Value of Propensity Score Matching for Equalizing Comparator Groups in Observational Database Studies: A Case Study in Anti-infectives.

PURPOSE: Propensity score methodologies can reduce bias and confounding in nonrandomized studies, including pharmaceutical comparative effectiveness studies. An observational case study was developed to demonstrate the impact of propensity score adjustments on outcomes (ie, discharge status) of patients hospitalized for complicated intra-abdominal infections. METHODS: Two cohorts were examined: intensive care unit (ICU) (vs non-ICU) patients and tigecycline-treated patients (vs patients receiving other antibiotics). Discharge status was captured before propensity scoring. FINDINGS: The impact of propensity scoring on discharge outcome was greater when comparing ICU patients versus non-ICU patients than when comparing tigecycline recipients versus nonrecipients. IMPLICATIONS: Propensity scoring should be examined carefully to optimize its effects. Moreover, propensity scoring only addresses bias and confounding in nonrandomized studies that are attributable to variables contained within the dataset (ie, so called "observables") and not to other variables that may influence the relationship between outcomes and other independent variables.

Treatment for Multiple Acute Cardiopulmonary Conditions in Older Adults Hospitalized with Pneumonia, Chronic Obstructive Pulmonary Disease, or Heart Failure.

OBJECTIVES: To determine how often hospitalized older adults principally diagnosed with pneumonia, chronic obstructive pulmonary disease (COPD), or heart failure (HF) are concurrently treated for two or more of these acute cardiopulmonary conditions. DESIGN: Retrospective cohort study. SETTING: 368 U.S. hospitals in the Premier research database. PARTICIPANTS: Individuals aged 65 and older principally hospitalized with pneumonia, COPD, or HF in 2009 or 2010. MEASUREMENTS: Proportion of diagnosed episodes of pneumonia, COPD, or HF concurrently treated for two or more of these acute cardiopulmonary conditions during the first 2 hospital days. RESULTS: Of 91,709 diagnosed pneumonia hospitalizations, 32% received treatment for two or more acute cardiopulmonary conditions (18% for HF, 18% for COPD, 4% for both). Of 41,052 diagnosed COPD hospitalizations, 19% received treatment for two or more acute cardiopulmonary conditions (all of which involved additional HF treatment). Of 118,061 diagnosed HF hospitalizations, 38% received treatment for two or more acute cardiopulmonary conditions (34% for pneumonia, 9% for COPD, 5% for both). CONCLUSION: Hospitalized older adults diagnosed with pneumonia, COPD, or HF are frequently treated for two or more acute cardiopulmonary conditions, suggesting that clinical syndromes often fall between traditional diagnostic categories. Research is needed to evaluate the risks and benefits of real-world treatment for the many older adults whose presentations elicit diagnostic uncertainty or concern about coexisting acute conditions.

Evaluation of Tigecycline Efficacy and Post-Discharge Outcomes in a Clinical Practice Population with Complicated Intra-Abdominal Infection: A Propensity Score-Matched Analysis.

BACKGROUND: The utility of tigecycline as compared with other antibiotic therapies in the treatment of patients with complicated intra-abdominal infection (cIAI) and the short- and long-term outcomes of a large cohort of severely ill patients were examined. We provide the first published data on post-discharge events for these patients. METHODS: Retrospective data for the cIAI cohort were obtained from a large clinical database. Patients aged ≥18 y were selected for inclusion based on hospitalization with a relevant diagnosis code and procedure code, and guideline-compliant antimicrobial therapy. Propensity scoring was used to reduce treatment-selection bias introduced by the use of observational data. Tigecycline patients were placed into quintiles based on propensity score and were matched 1:3. RESULTS: The final model based on propensity score matching included 2,424 patients: Tigecycline (n = 606) and other antibiotic therapy (n = 1,818). Treatment was successful in 426 (70.3%) tigecycline-treated patients and in 1,294 (71.2%) patients receiving other antibiotics. Similar treatment success occurred across all infection sites. Among survivors, treatment failure was associated with a greater need for all-cause re-hospitalization at 30 d and 180 d. No differences in cIAI-related re-hospitalization and discharge status were observed. CONCLUSIONS: Using propensity scores to match populations, similar outcomes were demonstrated between treatment with tigecycline and other antibiotics as expressed by treatment success, the need for re-admission, similar 30-d discharge status, and the need for re-admission at 180 d.

Perioperative Fluid Utilization Variability and Association With Outcomes: Considerations for Enhanced Recovery Efforts in Sample US Surgical Populations.

OBJECTIVES: To study current perioperative fluid administration and associated outcomes in common surgical cohorts in the United States. BACKGROUND: An element of enhanced recovery care protocols, optimized perioperative fluid administration may be associated with improved outcomes; however, there is currently no consensus in the United States on fluid use or the effects on outcomes of this use. METHODS: The study included all inpatients receiving colon, rectal, or primary hip or knee surgery, 18 years of age or older, who were discharged from a hospital between January 1, 2008 and June, 30 2012 in the Premier Research Database. Patient outcomes and intravenous fluid utilization on the day of surgery were summarized for each surgical cohort. Regression models were developed to evaluate associations of high or low day-of-surgery fluids with the likelihood of increased hospital length of stay (LOS), total costs, or postoperative ileus. RESULTS: The study showed significant associations between high fluid volume given on the day of surgery with both increased LOS (odds ratio 1.10-1.40) and increased total costs (odds ratio 1.10-1.50). High fluid utilization was associated with increased presence of postoperative ileus for both rectal and colon surgery patients. Low fluid utilization was also associated with worse outcomes. CONCLUSIONS: According to results from this review of current practice in US hospitals, fluid optimization would likely lead to decreased variability and improved outcomes.

Potential return on investment for implementation of perioperative goal-directed fluid therapy in major surgery: a nationwide database study.

BACKGROUND: Preventable postsurgical complications are increasingly recognized as a major clinical and economic burden. A recent meta-analysis showed a 17-29 % decrease in postoperative morbidity with goal-directed fluid therapy. Our objective was to estimate the potential economic impact of perioperative goal-directed fluid therapy. METHODS: We studied 204,680 adult patients from 541 US hospitals who had a major non-cardiac surgical procedure between January 2011 and June 2013. Hospital costs (including 30-day readmission costs) in patients with and without complications were extracted from the Premier Inc. research database, and potential cost-savings associated with a 17-29 % decrease in postoperative morbidity were estimated. RESULTS: A total of 76,807 patients developed one or more postsurgical complications (morbidity rate 37.5 %). In patients with and without complications, hospital costs were US$27,607 ± 32,788 and US$15,783 ± 12,282 (p < 0.0001), respectively. Morbidity rate was anticipated to decrease to 26.6-31.1 % with goal-directed fluid therapy, yielding potential gross cost-savings of US$153-263 million for the study period, US$61-105 million per year, or US$754-1286 per patient. Potential savings per patient were highly variable from one surgical procedure to the other, ranging from US$354-604 for femur and hip-fracture repair to US$3515-5996 for esophagectomies. When taking into account the volume of procedures, the total potential savings per year were the most significant (US$32-55 million) for colectomies. CONCLUSIONS: Postsurgical complications occurred in more than one third of our study population and had a dramatic impact on hospital costs. With goal-directed fluid therapy, potential cost-savings per patient were US$754-1286. The highest cost-savings per year were observed for colectomies. These projections should help hospitals estimate the return on investment when considering the implementation of goal-directed fluid therapy.

Impact of an integrated intervention program on atorvastatin adherence: a randomized controlled trial.

BACKGROUND: This trial evaluated the effectiveness of an integrated intervention program that included a 3-to-5-minute nurse counseling session, copay relief cards, and a monthly newsletter on adherence to atorvastatin treatment. METHODS AND RESULTS: A prospective, integrated (composed of nurse counseling, adherence tip sheet, copay relief card, opportunity to enroll in 12-week cholesterol management program) randomized interventional study was designed involving patients >21 years of age who were prescribed atorvastatin at a large single-specialty cardiovascular physician practice in Illinois from March 2010 to May 2011. Data from the practice's electronic medical record were matched/merged to IMS Health's longitudinal data. A total of 500 patients were enrolled (125 in the control arm; 375 in the intervention arm). After data linkage, 53 control patients and 155 intervention patients were included in the analysis. RESULTS: Mean age was 67.8 years (control) and 69.5 years (intervention); 67.9% and 58.7%, respectively, were male. The mean 6-month adherence rate was 0.82 in both arms. The mean proportion of days covered for both the new-user control and intervention groups was the same, averaging 0.70 day (standard deviation [SD], 0.27 day); for continuing users, the proportion of days covered for the control group was 0.83 (SD, 0.24) and for the intervention group was 0.84 (SD, 0.22). For continuing users, the control group had mean persistent days of 151.6 (SD, 50.2) compared with 150.9 days (SD, 50.9) for the intervention group. New users had fewer persistent days (control 111.4 days, SD, 69.6 days; intervention 112.0 days, SD, 58.8 days) compared with continuing users. The Cox proportional hazards model of the risk of discontinuation with index therapy was not significantly different between the intervention and control groups (hazard ratio 0.83, P = 0.55). CONCLUSION: The integrated intervention program did not significantly improve atorvastatin adherence relative to usual care in the studied patient population.