Shared patient analysis: a method to assess the clinical benefits of patient referrals.

BACKGROUND: Referral to specialized physicians or institutions often is deemed necessary in clinical medicine, but no method exists to assess the clinical benefit of such referrals. OBJECTIVES: To describe a method, which is shared patient analysis, to measure the expected improvement in clinical management associated with referrals and to apply that method in the field of abdominal and pelvic oncological radiology. SUBJECTS: All patients referred, during a 4-year period, to surgical oncologists at four academic centers (the referral providers, or RPs) with radiographs performed before referral at a community site (the initial providers, or IPs). Patients (n = 396) for whom both the IP interpretation and a final diagnosis was available were eligible. All IP and RP readings were placed in random order and presented to surgical oncologists, who then recommended a treatment course. MEASUREMENTS: Diagnostic accuracy of the IP and RP readings and the proportion of patients who were assigned to an appropriate treatment by the oncologist were determined. RESULTS: When the indication for imaging was primary diagnosis or staging, the kappa for presence of cancer was 0.70. When the indication was cancer follow-up, the kappa for presence of recurrent/progressing cancer was 0.66. There were disagreements between the IP and RP radiologists over the interpretation of 162 films, with the RP radiologists being correct in 153 (94%). Had the patients been treated using IP readings, there would have been 19 more inappropriate surgeries and 19 more admissions (both P <0.05) than if the oncologists had based their recommendations on RP readings. CONCLUSIONS: The technique of shared patient analysis permits assessment of the clinical benefits associated with referrals.

Treatment of unruptured cerebral aneurysms in California.

BACKGROUND AND PURPOSE: The impact of endovascular therapy on treatment outcomes of unruptured cerebral aneurysms has not been studied in a defined geographic area. METHODS: All primary diagnoses of unruptured aneurysms were retrieved from a statewide database of hospital discharges in California from January 1990 through December 1998. Admissions for initial treatment and all follow-up care were combined to reflect the entire course of therapy. An adverse outcome was defined as an in-hospital death or discharge to nursing home or rehabilitation hospital at any point during the treatment course. Multivariable analyses were performed with generalized estimating equations with adjustment for age, sex, ethnicity, source of admission, year of treatment, hospital volume, and clustering of observations at institutions. RESULTS: A total of 2069 patients were treated for unruptured aneurysms. Adverse outcomes were more frequent in the 1699 patients treated with surgery (25%) than in those treated with endovascular therapy (10%; P:<0.001). The difference persisted after multivariable adjustment (surgery versus endovascular therapy: odds ratio for adverse outcomes, 3.1; 95% CI, 2.5 to 4.0; P:<0.001). Adverse outcomes declined from 1991 to 1998 in patients treated with endovascular therapy (P:<0.005) but not for surgery. In-hospital deaths occurred in 3.5% of surgical cases and 0.5% of endovascular cases (P:=0.003), and the difference remained significant after adjustment (odds ratio, 6.3; 95% CI, 3.5 to 11.4; P:<0.001). Total length of stay and hospital charges were greater in surgical cases (both P:<0.001). Results were similar in a confirmatory analysis focusing on treatment differences between institutions. Institutional treatment volume was also associated with outcome but did not account for the differences between surgery and endovascular therapy. CONCLUSIONS: In California, endovascular therapy of unruptured aneurysms is associated with less risk of adverse outcomes and in-hospital death, lower hospital charges, and shorter hospital stays compared with surgery. Differences between therapies became more distinct through the years. Uncontrolled differences in prognosis of patients receiving endovascular therapy and surgery cannot be ruled out in this study of discharge abstracts.

Assessing the relationship between quality of care and the characteristics of health care organizations.

In the past two decades, relationships among health plans, medical groups, and providers have grown more complex and the number of clinical management strategies has increased. In this context, determining the independent effect of a particular organizational strategy on quality of care has become more difficult. The authors review some of the issues a researcher must address when studying the relationship between organizational characteristics and quality of care. They offer criteria for selecting a research question, list organizational characteristics that may influence quality, and suggest sampling and study design techniques to reduce confounding. Since this type of research often requires a health care organization as collaborator, the authors discuss strategies for developing research partnerships and collecting data from the partner organization. Finally, they offer suggestions for translating research into policy.

Current national health insurance coverage policies for breast and ovarian cancer prophylactic surgery.

BACKGROUND: The efficacy of prophylactic mastectomy and oophorectomy in reducing breast and ovarian carcinoma has recently been reported in high-risk women. Because cost has become central to medical decision-making, this study was designed to evaluate currently existing coverage policies for these procedures. METHODS: A confidential detailed cross-sectional nationwide survey of 481 medical directors from the American Association of Health Plans, Medicare, and Medicaid was conducted. RESULTS: Of the 150 respondents, 65% (n = 97) had 100,000 or more enrolled members and 35% (n = 53) had fewer than 100,000 enrolled members. Only 44% of private plans have specific policies for coverage of prophylactic mastectomy for a strong family history of breast cancer and 38% of plans for a BRCA mutation. Only 20% of total responding plans had a policy for coverage of prophylactic oophorectomy under any clinical circumstance. Governmental carriers were significantly less likely to have any policy for prophylactic surgery (range, 2%-12%) compared with nongovernmental plans (range, 24%-44%; P < .001). No significant regional differences for coverage policies were identified (P > .05). CONCLUSIONS: Significant variations currently exist for health insurance coverage of prophylactic mastectomy and oophorectomy. As genetic testing becomes widespread, more uniform policies should be established to enable appropriate high-risk candidates equal access and coverage for these procedures.

Selective referral to high-volume hospitals: estimating potentially avoidable deaths.

CONTEXT: Evidence exists that high-volume hospitals (HVHs) have lower mortality rates than low-volume hospitals (LVHs) for certain conditions. However, few employers, health plans, or government programs have attempted to increase the number of patients referred to HVHs. OBJECTIVES: To determine the difference in hospital mortality between HVHs and LVHs for conditions for which good quality data exist and to estimate how many deaths potentially would be avoided in California by referral to HVHs. DESIGN, SETTING, AND PATIENTS: Literature in MEDLINE, Current Contents, and First-Search Social Abstracts databases from January 1, 1983, to December 31, 1998, was searched using the key words hospital, outcome, mortality, volume, risk, and quality. The highest-quality study assessing the mortality-volume relationship for each given condition was identified and used to calculate odds ratios (ORs) for in-hospital mortality for LVHs vs HVHs. These ORs were then applied to the 1997 California database of hospital discharges maintained by the California Office of Statewide Health Planning and Development to estimate potentially avoidable deaths. MAIN OUTCOME MEASURES: Deaths that potentially could be avoided if patients with conditions for which a mortality-volume relationship had been treated at an HVH vs LVH. RESULTS: The articles identified in the literature search were grouped by condition, and predetermined criteria were applied to choose the best article for each condition. Mortality was significantly lower at HVHs for elective abdominal aortic aneurysm repair, carotid endarterectomy, lower extremity arterial bypass surgery, coronary artery bypass surgery, coronary angioplasty, heart transplantation, pediatric cardiac surgery, pancreatic cancer surgery, esophageal cancer surgery, cerebral aneurysm surgery, and treatment of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). A total of 58,306 of 121,609 patients with these conditions were admitted to LVHs in California in 1997. After applying the calculated ORs to these patient populations, we estimated that 602 deaths (95% confidence interval, 304-830) at LVHs could be attributed to their low volume. Additional analyses were performed to take into account emergent admissions and distance traveled, but the impact of loss of continuity of care for some patients and reduction in the availability of specialists for patients remaining at LVHs could not be assessed. CONCLUSIONS: Initiatives to facilitate referral of patients to HVHs have the potential to reduce overall hospital mortality in California for the conditions identified. Additional study is needed to determine the extent to which selective referral is feasible and to examine the potential consequences of such initiatives.

Reconciling quality measurement with financial risk adjustment in health plans.

BACKGROUND: Initiatives to improve quality measurement (QM) and to create systems for financial risk adjustment (RA) have developed in response to concerns about price competition's threat to quality and stimulation of risk selection. QM is designed to help purchasers identify best plans, to aid plans in their selection of providers, to facilitate quality improvement by plans and providers, and to assist patients faced with choices among plans and providers. The goal of RA is to eliminate incentives for plans and providers to avoid sick, high-cost patients in favor of healthy, low-cost patients. CONFLICTS BETWEEN QM AND RA: For QM it is often necessary to identify all patients with a particular condition, and many quality measures involve intervening on patients early in the course of their disease. Identifying patients through utilization decisions (for example, identifying patients with depression through receipt of an antidepressant prescription) may bias QM. For RA, the focus is on the highest-cost patients, and patient capture through resource utilization is more likely to be appropriate. DISCUSSION: Achieving QM and RA depends on improving information systems and patient identification processes and developing standard definitions for important variables. QM and RA could both be improved, and the conflicts between them reduced, if they were based more on detailed clinical data, if consensus definitions of quality of care for specific diagnoses could be achieved, if the number of QM measures that target acute and chronic care (versus preventive care) were increased, and if information systems were enhanced.

Changes in births to foreign-born women after welfare and immigration policy reforms in California.

OBJECTIVES: To determine whether passage of welfare and immigration policies was followed in California by changes in births to foreign-born women in California with respect to total numbers, payer sources, prenatal care use, or health outcomes. METHODS: Comparison of births to foreign-born and US-born women from 1990 to 1997 using adjusted odds ratios generated with multivariate logistic regression. RESULTS: Policies passed in 1994 and 1996 were followed by decreases in adjusted odds of births to foreign-born women with prenatal Medicaid coverage, without a corresponding increase in uninsured foreign-born women. There was no decline in the use of prenatal care by foreign-born women, and no worsening of birth outcomes after passage of the reforms. Foreign-born women, however, remained more likely to have inadequate prenatal care than US-born women, and the improvement in outcomes that occurred for US-born women from 1994 to 1997 did not occur for foreign-born women. CONCLUSIONS: In spite of the fact that pregnant immigrant women remained eligible for Medicaid after passage of welfare and immigration policies in California, the volume of births to foreign-born women using Medicaid declined. The lack of a corresponding increase in births to uninsured foreign-born women appears to have prevented deterioration in the use of prenatal care or birth outcomes.

Methods to estimate and analyze medical care resource use. An example from liver transplantation.

This paper describes a method to construct a standardized health care resource use database. Billing and clinical data were analyzed for 916 patients who received liver transplantations at three medical centers over a 4-year period. Data were checked for completeness by assessing whether each patient's bill included charges covering specified dates and for specific services, and for accuracy by comparing a sample of bills to medical records. Detailed services were matched to a standardized service list from one of the centers, and a single price list was applied. For certain services, clinical data were used to estimate service use or, if a match was not possible, adjusted charges for the services were used. Twenty-three patients were eliminated from the database because of incomplete resource use data. There was very good correspondence between bills and medical records, except for blood products. Direct matches to the standardized service list accounted for 69.3% of services overall; 9.4% of services could not be matched to the standardized service list and were thus adjusted for center and/or time period. Clinical data were used to estimate resource use for blood products, operating room time, and medications; these estimations accounted for 21.3% of services overall. A database can be constructed that allows comparison of standardized resource use and avoids biases due to accounting, geographic, or temporal factors. Clinical data are essential for the creation of such a database. The methods described are particularly useful in studies of the cost-effectiveness of medical technologies.

Population choice and variable selection in the estimation and application of risk models.

This paper shows that risk adjustment models based on demographic and employment variables are not easily transferable from one population to the next, and that administrative variables are not useful in predicting medical expenditures. We found statistically significant differences between models built on populations of employees from a single employer enrolled in two different health plans, and between models built on populations of enrollees from a single health plan employed at two different companies. Employment-based variables (e.g., length of employment) had little predictive power in any of these risk models. We conclude that policymakers should be careful in applying risk models across populations, and that future versions of risk models for use within large employers need not include employment-based variables.

Surgical and endovascular treatment of unruptured cerebral aneurysms at university hospitals.

OBJECTIVE: To compare complications of surgical clipping and coil embolization in the treatment of unruptured aneurysms. BACKGROUND: Surgical clipping has been the preferred treatment for unruptured cerebral aneurysms but endovascular coil embolization is an increasingly employed alternative. No direct comparisons of the techniques are available to guide clinical decision making. METHODS: We performed a cohort study of patients treated for unruptured cerebral aneurysms at 60 university hospitals from January 1994 through June 1997 using the University HealthSystem Consortium database. The database was validated by chart review from one of the participant universities. The main outcome measures were in-hospital mortality and adverse outcomes, defined as in-hospital deaths and discharges to nursing homes or rehabilitation hospitals. RESULTS: The primary treatment modality was surgical in 2,357 cases and endovascular in 255 cases. Adverse outcomes were significantly more common in surgical cases (18.5%) compared to endovascular cases (10.6%) (p = 0.002), and the difference was not altered after adjusting for age, sex, race, transfer admissions, emergency room admissions, and year of treatment (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.4 to 3.3; p = 0.001). In-hospital mortality was also increased in surgical cases (2.3% versus 0.4%; p = 0.039), but the difference was not significant in the multivariable model (OR 6.3, 95% CI 0.9 to 46.1; p = 0.07). Length of stay and hospital charges were significantly greater for surgical cases (p < 0.0001 for each), and these differences were not affected by risk adjustment. CONCLUSION: Endovascular coil embolization resulted in fewer adverse outcomes than surgery for unruptured cerebral aneurysms treated at the university hospitals studied. Although these results should be seen as preliminary, the magnitude of difference and current predominance of surgery appear to justify a randomized trial.

Resource utilization in liver transplantation: effects of patient characteristics and clinical practice. NIDDK Liver Transplantation Database Group.

CONTEXT: Liver transplantation is among the most costly of medical services, yet few studies have addressed the relationship between the resources utilized for this procedure and specific patient characteristics and clinical practices. OBJECTIVE: To assess the association of pretransplant patient characteristics and clinical practices with hospital resource utilization. DESIGN: Prospective cohort of patients who received liver transplants between January 1991 and July 1994. SETTING: University of California, San Francisco; Mayo Clinic, Rochester, Minn; and the University of Nebraska, Omaha. PATIENTS: Seven hundred eleven patients who received single-organ liver transplants, were at least 16 years old, and had nonfulminant liver disease. MAIN OUTCOME MEASURE: Standardized resource utilization derived from a database created by matching all services to a single price list. RESULTS: Higher adjusted resource utilization was associated with donor age of 60 years or older (28% [$53813] greater mean resource utilization; P=.005); recipient age of 60 years or older (17% [$32795]; P=.01); alcoholic liver disease (26% [$49596]; P=.002); Child-Pugh class C (41% [$67 658]; P<.001); care from the intensive care unit at time of transplant (42% [$77833]; P<.001); death in the hospital (35% [$67 076]; P<.001); and having multiple liver transplants during the index hospitalization (154% increase [$474 740 vs $186 726 for 1 transplant]; P<.001). Adjusted length of stay and resource utilization also differed significantly among transplant centers. CONCLUSIONS: Clinical, economic, and ethical dilemmas in liver transplantation are highlighted by these findings. Recipients who were older, had alcoholic liver disease, or were severely ill were the most expensive to treat; this suggests that organ allocation criteria may affect transplant costs. Clinical practices and resource utilization varied considerably among transplant centers; methods to reduce variation in practice patterns, such as clinical guidelines, might lower costs while maintaining quality of care.

The impact of financial incentives on quality of health care.

Purchasers of health care could offer financial incentives to plans or providers in order to increase quality. Unfortunately, the current health care market, in which quality is rarely measured and there is no risk adjustment, actively discourages both plans and providers from maximizing quality, resulting in a poor overall level of quality, both in fee-for-service arrangements and health maintenance organizations. Health plans and providers will not focus on quality until mechanisms to correct for risk differences among enrollees can be developed. Although such risk adjustment will be the most important stimulus for quality, it should also be linked to improvements in information systems and agreement on a minimum benefits package, quality reporting standards, and financial solvency requirements.

Comparison of analytic models for estimating the effect of clinical factors on the cost of coronary artery bypass graft surgery.

The cost of treating disease depends on patient characteristics, but standard tools for analyzing the clinical predictors of cost have deficiencies. To explore whether survival analysis techniques might overcome some of these deficiencies in the analysis of cost data, we compared ordinary least square (OLS) linear regression (with and without transformation of the data) and binary logistic regression with two survival models: the Cox proportional hazards model and a parametric model assuming a Weibull distribution. Each model was applied to data from 155 patients undergoing coronary artery bypass grafting. We examined the effects of age, sex, ejection fraction, unstable angina, and number of diseased vessels on univariable and multivariable predictions of costs. The significant univariable predictors of cost were consistent in all models: ejection fraction was significant in all five models, and age and number of diseased vessels were each significant in all but the OLS model, while sex and angina type were significant in none of the models. The significant multivariable predictors of cost, however, differed according to model: ejection fraction was a significant multivariable predictor of cost in all five models, age was significant in three models, and number of diseased vessels was significant in one model. All five models were also used to predict the costs for an average patient undergoing surgery. The Cox model provided the most accurate predictions of mean cost, median cost, and the proportion of patients with high cost. This study shows: (1) lower ejection fraction and older age are independent clinical predictors of increased cost of CABG, and (2) the Cox proportional hazards model shows considerable promise for the analysis of the impact of clinical factors upon cost.

Guidelines for immunoassay data processing.

These guidelines outline the minimum requirements for a data-processing package to be used in the immunoassay laboratory. They include recommendations on hardware, software, and program design. We outline the statistical analyses that should be performed to obtain the analyte concentrations of unknown specimens and to ensure adequate monitoring of within- and between-assay errors of measurement.