Moriarty, James P.

Propensity score (PS) methods have proliferated in recent years in observational studies in general and in observational comparative effectiveness research (CER) in particular. PS methods are an important set of tools for estimating treatment effects in observational studies, enabling adjustment for measured confounders in an easy-to-understand and transparent way. This article demonstrates how PS methods have been used to address specific CER questions from 2001 through to 2012 by identifying six impactful studies from this period. This article also discusses areas for improvement, including data infrastructure, and a unified set of guidelines in terms of PS implementation and reporting, which will boost confidence in evidence generated through observational CER using PS methods.

Study ObjectiveTo identify specific risk factors for excessive anticoagulation, defined as an international normalized ratio (INR) higher than 5, in hospitalized adults receiving warfarin therapy using a pharmacist‐managed dosing protocol.DesignRetrospective nested case‐control study.SettingLarge academic tertiary care medical center.PatientsHospitalized nonsurgical patients 18 years or older who received at least one dose of warfarin according to the pharmacist‐managed protocol from January 1, 2009, to January 31, 2012, were included. Patients who experienced an INR higher than 5 were designated as case patients; those who received warfarin for at least as many days as the case patients but who did not experience an INR more than 5 were deemed control patients. Controls were matched to cases in a 2:1 ratio by age, sex, INR goal, and type of warfarin therapy (new start or continuation).Measurements and Main ResultsA total of 87 case patients were matched to 174 controls. Ten different hypothesized risk factors were examined. Two variables, severity of illness score (odds ratio [OR] 4.89, p<0.001) and poor nutritional status (OR 4.27, p<0.001), demonstrated strong independent associations with risk of excessive anticoagulation. Administration of interacting drugs that highly potentiate warfarin's effect (OR 2.26, p=0.011) and concurrent diarrheal illness (OR 4.75, p<0.001) also displayed a statistically significant risk for excessive anticoagulation.ConclusionEven in a highly standardized system for warfarin dosing by a pharmacist‐managed protocol, higher disease severity and poor nutritional status placed hospitalized patients at greater risk of experiencing excessive anticoagulation. In addition, administration of interacting drugs that highly potentiate warfarin's effect or the occurrence of diarrheal illness may predict increased risk.

Established hospital palliative care consult services (PCCS) have been associated with reduced costs and length of stay, decreased symptom burden, and increased satisfaction with care. Using a retrospective case–control design, we analyzed administrative data of patients seen by PCCS while hospitalized at the Rochester, Minnesota Mayo Clinic hospitals from 2003 to 2008. The PCCS patients were matched to 3:1. A total of 1477 patients seen by the PCCS were matched with 4431 patients not seen. Costs for patients seen and discharged alive were US$35 449 (95% confidence interval [CI] US$34 157-US$36 686) compared to US$37 447 (95% CI US$36 734-US$38 126), without PCCS consultation. Costs for PCCS patients that died during hospitalization were US$54 940 (95% CI US$51 483-US$58 576) and non-PCCS patients were US$79 660 (95% CI US$76 614-US$83 398).

Objective To describe the extent of use and in‐hospital outcomes of open and laparoscopic pyeloplasty for paediatric pelvi‐ureteric junction ( PUJ ) obstruction in the USA . Patients and Methods Using the 2004–2008 N ationwide I npatient S ample, we identified 4590 paediatric patients (≤18 years old) who underwent open or laparoscopic pyeloplasty for PUJ obstruction at 195 hospitals. Multivariable regression models were used to test the associations between hospital and patient covariates (age, gender, race, primary health insurance), type of admission (emergent vs elective), and hospital characteristics (teaching vs non‐teaching status; rural vs urban location) with complications, length of stay ( LOS ), and total hospitalization costs. Results During the 5‐year study interval, 4426 (96.4%) and 164 (3.6%) paediatric patients diagnosed with PUJ obstruction underwent open and laparoscopic pyeloplasty, respectively. The proportion of patients undergoing laparoscopic pyeloplasty gradually increased from 2.4% in 2004 to 4.4% in 2008, but this increase was not significant ( P = 0.22 for trend). On multivariable analysis, laparoscopic pyeloplasty was observed to have rates of postoperative complications (2.51 vs 5.00; P = 0.67), LOS (2.42 vs 2.75; P = 0.33) and total hospitalization cost ($9755 vs $8537; P = 0.24) similar to those of open pyeloplasty. Conclusions While laparoscopic pyeloplasty was generally an infrequent operation performed for paediatric PUJ obstruction during the period studied, this minimally invasive surgery provided similar outcomes in terms of in‐hospital complications, LOS and total hospitalization costs. The results of this study inform policymakers about the comparative effectiveness of laparoscopic and open pyeloplasty.

Purpose Contralateral prophylactic mastectomy (CPM) rates in women with unilateral breast cancer are increasing despite controversy regarding survival advantage. Current scrutiny of the medical costs led us to evaluate the cost-effectiveness of CPM versus routine surveillance as an alternative contralateral breast cancer (CBC) risk management strategy. Methods Using a Markov model, we simulated patients with breast cancer from mastectomy to death. Model parameters were gathered from published literature or national databases. Base-case analysis focused on patients with average-risk breast cancer, 45 years of age at treatment. Outcomes were valued in quality-adjusted life-years (QALYs). Patients' age, risk level of breast cancer, and quality of life (QOL) were varied to assess their impact on results. Results Mean costs of treatment for women age 45 years are comparable: $36,594 for the CPM and $35,182 for surveillance. CPM provides 21.22 mean QALYs compared with 20.93 for surveillance, resulting in an incremental cost-effectiveness ratio (ICER) of $4,869/QALY gained for CPM. To prevent one CBC, six CPMs would be needed. CPM is no longer cost-effective for patients older than 70 years (ICER $62,750/QALY). For BRCA-positive patients, CPM is clearly cost-effective, providing more QALYs while being less costly. In non-BRCA patients, cost-effectiveness of CPM is highly dependent on assumptions regarding QOL for CPM versus surveillance strategy. Conclusion CPM is cost-effective compared with surveillance for patients with breast cancer who are younger than 70 years. Results are sensitive to BRCA-positive status and assumptions of QOL differences between CPM and surveillance patients. This highlights the importance of tailoring treatment for individual patients.