Borah, Bijan J.

Aim: Missing data, particularly missing variables, can create serious analytic challenges in observational comparative effectiveness research studies. Statistical linkage of datasets is a potential method for incorporating missing variables. Prior studies have focused upon the bias introduced by imperfect linkage. Methods: This analysis uses a case study of hepatitis C patients to estimate the net effect of statistical linkage on bias, also accounting for the potential reduction in missing variable bias. Results: The results show that statistical linkage can reduce bias while also enabling parameter estimates to be obtained for the formerly missing variables. Conclusion: The usefulness of statistical linkage will vary depending upon the strength of the correlations of the missing variables with the treatment variable, as well as the outcome variable of interest.

ABSTRACTBackgroundThe authors sought to estimate incremental economic impact of atrial fibrillation (AF) and the timing of its onset in myocardial infarction (MI) patients.HypothesisConcurrent AF and its timing are associated with higher costs in MI patients.MethodsThis retrospective cohort study included incident MI patients from Olmsted County, Minnesota, treated between November 1, 2002, and December 31, 2010. We compared inflation‐adjusted standardized costs accumulated between incident MI and end of follow‐up among 3 groups by AF status and timing: no AF, new‐onset AF (within 30 days after index MI), and prior AF. Multivariate adjustment of median costs accounted for right‐censoring in costs.ResultsThe final study cohort had 1389 patients, with 989 in no AF, 163 in new‐onset AF, and 237 in prior AF categories. Median follow‐up times were 3.98, 3.23, and 2.55 years, respectively. Mean age at index was 67 years, with significantly younger patients in the no AF group (64 years vs 76 and 77 years, respectively; P < 0.001). New‐onset and prior AF patients had more comorbid conditions (hypertension, heart failure, and chronic obstructive pulmonary disease). After accounting for differences in baseline characteristics, we found adjusted median (95% confidence interval) costs of $73 000 ($69 000‐$76 000) for no AF; $85 000 ($81 000‐$89 000) for new‐onset AF; and $97 000 ($94 000‐$100 000) for prior AF. Inpatient costs composed the largest share of total median costs (no AF, 82%; new‐onset AF, 84%; prior AF, 83%).ConclusionsAtrial fibrillation frequently coexists with MI and imposes incremental costs, mainly attributable to inpatient care. Timing of AF matters, as prior AF was found to be associated with higher costs than new‐onset AF.

Although ibrutinib and idelalisib are profound treatment advances, they will dramatically increase individual out-of-pocket and societal costs of caring for patients with CLL.

Objective:To evaluate the cost–effectiveness of the following three treatments of uterine fibroids in a population of premenopausal women who wish to preserve their uteri: myomectomy, magnetic resonance-guided focused ultrasound (MRgFUS) and uterine artery embolization (UAE).Materials & methods:A decision analytic Markov model was constructed. Cost–effectiveness was calculated in terms of US$ per quality-adjusted life year (QALY) over 5 years. Two types of costs were calculated: direct costs only, and the sum of direct and indirect (productivity) costs. Women in the hypothetical cohort were assessed for treatment type eligibility, were treated based on eligibility, and experienced adequate or inadequate symptom relief. Additional treatment (myomectomy) occurred for inadequate symptom relief or recurrence. Sensitivity analysis was conducted to evaluate uncertainty in the model parameters.Results: In the base case, myomectomy, MRgFUS and UAE had the following combinations of mean cost and mean QALYs, respectively: US$15,459, 3.957; US$15,274, 3.953; and US$18,653, 3.943. When incorporating productivity costs, MRgFUS incurred a mean cost of US$21,232; myomectomy US$22,599; and UAE US$22,819. Using probabilistic sensitivity analysis (PSA) and excluding productivity costs, myomectomy was cost effective at almost every decision threshold. Using PSA and incorporating productivity costs, myomectomy was cost effective at decision thresholds above US$105,000/QALY; MRgFUS was cost effective between US$30,000 and US$105,000/QALY; and UAE was cost effective below US$30,000/QALY.Conclusion:Myomectomy, MRgFUS, and UAE were similarly effective in terms of QALYs gained. Depending on assumptions about costs and willingness to pay for additional QALYs, all three treatments can be deemed cost effective in a 5-year time frame.

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.

ABSTRACTThe quantile regression (QR) framework provides a pragmatic approach in understanding the differential impacts of covariates along the distribution of an outcome. However, the QR framework that has pervaded the applied economics literature is based on the conditional quantile regression method. It is used to assess the impact of a covariate on a quantile of the outcome conditional on specific values of other covariates. In most cases, conditional quantile regression may generate results that are often not generalizable or interpretable in a policy or population context. In contrast, the unconditional quantile regression method provides more interpretable results as it marginalizes the effect over the distributions of other covariates in the model. In this paper, the differences between these two regression frameworks are highlighted, both conceptually and econometrically. Additionally, using real‐world claims data from a large US health insurer, alternative QR frameworks are implemented to assess the differential impacts of covariates along the distribution of medication adherence among elderly patients with Alzheimer's disease. Copyright © 2013 John Wiley & Sons, Ltd.

What's known on the subject? and What does the study add? Postoperative complications for open radical nephrectomy ( ORN ), laparoscopic radical nephrectomy ( LRN ), and open partial nephrectomy ( OPN ) and its relationship with hospitalisation costs and mortality remain poorly described. The present population‐based study suggests modest differences in postoperative complications estimated at 27%, 23%, and 24% among patients with kidney cancer undergoing ORN , LRN , and OPN , respectively. Moreover, postoperative complications were associated with higher mortality, length of stay and total costs of hospitalisation. Objectives The association of complications after renal surgery for renal cell carcinoma ( RCC ) with in‐hospital mortality and costs remains to be defined. To describe the incidence of complications after open radical nephrectomy ( ORN ), laparoscopic RN ( LRN ), and open partial nephrectomy ( OPN ); and to evaluate its relationship with in‐hospital mortality and total costs. Patients and Methods We identified 49 983 individuals who underwent ORN (35 712), LRN (5327), or OPN (8944) for RCC at 2037 hospitals from the Nationwide Inpatient Sample 2001–2008. The outcomes assessed were in‐hospital mortality and total hospitalisation costs. Multivariable logistic regression and generalised estimating equations were used to test the associations between complications and in‐hospital mortality and total costs. Results With 26.0% of patients experiencing postoperative complications, there were modest differences in the proportion of patients with complications after ORN , LRN , and OPN at 27.0%, 22.6%, and 24.0%, respectively ( P < 0.001). After adjusting for patient and hospital variables, postoperative complications resulted in higher odds of in‐hospital death for ORN (odds ratio [ OR ] 7.20; P < 0.001), LRN ( OR 12.04; P < 0.001), and OPN ( OR 7.82; P < 0.001). Adjusted total costs also rose significantly with the presence of any postoperative complications compared with those without any complications for ORN ($21 242 vs $13 183; P < 0.001), LRN ($19 548 vs $12 555; P < 0.001), and OPN ($18 883 vs $12 098; P < 0.001). Conclusions With about a quarter of patients experiencing postoperative complications, adverse events for ORN , LRN , and OPN carry a significant risk of in‐hospital death and higher total costs. Efforts to reduce postoperative complications may correlate with substantial reductions in hospital mortality and total costs.