Health services research in critical care using administrative data

Recent Trends in Admission Diagnosis and Related Mortality in the Medically Critically Ill

PURPOSE

With decades of declining ICU mortality, we hypothesized that the outcomes and distribution of diseases cared for in the ICU have changed and we aimed to further characterize them.

STUDY DESIGN AND METHODS

A retrospective cohort analysis of 287,154 nonsurgical-critically ill adults, from 237 U.S. ICUs, using the manually abstracted Cerner APACHE Outcomes database from 2008 to 2016 was performed. Surgical patients, rare admission diagnoses (<100 occurrences), and low volume hospitals (<100 total admissions) were excluded. Diagnoses were distributed into mutually exclusive organ system/disease-based categories based on admission diagnosis. Multi-level mixed-effects negative binomial regression was used to assess temporal trends in admission, in-hospital mortality, and length of stay (LOS).

RESULTS

The number of ICU admissions remained unchanged (IRR 0.99, 0.98-1.003) while certain organ system/disease groups increased (toxicology [25%], hematologic/oncologic [55%] while others decreased (gastrointestinal [31%], pulmonary [24%]). Overall risk-adjusted in-hospital mortality was unchanged (IRR 0.98, 0.96-1.0004). Risk-adjusted ICU LOS (Estimate -0.06 days/year, -0.07 to -0.04) decreased. Risk-adjusted mortality varied significantly by disease.

CONCLUSION

Risk-adjusted ICU mortality rate did not change over the study period, but there was evidence of shifting disease burden across the critical care population. Our data provides useful information regarding future ICU personnel and resource needs.

Critical illness in patients with hematologic malignancy: a population-based cohort study

PURPOSE

To describe the modern incidence and predictors of ICU admission for adult patients newly diagnosed with a hematologic malignancy.

METHODS

We conducted a population-based cohort study of adults with a new diagnosis of hematologic malignancy (April 1, 2006-March 31, 2017) in Ontario, Canada. We described the baseline demographic, clinical and laboratory predictors of ICU admission and subsequent mortality. The primary outcome was the incidence of ICU admission within 1 year of hematologic malignancy diagnosis. We assessed the predictors of ICU admission using Cox-proportional models that accounted for the competing risk of death and reported as subdistribution hazard ratios (sHR) with 95% confidence intervals (CI).

RESULTS

A total of 87,965 patients (mean [SD] age, 67.8 (15.7) years) were included. The 1-year incidence of ICU admission was 13.9% (median time 35 days), ranging from 7.3% (indolent lymphoma) to 22.5% (acute myeloid leukemia). After multivariable adjustment, compared to indolent lymphoma, acute myeloid leukemia (sHR, 3.09; 95% CI 2.84-3.35), aggressive non-Hodgkin lymphoma (sHR, 2.47; 95% CI 2.31-2.65) and acute lymphoblastic leukemia (sHR, 2.46; 95% CI 2.15-2.80) had the highest risk of ICU admission. Comorbidities such as cardiovascular disease (sHR, 2.09; 95% CI 2.01-2.19), chronic obstructive pulmonary disease (sHR, 1.33; 95% CI 1.26-1.39) and baseline laboratory abnormalities (anemia, thrombocytopenia and high creatinine) were also associated with ICU admission. Among ICU patients, 36.7% required invasive mechanical ventilation and in-hospital mortality was 31%.

CONCLUSION

Critical illness in patients with a newly diagnosed hematologic malignancy is frequent, occurring early after diagnosis. Certain baseline characteristics can help identify those patients at the highest risk.

Epidemiological trends of surgical admissions to the intensive care unit in the United States

BACKGROUND

Epidemiologic assessment of surgical admissions into intensive care units (ICUs) provides a framework to evaluate health care system efficiency and project future health care needs.

METHODS

We performed a 9-year (2008-2016), retrospective, cohort analysis of all adult admissions to 88 surgical ICUs using the prospectively and manually abstracted Cerner Acute Physiology and Chronic Health Evaluation Outcomes database. We stratified patients into 13 surgical cohorts and modeled temporal trends in admission, mortality, surgical ICU length of stay (LOS), and change in functional status (FS) using generalized mixed-effects and Quasi-Poisson models to obtain risk-adjusted outcomes.

RESULTS

We evaluated 78,053 ICU admissions and observed a significant decrease in admissions after transplant and thoracic surgery, with a concomitant increase in admissions after otolaryngological and facial reconstructive procedures (all p < 0.05). While overall risk-adjusted mortality remained stable over the study period; mortality significantly declined in orthopedic, cardiac, urologic, and neurosurgical patients (all p < 0.05). Cardiac, urologic, gastrointestinal, neurosurgical, and orthopedic admissions showed significant reductions in LOS (all p < 0.05). The overall rate of FS deterioration increased per year, suggesting ICU-related disability increased over the study period.

CONCLUSION

Temporal analysis demonstrates a significant change in the type of surgical patients admitted to the ICU over the last decade, with decreasing mortality and LOS in selected cohorts, but an increasing rate of FS deterioration. Improvement in ICU outcomes may highlight the success of health care advancements within certain surgical cohorts, while simultaneously identifying cohorts that may benefit from future intervention. Our findings have significant implications in health care systems planning, including resource and personnel allocation, education, and surgical training.

LEVEL OF EVIDENCE

Economic/decision, level IV.Epidemiologic, level IV.

Gastrostomy Tube Use in the Critically Ill, 1994-2014

Rationale: Although gastrostomy tubes have shown to be of limited benefit in patients with advanced dementia, they continue to be used to deliver nutritional support in critically ill patients. The epidemiology and short-term outcomes are unclear. Objectives: To quantify national practice patterns and short-term outcomes of gastrostomy tube placement among the critically ill over the last two decades in the United States. Methods: Using the U.S. Agency for Healthcare and Research Quality's Healthcare Cost and Utilization Project's National Inpatient Sample, we evaluated trends in annual population-standardized rates of gastrostomy tube placement among critically ill adults from 1994 to 2014; we also quantified trends in length of stay, in-hospital mortality, and discharge location. We conducted sensitivity analyses among mechanically ventilated patients, survivors, and decedents of critical illness, and in a critically ill population excluding patients with dementia. Results: From 1994 to 2014, population-based rates of gastrostomy tube use in critically ill patients increased from 11.9 to 28.8 gastrostomies per 100,000 U.S. adults (peak in incidence in 2010), an increase of 142% (31,392-91,990 gastrostomy tubes in critically ill patients; P < 0.001). Patients receiving gastrostomy tubes during critical illness occupied a growing proportion of all gastrostomy tube placements, accounting for 19.6% of all gastrostomy tubes placed in 1994 and 50.8% in 2014. The rate of gastrostomies in critically ill patients remained roughly stable, from 2.5% of critically ill patients in 1994 to a peak of 3.7% in 2002 before declining again to 2.4% in 2014. Hospital length of stay and in-hospital mortality decreased among gastrostomy tube recipients (28.7 d to 20.5 d, P < 0.001; 25.9-11.3%, P < 0.001; respectively), whereas discharges to long-term facilities increased significantly (49.6-70.6%; P < 0.001). Sensitivity analyses among mechanically ventilated patients revealed similar increases in population-based estimates of gastrostomy tube placement. Conclusions: The incidence of gastrostomy tube placement among critically ill patients more than doubled between 1994 and 2014, with most patients being discharged to long-term care facilities. Critically ill patients are now the primary utilizer of gastrostomy tubes placed in the United States. Additional research is needed to better characterize the long-term risk and benefits of gastrostomy tube use in critically ill patients.

Variation in mortality rates after admission to long-term acute care hospitals for ventilator weaning

PURPOSE

We sought to examine variation in long-term acute care hospital (LTACH) quality based on 90-day in-hospital mortality for patients admitted for weaning from mechanical ventilation.

METHODS

We developed an administrative risk-adjustment model using data from Medicare claims. We validated the administrative model against a clinical model using data from LTACHs participating in a 2002 to 2003 clinical registry. We then used our validated administrative model to assess national variation in 90-day in-hospital mortality rates in LTACHs from 2013.

RESULTS

The administrative risk-adjustment model was derived using data from 9447 patients admitted to 221 LTACHs in 2003. The model had good discrimination (C statistic=0.72) and calibration. Compared to a clinically derived model using data from 1163 patients admitted to 14 LTACHs, the administrative model generated similar performance estimates. National variation in risk-adjusted mortality was assessed using data from 20,453 patients admitted to 380 LTACHs in 2013. LTACH-specific risk-adjusted mortality rates varied from 8.4% to 48.1% (median: 24.2%, interquartile range: 19.7%-30.7%).

CONCLUSIONS

LTACHs vary widely in mortality rates, underscoring the need to better understand the sources of this variation and improve the quality of care for patients requiring long-term ventilator weaning.

Elderly patients hospitalized in the ICU in France: a population-based study using secondary data from the national hospital discharge database

RATIONALE, AIMS AND OBJECTIVES

In the global context of population ageing, understanding and monitoring intensive care use by the elderly is a strategic issue. National-level data are needed to overcome sampling biases that often limit epidemiologic studies of the critically ill elderly. The objective of this study was to describe intensive care use for hospitalized elderly patients using secondary data from the French national hospital discharge database.

METHOD

Structured assessment of the national database coverage and accuracy; cross-sectional analysis of hospitalizations including at least one admission in an intensive care unit (ICU) for patients aged ≥ 80 years from 1 January to 31 December 2009.

RESULTS

In 2009, people aged ≥ 80 years accounted for 5.4% of the population but 15.3% of the 215 210 adult hospitalizations involving intensive care in France. In this elderly group, the mean age was 84.0 (± 3.56) years, and 51.6% were male. In-hospital mortality was 33.9%. The median time spent in the ICU was 3 [interquartile range (IQR), 2-8] days, the median time spent in hospital was 14 (IQR, 8-24) days and 9% of hospitalizations ended by the patient's death involved intensive care. A surgical procedure was included in 43% of hospitalizations. Medical and surgical diagnosis-related group hospitalizations were characterized by significant differences in volume, mortality, ICU days and costs.

CONCLUSIONS

There was marked clinical heterogeneity in the population of elderly patients hospitalized in the ICU. These data provide baseline information and prompt further studies comparing intensive care utilization across age groups, between countries and over time.

Effectiveness of regionalized systems for stroke and myocardial infarction

BACKGROUND

Acute ischemic stroke (AIS) and ST-segment elevation myocardial infarction (STEMI) are ischemic emergencies. Guidelines recommend care delivery within formally regionalized systems of care at designated centers, with bypass of nearby centers of lesser or no designation. We review the evidence of the effectiveness of regionalized systems in AIS and STEMI.

METHODS

Literature was searched using terms corresponding to designation of AIS and STEMI systems and from 2010 to the present. Inclusion criteria included report of an outcome on any dependent variable mentioned in the rationale for regionalization in the guidelines and an independent variable comparing care to a non- or pre-regionalized system. Designation was defined in the AIS case as certification by the Joint Commission as either a primary (PSC) or comprehensive (CSC) stroke center. In the STEMI case, the search was conducted linking "regionalization" and "myocardial infarction" or citation as a model system by any American Heart Association statement.

RESULTS

For AIS, 17 publications met these criteria and were selected for review. In the STEMI case, four publications met these criteria; the search was therefore expanded by relaxing the criteria to include any historical or anecdotal comparison to a pre- or nonregionalized state. The final yield was nine papers from six systems.

CONCLUSION

Although regionalized care results in enhanced process and reduced unadjusted rates of disparity in access and adverse outcomes, these differences tend to become nonsignificant when adjusted for delayed presentation and hospital arrival by means other than emergency medical services. The benefits of regionalized care occur along with a temporal trend of improvement due to uptake of quality initiatives and guideline recommendations by all systems regardless of designation. Further research is justified with a randomized registry or cluster randomized design to support or refute recommendations that regionalization should be the standard of care.

Bayesian estimation of the accuracy of ICD-9-CM- and CPT-4-based algorithms to identify cholecystectomy procedures in administrative data without a reference standard

PURPOSE

To estimate the accuracy of two algorithms to identify cholecystectomy procedures using International Classification of Diseases, 9th Edition, Clinical Modification (ICD-9-CM) and Current Procedural Terminology (CPT-4) codes in administrative data.

METHODS

Private insurer medical claims for 30 853 patients 18-64 years with an inpatient hospitalization between 2006 and 2010, as indicated by providers/facilities place of service in addition to room and board charges, were cross-classified according to the presence of codes for cholecystectomy. The accuracy of ICD-9-CM- and CPT-4-based algorithms was estimated using a Bayesian latent class model.

RESULTS

The sensitivity and specificity were 0.92 [probability interval (PI): 0.92, 0.92] and 0.99 (PI: 0.97, 0.99) for ICD-9-CM-, and 0.93 (PI: 0.92, 0.93) and 0.99 (PI: 0.97, 0.99) for CPT-4-based algorithms, respectively. The parallel-joint scheme, where positivity of either algorithm was considered a positive outcome, yielded a sensitivity and specificity of 0.99 (PI: 0.99, 0.99) and 0.97 (PI: 0.95, 0.99), respectively.

CONCLUSIONS

Both ICD-9-CM- and CPT-4-based algorithms had high sensitivity to identify cholecystectomy procedures in administrative data when used individually and especially in a parallel-joint approach.

Use of Electronic Health-Related Datasets in Nursing and Health-Related Research

Datasets of gigabyte size are common in medical sciences. There is increasing consensus that significant untapped knowledge lies hidden in these large datasets. This review article aims to discuss Electronic Health-Related Datasets (EHRDs) in terms of types, features, advantages, limitations, and possible use in nursing and health-related research. Major scientific databases, MEDLINE, ScienceDirect, and Scopus, were searched for studies or review articles regarding using EHRDs in research. A total number of 442 articles were located. After application of study inclusion criteria, 113 articles were included in the final review. EHRDs were categorized into Electronic Administrative Health-Related Datasets and Electronic Clinical Health-Related Datasets. Subcategories of each major category were identified. EHRDs are invaluable assets for nursing the health-related research. Advanced research skills such as using analytical softwares, advanced statistical procedures, dealing with missing data and missing variables will maximize the efficient utilization of EHRDs in research.

Using existing data to address important clinical questions in critical care

OBJECTIVE

With important technological advances in healthcare delivery and the Internet, clinicians and scientists now have access to overwhelming number of available databases capturing patients with critical illness. Yet, investigators seeking to answer important clinical or research questions with existing data have few resources that adequately describe the available sources and the strengths and limitations of each. This article reviews an approach to selecting a database to address health services and outcomes research questions in critical care, examines several databases that are commonly used for this purpose, and briefly describes some strengths and limitations of each.

DATA SOURCES

Narrative review of the medical literature.

SUMMARY

The available databases that collect information on critically ill patients are numerous and vary in the types of questions they can optimally answer. Selection of a data source must consider not only accessibility but also the quality of the data contained within the database, and the extent to which it captures the necessary variables for the research question. Questions seeking causal associations (e.g., effect of treatment on mortality) usually either require secondary data that contain detailed information about demographics, laboratories, and physiology to best address nonrandom selection or sophisticated study design. Purely descriptive questions (e.g., incidence of respiratory failure) can often be addressed using secondary data with less detail such as administrative claims. Although each database has its own inherent limitations, all secondary analyses will be subject to the same challenges of appropriate study design and good observational research.

CONCLUSION

The literature demonstrates that secondary analyses can have significant impact on critical care practice. While selection of the optimal database for a particular question is a necessary part of high-quality analyses, it is not sufficient to guarantee an unbiased study. Thoughtful and well-constructed study design and analysis approaches remain equally important pillars of robust science. Only through responsible use of existing data will investigators ensure that their study has the greatest impact on critical care practice and outcomes.

Can administrative claim file review be used to gather physical therapy, occupational therapy, and psychology payment data and functional independence measure scores? Implications for rehabilitation providers in the private health sector

PURPOSE

Rehabilitation costs for spinal-cord injury (SCI) are increasingly borne by Canada's private health system. Because of poor outcomes, payers are questioning the value of their expenditures, but there is a paucity of data informing analysis of rehabilitation costs and outcomes. This study evaluated the feasibility of using administrative claim file review to extract rehabilitation payment data and functional status for a sample of persons with work-related SCI.

METHODS

Researchers reviewed 28 administrative e-claim files for persons who sustained a work-related SCI between 1996 and 2000. Payment data were extracted for physical therapy (PT), occupational therapy (OT), and psychology services. Functional Independence Measure (FIM) scores were targeted as a surrogate measure for functional outcome. Feasibility was tested using an existing approach for evaluating health services data.

RESULTS

The process of administrative e-claim file review was not practical for extraction of the targeted data.

CONCLUSIONS

While administrative claim files contain some rehabilitation payment and outcome data, in their present form the data are not suitable to inform rehabilitation services research. A new strategy to standardize collection, recording, and sharing of data in the rehabilitation industry should be explored as a means of promoting best practices.

The impact of paradoxical comorbidities on risk-adjusted mortality of Medicare beneficiaries with cardiovascular disease

BACKGROUND

Persistent uncertainty remains regarding assessments of patient comorbidity based on administrative data for mortality risk adjustment. Some models include comorbid conditions that are associated with improved mortality while other models exclude these so-called paradoxical conditions. The impact of these conditions on patient risk assessments is unknown.

OBJECTIVE

To examine trends in the prevalence of conditions with a paradoxical (protective) relationship with mortality, and the impact of including these conditions on assessments of risk adjusted mortality.

METHODS

Patients age 65 and older admitted for acute myocardial infarction (AMI) or coronary artery bypass graft (CABG) surgery during 1994 through 2005 were identified in Medicare Part A files. Comorbid conditions defined using a common algorithm were categorized as having a paradoxical or non-paradoxical relationship with 30-day mortality, based upon regression coefficients in multivariable logistic regression models.

RESULTS

For AMI, the proportion of patients with one or more paradoxical condition and one or more non-paradoxical condition increased by 24% and 3% respectively between 1994 and 2005. The odds of death for patients with one-or-more paradoxical comorbidities, relative to patients with no paradoxical comorbidity, declined from 0.69 to 0.54 over the study period. In contrast, the risk associated with having one or more non-paradoxical comorbidities increased from 2.66 to 4.62 for AMI. This pattern was even stronger for CABG. Risk adjustment models that included paradoxical comorbidities found larger improvements, in risk-adjusted mortality for AMI and CABG, over time than models that did not include paradoxical comorbidities.

CONCLUSION

The relationship between individual comorbid conditions and mortality is changing over time, with potential impact on estimates of hospital performance and trends in mortality. Development of a standard approach for handling conditions with a paradoxical relationship to mortality is needed.

Critical care and the global burden of critical illness in adults

Critical care has evolved from treatment of poliomyelitis victims with respiratory failure in an intensive care unit to treatment of severely ill patients irrespective of location or specific technology. Population-based studies in the developed world suggest that the burden of critical illness is higher than generally appreciated and will increase as the population ages. Critical care capacity has long been needed in the developing world, and efforts to improve the care of the critically ill in these settings are starting to occur. Expansion of critical care to handle the consequences of an ageing population, natural disasters, conflict, inadequate primary care, and higher-risk medical therapies will be challenged by high costs at a time of economic constraint. To meet this challenge, investigators in this discipline will need to measure the global burden of critical illness and available critical-care resources, and develop both preventive and therapeutic interventions that are generalisable across countries.

Accuracy of the discharge destination field in administrative data for identifying transfer to a long-term acute care hospital

BACKGROUND

Long-term acute care hospitals (LTACs) provide specialized care for patients recovering from severe acute illness. In order to facilitate research into LTAC utilization and outcomes, we studied whether or not the discharge destination field in administrative data accurately identifies patients transferred to an LTAC following acute care hospitalization.

FINDINGS

We used the 2006 hospitalization claims for United States Medicare beneficiaries to examine the performance characteristics of the discharge destination field in the administrative record, compared to the reference standard of directly observing LTAC transfers in the claims. We found that the discharge destination field was highly specific (99.7%, 95 percent CI: 99.7% - 99.8%) but modestly sensitive (77.3%, 95 percent CI: 77.0% - 77.6%), with corresponding low positive predictive value (72.6%, 95 percent CI: 72.3% - 72.9%) and high negative predictive value (99.8%, 95 percent CI: 99.8% - 99.8%). Sensitivity and specificity were similar when limiting the analysis to only intensive care unit patients and mechanically ventilated patients, two groups with higher rates of LTAC utilization. Performance characteristics were slightly better when limiting the analysis to Pennsylvania, a state with relatively high LTAC penetration.

CONCLUSIONS

The discharge destination field in administrative data can result in misclassification when used to identify patients transferred to long-term acute care hospitals. Directly observing transfers in the claims is the preferable method, although this approach is only feasible in identified data.

Health services research methods: tools for nurse leaders

A political competency for leaders is to effectively articulate the evidence behind management best practices. Evidence-based practice requires special skills from the nurse leader, many of which are found in health services research (HSR) methods. This review presents approaches associated with HSR, which can be used by nurse managers for the benefit of their units. HSR methods reviewed are cost analyses, small area analysis, geographic information systems, use of existing databases, quality of care measures, and risk adjustment. This review examines the kind of evidence various HSR methods provide, as well as examples of their use and resources needed to apply them.