Penelope S. Pekow

The Influence of Procedure Volumes and Standardization of Care on Quality and Efficiency in Total Joint Replacement Surgery

BACKGROUNDnThe relationship between surgeon and hospital procedure volumes and clinical outcomes in total joint arthroplasty has long fueled a debate over regionalization of care. At the same time, numerous policy initiatives are focusing on improving quality by incentivizing surgeons to adhere to evidence-based processes of care. The purpose of this study was to evaluate the independent contributions of surgeon procedure volume, hospital procedure volume, and standardization of care on short-term postoperative outcomes and resource utilization in lower-extremity total joint arthroplasty.nnnMETHODSnAn analysis of 182,146 consecutive patients who underwent primary total joint arthroplasty was performed with use of data entered into the Perspective database by 3421 physicians from 312 hospitals over a two-year period. Adherence to evidence-based processes of care was defined by administration of appropriate perioperative antibiotic prophylaxis, beta-blockade, and venous thromboembolism prophylaxis. Patient outcomes included mortality, length of hospital stay, discharge disposition, surgical complications, readmissions, and reoperations within the first thirty days after discharge. Hierarchical models were used to estimate the effects of hospital and surgeon procedure volume and process standardization on individual and combined surgical outcomes and length of stay.nnnRESULTSnAfter adjustment in multivariate models, higher surgeon volume was associated with lower risk of complications, lower rates of readmission and reoperation, shorter length of hospital stay, and higher likelihood of being discharged home. Higher hospital volume was associated with lower risk of mortality, lower risk of readmission, and higher likelihood of being discharged home. The impact of process standardization was substantial; maximizing adherence to evidence-based processes of care resulted in improved clinical outcomes and shorter length of hospital stay, independent of hospital or surgeon procedure volume.nnnCONCLUSIONSnAlthough surgeon and hospital procedure volumes are unquestionably correlated with patient outcomes in total joint arthroplasty, process standardization is also strongly associated with improved quality and efficiency of care. The exact relationship between individual processes of care and patient outcomes has not been established; however, our findings suggest that process standardization could help providers optimize quality and efficiency in total joint arthroplasty, independent of hospital or surgeon volume.

Antibiotic therapy and treatment failure in patients hospitalized for acute exacerbations of chronic obstructive pulmonary disease.

CONTEXTnGuidelines recommend antibiotic therapy for acute exacerbations of chronic obstructive pulmonary disease (COPD), but the evidence is based on small, heterogeneous trials, few of which include hospitalized patients.nnnOBJECTIVEnTo compare the outcomes of patients treated with antibiotics in the first 2 hospital days with those treated later or not at all.nnnDESIGN, SETTING, AND PATIENTSnRetrospective cohort of patients aged 40 years or older who were hospitalized from January 1, 2006, through December 31, 2007, for acute exacerbations of COPD at 413 acute care facilities throughout the United States.nnnMAIN OUTCOME MEASURESnA composite measure of treatment failure, defined as the initiation of mechanical ventilation after the second hospital day, inpatient mortality, or readmission for acute exacerbations of COPD within 30 days of discharge; length of stay, and hospital costs.nnnRESULTSnOf 84,621 patients, 79% received at least 2 consecutive days of antibiotic treatment. Treated patients were less likely than nontreated patients to receive mechanical ventilation after the second hospital day (1.07%; 95% confidence interval [CI], 1.06%-1.08% vs 1.80%; 95% CI, 1.78%-1.82%), had lower rates of inpatient mortality (1.04%; 95% CI, 1.03%-1.05% vs 1.59%; 95% CI, 1.57%-1.61%), and had lower rates of readmission for acute exacerbations of COPD (7.91%; 95% CI, 7.89%-7.94% vs 8.79%; 95% CI, 8.74%-8.83%). Patients treated with antibiotic agents had a higher rate of readmissions for Clostridium difficile (0.19%; 95% CI, 0.187%-0.193%) than those who were not treated (0.09%; 95% CI, 0.086%-0.094%). After multivariable adjustment, including the propensity for antibiotic treatment, the risk of treatment failure was lower in antibiotic-treated patients (odds ratio, 0.87; 95% CI, 0.82-0.92). A grouped treatment approach and hierarchical modeling to account for potential confounding of hospital effects yielded similar results. Analysis stratified by risk of treatment failure found similar magnitudes of benefit across all subgroups.nnnCONCLUSIONnEarly antibiotic administration was associated with improved outcomes among patients hospitalized for acute exacerbations of COPD regardless of the risk of treatment failure.

Influence of cardiopulmonary bypass perfusion temperature on neurologic and hematologic function after coronary artery bypass grafting

BACKGROUND AND METHODSnA National Institutes of Health-sponsored trial (1994 to 1998) randomized patients undergoing coronary artery bypass grafting that required three or more grafts to receive perfusion at either cold (20 degrees C), tepid (32 degrees C), or warm (37 degrees C) temperature. The goal of the study was to evaluate morbidity, primarily neurologic dysfunction and secondarily hematologic factors. One thousand seven hundred seventy-seven patients were screened and 291 enrolled. Neurologic function was studied by a dedicated pool of blinded neurologists. A standard test battery termed the Mathew Scale using three subscales--cognitive function, elemental skills, and disability--was used to study central nervous system function. Hematologic function was assessed in 53 of the 291 patients with measurements of postoperative fibrinolytic potential.nnnRESULTSnAll preoperative and operative data were comparable between groups. A decrease in Mathew Scale was seen in 69% of patient from before operation to immediately after operation. However, between the early postoperative study and the 1-month follow-up, 48% of patients had returned to baseline. There was no difference noted across temperature groups in any neurologic parameter of function. In all, 55% of the group were at or above their preoperative level at 1 month. Forty-nine patients suspect for cerebrovascular accident had a computed tomographic scan, but only 13 (4.5%) had a documented cerebrovascular accident (4 patients in the warm, 3 in the tepid, and 6 patients in the cold group). Fibrinolytic changes correlated with perfusion temperature documented that fibrinolysis was most active at 37 degrees C. Thus, increasing perfusate temperature increases fibrinolysis, which was associated with reoperation for bleeding in 4% warm group patients, 1% tepid, and 0% cold group patients (0.1 > p > 0.05). No other perioperative complications were temperature related. There were 4 deaths (1.4%) (1 in the warm group, 2 in the tepid group, and 1 in the cold group).nnnCONCLUSIONSn(1) Persistent postoperative neurologic dysfunction at 1 month occurs in 36% of patients undergoing coronary artery bypass grafting and is not related to a cerebrovascular accident; 2) perfusion temperature has no relationship to neurologic function after bypass; and 3) fibrinolytic activity is greatest at warm temperatures.

Variation in Diagnostic Coding of Patients With Pneumonia and Its Association With Hospital Risk-Standardized Mortality Rates: A Cross-sectional Analysis

Context Hospital risk-standardized mortality rates for pneumonia are publicly reported but exclude more severe cases of pneumonia, which are coded as sepsis or respiratory failure with pneumonia as a secondary diagnosis. Contribution A sample of U.S. hospitals varied widely in the proportion of all pneumonia cases coded as sepsis or respiratory failure with a secondary diagnosis of pneumonia, even after adjustment for indicators of disease severity. Caution Sampled hospitals may not be fully representative of all U.S. hospitals. Implication Variation among hospitals in risk-standardized rates of mortality from pneumonia may be related to variation in coding practices rather than the quality of care delivered. The Editors Pneumonia is the most common cause of emergency hospitalization in the United States (1). As such, it is an appropriate target for quality improvement initiatives and public reporting of hospital quality. Initial efforts at public reporting focused on processes of care, including the choice and timing of initial antibiotics, pneumococcal vaccination, and assessment of oxygenation within 24 hours of admission. However, these measures correlate only weakly with more important outcomes, such as 30-day mortality (2, 3). In 2008, the Centers for Medicare & Medicaid Services (CMS) added hospital-level risk-standardized mortality to its Hospital Compare Web site (4). These rates reflect adjustment for patient age, sex, and comorbid conditions, and mortality estimates from the administrative prediction model have been shown to correlate well with mortality as measured by reviews of clinical records (5). Beginning in 2012, under value-based purchasing, hospital reimbursement became partly tied to 30-day mortality rates (6). To estimate hospital 30-day risk-standardized mortality rates, CMS includes only patients with a principal diagnosis of pneumonia. The principal diagnosis is defined in the Uniform Hospital Discharge Data Set as that condition established after study to be chiefly responsible for occasioning the admission of the patient to the hospital for care (7). Patients who are assigned pneumonia as a secondary diagnosis are excluded because, in these cases, pneumonia may represent a complication of hospitalization rather than the reason for admission (5). However, many patients with pneumonia, especially the sicker ones, may also have sepsis or respiratory failure, the definitions of which are subject to interpretation. For example, CMS official coding guidelines recognize 2 or more of the following as indicative of the systemic inflammatory response syndrome: a temperature more than 101F or less than 96.8F, heart rate greater than 90 beats/min, respiratory rate greater than 20 breaths/min, or leukocyte count greater than 12109 cells/L or less than 4109 cells/L or with greater than 10% bands. Taken together with a source of infection, such as pneumonia, these signs fulfill the definition of sepsis (8). We have previously reported that the recent decrease in the mortality rate of patients hospitalized with pneumonia may be an artifact of the changing use of these codes, whereby the sickest patients have, over time, increasingly received a principal diagnosis of sepsis or respiratory failure. Thus, these patients are not considered in the measure of pneumonia mortality (9). Just as changes in coding over time could lead to erroneous conclusions about decreasing mortality rates, variation in coding across hospitals could lead to biased estimates of relative mortality rates. We hypothesized that hospitals would vary in their threshold for applying the sepsis and respiratory failure codes and that those that apply these principal diagnoses more frequently would seem to have a lower pneumonia mortality rate than similar hospitals that applied the codes less frequently. On its Hospital Compare Web site and for reimbursement purposes, CMS does not emphasize the mortality rates of individual hospitals but identifies each hospital as better, worse, or no different from the national average. We therefore examined changes in hospital outlier status that would result from inclusion or exclusion of patients with a secondary diagnosis of pneumonia but a principal diagnosis of sepsis or respiratory failure in a large and diverse group of U.S. hospitals. Methods Setting and Participants We included all hospitals that participated in Premiers Perspective database between 1 July 2007 and 30 June 2010. Perspective, an administrative database used to measure quality and resource utilization, has been used extensively for quality of care and comparative effectiveness research (10, 11). Participating hospitals represent all regions of the United States and include teaching and nonteaching hospitals of various sizes located in urban or rural settings. They are generally similar to U.S. hospitals as a whole, although the data set is weighted more heavily in the South, urban locations, and teaching hospitals. Available data elements for each patient include sociodemographic information; International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis and procedure codes; and date-stamped charges for all tests and treatments done during hospitalization. The institutional review board at Baystate Medical Center (Springfield, Massachusetts) determined that the study did not constitute human subjects research. We included all patients aged 18 years or older with a diagnosis of pneumonia (principal or secondary if paired with a principal diagnosis of sepsis or respiratory failure) (Appendix Table). We excluded patients with pneumonia marked as not present on admission. In addition, all patients had to have a chest radiograph and receive antibiotic therapy within 48 hours of admission. To ensure a stable mortality estimate, we excluded hospitals with fewer than 100 admissions during the study period. Appendix Table. ICD-9-CM Codes Used in the Definition of Pneumonia, Sepsis, and Respiratory Failure Outcomes Our primary outcome was the hospital risk-standardized mortality rate. For each admission, we identified patient age and sex. To be consistent with the approach used by CMS in calculating a hospitals risk-standardized mortality rate, we did not include race, marital status, or insurance type. CMS also adjusts for preexisting comorbid conditions by using the hierarchical condition categories. The CMS risk-adjustment model for hierarchical condition categories does not include comorbid conditions that may represent complications of care (5). This model requires information about outpatient diagnoses in the previous year, which is not available in Premiers Perspective database. Taking a similar approach, we identified comorbid conditions by using software provided by the Agency for Healthcare Research and Quality. This model, based on the work of Elixhauser and colleagues (12), uses International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify relevant comorbid conditions while excluding complications or other diagnoses related to the principal diagnosis. Both models have acceptable C statistics for predicting mortality, although the hierarchical condition categories model may have better discrimination (13). Statistical Analysis We examined associations of patient and hospital characteristics with principal diagnosis coding (pneumonia vs. sepsis or respiratory failure) by using generalized estimating equations models with a logit link (SAS PROC GENMOD), accounting for clustering of patients within hospitals. To see whether severity of illness varied as the proportion of sepsis or respiratory failure coding increased, we evaluated Spearman correlations of hospital proportion of patients with a diagnosis of sepsis or respiratory failure with mortality rates, as well as with rates of early initiation (hospital day 1 or 2) of mechanical ventilation or vasopressors and admission to the intensive care unit of patients with these principal diagnoses. To assess for nonlinear correlations, we stratified hospitals above and below the median proportion. Following the process that CMS uses to evaluate hospital outcomes (14, 15), we developed multivariable hierarchical generalized linear models by using SAS PROC GLIMMIX with a random effect for hospitals to predict each patients probability of mortality on the basis of age, sex, and comorbid conditions (Supplement). We fit 2 models, 1 limited to admissions with pneumonia coded as a principal diagnosis and 1 including all pneumonia admissions. From each model, each hospitals predicted mortality rate was computed as that which would be anticipated by using the hospitals random effect, given the patient case-mix. The expected mortality rate was computed as that which would be expected if the same patient mix was treated at an average hospital, using the average hospital effect. For each model, a hospital risk-standardized mortality rate was computed as the ratio of predicted to expected mortality standardized by the overall unadjusted mean mortality rate for all admissions in our model. Supplement. Risk-Standardized Mortality Modeling Next, we used bootstrap methods to develop a 95% CI estimate of risk-standardized mortality for each hospital, for admission with a principal diagnosis of pneumonia, and for all pneumonia admissions. Hospitals were rated as better than average if the interval was entirely below the overall patient mean mortality and worse than average if the interval was entirely above the mean. Hospitals with intervals overlapping the mean were rated as no different than average. Finally, to see the effect of sepsis or respiratory failure coding practices on reported performance, we identified hospitals whose ratings changed when cases of sepsis or respiratory failure were included and compared the change in outlier status across the quintiles of sepsis or respiratory failure coding. All analyses were done

Association Between Initial Route of Fluoroquinolone Administration and Outcomes in Patients Hospitalized for Community Acquired Pneumonia

BACKGROUNDnFluoroquinolones have equivalent oral and intravenous bioavailability, but hospitalized patients with community-acquired pneumonia (CAP) generally are treated intravenously. Our objectives were to compare outcomes of hospitalized CAP patients initially receiving intravenous vs oral respiratory fluoroquinolones.nnnMETHODSnThis was a retrospective cohort study utilizing data from 340 hospitals involving CAP patients admitted to a non-intensive care unit (ICU) setting from 2007 to 2010, who received intravenous or oral levofloxacin or moxifloxacin. The primary outcome was in-hospital mortality. Secondary outcomes included clinical deterioration (transfer to ICU, initiation of vasopressors, or invasive mechanical ventilation [IMV] initiated after the second hospital day), antibiotic escalation, length of stay (LOS), and cost.nnnRESULTSnOf 36 405 patients who met inclusion criteria, 34 200 (94%) initially received intravenous treatment and 2205 (6%) received oral treatment. Patients who received oral fluoroquinolones had lower unadjusted mortality (1.4% vs 2.5%; P = .002), and shorter mean LOS (5.0 vs 5.3; P < .001). Multivariable models using stabilized inverse propensity treatment weighting revealed lower rates of antibiotic escalation for oral vs intravenous therapy (odds ratio [OR], 0.84; 95% confidence interval [CI], .74-.96) but no differences in hospital mortality (OR, 0.82; 95% CI, .58-1.15), LOS (difference in days 0.03; 95% CI, -.09-.15), cost (difference in

Variation in Resource Utilization for the Management of Uncomplicated Community-Acquired Pneumonia across Community and Children's Hospitals

-7.7; 95% CI, -197.4-182.0), late ICU admission (OR, 1.04; 95% CI, .80-1.36), late IMV (OR, 1.17; 95% CI, .87-1.56), or late vasopressor use (OR, 0.94; 95% CI, .68-1.30).nnnCONCLUSIONSnAmong hospitalized patients who received fluoroquinolones for CAP, there was no association between initial route of administration and outcomes. More patients may be treated orally without worsening outcomes.

Using highly detailed administrative data to predict pneumonia mortality

OBJECTIVEnTo describe patterns of diagnostic testing and antibiotic management of uncomplicated pneumonia in general community hospitals and childrens hospitals within hospitals and to determine the association between diagnostic testing and length of hospital stay.nnnSTUDY DESIGNnWe conducted a retrospective cohort study of children 1-17 years of age hospitalized with the diagnosis of pneumonia from 2007 to 2010 to hospitals contributing data to Perspective Database Warehouse, assessing patterns of diagnostic testing and antibiotic management. We constructed logistic regression models of log-transformed length of stay (LOS) and grouped treatment models to ascertain whether performance of blood cultures and viral respiratory testing were associated with LOS.nnnRESULTSnA total of 17u2008299 pneumonia cases occurred at 125 hospitals, with considerable variability in pneumonia management. Only 40 (0.2%) received ampicillin/penicillin G alone or in combination with other antibiotics, and 1318 (7.4%) received macrolide monotherapy as initial antibiotic management. Performance of blood culture and testing for respiratory viruses was associated with a statistically significant longer LOS, but these differences did not persist in grouped treatment models.nnnCONCLUSIONSnWe observed greater rates of diagnostic testing in this cohort of structurally diverse hospitals than previously reported at freestanding childrens hospitals, with extremely low rates of narrow-spectrum antibiotic use. Tailored antibiotic stewardship initiatives at these hospitals are needed to achieve adherence to national guideline recommendations.

Comparative effectiveness of macrolides and quinolones for patients hospitalized with acute exacerbations of chronic obstructive pulmonary disease (AECOPD)

Background Mortality prediction models generally require clinical data or are derived from information coded at discharge, limiting adjustment for presenting severity of illness in observational studies using administrative data. Objectives To develop and validate a mortality prediction model using administrative data available in the first 2 hospital days. Research Design After dividing the dataset into derivation and validation sets, we created a hierarchical generalized linear mortality model that included patient demographics, comorbidities, medications, therapies, and diagnostic tests administered in the first 2 hospital days. We then applied the model to the validation set. Subjects Patients aged ≥18 years admitted with pneumonia between July 2007 and June 2010 to 347 hospitals in Premier, Inc.’s Perspective database. Measures In hospital mortality. Results The derivation cohort included 200,870 patients and the validation cohort had 50,037. Mortality was 7.2%. In the multivariable model, 3 demographic factors, 25 comorbidities, 41 medications, 7 diagnostic tests, and 9 treatments were associated with mortality. Factors that were most strongly associated with mortality included receipt of vasopressors, non-invasive ventilation, and bicarbonate. The model had a c-statistic of 0.85 in both cohorts. In the validation cohort, deciles of predicted risk ranged from 0.3% to 34.3% with observed risk over the same deciles from 0.1% to 33.7%. Conclusions A mortality model based on detailed administrative data available in the first 2 hospital days had good discrimination and calibration. The model compares favorably to clinically based prediction models and may be useful in observational studies when clinical data are not available.

Comparative Effectiveness of Ceftriaxone in Combination With a Macrolide Compared With Ceftriaxone Alone for Pediatric Patients Hospitalized With Community-acquired Pneumonia

BACKGROUNDnMeta-analyses of randomized trials have found that antibiotics are effective in acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but there is insufficient evidence to guide antibiotic selection. Current guidelines offer conflicting recommendations.nnnOBJECTIVEnTo compare the effectiveness of macrolides and quinolones for AECOPD DESIGN: Retrospective cohort study using logistic regression, propensity score-matching, and grouped treatment models.nnnSETTINGnA total of 375 acute care hospitals throughout the United States.nnnPATIENTSnAge > or =40 years and hospitalized for AECOPD.nnnINTERVENTIONnMacrolide or quinolone antibiotic begun in the first 2 hospital days.nnnMEASUREMENTSnTreatment failure (defined as the initiation of mechanical ventilation after hospital day 2, inpatient mortality, or readmission for AECOPD within 30 days), length of stay, and hospital costs.nnnRESULTSnOf the 19,608 patients who met the inclusion criteria, 6139 (31%) were treated initially with a macrolide and 13,469 (69%) with a quinolone. Compared to patients treated initially with a quinolone, those who received macrolides had a lower risk of treatment failure (6.8% vs. 8.1%; P < 0.01), a finding that was attenuated after multivariable adjustment (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.78-1.01), and disappeared in a grouped-treatment analysis (OR, 1.01; 95% CI, 0.75-1.35). There were no differences in adjusted length of stay (ratio, 0.98; 95% CI, 0.97-1.00) or adjusted cost (ratio, 1.00; 95% CI, 0.99-1.02). After propensity score-matching, antibiotic-associated diarrhea was more common with quinolones (1.2% vs. 0.6%; P < 0.001).nnnCONCLUSIONSnMacrolide and quinolone antibiotics are associated with similar rates of treatment failure in AECOPD; however, macrolides are less frequently associated with diarrhea.

Association of guideline-based antimicrobial therapy and outcomes in healthcare-associated pneumonia

Background: Guidelines for management of community-acquired pneumonia recommend empiric therapy with a macrolide and beta-lactam when infection with Mycoplasma pneumoniae is a significant consideration. Evidence to support this recommendation is limited. We sought to determine the effectiveness of ceftriaxone alone compared with ceftriaxone combined with a macrolide with respect to length of stay and total hospital costs. Methods: We conducted a retrospective cohort study of children 1–17 years with pneumonia, using Poisson regression and propensity score analyses to assess associations between antibiotic and length of stay. Multivariable linear regression and propensity score analyses were used to assess log-treatment costs, adjusting for patient and hospital characteristics and initial tests and therapies. Results: A total of 4701 children received combination therapy and 8892 received ceftriaxone alone. Among children 1–4 years of age, adjusted models revealed no significant difference in length of stay, with significantly higher costs in the combination therapy group [cost ratio: 1.08 (95% confidence interval: 1.05–1.11)]. Among children 5–17 years of age, children receiving combination therapy had a shorter length of stay [relative risk: 0.95 (95% confidence interval: 0.92–0.98)], with no significant difference in costs [cost ratio: 1.01 (95% confidence interval: 0.98–1.04)]. Conclusions: Combination therapy did not appear to benefit preschool children but was associated with higher costs. Among school-aged children, combination therapy was associated with a shorter length of stay without a significant impact on cost. Development of sensitive point-of-care diagnostic tests to identify children with M. pneumoniae infection may allow for more focused prescription of macrolides and enable comparative effectiveness studies of targeted provision of combination therapy.