Using Alzheimer's disease blood tests to accelerate clinical trial enrollment.

INTRODUCTION: Screening potential participants in Alzheimer's disease (AD) clinical trials with amyloid positron emission tomography (PET) is often time consuming and expensive. METHODS: A web-based application was developed to model the time and financial cost of screening for AD clinical trials. Four screening approaches were compared; three approaches included an AD blood test at different stages of the screening process. RESULTS: The traditional screening approach using only amyloid PET was the most time consuming and expensive. Incorporating an AD blood test at any point in the screening process decreased both the time and financial cost of trial enrollment. Improvements in AD blood test accuracy over currently available tests only marginally increased savings. Use of a high specificity cut-off may improve the feasibility of screening with only an AD blood test. DISCUSSION: Incorporating AD blood tests into screening for AD clinical trials may reduce the time and financial cost of enrollment. HIGHLIGHTS: The time and cost of enrolling participants in Alzheimer's disease (AD) clinical trials were modeled. A web-based application was developed to enable evaluation of key parameters. AD blood tests may decrease the time and financial cost of clinical trial enrollment. Improvements in AD blood test accuracy only marginally increased savings. Use of a high specificity cut-off may enable screening with only an AD blood test.

Making Meaningful Use of Price Transparency Data: Describing Price Variation of Spine Surgery and Imaging in a Single System.

Price transparency is an increasingly popular solution for high healthcare expenditures in the United States, but little is known about its potential to facilitate patient price shopping. Our objective was to analyze interhospital and interpayer price variability in spine surgery and spine imaging using newly public payer-specific negotiated charges (PNCs). We selected a subset of billing codes for spine surgery and spine imaging at 12 hospitals within a Saint Louis metropolitan area healthcare system. We then compared PNCs for these procedures and tested for significant differences in interhospital and interinsurer IQR using the Mann-Whitney U Test. We found significantly greater IQRs of PNCs as a factor of the insurance plan than as a factor of the hospital for cervical spinal fusions (interinsurer IQR $8256; interhospital IQR $533; P < .0001), noncervical spinal fusions (interinsurer IQR $28 423; interhospital IQR $5512; P < .001), computed tomographies of the lower spine (interinsurer IQR $595; interhospital IQR $113; P < .0001), and MRIs lower spinal canal (interinsurer IQR $1010; interhospital IQR $158; P < .0001). There was no significant difference between the interinsurer IQR and the interhospital IQR for lower spine x-rays (interinsurer IQR $107; interhospital IQR $67; P = .0543). Despite some between-hospital heterogeneity, we show significantly higher price variability between insurers than between hospitals. Our single system analysis limits our ability to generalize, but our results suggest that savings depend more on hospital and provider negotiations than patient price shopping, given the difficulty of switching insurers.

Health, Human Capital and Domestic Violence.

We treat health as a form of human capital and hypothesize that women with more human capital face stronger incentives to make costly investments with future payoffs, such as avoiding abusive partners and reducing drug use. To test this hypothesis, we exploit the unanticipated introduction of an HIV treatment, HAART, which dramatically improved HIV+ women's health. We find that after the introduction of HAART HIV+ women who experienced increases in expected longevity exhibited a decrease in domestic violence of 15% and in drug use of 1520%. We rule out confounding via secular trends using a control group of healthier women.

Health Care Access, Costs, and Treatment Dynamics: Evidence from In Vitro Fertilization.

We study public policies designed to improve access and reduce costs for in vitro fertilization (IVF). High out-of-pocket prices can deter potential patients from IVF, while active patients have an incentive to risk costly high-order pregnancies to improve their odds of treatment success. We analyze IVF's rich choice structure by estimating a dynamic model of patients' choices within and across treatments. Policy simulations show that insurance mandates for treatment or hard limits on treatment aggressiveness can improve access or costs, but not both. Insurance plus price-based incentives against risky treatment, however, can together improve patient welfare and reduce medical costs.

Use of Quantile Regression to Determine the Impact on Total Health Care Costs of Surgical Site Infections Following Common Ambulatory Procedures.

OBJECTIVE: To determine the impact of surgical site infections (SSIs) on health care costs following common ambulatory surgical procedures throughout the cost distribution. BACKGROUND: Data on costs of SSIs following ambulatory surgery are sparse, particularly variation beyond just mean costs. METHODS: We performed a retrospective cohort study of persons undergoing cholecystectomy, breast-conserving surgery, anterior cruciate ligament reconstruction, and hernia repair from December 31, 2004 to December 31, 2010 using commercial insurer claims data. SSIs within 90 days post-procedure were identified; infections during a hospitalization or requiring surgery were considered serious. We used quantile regression, controlling for patient, operative, and postoperative factors to examine the impact of SSIs on 180-day health care costs throughout the cost distribution. RESULTS: The incidence of serious and nonserious SSIs was 0.8% and 0.2%, respectively, after 21,062 anterior cruciate ligament reconstruction, 0.5% and 0.3% after 57,750 cholecystectomy, 0.6% and 0.5% after 60,681 hernia, and 0.8% and 0.8% after 42,489 breast-conserving surgery procedures. Serious SSIs were associated with significantly higher costs than nonserious SSIs for all 4 procedures throughout the cost distribution. The attributable cost of serious SSIs increased for both cholecystectomy and hernia repair as the quantile of total costs increased ($38,410 for cholecystectomy with serious SSI vs no SSI at the 70th percentile of costs, up to $89,371 at the 90th percentile). CONCLUSIONS: SSIs, particularly serious infections resulting in hospitalization or surgical treatment, were associated with significantly increased health care costs after 4 common surgical procedures. Quantile regression illustrated the differential effect of serious SSIs on health care costs at the upper end of the cost distribution.

Profiling Individual Surgeon Performance Using Information from a High-Quality Clinical Registry: Opportunities and Limitations.

BACKGROUND: There is increasing interest in profiling the quality of individual medical providers. Valid assessment of individuals should highlight improvement opportunities, but must be considered in the context of limitations. STUDY DESIGN: High quality clinical data from the American College of Surgeons NSQIP, gathered in accordance with strict policies and specifications, was used to construct individual surgeon-level assessments. There were 39,976 cases evaluated, performed by 197 surgeons across 9 hospitals. Both 2-level (cases by surgeon) and 3-level (cases by surgeon by hospital) risk-adjusted, hierarchical regression analyses were performed. Outcomes were 30-day postoperative morbidity, surgical site infection, and mortality. Surgeon performance was compared in both absolute and relative terms. "Signal-to-noise" reliability was calculated for surgeons and models. Projected case requirements for reliability levels were generated. RESULTS: Surgeon performances could be distinguished to different degrees: morbidity distinguished best, mortality least. Outliers could be identified for morbidity and infection, but not mortality. Reliability was also highest for morbidity and lowest for mortality. Even models with high overall reliability did not assess all providers reliably. Incorporating institutional effects had predictable effects: penalizing providers at "good" institutions, benefiting providers at "poor" institutions. CONCLUSIONS: Individual surgeon profiles can, at times, be distinguished with moderate or good reliability, but to different degrees in different models. Absolute and relative comparisons are feasible. Incorporating institutional level effects in individual provider modeling presents an interesting policy dilemma, appearing to benefit providers at "poor-performing" institutions, but penalizing those at "high-performing" ones. No portrayal of individual medical provider quality should be accepted without consideration of modeling rationale and, critically, reliability.

The effects of insurance mandates on choices and outcomes in infertility treatment markets.

For the 10% to 15% of American married couples who experience reproductive problems, in vitro fertilization (IVF) is the leading technologically advanced treatment procedure. However, IVF's expense may prevent many couples from receiving treatment, and those who are treated may take an overly aggressive approach to reduce the probability of failure. Aggressive treatment, which occurs through an increase in the number of embryos transferred during IVF, can lead to medically dangerous multiple births. We evaluated the principle policy proposal-insurance mandates-for improving IVF access and outcomes. We used data from US markets during 1995-2003 to show that broad insurance mandates for IVF result in not only large increases in treatment access but also significantly less aggressive treatment. More limited insurance mandates, which may apply to a subset of insurers or provide weaker guidelines for insurer behavior, generally have little effect on IVF markets.

The importance of assessing both inpatient and outpatient surgical quality.

OBJECTIVE: We aimed to determine whether hospital-level surgical performance was similar across outpatient and inpatient settings. BACKGROUND: The majority of surgical procedures in the United States are performed in an outpatient setting but most quality improvement focuses on inpatient care. METHODS: Using data from the 2006 to 2008 American College of Surgeons- National Surgical Quality Improvement Program, risk-adjusted hospital observed to expected ratios for morbidity and mortality were compared for inpatient and outpatient cases. In addition, hospital outpatient performance in each year was compared with performances in subsequent years. RESULTS: Hospitals demonstrated variation in outcomes for outpatient morbidity with both good and poor outliers in each year. Outpatient mortality was so rare as to not support robust modeling. There was a lack of congruence between hospital performance for outpatient morbidity and either inpatient morbidity or inpatient mortality in each year, indicating that inpatient performance is not interchangeable with outpatient performance. Outpatient morbidity performance correlation between years was only moderate (correlations 0.449-0.534, all P < 0.001) indicating that although outcomes from 1 year mildly predict subsequent years, substitution of data would likely lead to missed opportunities for improvement. CONCLUSIONS: Assessments of risk-adjusted hospital-level outpatient morbidity performance demonstrate (1) variability across American College of Surgeons- National Surgical Quality Improvement Program sites; (2) a lack of congruence between outpatient morbidity performance and either inpatient morbidity or mortality performance; (3) year-to-year variation of outpatient morbidity performance at individual institutions. Continuing evaluation of both outpatient and inpatient outcomes is supported. Given the substantial volume of outpatient care delivered, outpatient assessments are likely to be an important component of ongoing quality improvement efforts.

Improving American College of Surgeons National Surgical Quality Improvement Program risk adjustment: incorporation of a novel procedure risk score.

BACKGROUND: Risk-adjusted evaluation is a key component of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). The purpose of this study was to improve standard ACS NSQIP risk adjustment using a novel procedure risk score. STUDY DESIGN: Current Procedural Terminology codes (CPTs) represented in ACS NSQIP data were assigned to 136 procedure groups. Log odds predicted risk from preliminary logistic regression modeling generated a continuous risk score for each procedure group, used in subsequent modeling. Appropriate subsets of 271,368 patients in the 2008 ACS NSQIP were evaluated using logistic models for overall 30-day morbidity, 30-day mortality, and surgical site infection (SSI). Models were compared when including either work Relative Value Unit (RVU), RVU and the standard ACS NSQIP CPT range variable (CPT range), or RVU and the newly constructed CPT risk score (CPT risk), plus routine ACS NSQIP predictors. RESULTS: When comparing the CPT risk models with the CPT range models for morbidity in the overall general and vascular surgery dataset, CPT risk models provided better discrimination through higher c statistics at earlier steps (0.81 by step 3 vs 0.81 by step 46), more information through lower Akaike's information criterion (127,139 vs 130,019), and improved calibration through a smaller Hosmer-Lemeshow chi-square statistic (48.76 vs 116.79). Improved model characteristics of CPT risk over CPT range were most apparent for broader patient populations and outcomes. The CPT risk and standard CPT range models were moderately consistent in identification of outliers as well as assignment of hospitals to quality deciles (weighted kappa ≥ 0.870). CONCLUSIONS: Information from focused, clinically meaningful CPT procedure groups improves the risk estimation of ACS NSQIP models.

Missing data in the American College of Surgeons National Surgical Quality Improvement Program are not missing at random: implications and potential impact on quality assessments.

BACKGROUND: Studying risk-adjusted outcomes in health care relies on statistical approaches to handling missing data. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) provides risk-adjusted assessments of surgical programs, traditionally imputing certain missing data points using a single round of multivariable imputation. Such imputation assumes that data are missing at random-without systematic bias-and does not incorporate estimation uncertainty. Alternative approaches, including using multiple imputation to incorporate uncertainty or using an indicator of missingness, can enhance robustness of evaluations. STUDY DESIGN: One year of de-identified data from the ACS NSQIP, representing 117 institutions and 106,113 patients, was analyzed. Using albumin variables as the missing data modeled, several imputation/adjustment models were compared, including the traditional NSQIP imputation, a new single imputation, a multiple imputation, and use of a missing indicator. RESULTS: Coefficients for albumin values changed under new single imputation and multiple imputation approaches. Multiple imputation resulted in increased standard errors, as expected. An indicator of missingness was highly explanatory, disproving the missing-at-random assumption. The effects of changes in approach differed for different outcomes, such as mortality and morbidity, and effects were greatest in smaller datasets. However, ultimate changes in patient risk assessment and institutional assessment were minimal. CONCLUSIONS: Newer statistical approaches to modeling missing (albumin) values result in noticeable statistical distinctions, including improved incorporation of imputation uncertainty. In addition, the missing-at-random assumption is incorrect for albumin. Despite these findings, effects on institutional assessments are small. Although effects can be most important with smaller data-sets, the current approach to imputing missing values in the ACS NSQIP appears reasonably robust.

Attributable costs of surgical site infection and endometritis after low transverse cesarean delivery.

BACKGROUND: Accurate data on costs attributable to hospital-acquired infections are needed to determine their economic impact and the cost-benefit of potential preventive strategies. OBJECTIVE: To determine the attributable costs of surgical site infection (SSI) and endometritis (EMM) after cesarean section by means of 2 different methods. DESIGN: Retrospective cohort. SETTING: Barnes-Jewish Hospital, a 1,250-bed academic tertiary care hospital. PATIENTS: There were 1,605 women who underwent low transverse cesarean section from July 1999 through June 2001. METHODS: Attributable costs of SSI and EMM were determined by generalized least squares (GLS) and propensity score matched-pairs by means of administrative claims data to define underlying comorbidities and procedures. For the matched-pairs analyses, uninfected control patients were matched to patients with SSI or with EMM on the basis of their propensity to develop infection, and the median difference in costs was calculated. RESULTS: The attributable total hospital cost of SSI calculated by GLS was $3,529 and by propensity score matched-pairs was $2,852. The attributable total hospital cost of EMM calculated by GLS was $3,956 and by propensity score matched-pairs was $3,842. The majority of excess costs were associated with room and board and pharmacy costs. CONCLUSIONS: The costs of SSI and EMM were lower than SSI costs reported after more extensive operations. The attributable costs of EMM calculated by the 2 methods were very similar, whereas the costs of SSI calculated by propensity score matched-pairs were lower than the costs calculated by GLS. The difference in costs determined by the 2 methods needs to be considered by investigators who are performing cost analyses of hospital-acquired infections.

A preliminary analysis of the receipt of mental health services consistent with national standards among children in the child welfare system.

OBJECTIVES: We sought to examine the extent to which children in the child welfare system receive mental health care consistent with national standards. METHODS: We used data from 4 waves (3 years of follow-up) of the National Survey of Child and Adolescent Well-Being, the nation's first longitudinal study of children in the child welfare system, and the Area Resource File to examine rates of screening, assessment, and referral to mental health services among 3802 youths presenting to child welfare agencies. Weighted population-averaged logistic regression models were used to identify variables associated with standards-consistent care. RESULTS: Only half of all children in the sample received care consistent with any 1 national standard, and less than one tenth received care consistent with all of them. Older children, those exhibiting externalizing behaviors, and those placed in foster care had, on average, higher odds of receiving care consistent with national standards. CONCLUSIONS: Adverse consequences of childhood disadvantage cannot be reduced unless greater collaboration occurs between child welfare and mental health agencies. Current changes to Medicaid regulations that weaken entitlements to screening and assessment may also worsen mental health disparities among these vulnerable children.

Time-of-day effects on surgical outcomes in the private sector: a retrospective cohort study.

BACKGROUND: Surgical care is delivered around the clock. Elective cases within the Veterans Affairs health system starting after 4 pm appear to have an elevated risk of morbidity, but not mortality, compared with earlier cases. The relationship between operation start time and patient outcomes is not described in private-sector patients or for emergency cases. STUDY DESIGN: We performed a retrospective cohort study of 56,920 general and vascular surgical procedures performed from October 2001 through September 2004, and entered into the National Surgical Quality Improvement Program database. Operation start time was the independent variable of interest. Random effects, hierarchical logistic regression models adjusted for patient, operative, and facility characteristics. Two independent models determined associations between start time and morbidity or mortality. Subset analysis was performed for emergency and nonemergency cases. RESULTS: After adjustment for patient and procedure characteristics, mortality had a moderately strong association with start time, but only for nonemergency cases starting 9:30 pm to 7:30 am (odds ratio = 1.752; p = 0.028; reference 7:30 am to 9:30 am). As for morbidity, after adjustment, operations starting 9:30 am to 1:30 pm and 5:30 pm to 9:30 pm were associated with a weakly elevated risk of morbidity, but those starting 9:30 pm to 7:30 am demonstrated a strong effect on morbidity (odds ratio = 1.32; p < 0.0001). Subgroup analysis showed this effect was largely a result of elevated risk of morbidity in emergency cases from this overnight time period (odds ratio = 1.48; p = 0.001). CONCLUSIONS: Surgical start times are associated with risk-adjusted patient outcomes. In terms of facility operations management and resource allocation, consideration should be given to the capacity to accommodate cases with differences in risk during different time periods.

Does surgical quality improve in the American College of Surgeons National Surgical Quality Improvement Program: an evaluation of all participating hospitals.

BACKGROUND/OBJECTIVE: The National Surgical Quality Improvement Program (NSQIP) has demonstrated quality improvement in the VA and pilot study of 14 academic institutions. The objective was to show that American College of Surgeons (ACS)-NSQIP helps all enrolled hospitals. METHODS: ACS-NSQIP data was used to evaluate improvement in hospitals longitudinally over 3 years (2005-2007). Improvement was defined as reduction in risk-adjusted "Observed/Expected" (O/E) ratios between periods with risk adjustment held constant. Multivariable logistic regression-based adjustment was performed and included indicators for procedure groups. Additionally, morbidity counts were modeled using a negative binomial model, to estimate the number of avoided complications. RESULTS: Multiple perspectives reflected improvement over time. In the analysis of 118 hospitals (2006-2007), 66% of hospitals improved risk-adjusted mortality (mean O/E improvement: 0.174; P < 0.05) and 82% improved risk adjusted complication rates (mean improvement: 0.114; P < 0.05). Correlations between starting O/E and improvement (0.834 for mortality, 0.652 for morbidity), as well as relative risk, revealed that initially worse-performing hospitals had more likelihood of improvement. Nonetheless, well-performing hospitals also improved. Modeling morbidity counts, 183 hospitals (2007), avoided ~9598 potential complications: ~52/hospital. Due to sampling this may represent only 1 of 5 to 1of 10 of the true total. Improvement reflected aggregate performance across all types of hospitals (academic/community, urban/rural). Changes in patient risk over time had important contributions to the effect. CONCLUSIONS: ACS-NSQIP indicates that surgical outcomes improve across all participating hospitals in the private sector. Improvement is reflected for both poor- and well-performing facilities. NSQIP hospitals appear to be avoiding substantial numbers of complications- improving care, and reducing costs. Changes in risk over time merit further study.

The impact of surgeon specialization on patient mortality: examination of a continuous Herfindahl-Hirschman index.

OBJECTIVE: To examine the effect of surgeon specialization on patient outcomes, controlling for volume. BACKGROUND: There is great interest in the degree to which surgical specialization affects outcomes, particularly considering drives to measure and reward quality in healthcare. Although surgical specialization has been previously analyzed with respect to outcomes, most studies have treated it as a dichotomous variable based on academic credentials. We treat it here as a continuous variable defined quantitatively by procedural diversity. METHODS: We used 2002 to 2005 patient data from the National Surgical Quality Improvement Program for the Department of Surgery, Barnes Jewish Hospital, St. Louis, Missouri. To quantitate procedural specialization, Herfindahl-Hirschman indices for surgeons were calculated using billing codes. These indices were calculated according to 3 different levels of procedural aggregation. Using conditional logit models, we examined the relationship between these indices and 30-day postoperative mortality rates. RESULTS: Surgeon specialization was inversely related to mortality rates after adjusting for case volume when indices were calculated using medium procedural aggregation (odds ratio for mortality = 0.580 per 0.1 unit Herfindahl increase; P = 0.025) or low aggregation (odds ratio for mortality = 0.510 per 0.1 unit Herfindahl increase; P = 0.015). No relationship was observed at the high level of aggregation. CONCLUSIONS: The procedural concentration component of surgical specialization is correlated with improved mortality rates independently of case volume. However, how broadly or narrowly "specialization" is defined has an impact on this relationship.

Employee choice of flexible spending account participation and health plan.

Despite the fact that flexible spending accounts (FSAs) are becoming an increasingly popular employer-provided health benefit, there has been very little empirical study of FSA use among employees at the individual level. This study contributes to the literature on FSAs using a unique data set that provides three years of employee-level-matched benefits data. Motivated by the theoretical model of FSA choice presented in Cardon and Showalter (J. Health Econ. 2001; 20(6):935-954), we examine the determinants of FSA participation and contribution levels using cross-sectional and random-effect two-part models. FSA participation and health plan choice are also modeled jointly in each year using conditional logit models. We find that, even after controlling for a number of other demographic characteristics, non-whites are less likely to participate in the FSA program, have lower contributions conditional on participation, and have a lower probability of switching to new lower cost share, higher premium plans when they were introduced. We also find evidence that choosing health plans with more expected out-of-pocket expenses is correlated with participation in the FSA program.

Thyroid and parathyroid operations in veterans affairs and selected university medical centers: results of the patient safety in surgery study.

BACKGROUND: There is increasing interest in surgical outcomes. The Patient Safety in Surgery (PSS) Study database was examined about thyroid and parathyroid procedures to determine risk factors for adverse outcomes and outcomes rates. Relative outcomes performance for the Veterans Affairs (VA) and private-sector populations was compared after risk adjustment. STUDY DESIGN: Preoperative, operative, and postoperative data were analyzed for 7,082 patients: 2,814 VA patients and 4,268 private sector patients. Prevalence of risk or process factors was described. Occurrence rates and unadjusted odds ratios (OR) for adverse outcomes were calculated. Stepwise multiple logistic regressions were performed to model the impact of various factors on outcomes and to calculate the adjusted OR for any adverse event for the VA population compared with the private sector. RESULTS: Overall mortality rate was 0.35% and 0.60% in the VA and 0.19% in the private sector. Overall rate of any adverse outcomes was 2.90% and 4.48% in the VA and 1.97% in the private sector. Adjusted OR for thyroid versus parathyroid operation was 0.94 (95% CI, 0.67-1.31). Adjusted OR for operation in the VA versus private sector was 1.25 (95% CI, 0.87-1.78). CONCLUSIONS: Overall rates of mortality and any morbidity were low and consistent with previous reports. Based on adjusted OR, there was no significant difference in outcomes for thyroid versus parathyroid operation. Similarly, there was no apparent significant difference in surgical outcomes between the VA and private-sector groups after risk adjustment.