A systematic review of validated methods for identifying acute respiratory failure using administrative and claims data

Comparative safety of tramadol and other opioids following total hip and knee arthroplasty

BACKGROUND

Tramadol is increasingly used to treat acute postoperative pain among older adults following total hip and knee arthroplasty (THA/TKA). However, tramadol has a complex pharmacology and may be no safer than full opioid agonists. We compared the safety of tramadol, oxycodone, and hydrocodone among opioid-naïve older adults following elective THA/TKA.

METHODS

This retrospective cohort included Medicare Fee-for-Service beneficiaries ≥ 65 years with elective THA/TKA between January 1, 2010 and September 30, 2015, 12 months of continuous Parts A and B enrollment, 6 months of continuous Part D enrollment, and no opioid use in the 6 months prior to THA/TKA. Participants initiated single-opioid therapy with tramadol, oxycodone, or hydrocodone within 7 days of discharge from THA/TKA hospitalization, regardless of concurrently administered nonopioid analgesics. Outcomes of interest included all-cause hospitalizations or emergency department visits (serious adverse events (SAEs)) and a composite of 10 surgical- and opioid-related SAEs within 90-days of THA/TKA. The intention-to-treat (ITT) and per-protocol (PP) hazard ratios (HRs) for tramadol versus other opioids were estimated using inverse-probability-of-treatment-weighted pooled logistic regression models.

RESULTS

The study population included 2,697 tramadol, 11,407 oxycodone, and 14,665 hydrocodone initiators. Compared to oxycodone, tramadol increased the rate of all-cause SAEs in ITT analyses only (ITT HR 1.19, 95%CLs, 1.02, 1.41; PP HR 1.05, 95%CLs, 0.86, 1.29). Rates of composite SAEs were not significant across comparisons. Compared to hydrocodone, tramadol increased the rate of all-cause SAEs in the ITT and PP analyses (ITT HR 1.40, 95%CLs, 1.10, 1.76; PP HR 1.34, 95%CLs, 1.03, 1.75), but rates of composite SAEs were not significant across comparisons.

CONCLUSIONS

Postoperative tramadol was associated with increased rates of all-cause SAEs, but not composite SAEs, compared to oxycodone and hydrocodone. Tramadol does not appear to have a superior safety profile and should not be preferentially prescribed to opioid-naïve older adults following THA/TKA.

Sleep-disordered Breathing and Inpatient Outcomes in Nonsurgical Patients: Analysis of the Nationwide Inpatient Cohort

Rationale: Sleep-disordered breathing (SDB) is associated with increased complications and length of stay (LOS) after surgery. SDB-related adverse consequences for nonsurgical admissions are not well defined. Objectives: Evaluate associations between SDB and subtypes and LOS, cost, and mortality in nonsurgical patients. Methods: This retrospective cohort analysis used adult nonsurgical admissions from the 2017 National Inpatient Sample of the Healthcare Costs and Utilization Project. SDB associations with LOS (primary outcome), costs, and mortality were evaluated via logistic regression. Covariates included age, sex, Elixhauser Comorbidity Index, socioeconomic status, hospital type, and insurance type. Results: The cohort included 6,046,544 hospitalizations. Compared with those without SDB, patients with SDB were older (63.6 ± 13.5 vs. 57.4 ± 20.7 yr), higher proportion male (55.8% vs. 40.9%), and more likely to be White (75.7% vs. 66.5%). SDB was associated with increased odds of increased LOS and hospitalization costs (odds ratio [OR], 1.17; 95% confidence interval [CI], 1.16-1.17 and OR, 1.67; 95% CI, 1.66-1.67 in adjusted analyses, respectively) but lower mortality (OR, 0.79; 95% CI, 0.77-0.81). The results for obstructive sleep apnea (OSA) echoed those for SDB. Obesity hypoventilation syndrome had substantially increased LOS (OR, 3.05; 95% CI, 2.98-3.13), mortality (1.76; 95% CI, 1.66-1.86), and costs (OR, 2.67; 95% CI, 2.60-2.73) even after adjustment. Conclusions: Obesity hypoventilation syndrome is associated with higher LOS, mortality, and costs during hospitalization, whereas OSA, despite higher LOS and costs, is associated with decreased mortality. Investigation is warranted on whether paradoxically higher costs but lower mortality in OSA may be indicative of less vigilance in hospitalized patients with undiagnosed SDB.

Causes of hypercapnic respiratory failure and associated in-hospital mortality

BACKGROUND AND OBJECTIVE

Hypercapnic respiratory failure (HRF) can occur due to severe respiratory disease but also because of multiple coexistent causes. There are few data on the prevalence of antecedent causes for HRF and the effect of these causes on prognosis, especially where study inclusion has not been biased with respect to primary diagnosis, interventions received or clinical outcome. We sought to determine the prevalence of pre-specified conditions among patients with HRF and to determine the effect of these causes on in-hospital mortality.

METHODS

Cross-sectional study of patients with HRF from 2013 to 2017. Inclusion criteria were PaCO₂  >45 mm Hg and pH ≤7.45. Causes of interest were identified using diagnosis codes from hospital records. We used directed acyclic graphs to inform logistic regression models for the outcome of in-hospital death.

RESULTS

We identified 873 persons with HRF in the study period. Mean (SD) age was 69 years and 50.4% were males. Acidosis (pH <7.35) was present in 488 (55%) cases. Most (83%) had one or more of the following: obstructive lung disease, lower respiratory tract infection, congestive cardiac failure, sleep disordered breathing, neuromuscular disease, opioid or benzodiazepine use. In-hospital mortality was 12.8%. Obstructive lung disease and cardiac failure were associated with a lower risk of death, whereas respiratory tract infection and neuromuscular disease were associated with increased risk of death.

CONCLUSION

HRF is associated with a range of potentially causative conditions, which significantly impact hospital survival. Systematic evaluation of patients with HRF may increase detection of treatable comorbidities.

Trends in Therapy and Outcomes Associated With Respiratory Failure in Patients Admitted to the Cardiac Intensive Care Unit

PURPOSE

To describe the epidemiology, outcomes, and temporal trends of respiratory failure in the cardiac intensive care unit (CICU).

MATERIALS AND METHODS

Retrospective cohort analysis of 2,986 unique Mayo Clinic CICU patients from 2007 to 2018 with respiratory failure. Temporal trends were analyzed, along with hospital and 1-year mortality. Multivariable logistic regression was used to determine adjusted hospital mortality trends.

RESULTS

The prevalence of respiratory failure in the CICU increased from 15% to 38% during the study period (P < 0.001 for trend). Among patients with respiratory failure, the utilization of invasive ventilation decreased and noninvasive ventilation modalities increased over time. Hospital mortality and 1-year mortality were 24% and 54%, respectively, with variation according to the type of respiratory support (highest among patients receiving invasive ventilation alone: 35% and 46%, respectively). Hospital mortality was highest among patients with concomitant cardiac arrest and/or shock (52% for patients with both). Hospital mortality decreased in the overall population from 35% to 25% (P < 0.001 for trend), but was unchanged among patients receiving positive-pressure ventilation.

CONCLUSIONS

The prevalence of respiratory failure in CICU more than doubled during the last decade. The use of noninvasive respiratory support increased, while overall mortality declined over time. Cardiac arrest and shock accounted for the majority of deaths. Further research is needed to optimize the outcomes of high-risk CICU patients with respiratory failure.

Coronary Artery Bypass Grafting Among Older Adults: Patterns, Outcomes, and Trends

INTRODUCTION

Although the numbers of older adults in the US are rapidly increasing, there is sparse recent data on the use and outcomes of coronary artery bypass grafting (CABG) among this population. We aimed to evaluate the characteristics and outcomes of older adults undergoing CABG and to measure temporal trends.

MATERIALS AND METHODS

Using data from the National Inpatient Sample (2005-2014), patients aged 85 y and older who underwent CABG were selected. Demographic, clinical, and hospital characteristics were extracted. Outcomes measured were hospital mortality, hospital length of stay, discharge home, and operative complications. Patients were grouped by 2-year increments. Differences in clinical characteristics and outcomes over time were evaluated using trend analyses.

RESULTS

There were 60,124 patients included in the cohort. The mean age was 86.8 y with majority being men (61%), white (88%), and treated in teaching hospitals (61%). Over the study period, the annual surgical volume decreased from 6689 in 2005/06 to 5150 in 2013/14. Mortality decreased from 8.5% to 5.5% (P-trend <0.001) and mean hospital length of stay decreased from 13.9 d to 12.0 d (P-trend <0.001), whereas the rate of discharge home remained stable (14.1% versus 11.6%, P-trend = 0.056). Compared with patients in 2005/06, those in 2013/14 had higher comorbidities [diabetes: 27.6% versus 17.3%; chronic kidney disease: 29.8% versus 9.2%; peripheral artery disease: 7.5% versus 6.0%; and hypertension: 83.7% versus 64.5% (all P-trend <0.001)].

CONCLUSIONS

CABG volumes are decreasing among older adults, and comorbidity burden is increasing, but outcomes are improving. These data may indicate improved preoperative optimization and better perioperative care processes.

Predictors and outcomes of acute respiratory failure in hospitalised patients with acute pancreatitis

BACKGROUND AND AIM

Acute pancreatitis (AP) is associated with organ failures and systemic complications, most commonly acute respiratory failure (ARF) and acute kidney injury. So far, no studies have analysed the predictors and hospitalisation outcomes, of patients with AP who developed ARF. The aim of this study was to measure the prevalence of ARF in AP and to determine the clinical predictors for ARF and mortality in AP.

METHODS

This is a retrospective cohort study using the Nationwide Inpatient Sample database from the year 2005-2014. The study population consisted of all hospitalisations with a primary or secondary discharge diagnosis of AP, which is further stratified based on the presence of ARF. The outcome measures include in-hospital mortality, hospital length of stay and hospitalisation cost.

RESULTS

In our study, about 5.4% of patients with AP had a codiagnosis of ARF, with a mortality rate of 26.5%. The significant predictors for ARF include sepsis, pleural effusion, pneumonia and cardiogenic shock. Key variables that were associated with a higher risk of mortality include mechanical ventilation, age more than 65 years, sepsis and cancer (excluding pancreatic cancer). The presence of ARF increased hospital stay by 8.3 days and hospitalisation charges by US$103 460.

CONCLUSION

In this study, we demonstrate that ARF is a significant risk factor for increased hospital mortality, greater length of stay and higher hospitalisation charges in patients with AP. This underlines significantly higher resource utilisation in patients with a dual diagnosis of AP-ARF.

Association of Preoperative Opioid Use With Mortality and Short-term Safety Outcomes After Total Knee Replacement

IMPORTANCE

Prescription opioid use is common among patients with moderate to severe knee osteoarthritis before undergoing total knee replacement (TKR). Preoperative opioid use may be associated with worse clinical and safety outcomes after TKR.

OBJECTIVE

To determine the association of preoperative opioid use among patients 65 years and older with mortality and other complications at 30 days post-TKR.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used claims data from January 1, 2010, to December 31, 2014, from a random sample of US Medicare enrollees 65 years and older who underwent TKR. Based on opioid dispensing in 360 days prior to TKR, patients were classified as continuous (≥1 opioid dispensing in each of the past 12 months) or intermittent (any dispensing of opioids in the past 12 months but not continuous use) opioid users or as opioid-naive patients (no opioids dispensed in the past 12 months). Data analyses were conducted from October 3, 2017, to November 8, 2018.

MAIN OUTCOMES AND MEASURES

Primary outcomes included in-hospital mortality and 30-day post-TKR mortality, hospital readmission, and revision operation. Secondary safety outcomes at 30 days post-TKR included opioid overdose and vertebral and nonvertebral fracture. Multivariable Cox proportional hazards models estimated hazard ratios (HRs) and 95% CIs.

RESULTS

Of 316 593 patients (mean [SD] age, 73.9 [5.8] years; 214 677 [67.8%] women) who underwent TKR, 22 895 (7.2%) were continuous opioid users, 161 511 (51.0%) were intermittent opioid users, and 132 187 (41.7%) were opioid naive. In-hospital mortality occurred in 276 patients (0.09%). At 30 days post-TKR, 828 patients (0.26%) died, 16 786 patients (5.30%) had hospital readmission, and 921 patients (0.29%) had a revision operation. All primary and secondary outcomes occurred more frequently among continuous opioid users compared with opioid-naive patients. Compared with opioid-naive patients and after adjusting for demographic characteristics, combined comorbidity score, number of different prescription medications, and frailty, continuous opioid users had greater risk of revision operations (HR, 1.63; 95% CI, 1.15-2.32), vertebral fractures (HR, 2.37; 95% CI, 1.37-4.09), and opioid overdose (HR, 4.82; 95% CI, 1.36-17.07) at 30 days post-TKR. However, after adjusting covariates, there were no statistically significant differences in in-hospital (HR, 1.18; 95% CI, 0.73-1.90) or 30-day (HR, 1.05; 95% CI, 0.73-1.51) mortality between continuous opioid users and opioid-naive patients.

CONCLUSIONS AND RELEVANCE

After adjusting for baseline risk profiles, including comorbidities and frailty, continuous opioid users had a higher risk of revision operations, vertebral fractures, and opioid overdose at 30 days post-TKR but not of in-hospital or 30-day mortality, compared with opioid-naive patients. These results highlight the need for better understanding of patient characteristics associated with chronic opioid use to optimize preoperative assessment of overall risk after TKR.

Epidemiological trends in invasive mechanical ventilation in the United States: A population-based study

PURPOSE

Epidemiological trends for invasive mechanical ventilation (IMV) have not been clearly defined. We sought to define trends for IMV in the United States and assess for disease-specific variation for 3 common causes of respiratory failure: pneumonia, heart failure (HF), and chronic obstructive pulmonary disease (COPD).

METHODS

We calculated national estimates for utilization of nonsurgical IMV cases from the Nationwide Inpatient Sample from 1993 to 2009 and compared trends for COPD, HF, and pneumonia.

RESULTS

We identified 8309344 cases of IMV from 1993 to 2009. Utilization of IMV for nonsurgical indications increased from 178.9 per 100000 in 1993 to 310.9 per 100000 US adults in 2009. Pneumonia cases requiring IMV showed the largest increase (103.6%), whereas COPD cases remained relatively stable (2.5% increase) and HF cases decreased by 55.4%. Similar demographic and clinical changes were observed for pneumonia, COPD, and HF, with cases of IMV becoming younger, more ethnically diverse, and more frequently insured by Medicaid. Outcome trends for patients differed based on diagnosis. Adjusted hospital mortality decreased over time for cases of pneumonia (odds ratio [OR] per 5 years, 0.89; 95% confidence interval [CI], 0.88-0.90) and COPD (OR per 5 years, 0.97; 95% CI, 0.97-0.98) but increased for HF (OR per 5 years, 1.10; 95% CI, 1.09-1.12).

CONCLUSION

Utilization of IMV in the US increased from 1993 to 2009 with a decrease in overall mortality. However, trends in utilization and outcomes of IMV differed markedly based on diagnosis. Unlike favorable outcome trends in pneumonia and COPD, hospital mortality for HF has not improved. Further studies to investigate the outcome gap between HF and other causes of respiratory failure are needed.

Database queries for hospitalizations for acute congestive heart failure: flexible methods and validation based on set theory

BACKGROUND AND OBJECTIVE

Electronic health records databases are increasingly used for identifying cohort populations, covariates, or outcomes, but discerning such clinical 'phenotypes' accurately is an ongoing challenge. We developed a flexible method using overlapping (Venn diagram) queries. Here we describe this approach to find patients hospitalized with acute congestive heart failure (CHF), a sampling strategy for one-by-one 'gold standard' chart review, and calculation of positive predictive value (PPV) and sensitivities, with SEs, across different definitions.

MATERIALS AND METHODS

We used retrospective queries of hospitalizations (2002-2011) in the Indiana Network for Patient Care with any CHF ICD-9 diagnoses, a primary diagnosis, an echocardiogram performed, a B-natriuretic peptide (BNP) drawn, or BNP >500 pg/mL. We used a hybrid between proportional sampling by Venn zone and over-sampling non-overlapping zones. The acute CHF (presence/absence) outcome was based on expert chart review using a priori criteria.

RESULTS

Among 79,091 hospitalizations, we reviewed 908. A query for any ICD-9 code for CHF had PPV 42.8% (SE 1.5%) for acute CHF and sensitivity 94.3% (1.3%). Primary diagnosis of 428 and BNP >500 pg/mL had PPV 90.4% (SE 2.4%) and sensitivity 28.8% (1.1%). PPV was <10% when there was no echocardiogram, no BNP, and no primary diagnosis. 'False positive' hospitalizations were for other heart disease, lung disease, or other reasons.

CONCLUSIONS

This novel method successfully allowed flexible application and validation of queries for patients hospitalized with acute CHF.

The U.S. Food and Drug Administration's Mini-Sentinel program: status and direction

The Mini-Sentinel is a pilot program that is developing methods, tools, resources, policies, and procedures to facilitate the use of routinely collected electronic healthcare data to perform active surveillance of the safety of marketed medical products, including drugs, biologics, and medical devices. The U.S. Food and Drug Administration (FDA) initiated the program in 2009 as part of its Sentinel Initiative, in response to a Congressional mandate in the FDA Amendments Act of 2007. After two years, Mini-Sentinel includes 31 academic and private organizations. It has developed policies, procedures, and technical specifications for developing and operating a secure distributed data system comprised of separate data sets that conform to a common data model covering enrollment, demographics, encounters, diagnoses, procedures, and ambulatory dispensing of prescription drugs. The distributed data sets currently include administrative and claims data from 2000 to 2011 for over 300 million person-years, 2.4 billion encounters, 38 million inpatient hospitalizations, and 2.9 billion dispensings. Selected laboratory results and vital signs data recorded after 2005 are also available. There is an active data quality assessment and characterization program, and eligibility for medical care and pharmacy benefits is known. Systematic reviews of the literature have assessed the ability of administrative data to identify health outcomes of interest, and procedures have been developed and tested to obtain, abstract, and adjudicate full-text medical records to validate coded diagnoses. Mini-Sentinel has also created a taxonomy of study designs and analytical approaches for many commonly occurring situations, and it is developing new statistical and epidemiologic methods to address certain gaps in analytic capabilities. Assessments are performed by distributing computer programs that are executed locally by each data partner. The system is in active use by FDA, with the majority of assessments performed using customizable, reusable queries (programs). Prospective and retrospective assessments that use customized protocols are conducted as well. To date, several hundred unique programs have been distributed and executed. Current activities include active surveillance of several drugs and vaccines, expansion of the population, enhancement of the common data model to include additional types of data from electronic health records and registries, development of new methodologic capabilities, and assessment of methods to identify and validate additional health outcomes of interest.