic and Cox regression analysis, and Kaplan-Meier curves were used. Maximally selected rank statistics were used to identify best cutoff of CCI for late mortality.

RESULTS

186 patients (median age 65 [interquartile range (IQR): 54-76] and 69% males) were included with a median CCI of 4 [IQR: 3-6]. Five and ten-years overall survival were 95.9% and 67.1% vs 59.7%, and 19.9% in CCI ≤ 5 vs >5 (P < 0.001). On multivariate Cox regression analysis, higher CCI (HR 1.60 [1.17;2.18], P = 0.00), and lower EF (HR 0.89 [0.83;0.96], P = 0.002) were associated with late mortality. There was a trend to lower mortality in recent surgery years (HR 0.91 [0.83;1.01], P = 0.070)). Perioperative MAE was higher in CCI >5 (11.0% vs 2.1%, P = 0.017), and postoperative need for tracheostomy and CVA had a trend to be higher in CCI > 5 (P = 0.055). Logistic regression revealed that higher CCI, as a continuous variable, was associated with significantly higher odds of MAE, postoperative dialysis, and need for tracheostomy.

CONCLUSIONS

The CCI can be a helpful tool in predicting outcomes of patients undergoing concomitant mitral valve intervention with ascending aortic surgery.

The relationship of hospital and surgeon volume indicators and post-operative outcomes in pancreatic surgery: a systematic literature review, meta-analysis and guidance for valid outcome assessment

BACKGROUND

Available evidence on the volume-outcome relationship after pancreatic surgery is limited due to the narrow focus of interventions, volume indicators and outcomes considered as well as due to methodological differences of the included studies. Therefore, we aim to evaluate the volume-outcome relationship following pancreatic surgery following strict study selection and quality criteria, to identify aspects of methodological variation and to define a set of key methodological indicators to consider when aiming for comparable and valid outcome assessment.

METHODS

Four electronic databases were searched to identify studies on the volume-outcome relationship in pancreatic surgery published between the years 2000-2018. Following a double-screening process, data extraction, quality appraisal, and subgroup analysis, results of included studies were stratified and pooled using random effects meta-analysis.

RESULTS

Consistent associations were found between high hospital volume and both postoperative mortality (OR 0.35, 95% CI: 0.29-0.44) and major complications (OR 0.87, 95% CI: 0.80-0.94). A significant decrease in the odds ratio was also found for high surgeon volume and postoperative mortality (OR 0.29, 95%CI: 0.22-0.37).

DISCUSSION

Our meta-analysis confirms a positive effect for both hospital and surgeon volume indicators for pancreatic surgery. Further harmonization (e.g. surgery types, volume cut-offs/definition, case-mix adjustment, reported outcomes) are recommended for future empirical studies.

Incidence and management patterns of alcohol-related liver disease in Korea: a nationwide standard cohort study

The recent incidence and management patterns of alcohol-related liver disease (ARLD) are not well defined in Korea. We sought to evaluate the epidemiology of ARLD with regard to disease severity and alcohol cessation management after diagnosis. We performed an observational cohort study of standardized Common Data Model data from the Health Insurance Review and Assessment-National Patient Samples database between 2012 and 2016. The incidence and demographic properties of ARLD were extracted and divided into non-cirrhotic alcoholic liver disease (ALD) and alcoholic liver cirrhosis (ALC). ALC was compared with non-alcoholic cirrhosis by severity at diagnosis. The management patterns were captured by the initiation of pharmaco- and behavioral therapy for alcohol cessation. We analyzed data from 72,556 ALD to 7295 ALC patients. The ALD incidence was stable from 990 to 1025 per 100,000 people. In ALD, the proportion of patients who were ≥ 65 years old, the proportion of female patients, and the comorbidity index increased significantly during the study period (all P values < 0.001). ALC accounted for > 20% of all cirrhosis, with decompensation occurring twice as often as in non-alcoholic cirrhosis. The initiation of alcoholism management was stationary in ARLD, remaining at < 10% for both pharmacotherapy and behavioral therapy, regardless of severity or the site of diagnosis. The incidence of ARLD did not decrease during the study period. Moreover, an increasing trend in the proportion of people vulnerable to drinking was observed. Unfortunately, management for the cessation of alcohol use remains very low. The best way to manage ARLD should be evaluated in further study.

(Dis)concordance of comorbidity data and cancer status across administrative datasets, medical charts, and self-reports

BACKGROUND

Benchmarking outcomes across settings commonly requires risk-adjustment for co-morbidities that must be derived from extant sources that were designed for other purposes. A question arises as to the extent to which differing available sources for health data will be concordant when inferring the type and severity of co-morbidities, how close are these to the "truth". We studied the level of concordance for same-patient comorbidity data extracted from administrative data (coded from International Classification of Diseases, Australian modification,10th edition [ICD-10 AM]), from the medical chart audit, and data self-reported by men with prostate cancer who had undergone a radical prostatectomy.

METHODS

We included six hospitals (5 public and 1 private) contributing to the Prostate Cancer Outcomes Registry-Victoria (PCOR-Vic) in the study. Eligible patients from the PCOR-Vic underwent a radical prostatectomy between January 2017 and April 2018.Health Information Manager's in each hospital, provided each patient's associated administrative ICD-10 AM comorbidity codes. Medical charts were reviewed to extract comorbidity data. The self-reported comorbidity questionnaire (SCQ) was distributed through PCOR-Vic to eligible men.

RESULTS

The percentage agreement between the administrative data, medical charts and self-reports ranged from 92 to 99% in the 122 patients from the 217 eligible participants who responded to the questionnaire. The presence of comorbidities showed a poor level of agreement between data sources.

CONCLUSION

Relying on a single data source to generate comorbidity indices for risk-modelling purposes may fail to capture the reality of a patient's disease profile. There does not appear to be a 'gold-standard' data source for the collection of data on comorbidities.

Morbidity Measures Predicting Mortality in Inpatients: A Systematic Review

OBJECTIVES

Morbidity is an important risk factor for mortality and a variety of morbidity measures have been developed to predict patients' health outcomes. The objective of this systematic review was to compare the capacity of morbidity measures in predicting mortality among inpatients admitted to internal medicine, geriatric, or all hospital wards.

DESIGN

A systematic literature search was conducted from inception to March 6, 2019 using 4 databases: Medline, Embase, Cochrane, and CINAHL. Articles were included if morbidity measures were used to predict mortality (registration CRD42019126674).

SETTING AND PARTICIPANTS

Inpatients with a mean or median age ≥65 years.

MEASUREMENTS

Morbidity measures predicting mortality.

RESULTS

Of the 12,800 articles retrieved from the databases, a total of 34 articles were included reporting on inpatients admitted to internal medicine, geriatric, or all hospital wards. The Charlson Comorbidity Index (CCI) was reported most frequently and a higher CCI score was associated with greater mortality risk, primarily at longer follow-up periods. Articles comparing morbidity measures revealed that the Geriatric Index of Comorbidity was better predicting mortality risk than the CCI, Cumulative Illness Rating Scale, Index of Coexistent Disease, and disease count.

CONCLUSIONS AND IMPLICATIONS

Higher morbidity measure scores are better in predicting mortality at longer follow-up period. The Geriatric Index of Comorbidity was best in predicting mortality and should be used more often in clinical practice to assist clinical decision making.

Feasibility analysis of conducting observational studies with the electronic health record

Background

The secondary use of electronic health records (EHRs) promises to facilitate medical research. We reviewed general data requirements in observational studies and analyzed the feasibility of conducting observational studies with structured EHR data, in particular diagnosis and procedure codes.

Methods

After reviewing published observational studies from the University Hospital of Erlangen for general data requirements, we identified three different study populations for the feasibility analysis with eligibility criteria from three exemplary observational studies. For each study population, we evaluated the availability of relevant patient characteristics in our EHR, including outcome and exposure variables. To assess data quality, we computed distributions of relevant patient characteristics from the available structured EHR data and compared them to those of the original studies. We implemented computed phenotypes for patient characteristics where necessary. In random samples, we evaluated how well structured patient characteristics agreed with a gold standard from manually interpreted free texts. We categorized our findings using the four data quality dimensions “completeness”, “correctness”, “currency” and “granularity”.

Results

Reviewing general data requirements, we found that some investigators supplement routine data with questionnaires, interviews and follow-up examinations. We included 847 subjects in the feasibility analysis (Study 1 n = 411, Study 2 n = 423, Study 3 n = 13). All eligibility criteria from two studies were available in structured data, while one study required computed phenotypes in eligibility criteria. In one study, we found that all necessary patient characteristics were documented at least once in either structured or unstructured data. In another study, all exposure and outcome variables were available in structured data, while in the other one unstructured data had to be consulted. The comparison of patient characteristics distributions, as computed from structured data, with those from the original study yielded similar distributions as well as indications of underreporting. We observed violations in all four data quality dimensions.

Conclusions

While we found relevant patient characteristics available in structured EHR data, data quality problems may entail that it remains a case-by-case decision whether diagnosis and procedure codes are sufficient to underpin observational studies. Free-text data or subsequently supplementary study data may be important to complement a comprehensive patient history.

The Impact of Body Mass Index (BMI) on 30-day Outcomes Following Posterior Spinal Fusion in Neuromuscular Scoliosis

STUDY DESIGN

Retrospective.

OBJECTIVE

Assess the impact of varying severity of BMI on 30-day outcomes following posterior spinal fusions in neuromuscular scoliosis.

SUMMARY OF BACKGROUND DATA

Obesity in the pediatric population is shown to be associated with adverse outcomes across varying specialties. The weight-outcome relationship in neuromuscular scoliosis has not been thoroughly investigated.

METHODS

The 2012-2016 American College of Surgeons - National Surgical Quality Improvement (ACS-NSQIP) database was queried using Current Procedural Terminology codes 22800, 22802, and 22804 to identify patients undergoing posterior spinal fusion for neuromuscular scoliosis only. BMI was classified into four groups based on the Center for Disease Control (CDC) BMI-for-age percentile chart - Normal weight (BMI ≥5th to <85th percentile), Underweight (<5th percentile), Overweight (≥85th to <95th percentile) and Obese (≥95th percentile). Multivariate regression models were built to understand the impact of varying BMI severity classes on 30-day outcomes.

RESULTS

A total of 1291 patients underwent posterior spinal fusion for neuromuscular scoliosis. A total of 695 (53.8%) were normal weight, 286 (22.2%) were underweight, 145 (11.2%) were overweight, and 165 (12.8%) were obese. Obese patients versus normal weight patients were at a significantly higher risk of surgical site infections (OR 2.15; P = 0.035), wound dehiscence (OR 1.58; P = 0.037), urinary tract infections (OR 3.41; P = 0.010), and 30-day readmissions (OR 1.94; P = 0.029). Of note, overweight versus normal weight individuals had higher odds of cardiopulmonary complications (OR 8.82; P = 0.024). No significant associations were seen for varying BMI and other 30-day outcomes.

CONCLUSIONS

Obese neuromuscular patients undergoing PSF have higher odds of experiencing adverse outcomes, particularly surgical site infections, urinary tract infections, and readmissions. Providers should promote prevention strategies, such as dietary modification and/or early physical activity in these high-risk patients to minimize the risks of experiencing complications in the acute postoperative period.

LEVEL OF EVIDENCE

3.

Reliability of comorbidity scores derived from administrative data in the tertiary hospital intensive care setting: a cross-sectional study

Background

Hospital reporting systems commonly use administrative data to calculate comorbidity scores in order to provide risk-adjustment to outcome indicators.

Objective

We aimed to elucidate the level of agreement between administrative coding data and medical chart review for extraction of comorbidities included in the Charlson Comorbidity Index (CCI) and Elixhauser Index (EI) for patients admitted to the intensive care unit of a university-affiliated hospital.

Method

We conducted an examination of a random cross-section of 100 patient episodes over 12 months (July 2012 to June 2013) for the 19 CCI and 30 EI comorbidities reported in administrative data and the manual medical record system. CCI and EI comorbidities were collected in order to ascertain the difference in mean indices, detect any systematic bias, and ascertain inter-rater agreement.

Results

We found reasonable inter-rater agreement (kappa (κ) coefficient ≥0.4) for cardiorespiratory and oncological comorbidities, but little agreement (κ<0.4) for other comorbidities. Comorbidity indices derived from administrative data were significantly lower than from chart review: −0.81 (95% CI − 1.29 to − 0.33; p=0.001) for CCI, and −2.57 (95% CI −4.46 to −0.68; p=0.008) for EI.

Conclusion

While cardiorespiratory and oncological comorbidities were reliably coded in administrative data, most other comorbidities were under-reported and an unreliable source for estimation of CCI or EI in intensive care patients. Further examination of a large multicentre population is required to confirm our findings.

Importance of coding co-morbidities for APR-DRG assignment: Focus on cardiovascular and respiratory diseases

BACKGROUND

The All Patient-Refined Diagnosis-Related Groups (APR-DRGs) system has adjusted the basic DRG structure by incorporating four severity of illness (SOI) levels, which are used for determining hospital payment. A comprehensive report of all relevant diagnoses, namely the patient's underlying co-morbidities, is a key factor for ensuring that SOI determination will be adequate.

OBJECTIVE

In this study, we aimed to characterise the individual impact of co-morbidities on APR-DRG classification and hospital funding in the context of respiratory and cardiovascular diseases.

METHODS

Using 6 years of coded clinical data from a nationwide Portuguese inpatient database and support vector machine (SVM) models, we simulated and explored the APR-DRG classification to understand its response to individual removal of Charlson and Elixhauser co-morbidities. We also estimated the amount of hospital payments that could have been lost when co-morbidities are under-reported.

RESULTS

In our scenario, most Charlson and Elixhauser co-morbidities did considerably influence SOI determination but had little impact on base APR-DRG assignment. The degree of influence of each co-morbidity on SOI was, however, quite specific to the base APR-DRG. Under-coding of all studied co-morbidities led to losses in hospital payments. Furthermore, our results based on the SVM models were consistent with overall APR-DRG grouping logics.

CONCLUSION AND IMPLICATIONS

Comprehensive reporting of pre-existing or newly acquired co-morbidities should be encouraged in hospitals as they have an important influence on SOI assignment and thus on hospital funding. Furthermore, we recommend that future guidelines to be used by medical coders should include specific rules concerning coding of co-morbidities.

Mind the gap: observation windows to define periods of event ascertainment as a quality control method for longitudinal electronic health record data

PURPOSE

Use of electronic health records (EHRs) in health research may lead to the false assumption of complete event ascertainment. We estimated "observation windows" (OWs), defined as periods within which the assumption of complete ascertainment of events is more likely to hold, as a quality control approach to reducing the likelihood of this false assumption. We demonstrated the impact of OWs on estimating the rates of type II diabetes mellitus (diabetes) from HIV clinical cohorts.

METHODS

Data contributed by 16 HIV clinical cohorts to the NA-ACCORD were used to identify and evaluate OWs for an operationalized definition of diabetes occurrence as a case study. Procedures included (1) gathering cohort-level data; (2) visualizing and summarizing gaps in observations; (3) systematically establishing start and stop dates during which the assumption of complete ascertainment of diabetes events was reasonable; and (4) visualizing the diabetes OWs relative to the cohort open and close dates to identify immortal person-time. We estimated diabetes occurrence event rates and 95% confidence intervals in the most recent decade that data were available (January 1, 2007, to December 31, 2016).

RESULTS

The number of diabetes events decreased by 17% with the use of the diabetes OWs; immortal person-time was removed decreasing total person-years by 23%. Consequently, the diabetes rate increased from 1.23 (95% confidence interval [1.20, 1.25]) per 100 person-years to 1.32 [1.29, 1.35] per 100 person-years with the use of diabetes OWs.

CONCLUSIONS

As the use of EHR-curated data for event-driven health research continues to expand, OWs have utility as a quality control approach to complete event ascertainment, helping to improve accuracy of estimates by removing immortal person-time when ascertainment is incomplete.

Developing and Testing a Chart Abstraction Tool for ICU Quality Measurement

Quality measures are increasingly used to measure the performance of providers, hospitals, and health care systems. Intensive care units (ICUs) are an important clinical area in hospitals, given that they generate high costs and present high risks to patients. Yet, currently, few valid and clinically significant ICU-specific outcome measures are reported nationally. This study reports on the creation and evaluation of new abstraction tools that evaluate ICU patients for the following clinically important outcomes: central line-associated bloodstream infection, methicillin-resistant Staphylococcus aureus, gastrointestinal bleed, and pressure ulcer. To allow ICUs and institutions to compare their outcomes, the tools include risk-adjustment variables that can be abstracted from the chart.

Racial and Ethnic Variability in the Prevalence and Incidence of Comorbidities Associated with Gastric Cancer in the United States

PURPOSE

Comorbidities are known to impact quality of life, treatment choices, and survival. Our objectives were to characterize comorbid conditions in a cohort of elderly gastric cancer patients and to determine if there is variability in the prevalence or incidence of the comorbid conditions across racial/ethnic groups.

METHODS

A total of 12,612 individuals, ≥66 years of age, diagnosed with gastric cancer between 2000 and 2007, and an equal number of gender- and region-matched cancer-free individuals, were identified using the National Cancer Institute's Surveillance, Epidemiology, and End Results registry linked to Medicare claims in the United States. The prevalence (%) in the year before diagnosis and the 12-month incidence rates after diagnosis were estimated for 32 chronic and ten acute comorbid conditions for the entire cohort and by race/ethnicity (Asian, Black, Hispanic, White, and other) and Asian subgroups (e.g., Chinese, Filipino, Japanese, Pacific Islander).

RESULTS

White and Black cases exhibited the highest prevalence of most comorbid conditions. Asian and Pacific Islander cases exhibited the lowest. There was substantial variability in the 12-month incidence of the comorbidities across the racial/ethnic groups. Electrolyte disorder was the most common incident condition among Whites and Blacks. With the exception of Whites, anemia was the most common incident condition in all racial and ethnic groups 180 days following chemotherapy.

CONCLUSIONS

There is variability in the prevalence and incidence in comorbidities across racial/ethnic groups.

Opportunities and Challenges for Measuring Cost, Quality, and Clinical Effectiveness in Health Care

Empirical studies of health care cost, productivity, and output have focused primarily on intermediate goods and services. Consumers are ultimately interested in final goods such as improved health or health-related quality of life, but health services research continues to address whether health services financing and delivery are structured in ways to maximize production of intermediate goods, regardless of the link between these services and final outcomes. Increasing rates of growth of health care cost and dissatisfaction with the quality of U.S. health care force us to reexamine how productivity and cost are analyzed so that research properly informs policy and practice. The authors examine recent changes in the U.S. health care sector that suggest the need to revise how health services research approaches analyses of cost, production, and output; consider alternative notions of final goods; and review the availability and quality of data necessary to conduct this research.

Chronic health conditions in Medicare beneficiaries 65 years old, and older with HIV infection

OBJECTIVES

To examine sociodemographic factors and chronic health conditions of people living with HIV (PLWHIV/HIV+) at least 65 years old and compare their chronic disease prevalence with beneficiaries without HIV.

DESIGN

National fee-for-service Medicare claims data (parts A and B) from 2006 to 2009 were used to create a retrospective cohort of beneficiaries at least 65 years old.

METHODS

Beneficiaries with an inpatient or skilled nursing facility claim, or outpatient claims with HIV diagnosis codes were considered HIV+. HIV+ beneficiaries were compared with uninfected beneficiaries on demographic factors and on the prevalence of hypertension, hyperlipidemia, ischemic heart disease, rheumatoid arthritis/osteoarthritis, and diabetes. Odds ratios (OR), 95% confidence intervals (CIs), and P values were calculated. Adjustment variables included age, sex, race/ethnicity, end stage renal disease (ESRD), and dual Medicare-Medicaid enrollment. Chronic conditions were examined individually and as an index from zero to all five conditions.

RESULTS

Of 29 060 418 eligible beneficiaries, 24 735 (0.09%) were HIV+. HIV+ beneficiaries were more likely to be Hispanic, African-American, male, and younger (P > 0.0001) and were 1.5-2.1 times as likely to have a chronic disease [diabetes (adjusted OR) 1.51, 95% CI (1.47, 1.55): rheumatoid arthritis/osteoarthritis 2.14, 95% CI (2.08, 2.19)], and 2.4-7 times as likely to have 1-5 comorbid chronic conditions [1 condition (adjusted OR) 2.38, 95% CI (2.21, 2.57): 5 conditions 7.07, 95% CI (6.61, 7.56)].

CONCLUSION

Our results show that PLWHIV at least 65 years old are at higher risk of comorbidities than other fee-for-service Medicare beneficiaries. This finding has implications for the cost and health management of PLWHIV 65 years and older.

-Omic and Electronic Health Record Big Data Analytics for Precision Medicine

OBJECTIVE

Rapid advances of high-throughput technologies and wide adoption of electronic health records (EHRs) have led to fast accumulation of -omic and EHR data. These voluminous complex data contain abundant information for precision medicine, and big data analytics can extract such knowledge to improve the quality of healthcare.

METHODS

In this paper, we present -omic and EHR data characteristics, associated challenges, and data analytics including data preprocessing, mining, and modeling.

RESULTS

To demonstrate how big data analytics enables precision medicine, we provide two case studies, including identifying disease biomarkers from multi-omic data and incorporating -omic information into EHR.

CONCLUSION

Big data analytics is able to address -omic and EHR data challenges for paradigm shift toward precision medicine.

SIGNIFICANCE

Big data analytics makes sense of -omic and EHR data to improve healthcare outcome. It has long lasting societal impact.

Evaluating the Quality of Sexual Health Care Provided to Adolescents in Medicaid Managed Care: A Comparison of Two Data Sources

This study compares 2 data sources to evaluate the quality of sexual health care provided to adolescents in Medicaid managed care: (a) Medicaid encounter data and (b) medical record data. Data from 1998 for 1112 adolescent enrollees came from 3 Seattle-area managed care organizations (MCOs): a group model health maintenance organization, an independent practice association, and a clinic network. Quality of care was tracked by estimating within-MCO chlamydia testing rates for sexually active female enrollees. Rates varied dramatically depending on which data source was used. Logistic regression models indicated substantially less difference between MCOs when analysis was based on data from the 2 sources combined than when based on either data source alone. Study results did not support the use of Medicaid encounter data as a sole data source for evaluating quality of adolescent sexual health care, despite the cost savings this would represent. However, encounter data, used as an adjunct to medical record review, may increase the reliability of quality evaluations.

Pharmacosurveillance without borders: electronic health records in different countries can be used to address important methodological issues in estimating the risk of adverse events

OBJECTIVES

Evaluate methodological advantages and limitations of an international pharmacosurveillance system based on electronic health records (EHRs).

STUDY DESIGN AND SETTINGS

Type 2 diabetes was used as an exemplar. Cohorts of newly treated diabetics were followed in each country (Quebec, Canada; Massachusetts, United States; Manchester, UK) from 2009 to 2012 using local EHR systems. Cox proportional hazards models were used to assess the risk of cardiovascular events.

RESULTS

A total of 44,913 newly treated diabetics were identified; 82.6% (United States) to 93.1% (Canada) were started on biguanides; 13% of patients failed to fill initial prescriptions. An increased risk of cardiovascular events with sulfonylureas was observed when dispensing [hazard ratio (HR): 2.83] vs. EHR prescribing (HR: 2.47) data were used. The addition of clinical data produced a threefold to 10-fold increase in comorbidity for obesity and renal disease, but had no impact on the risk of different hypoglycemic therapies. The risk of cardiovascular events with sulfonylureas was higher in the United States [HR: 3.4; 95% confidence interval (CI): 2.1, 5.5] compared to England (HR: 1.3; 95% CI: 1.1, 1.6).

CONCLUSION

An international surveillance system based on EHRs may provide more timely information about drug safety and new opportunities to estimate potential sources of bias and health system effects on drug-related outcomes.

The relationship between the number of cardiologists and clinical practice patterns in acute heart failure: a cross-sectional observational study

OBJECTIVES

Despite the increasing burden of acute heart failure (AHF) on healthcare systems, the association between centralised cardiovascular specialist care and the quality of AHF care remains unknown. We examine the relationship between the number of cardiologists per hospital and hospital practice variations.

DESIGN, SETTING AND PARTICIPANTS

In a retrospective observational study, we analysed 38,668 patients with AHF admitted to 546 Japanese acute care hospitals between 2010 and 2011 using the Diagnosis Procedure Combination administrative claims database. Sample hospitals were categorised into four groups according to the number of cardiologists per facility (none, 1-4, 5-9 and ≥10). To confirm the capability of administrative data to identify patients with AHF, the ≥10 cardiologists group was compared with two recent clinical registries in Japan.

MAIN OUTCOME MEASURES

Using multivariable logistic regression models, patient risk-adjusted in-hospital mortality rates and age-sex-adjusted ORs of various AHF therapies were calculated and compared among four hospital groups.

RESULTS

The ≥10 cardiologists group of hospitals from the administrative database had similar major underlying disease incidence and therapeutic practices to those of the clinical registry hospitals. Age-adjusted and sex-adjusted ORs of various AHF therapies in the four hospital groups revealed wide practice variations associated with the number of cardiologists. Adjusted in-hospital mortality demonstrated a negative association with the number of cardiologists. In addition, the different hospital-level distribution patterns of specific therapeutic practices illustrated the diffusion process of therapies across facilities.

CONCLUSIONS

Wide practice variations in AHF care were associated with the number of cardiologists per facility, indicating a possible relationship between the quality of AHF care and manpower resources. The provision of recommended therapies increased together with the number of cardiologists.

Field methods in medical record abstraction: assessing the properties of comparative effectiveness estimates

BACKGROUND

Comparative effectiveness studies using Medicare claims data are vulnerable to treatment selection biases and supplemental data from a sample of patients has been recommended for examining the magnitude of this bias. Previous research using nationwide Medicare claims data has typically relied on the Medicare Current Beneficiary Survey (MCBS) for supplemental data. Because many important clinical variables for our specific research question are not available in the MCBS, we collected medical record data from a subsample of patients to assess the validity of assumptions and to aid in the interpretation of our estimates. This paper seeks to describe and document the process used to collect and validate this supplemental information.

METHODS

Medicare claims data files for all patients with fee-for-service Medicare benefits who had an acute myocardial infarction (AMI) in 2007 or 2008 were obtained. Medical records were obtained and abstracted for a stratified subsample of 1,601 of these patients, using strata defined by claims-based measures of physician prescribing practices and drug treatment combinations. The abstraction tool was developed collaboratively by study clinicians and researchers, leveraging important elements from previously validated tools.

RESULTS

Records for 2,707 AMI patients were requested from the admitting hospitals and 1,751 were received for an overall response rate of 65%; 1,601 cases were abstracted by trained personnel at a contracted firm. Data were collected with overall 96% inter-abstractor agreement across all variables. Some non-response bias was detected at the patient and facility level.

CONCLUSION

Although Medicare claims data are a potentially powerful resource for conducting comparative effectiveness analyses, observational databases are vulnerable to treatment selection biases. This study demonstrates that it is feasible to abstract medical records for Medicare patients nationwide and collect high quality data, to design the sampling purposively to address specific research questions, and to more thoroughly evaluate the appropriateness of care delivered to AMI patients.

Comparative inpatient resource utilization for patients undergoing endoscopic or microscopic transsphenoidal surgery for pituitary lesions

Object

An increasingly important measure in the health care field is utilization of hospital resources, particularly in the context of emerging surgical techniques. Despite the recent widespread adoption of the endoscopic transsphenoidal approach for pituitary lesion surgery, the health care resources utilized with this approach have not been compared with those utilized with the traditional microscopic approach. The purpose of this study was to determine the drivers of resource utilization by comparing hospital charges for patients with pituitary tumors who had undergone either endoscopic or microscopic transsphenoidal surgery.

Methods

A complete accounting of all hospital charges for 166 patients prospectively enrolled in a surgical quality-of-life study at a single pituitary center during October 2011–June 2013 was undertaken. Patients were assigned to surgical technique group according to surgeon preference and then managed according to a standard postoperative institutional set of orders. Individual line-item charges were assigned to categories (such as pharmacy, imaging, surgical, laboratory, room, pathology, and recovery unit), and univariate and multivariate statistical analyses were conducted.

Results

Of the 166 patients, 99 underwent microscopic surgery and 67 underwent endoscopic surgery. Baseline demographic descriptors and tumor characteristics did not differ significantly. Mean total hospital charges were $74,703 ± $15,142 and $72,311 ± $16,576 for microscopic and endoscopic surgery patients, respectively (p = 0.33). Furthermore, other than for pathology, charge categories did not differ significantly between groups. A 2-step multivariate regression model revealed that length of stay was the most influential variable, followed by a diagnosis of Cushing's disease, and then by endoscopic surgical technique. The model accounts for 42% of the variance in hospital charges.

Conclusions

Study findings suggest that adoption of the endoscopic transsphenoidal technique for pituitary lesions does not adversely affect utilization of resources for inpatients. The primary drivers of hospital charges, in order of importance, were length of stay, a diagnosis of Cushing's disease, and, to a lesser extent, use of the endoscopic technique. This study also highlights the influence of individual surgeon practice patterns on resource utilization.

Would screening for lung cancer benefit 75- to 84-year-old residents of the United States?

Background: The National Lung Screening Trial demonstrated that screening for lung cancer improved overall survival (OS) and reduced lung cancer mortality in the 55- to 74-year-old age group by increasing the proportion of cancers detected at an early stage. Because of the increasing life expectancy of the American population, we investigated whether screening for lung cancer might benefit men and women aged 75–84 years.

Materials/Methods: Rates of non-small cell lung cancer (NSCLC) from 2000 to 2009 were calculated in both younger and older age groups using the surveillance epidemiology and end reporting database. OS and lung cancer-specific survival (LCSS) in patients with Stage I NSCLC diagnosed from 2004 to 2009 were analyzed to determine the effects of age and treatment.

Results: The per capita incidence of NSCLC decreased in the 55–74 cohort, but increased in the 75–84 cohort over the study period. Crude lung cancer death rates in the two age groups who had no specific treatment were 39.5 and 44.9%, respectively. These rates fell in both age groups when increasingly aggressive treatment was used. Rates of OS and LCSS improved significantly with increasingly aggressive treatment in the 75–84 age group. The survival benefits of increasingly aggressive treatment in 75- to 84-year-old females did not differ from their counterparts in the younger cohort.

Conclusion: Screening for lung cancer might be of benefit to individuals at increased risk of lung cancer in the 75–84 age group. The survival benefits of aggressive therapy are similar in females between 55–74 and 75–84 years old.

Undiagnosed diabetes in breast, colorectal, lung, and prostate cancer: incidence and risk factors

Our study describes the incidence and risk factors for undiagnosed diabetes in elderly cancer patients. Using Surveillance, Epidemiology, and End Results-Medicare data, we followed patients with breast, colorectal, lung, or prostate cancer from 24 months before to 3 months after cancer diagnosis. Medicare claims were used to exclude patients with diabetes 24 to 4 months before cancer (look-back period), identify those with diabetes undiagnosed until cancer, and construct indicators of preventive services, physician contact, and comorbidity during the look-back period. Logistic regression analyses were performed to identify factors associated with undiagnosed diabetes. Overall, 2,678 patients had diabetes undiagnosed until cancer. Rates were the highest in patients with both advanced-stage cancer and low prior primary care/medical specialist contact (breast 8.2%, colorectal 5.9%, lung 4.4%). Nonwhite race/ethnicity, living in a census tract with a higher percent of the population in poverty and a lower percent college educated, lower prior preventive services use, and lack of primary care and/or medical specialist care prior to cancer all were associated with higher (P ≤ 0.05) adjusted odds of undiagnosed diabetes. Undiagnosed diabetes is relatively common in selected subgroups of cancer patients, including those already at high risk of poor outcomes due to advanced cancer stage.

Deriving comorbidities from medical records using natural language processing

Extracting comorbidity information is crucial for phenotypic studies because of the confounding effect of comorbidities. We developed an automated method that accurately determines comorbidities from electronic medical records. Using a modified version of the Charlson comorbidity index (CCI), two physicians created a reference standard of comorbidities by manual review of 100 admission notes. We processed the notes using the MedLEE natural language processing system, and wrote queries to extract comorbidities automatically from its structured output. Interrater agreement for the reference set was very high (97.7%). Our method yielded an F1 score of 0.761 and the summed CCI score was not different from the reference standard (p=0.329, power 80.4%). In comparison, obtaining comorbidities from claims data yielded an F1 score of 0.741, due to lower sensitivity (66.1%). Because CCI has previously been validated as a predictor of mortality and readmission, our method could allow automated prediction of these outcomes.

Electronic medical record: research tool for pancreatic cancer?

BACKGROUND

A novel data warehouse based on automated retrieval from an institutional health care information system (HIS) was made available to be compared with a traditional prospectively maintained surgical database.

METHODS

A newly established institutional data warehouse at a single-institution academic medical center autopopulated by HIS was queried for International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis codes for pancreatic neoplasm. Patients with ICD-9-CM diagnosis codes for pancreatic neoplasm were captured. A parallel query was performed using a prospective database populated by manual entry. Duplicated patients and those unique to either data set were identified. All patients were manually reviewed to determine the accuracy of diagnosis.

RESULTS

A total of 1107 patients were identified from the HIS-linked data set with pancreatic neoplasm from 1999-2009. Of these, 254 (22.9%) patients were also captured by the surgical database, whereas 853 (77.1%) patients were only in the HIS-linked data set. Manual review of the HIS-only group demonstrated that 45.0% of patients were without identifiable pancreatic pathology, suggesting erroneous capture, whereas 36.3% of patients were consistent with pancreatic neoplasm and 18.7% with other pancreatic pathology. Of the 394 patients identified by the surgical database, 254 (64.5%) patients were captured by HIS, whereas 140 (35.5%) patients were not. Manual review of patients only captured by the surgical database demonstrated 85.9% with pancreatic neoplasm and 14.1% with other pancreatic pathology. Finally, review of the 254 patient overlap demonstrated that 80.3% of patients had pancreatic neoplasm and 19.7% had other pancreatic pathology.

CONCLUSIONS

These results suggest that cautious interpretation of administrative data rely only on ICD-9-CM diagnosis codes and clinical correlation through previously validated mechanisms.

Predictors of resource utilization in transsphenoidal surgery for Cushing disease

Object

The short-term cost associated with subspecialized surgical care is an increasingly important metric and economic concern. This study sought to determine factors associated with hospital charges in patients undergoing transsphenoidal surgery for Cushing disease in an effort to identify the drivers of resource utilization.

Methods

The authors analyzed the Nationwide Inpatient Sample (NIS) hospital discharge database from 2007 to 2009 to determine factors that influenced hospital charges in patients who had undergone transsphenoidal surgery for Cushing disease. The NIS discharge database approximates a 20% sample of all inpatient admissions to nonfederal US hospitals. A multistep regression model was developed that adjusted for patient demographics, acuity measures, comorbidities, hospital characteristics, and complications.

Results

In 116 hospitals, 454 transsphenoidal operations were performed. The mean hospital charge was $48,272 ± $32,060. A multivariate regression model suggested that the primary driver of resource utilization was length of stay (LOS), followed by surgeon volume, hospital characteristics, and postoperative complications. A 1% increase in LOS increased hospital charges by 0.60%. Patient charges were 13% lower when performed by high-volume surgeons compared with low-volume surgeons and 22% lower in large hospitals compared with small hospitals. Hospital charges were 12% lower in cases with no postoperative neurological complications. The proposed model accounted for 46% of hospital charge variance.

Conclusions

This analysis of hospital charges in transsphenoidal surgery for Cushing disease suggested that LOS, hospital characteristics, surgeon volume, and postoperative complications are important predictors of resource utilization. These findings may suggest opportunities for improvement.

Prevalence and incidence of comorbidities in elderly women with ovarian cancer

OBJECTIVE

Studies suggest comorbidity plays an important role in ovarian cancer. We characterized the epidemiology of comorbid conditions in elderly U.S. women with ovarian cancer.

METHODS

Women with ovarian cancer age ≥66 years, and matched cancer-free women, were identified using the National Cancer Institute's Surveillance, Epidemiology, and End Results registry linked to Medicare claims. Prevalence before diagnosis/index date and 3- and 12-month incidence rates (per 1000 person-years) after diagnosis/index date were estimated for 34 chronic and acute conditions across a broad range of diagnostic categories.

RESULTS

There were 5087 each of women with ovarian cancer and cancer-free women. The prevalence of most conditions was similar between cancer and cancer-free patients, but exceptions included hypertension (51.8% and 43.5%, respectively), osteoarthritis (13.4% and 17.3%, respectively), and cerebrovascular disease (8.0% and 9.8%, respectively). In contrast, 3- and 12-month incidence rates (per 1000 person years) of most conditions were significantly higher in cancer than in cancer-free patients: hypertension (177.3 and 47.4, respectively); thromboembolic event (145.3 and 5.5, respectively); congestive heart failure (113.3 and 28.6, respectively); infection (664.4 and 55.2, respectively); and anemia (408.3 and 33.1, respectively) at 12 months.

CONCLUSIONS

Comorbidities were common among elderly women. After cancer diagnosis, women with ovarian cancer had a much higher incidence of comorbidities than cancer-free women. The high incidence of some of these comorbidities may be related to the cancer or its treatment, but others may have been prevalent but undiagnosed until the cancer diagnosis. The presence of comorbidities may affect treatment decisions.

Is administratively coded comorbidity and complication data in total joint arthroplasty valid?

BACKGROUND

Administrative claims data are increasingly being used in public reporting of provider performance and health services research. However, the concordance between administrative claims data and the clinical record in lower extremity total joint arthroplasty (TJA) is unknown.

QUESTIONS/PURPOSES

We evaluated the concordance between administrative claims and the clinical record for 13 commonly reported comorbidities and complications in patients undergoing TJA.

METHODS

We compared 13 administratively coded comorbidities and complications derived from hospital billing records with clinical documentation from a consecutive series of 1350 primary and revision TJAs performed at three high-volume institutions during 2009.

RESULTS

Concordance between administrative claims and the clinical record varied across comorbidities and complications. Concordance between diabetes and postoperative myocardial infarction was reflected by a kappa value > 0.80; chronic lung disease, coronary artery disease, and postoperative venous thromboembolic events by kappa values between 0.60 and 0.79; and for congestive heart failure, obesity, prior myocardial infarction, peripheral arterial disease, bleeding complications, history of venous thromboembolism, prosthetic-related complications, and postoperative renal failure by kappa values between 0.40 and 0.59. All comorbidities and complications had a high degree of specificity (> 92%) but lower sensitivity (29%-100%).

CONCLUSIONS

The data suggest administratively coded comorbidities and complications correlate reasonably well with the clinical record. However, the specificity of administrative claims is much higher than the sensitivity, indicating that comorbidities and complications coded in the administrative record were accurate but often incomplete.

Epidemiology and outcomes of previously undiagnosed diabetes in older women with breast cancer: an observational cohort study based on SEER-Medicare

Background

In breast cancer, diabetes diagnosed prior to cancer (previously diagnosed) is associated with advanced cancer stage and increased mortality. However, in the general population, 40% of diabetes is undiagnosed until glucose testing, and evidence suggests one consequence of increased evaluation and management around breast cancer diagnosis is the increased detection of previously undiagnosed diabetes. Biological factors – for instance, higher insulin levels due to untreated disease - and others underlying the association between previously diagnosed diabetes and breast cancer could differ in those whose diabetes remains undiagnosed until cancer. Our objectives were to identify factors associated with previously undiagnosed diabetes in breast cancer, and to examine associations between previously undiagnosed diabetes and cancer stage, treatment patterns, and mortality.

Methods

Using Surveillance, Epidemiology, and End Results-Medicare, we identified women diagnosed with breast cancer and diabetes between 01/2001 and 12/2005. Diabetes was classified as previously diagnosed if it was identified within Medicare claims between 24 and 4 months before cancer diagnosis, and previously undiagnosed if it was identified from 3 months before to ≤ 3 months after cancer. Patients were followed until 12/2007 or death, whichever came first. Multivariate analyses were performed to examine risk factors for previously undiagnosed diabetes and associations between undiagnosed (compared to previously diagnosed) diabetes, cancer stage, treatment, and mortality.

Results

Of 2,418 patients, 634 (26%) had previously undiagnosed diabetes; the remainder had previously diagnosed diabetes. The mean age was 77.8 years, and 49.4% were diagnosed with in situ or stage I disease. Age > 80 years (40% of the cohort) and limited health system contact (primary care physician and/or preventive services) prior to cancer were associated with higher adjusted odds of previously undiagnosed diabetes. Previously undiagnosed diabetes was associated with higher adjusted odds of advanced stage (III/IV) cancer (Odds Ratio = 1.37: 95% Confidence Interval (CI) 1.05 – 1.80; P = 0.02), and a higher adjusted mortality rate due to causes other than cancer (Hazard Ratio = 1.29; 95% CI 1.02 – 1.63; P = 0.03).

Conclusions

In breast cancer, previously undiagnosed diabetes is associated with advanced stage cancer and increased mortality. Identifying biological factors would require further investigation.

Derivation and validation of automated electronic search strategies to extract Charlson comorbidities from electronic medical records

OBJECTIVE

To develop and validate automated electronic note search strategies (automated digital algorithm) to identify Charlson comorbidities.

PATIENTS AND METHODS

The automated digital algorithm was built by a series of programmatic queries applied to an institutional electronic medical record database. The automated digital algorithm was derived from secondary analysis of an observational cohort study of 1447 patients admitted to the intensive care unit from January 1 through December 31, 2006, and validated in an independent cohort of 240 patients. The sensitivity, specificity, and positive and negative predictive values of the automated digital algorithm and International Classification of Diseases, Ninth Revision (ICD-9) codes were compared with comprehensive medical record review (reference standard) for the Charlson comorbidities.

RESULTS

In the derivation cohort, the automated digital algorithm achieved a median sensitivity of 100% (range, 99%-100%) and a median specificity of 99.7% (range, 99%-100%). In the validation cohort, the sensitivity of the automated digital algorithm ranged from 91% to 100%, and the specificity ranged from 98% to 100%. The sensitivity of the ICD-9 codes ranged from 8% for dementia to 100% for leukemia, whereas specificity ranged from 86% for congestive heart failure to 100% for leukemia, dementia, and AIDS.

CONCLUSION

Our results suggest that search strategies that use automated electronic search strategies to extract Charlson comorbidities from the clinical notes contained within the electronic medical record are feasible and reliable. Automated digital algorithm outperformed ICD-9 codes in all the Charlson variables except leukemia, with greater sensitivity, specificity, and positive and negative predictive values.

Survival for older patients with acute myeloid leukemia: a population-based study

BACKGROUND

Acute myeloid leukemia is the second most common leukemia among United States adults with a median age of 69 years. We investigated recent clinical practices related to treatments and disease outcomes in older patients with acute myeloid leukemia in the United States.

DESIGN AND METHODS

In this retrospective cohort study, we used Surveillance, Epidemiology, and End Results program data from 2000 through 2007 linked to Medicare enrollment and utilization data in the United States.

RESULTS

Among 5,480 patients with acute myeloid leukemia (median age 78 years, range 65-93), 38.6% received leukemia therapy within three months of diagnosis (treated group). Practice changed with 16.3% of treated patients receiving hypomethylating agents after 2004 when those agents became available. Median survival was two months in the untreated group versus six months in the treated group (P<0.01) with the biggest improvements seen in those aged 65-69 years (10 months vs. 4 months; P<0.01) and 70-74 years (8 months vs. 3 months; P<0.01). In 46 patients receiving allogeneic hematopoietic cell transplantation (0.8%), the median survival from diagnosis was 22 months.

CONCLUSIONS

Therapy for leukemia improves overall survival in older acute myeloid leukemia patients. Based on their comorbidities, most patients up to 80 years of age should be considered for treatment. New therapies including hypomethylating agents and allogeneic hematopoietic cell transplantation are promising and must be compared with other chemotherapy regimens.

Effect of central nervous system metastases on treatment discontinuation and survival in older women receiving trastuzumab for metastatic breast cancer

Background. Trastuzumab improves survival in HER2-positive women with metastatic breast cancer (MBC). The consequences of longer survival include a higher likelihood of additional metastases, including those in the central nervous system (CNS). The effect of CNS metastases on both trastuzumab discontinuation and survival in older patients has not been described. Patients and Methods. We used the Surveillance Epidemiology and End Results (SEER) Medicare data to identify a cohort of 562 women age 66 or older with MBC who were diagnosed between January 1, 2000 and December 31, 2005, free of CNS metastases, and initiated trastuzumab after MBC diagnosis. Time to discontinuation and time to death were analyzed using proportional hazards models. Results. Newly diagnosed CNS metastases were associated with both higher risk of trastuzumab discontinuation (relative hazard [RH] = 1.78, 95% CI 1.11-2.87) and higher risk of death (RH = 2.49, 95% CI 1.84-3.37). The incidence rate of new CNS metastases was comparable among various sites of metastasis (10.7 to 14.7 per 1,000 patient-months), except for bone which was higher (24.1 per 1,000). Conclusion. The diagnosis of CNS metastases was associated with an increase in both the likelihood of discontinuing trastuzumab therapy as well as the risk of death.

Prognostic value of cardiac troponin T after myocardial infarction: a contemporary community experience

OBJECTIVE

To evaluate the role of cardiac troponin T (cTnT) in predicting death, recurrent ischemic events, and heart failure among community-dwelling persons with first myocardial infarction (MI).

PATIENTS AND METHODS

Consecutive Olmsted County, Minnesota, residents with an incident MI between November 6, 2002, and December 31, 2007, were studied (N=1177; mean age, 68 years). Maximal cTnT value was measured at a median of 1 day after MI (median, 0.52 ng/mL; interquartile range, 0.16-1.75 ng/mL) and evaluated as a prognostic factor using measures of absolute risk.

RESULTS

During a mean follow-up of 16 months, 276 deaths (23%) occurred, 341 patients (29%) experienced a recurrent ischemic event, and 326 patients (28%) experienced heart failure. A dose-response relationship was demonstrated early after MI between cTnT and the adjusted cumulative incidence of all outcomes. The multivariate-adjusted absolute risk differences (events per 100 patients) between the upper and lower cTnT tertiles at 30 days were 5.8 (95% confidence interval [CI], 1.4-10.2) for death, 5.2 (95% CI, 0.2-10.3) for recurrent ischemic event, and 6.9 (95% CI, 1.4-12.4) for heart failure. These differences were either maintained or increased at 2 years.

CONCLUSION

In the community, cTnT level predicts death and nonfatal cardiac events independently of other prognostic factors. The increased risk associated with elevated cTnT level appears shortly after MI and persists for at least 2 years.

Granulocyte-colony stimulating factor use and medical costs after initial adjuvant chemotherapy in older patients with early-stage breast cancer

BACKGROUND

Granulocyte-colony stimulating factor (G-CSF) reduces the risk of severe neutropenia associated with chemotherapy, but its cost implications following chemotherapy are unknown.

OBJECTIVE

Our objective was to examine associations between G-CSF use and medical costs after initial adjuvant chemotherapy in early-stage (stage I-III) breast cancer (ESBC).

METHODS

Women diagnosed with ESBC from 1999 to 2005, who had an initial course of chemotherapy beginning within 180 days of diagnosis and including ≥1 highly myelosuppressive agent, were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Medicare claims were used to describe the initial chemotherapy regimen according to the classes of agents used: anthracycline ([A]: doxorubicin or epirubicin); cyclophosphamide (C); taxane ([T]: paclitaxel or docetaxel); and fluorouracil (F). Patients were classified into four study groups according to their G-CSF use: (i) primary prophylaxis, if the first G-CSF claim was within 5 days of the start of the first chemotherapy cycle; (ii) secondary prophylaxis, if the first claim was within 5 days of the start of the second or subsequent cycles; (iii) G-CSF treatment, if the first claim occurred outside of prophylactic use; and (iv) no G-CSF. Patients were described by age, race, year of diagnosis, stage, grade, estrogen (ER) and progesterone (PR) receptor status, National Cancer Institute (NCI) Co-morbidity Index, chemotherapy regimen and G-CSF use. Total direct medical costs ($US, year 2009 values) to Medicare were estimated from 4 weeks after the last chemotherapy administration up to 48 months. Medical costs included those for ESBC treatment and all other medical services received after chemotherapy. Least squares regression, using inverse probability weighting (IPW) to account for censoring within the cohort, was used to evaluate adjusted associations between G-CSF use and costs.

RESULTS

A total of 7026 patients were identified, with an average age of 72 years, of which 63% had stage II disease, and 59% were ER and/or PR positive. Compared with no G-CSF, those receiving G-CSF primary prophylaxis were more likely to have stage III disease (30% vs. 16%; p < 0.0001), to be diagnosed in 2003-5 (87% vs. 26%; p < 0.0001), and to receive dose-dense AC-T (26% vs. 1%; p < 0.0001), while they were less likely to receive an F-based regimen (12% vs. 42%; p < 0.0001). Overall, the estimated average direct medical cost over 48 months after initial chemotherapy was $US 42,628. In multivariate analysis, stage II or III diagnosis (compared with stage I), NCI Co-morbidity Index score 1 or ≥2 (compared with 0), or FAC or standard AC-T (each compared with AC) were associated with significantly higher IPW 48-month costs. Adjusting for patient demographic and clinical factors, costs in the G-CSF primary prophylaxis group were not significantly different from those not receiving primary prophylaxis (the other three study groups combined). In an analysis that included four separate study groups, G-CSF treatment was associated with significantly greater costs (incremental cost = $US 2938; 95% CI 285, 5590) than no G-CSF.

CONCLUSIONS

Direct medical costs after initial chemotherapy were not statistically different between those receiving G-CSF primary prophylaxis and those receiving no G-CSF, after adjusting for potential confounders.

The relationship between hospital lung cancer resection volume and patient mortality risk

OBJECTIVE

To evaluate the volume-outcome relationship after lung cancer resection using 3 alternative measures of the effect of volume.

SUMMARY BACKGROUND DATA

Many studies of lung cancer resection indicate that hospital volume predicts mortality. However, controversy exists regarding the strength and validity of this association. Because thresholds of procedure volume are used to recommend the regionalization of care, investigation of the validity of the volume-outcome relationship is necessary.

METHODS

Lung cancer resection patients were identified in the 2007 Nationwide Inpatient Sample. Hospital volume was measured using 3 different methods: as a continuous linear function, as a nonlinear function using restricted cubic splines, and as the frequently used method of quintile categories. The statistical significance of the relationship between hospital volume and mortality risk was assessed, adjusted for patient age, comorbid disease, and for correlated events within hospitals.

RESULTS

Forty thousand four hundred and sixty lung cancer resection patients from 436 hospitals were identified. All 3 models demonstrated excellent performance characteristics (C index = 0.92, Nagelkerke R = 0.37). No significant association was demonstrated between hospital procedure volume and in-hospital mortality when measured as a linear or nonlinear function using splines. However, a statistically significant relationship was found for volume categorized into quintiles, although its relative contribution to the predictive capacity of the model was very small (likelihood ratio = 2.55, P = 0.04).

CONCLUSIONS

The apparent impact of hospital lung cancer resection volume on mortality is dependent on how volume is defined and entered into the regression equation. Hospital lung cancer resection volume is not a predictor of mortality and should not be used as a proxy measure for surgical quality.

Validity of the International Classification of Diseases 10th revision code for hyperkalaemia in elderly patients at presentation to an emergency department and at hospital admission

OBJECTIVES

Evaluate the validity of the International Classification of Diseases, 10th revision (ICD-10) code for hyperkalaemia (E87.5) in two settings: at presentation to an emergency department and at hospital admission.

DESIGN

Population-based validation study.

SETTING

12 hospitals in Southwestern Ontario, Canada, from 2003 to 2010.

PARTICIPANTS

Elderly patients with serum potassium values at presentation to an emergency department (n=64 579) and at hospital admission (n=64 497).

PRIMARY OUTCOME

Sensitivity, specificity, positive-predictive value and negative-predictive value. Serum potassium values in patients with and without a hyperkalaemia code (code positive and code negative, respectively).

RESULTS

The sensitivity of the best-performing ICD-10 coding algorithm for hyperkalaemia (defined by serum potassium >5.5 mmol/l) was 14.1% (95% CI 12.5% to 15.9%) at presentation to an emergency department and 14.6% (95% CI 13.3% to 16.1%) at hospital admission. Both specificities were greater than 99%. In the two settings, the positive-predictive values were 83.2% (95% CI 78.4% to 87.1%) and 62.0% (95% CI 57.9% to 66.0%), while the negative-predictive values were 97.8% (95% CI 97.6% to 97.9%) and 96.9% (95% CI 96.8% to 97.1%). In patients who were code positive for hyperkalaemia, median (IQR) serum potassium values were 6.1 (5.7 to 6.8) mmol/l at presentation to an emergency department and 6.0 (5.1 to 6.7) mmol/l at hospital admission. For code-negative patients median (IQR) serum potassium values were 4.0 (3.7 to 4.4) mmol/l and 4.1 (3.8 to 4.5) mmol/l in each of the two settings, respectively.

CONCLUSIONS

Patients with hospital encounters who were ICD-10 E87.5 hyperkalaemia code positive and negative had distinct higher and lower serum potassium values, respectively. However, due to very low sensitivity, the incidence of hyperkalaemia is underestimated.

Validity of the International Classification of Diseases 10th revision code for hospitalisation with hyponatraemia in elderly patients

OBJECTIVE

To evaluate the validity of the International Classification of Diseases, 10th Revision (ICD-10) diagnosis code for hyponatraemia (E87.1) in two settings: at presentation to the emergency department and at hospital admission.

DESIGN

Population-based retrospective validation study.

SETTING

Twelve hospitals in Southwestern Ontario, Canada, from 2003 to 2010.

PARTICIPANTS

Patients aged 66 years and older with serum sodium laboratory measurements at presentation to the emergency department (n=64 581) and at hospital admission (n=64 499).

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value and negative predictive value comparing various ICD-10 diagnostic coding algorithms for hyponatraemia to serum sodium laboratory measurements (reference standard). Median serum sodium values comparing patients who were code positive and code negative for hyponatraemia.

RESULTS

The sensitivity of hyponatraemia (defined by a serum sodium ≤132 mmol/l) for the best-performing ICD-10 coding algorithm was 7.5% at presentation to the emergency department (95% CI 7.0% to 8.2%) and 10.6% at hospital admission (95% CI 9.9% to 11.2%). Both specificities were greater than 99%. In the two settings, the positive predictive values were 96.4% (95% CI 94.6% to 97.6%) and 82.3% (95% CI 80.0% to 84.4%), while the negative predictive values were 89.2% (95% CI 89.0% to 89.5%) and 87.1% (95% CI 86.8% to 87.4%). In patients who were code positive for hyponatraemia, the median (IQR) serum sodium measurements were 123 (119-126) mmol/l and 125 (120-130) mmol/l in the two settings. In code negative patients, the measurements were 138 (136-140) mmol/l and 137 (135-139) mmol/l.

CONCLUSIONS

The ICD-10 diagnostic code for hyponatraemia differentiates between two groups of patients with distinct serum sodium measurements at both presentation to the emergency department and at hospital admission. However, these codes underestimate the true incidence of hyponatraemia due to low sensitivity.

Addition of rituximab to chemotherapy alone as first-line therapy improves overall survival in elderly patients with mantle cell lymphoma

Clinical trials have demonstrated that rituximab improves overall survival in non-Hodgkin lymphoma (NHL), except in mantle cell lymphoma (MCL). We used Surveillance Epidemiology and End Results (SEER)-Medicare data to compare survival in older MCL patients who began chemotherapy with or without rituximab within 180 days of diagnosis. Patients were followed from diagnosis (January 1999 to December 2005) until death or the end of observation (December 2007). Medicare administrative and claims data were used to identify the date and cause of death and the immunochemotherapy regimen. Of 638 patients, the mean age at diagnosis was 75 years, 75% had stage III/IV disease, 67% had extranodal involvement, and 64% received rituximab. The average length of first-line treatment was 21 weeks, with no difference between the 2 groups (P = .76). Median survival was 27 months for chemotherapy alone, compared with 37 months for chemotherapy plus rituximab (P < .001). In multivariate analysis of 2-year survival, rituximab plus chemotherapy was associated with lower all-cause (hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.41-0.82; P < .01), and cancer-specific (HR 0.56; 95% CI 0.37-0.84; P < .01) mortality. Results were similar when using the entire observation period, propensity score analysis, and limiting chemotherapy to CHOP/CHOP-like. We conclude that first-line chemotherapy including rituximab is associated with significantly improved survival in older patients diagnosed with MCL.

An observational study of the prevalence and incidence of comorbid conditions in older women with breast cancer

Background

Longitudinal analyses of comorbid conditions in women with breast cancer are few.

Methods

Using Surveillance, Epidemiology, and End Results–Medicare data, we included 51 950 women aged ≥66 years with in situ and stage I to IV breast cancer diagnosed in 1998–2002. We identified the prevalence and incidence of 34 comorbid conditions in these women, as well as in a matched cohort without cancer whose rates were standardized to the age and race/ethnicity distribution of the cancer patients. We also estimated rates of office encounters and diagnostic or testing procedures during the 12 months before diagnosis.

Results

The prevalence of most conditions at diagnosis was comparable among breast cancer and noncancer patients. New conditions after diagnosis were more common in breast cancer patients, and the incidence rates increased with higher stage at diagnosis. Before diagnosis, women presenting with stage IV disease had 41% [95% confidence interval (CI) 38% to 43%] fewer physician encounters and 34% (95% CI 24% to 31%) fewer unique diagnostic tests than women diagnosed with carcinoma in situ.

Conclusions

Many comorbid conditions are identified as a consequence of the breast cancer diagnosis. There appears to be an important contribution from a lack of interaction with the health care system before diagnosis.

Infused therapy and survival in older patients diagnosed with metastatic breast cancer who received trastuzumab

We used Surveillance, Epidemiology, and End Results-Medicare data (2000-2006) to describe treatment and survival in women diagnosed with metastatic breast cancer (MBC) who received trastuzumab. There were 610 patients with a mean age of 74 years. Overall, 32% received trastuzumab alone and 47% received trastuzumab plus a taxane. In multivariate analysis, trastuzumab plus chemotherapy was associated with a lower adjusted cancer mortality rate (Hazard Ratio [HR] 0.54; 95% Confidence Interval [CI] 0.39-0.74; p < .001) than trastuzumab alone among patients who received trastuzumab as part of first-line therapy. Adding chemotherapy to first-line trastuzumab for metastatic breast cancer is associated with improved cancer survival.

Hospital-wide mortality as a quality metric: conceptual and methodological challenges

Hospital-wide mortality rates are used as a measure of overall hospital quality. However, their parsimony and apparent simplicity belie significant conceptual and methodological concerns. For many diagnoses included in hospital-wide mortality, the association between short-term mortality and quality of care is not well established. Furthermore, compared with condition-specific or procedure-specific mortality, hospital-wide mortality rates pose greater methodological challenges (ie, eligibility and exclusion criteria, risk adjustment, statistical techniques for aggregating across diagnoses, usability). Many of these result from substantial interprovider heterogeneity in diagnosis frequency, sample sizes, and patient severity. Hospital-wide mortality is problematic as a quality metric for public reporting, although hospitals may elect to use such measures for other purposes. Potential alternative approaches include multidimensional composite metrics or mortality measurement limited to selected conditions and procedures for which the link between hospital mortality and quality is clear, legitimate exclusions are uncommon, and sample sizes, end points, and risk adjustment are adequate.