The mechanics of risk adjustment and incentives for coding intensity in Medicare

OBJECTIVE

To study diagnosis coding intensity across Medicare programs, and to examine the impacts of changes in the risk model adopted by the Centers for Medicare and Medicaid Services (CMS) for 2024.

DATA SOURCES AND STUDY SETTING

Claims and encounter data from the CMS data warehouse for Traditional Medicare (TM) beneficiaries and Medicare Advantage (MA) enrollees.

STUDY DESIGN

We created cohorts of MA enrollees, TM beneficiaries attributed to Accountable Care Organizations (ACOs), and TM non-ACO beneficiaries. Using the 2019 Hierarchical Condition Category (HCC) software from CMS, we computed HCC prevalence and scores from base records, then computed incremental prevalence and scores from health risk assessments (HRA) and chart review (CR) records.

DATA COLLECTION/EXTRACTION METHODS

We used CMS's 2019 random 20% sample of individuals and their 2018 diagnosis history, retaining those with 12 months of Parts A/B/D coverage in 2018.

PRINCIPAL FINDINGS

Measured health risks for MA and TM ACO individuals were comparable in base records for propensity-score matched cohorts, while TM non-ACO beneficiaries had lower risk. Incremental health risk due to diagnoses in HRA records increased across coverage cohorts in line with incentives to maximize risk scores: +0.9% for TM non-ACO, +1.2% for TM ACO, and + 3.6% for MA. Including HRA and CR records, the MA risk scores increased by 9.8% in the matched cohort. We identify the HCC groups with the greatest sensitivity to these sources of coding intensity among MA enrollees, comparing those groups to the new model's areas of targeted change.

CONCLUSIONS

Consistent with previous literature, we find increased health risk in MA associated with HRA and CR records. We also demonstrate the meaningful impacts of HRAs on health risk measurement for TM coverage cohorts. CMS's model changes have the potential to reduce coding intensity, but they do not target the full scope of hierarchies sensitive to coding intensity.

Gaps In Quality Of Care Not Consistent Between Traditional Medicare, Medicare Advantage For Racial And Ethnic Groups

The quality of care experienced by members of racial and ethnic minority groups in Medicare Advantage, which is an increasingly important source of Medicare coverage for these groups, has critical implications for health equity. Comparing gaps in Medicare Advantage and traditional Medicare for three quality-of-care outcomes, measured by adverse health events, between minority and non-Hispanic White populations, we found that the relative magnitude of the gaps varied both by racial and ethnic minority group and by quality measure. Hispanic versus non-Hispanic White gaps were smaller in Medicare Advantage than in traditional Medicare for all outcomes: avoidable emergency department use, preventable hospitalizations, and thirty-day hospital readmissions. The gap between non-Hispanic Black and non-Hispanic White populations was larger in Medicare Advantage than in traditional Medicare for avoidable emergency department use but was no different for hospital readmissions and was smaller for preventable hospitalizations. The Asian versus non-Hispanic White gap was similar in Medicare Advantage and traditional Medicare for avoidable emergency department use and preventable hospitalizations but was larger in Medicare Advantage for hospital readmissions. As Medicare Advantage enrollment expands, monitoring the quality of care for enrollees who are members of racial and ethnic minority groups will remain important.

Using 15-Minute Serial Blood Pressures as an Alternative to Measuring a Single Blood Pressure

Thirty-minute office blood pressure (OBP-30) is an alternative to ambulatory blood pressure (BP) measurement, yet is impractical to implement. This study aimed to determine whether unattended BP readings over 15 minutes would result in a similar probability of obtaining a BP of <140/90. Sixty-seven adults self-described as having high BP were analyzed. BP was measured at baseline and every 5 minutes for 15 minutes with the initial reading compared to the average of the last three readings (OBP-15). Compared to baseline, there was a decline in both average systolic (4.2 points) and diastolic (2.8 points) BP. The probability of BP control predicted by multivariate model was 71.6% at baseline and 78.0% using OBP-15 (p=0.011). The increase in BP control from initial to OBP-15 measurement was significant for indigenous or persons of color compared to whites, and men compared to women. OBP-15 is convenient and results in lower BP readings and higher probability of BP control compared to the initial reading.

Care Management Processes Important for High-Quality Diabetes Care

OBJECTIVE

Identify the improvement in diabetes performance measures and population-based clinical outcomes resulting from changes in care management processes (CMP) in primary care practices over 3 years.

RESEARCH DESIGN AND METHODS

This repeated cross-sectional study tracked clinical performance measures for all diabetes patients seen in a cohort of 330 primary care practices in 2017 and 2019. Unit of analysis was patient-year with practice-level CMP exposures. Causal inference is based on dynamic changes in individual CMPs between years by practice. We used the Bayesian method to simultaneously estimate a five-outcome model: A1c, systolic and diastolic blood pressure, guideline-based statin use, and Optimal Diabetes Care (ODC). We control for unobserved time-invariant practice characteristics and secular change. We modeled correlation of errors across outcomes. Statistical significance was identified using 99% Bayesian credible intervals (analogous to P < 0.01).

RESULTS

Implementation of 18 of 62 CMPs was associated with statistically significant improvements in patient outcomes. Together, these resulted in 12.1% more patients meeting ODC performance measures. Different CMPs affected different outcomes. Three CMPs accounted for 47% of the total ODC improvement, 68% of A1c decrease, 21% of SBP reduction, and 55% of statin use increase: 1) systems for identifying and reminding patients due for testing, 2) after-visit follow-up by a nonclinician, and 3) guideline-based clinician reminders for preventive services during a clinic visit.

CONCLUSIONS

Effective quality improvement in primary care focuses on practice redesign that clearly improves diabetes outcomes. Tailoring CMP adoption in primary care provides effective improvement in ODC performance through focused changes in diabetes outcomes.

Evaluating the Clinical Effect of Personal Continuous Glucose Monitoring in a Diverse Population With Type 2 Diabetes

Objective: To determine the clinical effect of personal continuous glucose monitoring (CGM) in a diverse population with type 2 diabetes (T2D). Research Design and Methods: A report was created from the electronic health record identifying adults prescribed CGM at an urban family medicine clinic between January 1, 2019, and February 23, 2022. An "index date" was identified as the start of CGM. The closest hemoglobin A1c (A1c) 6 months or more after the index date was identified as the "follow-up date." The primary outcome of this study was to compare the percentage of individuals meeting the MN Community Measure (MNCM) D5 HbA1c goal of <8% at the follow-up date versus the index date. Results: Seventy-two patients were identified after the exclusion criteria were applied. Approximately one-third of patients required utilization of an interpreter and 76% of patients were of a racial or ethnic minority. The mean HbA1c prior to CGM use was 9.8%, with 16.7% of the population meeting the MNCM D5 A1c goal of <8%. At the follow-up date, the mean A1c was 8.4% (mean difference -1.4%; p < 0.001), with 41.7% of the population meeting goal (mean difference +25%; p < 0.001). Subgroup analyses affirm that the results of the primary outcome were sustained despite insulin use status. Conclusion: A diverse population with T2D had a significant reduction in A1c and was more likely to meet the MNCM D5 A1c goal of <8% after an average of 6 months using personal CGM.

Wide Variation In Differences In Resource Use Seen Across Conditions Between Medicare Advantage, Traditional Medicare

Medicare Advantage (MA) is a rapidly growing source of coverage for Medicare beneficiaries. Examining how MA performs compared with traditional Medicare is an important policy issue. We analyzed national MA encounter data and found that the adjusted differences in resource use between MA and traditional Medicare varied widely across medical conditions in 2019. Total resource use in MA was generally lower than in traditional Medicare but by varying amounts across conditions, and it was not significantly different from traditional Medicare for some conditions. This variation was explained by resource use for hospital inpatient services in MA relative to traditional Medicare. Resource use for treatments was considerably lower in MA than in traditional Medicare across all conditions, whereas resource use for imaging and testing was consistently higher in MA for all conditions. As MA grows, efforts are needed to identify mechanisms driving differences in resource use between MA and traditional Medicare and to assess their implications for patient care.

Successful Change Management Strategies for Improving Diabetes Care Delivery Among High-Performing Practices

PURPOSE

To learn how the highest-performing primary care practices manage change when implementing improvements to diabetes care delivery.

METHODS

We ranked a total of 330 primary care practices submitting practice management assessments and diabetes reports to the Understanding Infrastructure Transformation Effects on Diabetes study in 2017 and 2019 by Optimal Diabetes Care performance. We ranked practices from the top quartile by greatest annual improvement to capture dynamic change. Starting with the top performers, we interviewed practice leaders to identify their most effective strategies for managing change. Interview transcripts were qualitatively analyzed to identify change management strategies. Saturation occurred when no new strategies were identified over 2 consecutive interviews.

RESULTS

Ten of the top 13 practices agreed to interviews. We identified 199 key comments representing 48 key care management concepts. We also categorized concepts into 6 care management themes and 37 strategic approaches. We categorized strategic approaches into 13 distinct change management strategies. The most common strategies identified were (1) standardizing the care process, (2) performance awareness, (3) enhancing care teams, (4) health care organization participation, (5) improving reporting systems, (6) engaging staff and clinicians, (7) accountability for tasks, (8) engaging leadership, and (9) tracking change. Care management themes identified by most practices included proactive care, improving patient relationships, and previsit planning.

CONCLUSIONS

Top-performing primary care practices identify a similar group of strategies as important for managing change during quality improvement activities. Practices involved in diabetes improvement activities, and perhaps other chronic conditions, should consider adopting these change management strategies.

Osteopathic manipulative treatment for the allopathic resident elective: does it change practice after graduation?

CONTEXT

Osteopathic manipulative treatment (OMT) for the allopathic resident is an elective at the University of Minnesota North Memorial Residency that engages the resident in the basic tenants of osteopathic medicine, with exposure to the vast application of OMT with a curricular focus on low back pain management. Implementing an elective curriculum is a feasible way to improve attitudes in OMT for MDs in a Family Medicine residency, and residents can learn OMT in an elective rotation.

OBJECTIVES

This article aims to determine if MDs who complete an OMT for the allopathic physician elective rotation have higher comfort caring for patients with back pain compared to those who do not complete the elective. Further, this article is designed to evaluate if these MDs continue to incorporate OMT into the care they provide once they graduate from their residency programs.

METHODS

Graduates from the University of Minnesota North Memorial Family Medicine Residency (2013 to 2019) were sent an email invitation in August 2020 to complete a Qualtrics survey regarding their comfort with caring for patients with back pain, referral patterns for these patients, and the ongoing use of OMT in their practices. Doctor of Osteopathic Medicine (DO) graduates who responded to the survey were removed from the analysis.

RESULTS

Among emailed graduates, 61.8% (42/68) completed the survey, with representation from each class ranging from 1 to 7 years postresidency. The five DO graduates who responded were removed from the analysis. Among the remaining 37 respondents, 27 had completed the OMT for the allopathic rotation ("elective participants") during their residency training and 10 had not ("control"). Half (50.0%) of the control group provide OMT care compared to 66.7% of the elective participants, with a comfort score of 22.6 (standard deviation [SD] 32.7) in the control group vs. 34.0 (SD 21.0) in elective participants (on a 0-100 scale; 100 being completely comfortable; p=0.091). Among the control group, 40.0% regularly refer to a DO provider compared to 66.7% of those who completed the elective (p=0.257). The mean comfort score for performing a physical examination on patients presenting with back pain was 78.7 (SD 13.1) and 80.9 (SD 19.3) in the control and elective participants groups, respectively (p=0.198).

CONCLUSIONS

Allopathic Family Medicine residents who completed an elective rotation in OMT have a slight increase in frequency of referring to DOs. They also have a meaningful increase in comfort performing OMT. With the limited number of DOs being a common barrier to OMT care, more widely implemented training in OMT for allopathic Family Medicine residents may be a reasonable intervention to improve the care of patients with back pain.

COVID-19 Impacts on Primary Care Clinic Care Management Processes

PURPOSE

To learn whether the COVID-19 pandemic's disruptions and associated reduced health outcomes for people with chronic conditions might have been caused by a decrease in care management processes (CMPs) in primary care clinics METHODS: Longitudinal cohort design with repeated survey-based measures of CMPs from 2017, 2019, and 2021 in 269 primary care clinics in Minnesota.

RESULTS

There were only small differences in organizational characteristics and no differences in overall CMPs between the 269 clinics analyzed and the 287 that only completed surveys in 1 or 2 years. Overall CMP scores rose by similar amounts (1.6% and 2.1%) from 2017 to 2019 and from 2019 to 2021. In 2021, CMP scores were lower in small medical groups than in large medical groups in 2017 (66.1% vs 78.5%, P <.001), a similar difference to that in 2017. Care management process scores were also lower in clinics in urban areas compared with rural areas (73.9% vs 79.0%, P <.001), but overall scores in all subgroups were higher in 2021 than in 2017. This improvement occurred despite reports from 55% of clinic leaders that the pandemic had been very or extremely disruptive.

CONCLUSIONS

Although quite disrupted by the pandemic, care management processes for chronic disease care in these resilient primary care clinics actually increased from 2019 to 2021, at least in clinics that were part of large organizations. However, that was not true for clinics from smaller groups and perhaps for other areas of care.

Bayesian variable selection in hierarchical difference-in-differences models

A popular method for estimating a causal treatment effect with observational data is the difference-in-differences model. In this work, we consider an extension of the classical difference-in-differences setting to the hierarchical context in which data cannot be matched at the most granular level. Our motivating example is an application to assess the impact of primary care redesign policy on diabetes outcomes in Minnesota, in which the policy is administered at the clinic level and individual outcomes are not matched from pre- to post-intervention. We propose a Bayesian hierarchical difference-in-differences model, which estimates the policy effect by regressing the treatment on a latent variable representing the mean change in group-level outcome. We present theoretical and empirical results showing a hierarchical difference-in-differences model that fails to adjust for a particular class of confounding variables, biases the policy effect estimate. Using a structured Bayesian spike-and-slab model that leverages the temporal structure of the difference-in-differences context, we propose and implement variable selection approaches that target sets of confounding variables leading to unbiased and efficient estimation of the policy effect. We evaluate the methods' properties through simulation, and we use them to assess the impact of primary care redesign of clinics in Minnesota on the management of diabetes outcomes from 2008 to 2017.

Evaluation of 30-Minute Office Blood Pressure in a Diverse Urban Population

BACKGROUND

Previous studies have shown benefits of 30-minute office blood pressure (OBP-30) but did not report on race and gender. The purpose of this study was to determine if similar effects are seen in a diverse urban population.

METHODS

Patients with diabetes and/or cardiovascular disease (age 18-89) were invited to participate. Blood pressure was measured using standard procedure (SOBP). Patients were left alone in an exam room connected to an automated office blood pressure monitor which obtained BP readings every 5 minutes for 30 minutes. The last 5 measurements were averaged for the OBP-30 measurement. Primary outcomes were BPs measured using SOBP and OBP-30. Multivariate logit methods were used to estimate the average probability of having a BP measured <140/90 mm Hg (BPM <140/90) for the 2 measurement methods. Differences were computed across methods, in total and by sex and race, all other factors held constant.

RESULTS

The adjusted probability of having a BPM <140/90 was 47.1% using SOBP and 66.7% using OBP-30 (P < 0.01). Using SOBP, females had a 26.2 PP lower probability of having a BPM <140/90 (P < 0.001) than males. Relative to white patients, Black patients had a 43.9 PP lower (P < 0.001) and other races a 38.5 PP lower (P < 0.001) probability of having a BPM <140/90 using SOBP. Using OBP-30, these differences narrowed and became statistically insignificant.

CONCLUSIONS

OBP-30 may increase the probability of BPM meeting goals, especially in females and patients who are Black, indigenous, or persons of color.

Strategies and Factors Associated With Top Performance in Primary Care for Diabetes: Insights From a Mixed Methods Study

PURPOSE

The aim of this study was to determine what strategies and factors are most important for high performance in the primary care of patients with diabetes.

METHODS

We performed a mixed-methods, cross-sectional, observational analysis of interviews and characteristics of primary care clinics in Minnesota and bordering areas. We compared strategies, facilitators, and barriers identified by 31 leaders of 17 clinics in high-, middle-, and low-performance quartiles on a standardized composite measure of diabetes outcomes for 416 of 586 primary care clinics. Semistructured interview data were combined with quantitative data regarding clinic performance and a survey of the presence of care management processes.

RESULTS

The interview analysis identified 10 themes providing unique insights into the factors and strategies characterizing the 3 performance groups. The main difference was the degree to which top-performing clinics used patient data to guide proactive and outreach methods to intensify treatment and monitor effect. Top clinics also appeared to view visit-based care management processes as necessary but insufficient, whereas all respondents regarded being part of a large system as mostly helpful.

CONCLUSIONS

Top-performing clinic approaches to diabetes care differ from lower-performing clinics primarily by emphasizing data-driven proactive outreach to patients to intensify treatment. Although confirmatory studies are needed, clinical leaders should consider the value of this paradigm shift in approach to care.

The impact of patient-centered medical home certification on quality of care for patients with diabetes

OBJECTIVE

To identify the impact of changes surrounding certification as a patient-centered medical home (PCMH) on outcomes for patients with diabetes.

STUDY SETTING

Minnesota legislation established mandatory quality reporting for patients with diabetes and statewide standards for certification as a PCMH. Patient-level quality reporting data (2008-2018) were used to study the impact of transition to a PCMH.

STUDY DESIGN

Achievement of Minnesota's optimal diabetes care standard-in aggregate and by component-was modeled for adult patients with Type 1 or Type 2 diabetes as a function of time relative to the year the patient's primary care practice achieved PCMH certification. Patients from uncertified practices were used to control for general trend. Practice-level random effects captured time-invariant characteristics of practices and the practices' average patient.

DATA COLLECTION

Electronic health record data were submitted by 695 Minnesota practices capturing components of the quality standard: blood sugar control, cholesterol control, blood pressure control, nonsmoking status, and use of aspirin.

PRINCIPAL FINDINGS

The first cohort of practices achieving PCMH certification (July 2010-June 2014) showed statistically insignificant changes in optimal care. The next cohort of practices (July 2014-June 2018) achieved larger, clinically meaningful increases in quality of care during the time prior to and following certification. Specifically, this second cohort of practices was estimated to achieve a 12.8 percentage-point improvement (P < .001) in the predicted probability of providing optimal diabetes care over the period spanning 3 years before to 3 years after certification.

CONCLUSIONS

Our results suggest that the initial cohort of certified practices was already performing at a high level before certification, perhaps requiring little change in their operations to achieve PCMH certification. The second cohort, on the other hand, made meaningful, quality-improving changes in the years surrounding certification. Differences by cohort may partially explain the inconsistent PCMH impacts found in the literature.

Narrow provider networks and willingness to pay for continuity of care and network breadth

Tiered and narrow provider networks are mechanisms implemented by health plans to reduce health care costs. The benefits of narrow networks for consumers usually come in the form of lower premiums in exchange for access to fewer providers. Narrow networks may disrupt continuity of care and access to usual sources of care. We examine choices of health plans in a private health insurance exchange where consumers choose among one broad network and four narrow network plans. Using a discrete choice model with repeated choices, we estimate the willingness to pay for a health plan that covers consumers' usual sources of care. Willingness to pay for a network that covers consumers' usual source of care is between $84 and $275/month (for primary care) and between $0 and $115/month (for specialists). We find that, given that a network covers their usual source of care, consumers show aversion only to the narrowest networks.

Affordable Care Act's Mandate Eliminating Contraceptive Cost Sharing Influenced Choices Of Women With Employer Coverage

Patient cost sharing for contraceptive prescriptions was eliminated for certain insurance plans as part of the Affordable Care Act. We examined the impact of this change on women's patterns of choosing prescription contraceptive methods. Using claims data for a sample of midwestern women ages 18-46 with employer-sponsored coverage, we examined the contraceptive choices made by women in employer groups whose coverage complied with the mandate, compared to the choices of women in groups whose coverage did not comply. We found that the reduction in cost sharing was associated with a 2.3-percentage-point increase in the choice of any prescription contraceptive, relative to the 30 percent rate of choosing prescription contraceptives before the change in cost sharing. A disproportionate share of this increase came from increased selection of long-term contraception methods. Thus, the removal of cost as a barrier seems to be an important factor in contraceptive choice, and our findings about long-term methods may have implications for rates of unintended pregnancy that require further study.

The impact of provider consolidation on physician prices

When a clinic system is acquired by an integrated delivery system (IDS), the ownership change includes both vertical integration with the hospital(s), and horizontal integration with the IDS's previously owned or "legacy" clinics, causing increased market concentration in physician services. Although there is a robust literature on the impact of hospital market concentration, the literature on physician market concentration is sparse. The objective of this study is to determine the impact on physician prices when two IDSs acquired three multispecialty clinic systems in Minneapolis-St Paul, Minnesota at the end of 2007, using commercial claims data from a large health plan (2006-2011). Using a difference-in-differences model and nonacquired clinics as controls, we found that four years after the acquisitions (2011), average physician price indices in the acquired clinic systems were 32-47% higher than expected in absence of the acquisitions. Average physician prices in the IDS legacy clinics were 14-20% higher in 2011 than expected. Procedure-specific prices for common office visit and inpatient procedures also increased following the acquisitions.

Improving Patient-Centered Care by Assessing Patient Preferences for Multiple Sclerosis Disease-Modifying Agents: A Stated-Choice Experiment

CONTEXT

Long-term adherence to pharmaceutical treatment for multiple sclerosis (MS) is poor. A focus on patient preferences when determining the patient's therapeutic plan may improve this experience.

OBJECTIVE

To identify factors important to patients with MS when evaluating their options for pharmaceutical agents that deliver disease-modifying therapy.

DESIGN

Stated-choice experiment to a sample of patients with MS from privately and publicly insured enrollees in a regional health plan. The experiment presented each respondent with a set of 8 drug choices for MS, asking them to select their preferred disease-modifying agent (DMA). Each respondent was randomized to 1 of 6 possible sets of 8 drug choices, for a total of 48 drug pairings in the experiment. Each choice included 2 hypothetical DMAs and a "no drug" option. Drug attributes included dosage type and modality, efficacy, relapse risk, and drug side effects.

RESULTS

The "no drug" alternative was a stronger substitute than the alternative drug when the focal drug characteristics changed, and the most important drivers of choice were type of side effects and risk of severe relapse.

DISCUSSION

The heterogeneity of our sample and the inclusion of a "no drug" alternative in the DMA choice scenarios make this study an important contribution to this body of literature. The importance of the "no drug" alternative in our results is consistent with poor long-term adherence to DMAs.

CONCLUSION

Patient-centered MS therapy using DMAs should include discussion of side effects and relapse risk.

Adherence to Disease-Modifying Therapies for Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is a neurological degenerative chronic condition without cure. However, long-term disease-modifying therapies (DMTs) help reduce the severity of MS symptoms. Adherence to DMTs is key to their success. Several studies have analyzed what makes patients adherent to their DMTs. As new DMTs have entered the market, few studies have analyzed factors of adherence using all currently available DMTs.

OBJECTIVE

To analyze different factors of adherence to DMTs for MS, in particular how the type of DMT affects adherence.

METHODS

This retrospective cohort study used enrollment and claims data from an upper Midwest health plan in the United States between 2011 and 2013. Patients entered the study if they had any medical claim with an MS diagnosis and used only 1 DMT during the study time frame. Medication possession ratios (MPRs) were computed as the fraction of days with medication supplied during the year; patients with MPRs of 0.8 or higher were considered adherent. Multivariate probit models with patient-specific random effects were estimated, with controls for demographic characteristics, type of DMT, health plan type, and measures of health status.

RESULTS

Patients aged over 45 years were between 13.7 to 18.6 percentage points more likely to be adherent than younger patients. Women had a 5.5 percentage-point lower probability of being adherent than men. Patients using self-injectable DMTs with injection site reactions as the most likely side effect were 9.1 percentage points less likely to be adherent than patients using oral, infusible, and other self-injectable DMTs. Patients with depression had a 5.5 percentage-point lower probability of being adherent. These results were robust to changes in controls for type of plan and neighborhood socioeconomic characteristics.

CONCLUSIONS

This study found statistically significant differences in adherence to DMTs by age, sex, type of DMT, and a depression diagnosis.

DISCLOSURES

TEVA provided funding for this study and had the option to review the manuscript. The authors retained autonomy in the determination of the final content of this work. Study concept and design were contributed by Carlin, Anderson, and Higuera. Data interpretation was primarily performed by Higuera and Carlin, along with Anderson. The manuscript was written and revised by Higuera, Carlin, and Anderson.

The Impact of Hospital Acquisition of Physician Practices on Referral Patterns

Multiple parties influence the choice of facility for hospital-based inpatient and outpatient services. The patient is the central figure, but their choice of facility is guided by their physician and influenced by hospital characteristics. This study estimated changes in referral patterns for inpatient admissions and outpatient diagnostic imaging associated with changes in ownership of three multispecialty clinic systems headquartered in Minneapolis-St. Paul, MN. These clinic systems were acquired by two hospital-owned integrated delivery systems (IDSs) in 2007, increasing the probability that hospital preferences influenced physician guidance on facility choice. We used a longitudinal dataset that allowed us to predict changes in referral patterns, controlling for health plan enrollee, coverage, and clinic system characteristics. The results are an important empirical contribution to the literature examining the impact of hospital ownership on location of service. When this change in ownership forged new relationships, there was a significant reduction in the use of facilities historically selected for inpatient admissions and outpatient imaging and an increase in the use of the acquiring IDS's facilities. These changes were weaker in the IDS acquiring two clinic systems, suggesting that management of multiple acquisitions simultaneously may impact the ability of the IDS to build strong referral relationships.

Changes in Quality of Health Care Delivery after Vertical Integration

OBJECTIVES

To fill an empirical gap in the literature by examining changes in quality of care measures occurring when multispecialty clinic systems were acquired by hospital-owned, vertically integrated health care delivery systems in the Twin Cities area.

DATA SOURCES/STUDY SETTING

Administrative data for health plan enrollees attributed to treatment and control clinic systems, merged with U.S. Census data.

STUDY DESIGN

We compared changes in quality measures for health plan enrollees in the acquired clinics to enrollees in nine control groups using a differences-in-differences model. Our dataset spans 2 years prior to and 4 years after the acquisitions. We estimated probit models with errors clustered within enrollees.

DATA COLLECTION/EXTRACTION METHODS

Data were assembled by the health plan's informatics team.

PRINCIPAL FINDINGS

Vertical integration is associated with increased rates of colorectal and cervical cancer screening and more appropriate emergency department use. The probability of ambulatory care-sensitive admissions increased when the acquisition caused disruption in admitting patterns.

CONCLUSIONS

Moving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Caution is warranted when the acquisition causes disruption in referral patterns.

The dynamics of community health care consolidation: acquisition of physician practices

CONTEXT

Health care delivery systems are becoming increasingly consolidated in urban areas of the United States. While this consolidation could increase efficiency and improve quality, it also could raise the cost of health care for payers. This article traces the consolidation trajectory in a single community, focusing on factors influencing recent acquisitions of physician practices by integrated delivery systems.

METHODS

We used key informant interviews, supplemented by document analysis.

FINDINGS

The acquisition of physician practices is a process that will be difficult to reverse in the current health care environment. Provider revenue uncertainty is a key factor driving consolidation, with public and private attempts to control health care costs contributing to that uncertainty. As these efforts will likely continue, and possibly intensify, community health care systems now are less consolidated than they will be in the future. Acquisitions of multispecialty and primary care practices by integrated delivery systems follow a common process, with relatively predictable issues relating to purchase agreements, employment contracts, and compensation. Acquisitions of single-specialty practices are less common, with motivations for acquisitions likely to vary by specialty type, group size, and market structure. Total cost of care contracting could be an important catalyst for practice acquisitions in the future.

CONCLUSIONS

In the past, market and regulatory forces aimed at controlling costs have both encouraged and rewarded the consolidation of providers, with important new developments likely to create momentum for further consolidation, including acquisitions of physician practices.

An approach to addressing selection bias in survival analysis

This work proposes a frailty model that accounts for non-random treatment assignment in survival analysis. Using Monte Carlo simulation, we found that estimated treatment parameters from our proposed endogenous selection survival model (esSurv) closely parallel the consistent two-stage residual inclusion (2SRI) results, while offering computational and interpretive advantages. The esSurv method greatly enhances computational speed relative to 2SRI by eliminating the need for bootstrapped standard errors and generally results in smaller standard errors than those estimated by 2SRI. In addition, esSurv explicitly estimates the correlation of unobservable factors contributing to both treatment assignment and the outcome of interest, providing an interpretive advantage over the residual parameter estimate in the 2SRI method. Comparisons with commonly used propensity score methods and with a model that does not account for non-random treatment assignment show clear bias in these methods, which is not mitigated by increased sample size. We illustrate using actual dialysis patient data comparing mortality of patients with mature arteriovenous grafts for venous access to mortality of patients with grafts placed but not yet ready for use at the initiation of dialysis. We find strong evidence of endogeneity (with estimate of correlation in unobserved factors ρ^=0.55) and estimate a mature-graft hazard ratio of 0.197 in our proposed method, with a similar 0.173 hazard ratio using 2SRI. The 0.630 hazard ratio from a frailty model without a correction for the non-random nature of treatment assignment illustrates the importance of accounting for endogeneity.

Patient loyalty in a mature IDS market: is population health management worth it?

OBJECTIVE

To understand patient loyalty to providers over time, informing effective population health management.

STUDY SETTING

Patient care-seeking patterns over a 6-year timeframe in Minnesota, where care systems have a significant portion of their revenue generated by shared-saving contracts with public and private payers.

STUDY DESIGN

Weibull duration and probit models were used to examine patterns of patient attribution to a care system and the continuity of patient affiliation with a care system. Clustering of errors within family unit was used to account for within-family correlation in unobserved characteristics that affect patient loyalty.

DATA COLLECTION

The payer provided data from health plan administrative files, matched to U.S. Census-based characteristics of the patient's neighborhood. Patients were retrospectively attributed to health care systems based on patterns of primary care.

PRINCIPAL FINDINGS

I find significant patient loyalty, with past loyalty a very strong predictor of future relationship. Relationships were shorter when the patient's health status was complex and when the patient's care system was smaller.

CONCLUSIONS

Population health management can be beneficial to the care system making this investment, particularly for patients exhibiting prior continuity in care system choice. The results suggest that co-located primary and specialty services are important in maintaining primary care loyalty.

Sources of information used in selection of surgeons

OBJECTIVES

We explored the process of physician selection, focusing on selection of surgeons for knee and hip replacement to increase the probability of a new relationship, making cost and quality scorecard information more relevant.

STUDY DESIGN

We collected data using a mailed survey sent to patients with knee or hip replacement surgery shortly after March 1, 2010. This time period followed a period of publicity about the new cost and quality scorecard.

METHODS

We used multivariate probit models to predict awareness of the scorecard and willingness to switch providers. Multinomial logit methods were used to predict the primary factor influencing the choice of surgeon (physician referral, family or friend referral, surgeon location, previous experience with the surgeon, or other).

RESULTS

Internet access and higher neighborhood incomes are associated with an increased probability of being aware of the scorecards. Male patients and patients with Internet access or in highly educated neighborhoods are more likely to be willing to switch providers for a reduced copay. Urban residents are more likely to rely on physician referrals, and rural patients on family/friend referrals when selecting a surgeon; Internet access reduces importance of surgeon location.

CONCLUSIONS

Additional research is needed to determine whether Internet access is causal in improved responsiveness to market information and incentives, or a proxy for other factors. In addition, we see evidence that efforts to improve healthcare quality and costs through market forces should be tailored to the patient's place of residence.

Chronic illness and patient satisfaction

OBJECTIVE

To examine how the relationship between patient characteristics, patient experience with the health care system, and overall satisfaction with care varies with illness complexity.

DATA SOURCES/STUDY SETTING

Telephone survey in 14 U.S. geographical areas.

STUDY DESIGN

Structural equation modeling was used to examine how relationships among patient characteristics, three constructs representing patient experience with the health care system, and overall satisfaction with care vary across patients by number of chronic illnesses.

DATA COLLECTION/EXTRACTION METHODS

Random digital dial telephone survey of adults with one or more chronic illnesses.

PRINCIPAL FINDINGS

Patients with more chronic illnesses report higher overall satisfaction. The total effects of better patient-provider interaction and support for patient self-management are associated with higher satisfaction for all levels of chronic illness. The latter effect increases with illness burden. Older, female, or insured patients are more satisfied; highly educated patients are less satisfied.

CONCLUSIONS

Providers seeking to improve their patient satisfaction scores could do so by considering patient characteristics when accepting new patients or deciding who to refer to other providers for treatment. However, our findings suggest constructive actions that providers can take to improve their patient satisfaction scores without selection on patient characteristics.