Effects of Home-Based Primary Care on Hospital Use for High-Need Medicare Patients: an Observational Study.

BACKGROUND: High-need, high-cost Medicare patients can have difficulties accessing office-based primary care. Home-based primary care (HBPC) can reduce access barriers and allow a clinician to obtain valuable information not obtained during office visit, possibly leading to reductions in hospital use. OBJECTIVE: To determine whether HBPC for high-need, high-cost patients reduces hospitalizations and Medicare inpatient expenditures. DESIGN: We conducted a matched retrospective cohort study using a difference-in-differences analysis to examine patients 2 years before and 2 years after their first home visit (HBPC group). PARTICIPANTS: The study included high-need, high-cost fee-for-service Medicare patients without prior HBPC use, of which 55,303 were new HBPC recipients and 156,142 were matched comparison patients. INTERVENTION: Receipt of at least two HBPC visits and, within 6 months of the index HBPC visit, a majority of a patient's primary care visits in the home. MAIN MEASURES: Total and potentially avoidable hospitalizations and Medicare inpatient expenditures. KEY RESULTS: HBPC reduced total hospitalization rates, but the marginal effects were not statistically significant: a reduction of 11 total hospitalizations per 1000 patients in the first year (- 0.6%, p = 0.19) and 14 in the second year (- 0.7%, p = 0.16). However, HBPC reduced potentially avoidable hospitalization rates in the second year. The estimated marginal effect was a reduction of 6 potentially avoidable hospitalizations per 1000 patients in the first year (- 1.6%, p = 0.16) and 11 in the second (- 3.1%, p = 0.01). The estimated effect of HBPC was a small decrease in inpatient expenditures of $24 per patient per month (- 1.1%, p = 0.10) in the first year and $0 (0.0%, p = 0.99) in the second. CONCLUSIONS: After high-need, high-cost patients started receiving HBPC, they did not experience fewer total hospitalizations or lower inpatient spending but may have had lower rates of potentially avoidable hospitalizations after 2 years.

Early Effects of an Accountable Care Organization Model for Underserved Areas.

BACKGROUND: The Centers for Medicare and Medicaid Services (CMS) developed the Accountable Care Organization (ACO) Investment Model (AIM) to encourage the growth of Medicare Shared Savings Program (MSSP) ACOs in rural and underserved areas. AIM provides financial support to eligible MSSP ACOs by means of prepayment of shared savings. Estimation of the performance of AIM ACOs on measures of spending and utilization in their first performance year would be useful for understanding the viability of ACOs located in these areas. METHODS: We analyzed Medicare claims and enrollment data for a group of fee-for-service beneficiaries who had been attributed to 41 AIM ACOs and for a comparable group of beneficiaries who resided in the ACO markets but were served primarily by non-ACO providers. We used a difference-in-differences study design to compare changes in outcomes from the baseline period (2013 through 2015) to the performance period (2016) among beneficiaries attributed to AIM ACOs with concurrent changes among beneficiaries in the comparison group. The primary outcome of interest was total Medicare Part A and B spending. RESULTS: Provider participation in AIM was associated with a differential reduction in total Medicare spending of $28.21 per beneficiary per month relative to the comparison group, which amounted to an aggregate decrease of $131.0 million. Over the same period, CMS made $76.2 million in prepayments and paid an additional $6.2 million in shared savings to ACOs in which shared savings exceeded the prepayments. After we accounted for this $82.4 million in CMS spending, the aggregate net reduction was $48.6 million, which corresponded to a net reduction of $10.46 per beneficiary per month. Decreases in the number of hospitalizations and use of institutional post-acute care contributed to the observed reduction in overall spending. CONCLUSIONS: With up-front investments, participation in ACO shared savings contracts by providers serving rural and underserved areas was associated with lower Medicare spending than that among non-ACO providers. (Funded by the Centers for Medicare and Medicaid Services.).

Resource Use Among Diabetes Patients Who Mainly Visit Primary Care Physicians Versus Medical Specialists: a Retrospective Cohort Study.

BACKGROUND: It is not uncommon for medical specialists to predominantly care for patients with certain chronic conditions rather than primary care physicians (PCPs), yet the resource implications from such patterns of care are not well understood. OBJECTIVE: To assess resource use of diabetes patients who predominantly visit a PCP versus a medical specialist. DESIGN: Retrospective cohort study of diabetes patients aging into the traditional Medicare program. Patients were attributed to a PCP or medical specialist annually based on a preponderance of ambulatory care visits and categorized according to whether attribution changed year to year. Propensity score weighting was used to balance baseline demographic characteristics, diabetes complications, and underlying health conditions between patients attributed to PCPs and to medical specialists. Spending and utilization were measured up to 3 patient-years. SUBJECTS: A total of 141,558 patient-years. MAIN MEASURES: Total visits, unique physicians, hospital admissions, emergency department visits, procedures, imaging, and tests. KEY RESULTS: Each year, roughly 70% of patients maintained attribution to a PCP and 15% to a medical specialist relative to the previous year. After propensity weighting, patients continuously attributed to a PCP versus medical specialist from 1 year to the next had lower average total payer payments ($10,326 [SD $57,386] versus $14,971 [SD $74,112], P<0.0001) and lower total patient out-of-pocket payments ($1,707 [SD $6,020] versus $2,443 [SD $7,984], P<0.0001). Rates of hospitalization, emergency department visits, procedures, imaging, and tests were lower among patients attributed to PCPs as well. CONCLUSIONS: Older adults with diabetes who receive more of their ambulatory care from a PCP instead of a medical specialist show evidence of lower resource use.

Relationship Between Continuity of Ambulatory Care and Risk of Emergency Department Episodes Among Older Adults.

STUDY OBJECTIVE: We determine whether visit patterns indicative of higher continuity are related to a lower risk of presenting at the emergency department (ED) among older adults. METHODS: This study was a survival analysis between 2011 and 2013 of a 20% random sample of fee-for-service Medicare beneficiaries aged 66 years or older. Ambulatory visit patterns were measured starting in 2011 for up to 24 months using 2 continuity metrics measured on a 0 to 1 scale-Continuity of Care (COC) score and the Usual Provider Continuity (UPC) score. The composite outcome of an ED episode was defined as occurrence of an ED visit with discharge home, an observation stay, or hospital admission. Time-dependent Cox proportional hazards regression models controlled for patient demographic characteristics, comorbidities, previous use, and regional factors, with censoring for death or occurrence of the composite outcome. In a secondary analysis, continuity was measured in the 12 months preceding an ED episode to test whether it was associated with type of ED episode. RESULTS: The relative rate of ED episodes decreased approximately 1% for every 0.1-point increase in the COC score (adjusted hazard ratio 0.99; 95% confidence interval 0.99 to 0.99; P<.001) and 2% for every 0.1-point increase in the UPC score (adjusted hazard ratio 0.98; 95% CI 0.98 to 0.99; P<.001), or up to a 10% lower rate between the lowest and highest COC score and a 20% lower rate for the UPC score. Among beneficiaries with an ED episode, higher continuity was associated with a 1% lower risk of observation stay but a 3% to 4% higher risk of hospital admission relative to an ED visit with discharge home. CONCLUSION: Ambulatory visit patterns exhibiting more continuity were associated with a lower rate of ED utilization for older adults with fee-for-service Medicare coverage. The association of higher continuity with lower risk of ED use but differences in outcome when an ED visit does occur may reflect more appropriate referral to the ED when outpatient management is no longer adequate.

Physician Networks and Ambulatory Care-sensitive Admissions.

BACKGROUND: Research on the quality and cost of care traditionally focuses on individual physicians or medical groups. Social network theory suggests that the care a patient receives also depends on the network of physicians with whom a patient's physician is connected. OBJECTIVES: The objectives of the study are: (1) identify physician networks; (2) determine whether the rate of ambulatory care-sensitive hospital admissions (ACSAs) varies across networks--even different networks at the same hospital; and (3) determine the relationship between ACSA rates and network characteristics. RESEARCH DESIGN: We identified networks by applying network detection algorithms to Medicare 2008 claims for 987,000 beneficiaries in 5 states. We estimated a fixed-effects model to determine the relationship between networks and ACSAs and a multivariable model to determine the relationship between network characteristics and ACSAs. RESULTS: We identified 417 networks. Mean size: 129 physicians; range, 26-963. In the fixed-effects model, ACSA rates varied significantly across networks: there was a 46% difference in rates between networks at the 25th and 75th performance percentiles. At 95% of hospitals with admissions from 2 networks, the networks had significantly different ACSA rates; the mean difference was 36% of the mean ACSA rate. Networks with a higher percentage of primary-care physicians and networks in which patients received care from a larger number of physicians had higher ACSA rates. CONCLUSIONS: Physician networks have a relationship with ACSAs that is independent of the physicians in the network. Physician networks could be an important focus for understanding variations in medical care and for intervening to improve care.

Association of Pioneer Accountable Care Organizations vs traditional Medicare fee for service with spending, utilization, and patient experience.

IMPORTANCE: The Pioneer Accountable Care Organization (ACO) Model aims to drive health care organizations to reduce expenditures while improving quality for fee-for-service (FFS) Medicare beneficiaries. OBJECTIVE: To determine whether FFS beneficiaries aligned with Pioneer ACOs had smaller increases in spending and utilization than other FFS beneficiaries while retaining similar levels of care satisfaction in the first 2 years of the Pioneer ACO Model. DESIGN, SETTING, AND PARTICIPANTS: Participants were FFS Medicare beneficiaries aligned with 32 ACOs (n = 675,712 in 2012; n = 806,258 in 2013) and a comparison group of alignment-eligible beneficiaries in the same markets (n = 13,203,694 in 2012; n = 12,134,154 in 2013). Analyses comprised difference-in-differences multivariable regression with Oaxaca-Blinder reweighting to model expenditure and utilization outcomes over a 2-year performance period (2012-2013) and 2-year baseline period (2010-2011) as well as adjusted analyses of Consumer Assessment of Healthcare Providers & Systems (CAHPS) survey responses among random samples of beneficiaries in Pioneer ACOs (n = 13,097), FFS (n = 116,255), or Medicare Advantage (n = 203,736) for 2012 care. EXPOSURES: Beneficiary alignment with a Pioneer ACO in 2012 or 2013. MAIN OUTCOMES AND MEASURES: Medicare spending, utilization, and CAHPS domain scores. RESULTS: Total spending for beneficiaries aligned with Pioneer ACOs in 2012 or 2013 increased from baseline to a lesser degree relative to comparison populations. Differential changes in spending were approximately -$35.62 (95% CI, -$40.12 to -$31.12) per-beneficiary-per-month (PBPM) in 2012 and -$11.18 (95% CI, -$15.84 to -$6.51) PBPM in 2013, which amounted to aggregate reductions in increases of approximately -$280 (95% CI, -$315 to -$244) million in 2012 and -$105 (95% CI, -$148 to -$61) million in 2013. Inpatient spending showed the largest differential change of any spending category (-$14.40 [95% CI, -$17.31 to -$11.49] PBPM in 2012; -$6.46 [95% CI, -$9.26 to -$3.66] PBPM in 2013). Changes in utilization of physician services, emergency department, and postacute care followed a similar pattern. Compared with other Medicare beneficiaries, ACO-aligned beneficiaries reported higher mean scores for timely care (77.2 [ACO] vs 71.2 [FFS] vs 72.7 [MA]) and for clinician communication (91.9 [ACO] vs 88.3 [FFS] vs 88.7 [MA]). CONCLUSIONS AND RELEVANCE: In the first 2 years of the Pioneer ACO Model, beneficiaries aligned with Pioneer ACOs, as compared with general Medicare FFS beneficiaries, exhibited smaller increases in total Medicare expenditures and differential reductions in utilization of different health services, with little difference in patient experience.

Accountable Care Organizations' Increase In Nonphysician Practitioners May Signal Shift For Health Care Workforce.

Both the number and the size of accountable care organizations (ACOs) in the Medicare Shared Savings Program have been increasing. The number of ACOs rose from 220 in 2013 to 548 in 2018, while the average number of participating clinicians in ACOs increased from 263 to 653. Although increases occurred for primary care physicians (from an average of 141 to 251) and medical specialists (from an average of 76 to 157), the increase for nonphysician practitioners (from an average of 47 to 245) was the largest. These differential increases changed the ACO workforce composition over time. The average proportion of nonphysician practitioners in ACOs grew from 18.1 percent to 38.7 percent, with a commensurate decline in the average share of primary care physicians from 60.0 percent to 42.2 percent. As value-based care models grow in prevalence, their evolving clinician composition may affect workforce patterns in the broader health care delivery system.

Association of Variation in Consultant Use Among Hospitalist Physicians With Outcomes Among Medicare Beneficiaries.

Importance: Evidence is lacking on the consequences of high rates of inpatient consultation. Objective: To examine outcomes and resource use of patients cared for by hospitalists who use more inpatient consultation than their colleagues. Design, Setting, and Participants: A retrospective cohort study of medical admissions to hospitalists among fee-for-service Medicare beneficiaries was conducted. Hospitalist consultation tendency was identified from January 1, 2013, to December 31, 2014; admissions were calculated in 2013; and outcomes were measured in 2014. Data were analyzed from January 31, 2017, to May 9, 2019. A total of 711 654 admissions with patients receiving care from 14 584 hospitalists at 737 hospitals were included. Exposure: Admission to high-consulting hospitalists, considered to be those who were in the top 25% of the distribution of consulting frequency at their own hospital (adjusted for patient case mix). Main Outcomes and Measures: Outcomes included length of stay, Medicare Part B inpatient charges, discharge destination, all-cause 7- and 30-day readmissions, 90-day outpatient specialist visits, and 30-day mortality. Results: The 711 654 hospital admissions included 408 489 women (57.4%); mean (SD) age of the population was 80 (8.5) years. Length of stay of patients cared for by high-consulting hospitalists was longer compared with other hospitalists (adjusted incidence rate ratio, 1.04; 95% CI, 1.03-1.05). The admissions resulted in a mean of $137.91 (95% CI, $118.89-$156.93) more in Medicare Part B charges and were less likely to end with the patient going home (adjusted odds ratio [aOR], 0.96; 95% CI, 0.94-0.98) compared with patients cared for by other hospitalists in the cohort. Patients cared for by high-consulting hospitalists also were 7% more likely than patients cared for by other hospitalists to see an outpatient specialist at 90 days (aOR 1.07; 95% CI, 1.05-1.09), with no significant differences in 30-day mortality (aOR 1.01, 95% CI, 0.98-1.03) or readmissions (7-day readmissions: aOR 1.01; 95% CI, 0.98-1.03; 30-day readmissions: aOR, 1.01; 95% CI, 0.99-1.03). Conclusions and Relevance: Hospitalists who obtain consultations more than their colleagues at the same institution were associated with greater use of health care resources without apparent mortality benefit. Further investigation should identify whether reducing high rates of consultation can reduce resource use without harming patients.

Spending variation among ACOs in the Medicare Shared Savings Program.

OBJECTIVES: Understanding variation in spending across organizations, rather than across geographic areas, is important because care is delivered by organizations and interventions increasingly focus on organizations. Accountable care organizations (ACOs) are particularly important to study given their incentives to reduce spending. Analyzing spending differences across ACOs may help identify cost savings opportunities. STUDY DESIGN: Cross-sectional analysis of Medicare claims. METHODS: We stratified ACOs into quartiles based on the deviation between each ACO's risk-adjusted spending and average risk-adjusted fee-for-service spending in the same market (hospital referral region). We compared spending between top- and bottom-quartile ACOs on each of 7 major service categories and 10 clinical condition groups to identify areas of potential savings. We simulated spending reductions if ACOs with high adjusted spending reduced spending to the levels of lower-spending ACOs. RESULTS: In 2016, geographically adjusted and risk-adjusted total per-beneficiary spending for the highest-spending quartile of ACOs was 14% higher than for ACOs in the lowest quartile. Variation between high- and low-spending ACOs was greatest, at 27%, in the use of skilled nursing facilities-a service category in which ACOs have reduced spending by the greatest percentage. Inpatient care was the largest driver of absolute dollar differences in spending, however, accounting for 37% of the total spread. If spending in ACOs above median adjusted spending were brought down to the median, savings would be 3% to 4%. CONCLUSIONS: By extending the variations literature to focus on ACOs, we illustrated that meaningful further savings opportunities exist both within and across markets.

Relationship of primary care physicians' patient caseload with measurement of quality and cost performance.

CONTEXT: Sufficient numbers of patients are necessary to generate statistically reliable measurements of physicians' quality and cost performance. OBJECTIVE: To determine whether primary care physicians in the same physician practice collectively see enough Medicare patients annually to detect meaningful differences between practices in ambulatory quality and cost measures. DESIGN, SETTING, AND PATIENTS: Primary care physicians in the United States were linked to their physician practices using the Healthcare Organization Services database maintained by IMS Health. Patients who visited primary care physicians in the 2005 Medicare Part B 20% sample were used to estimate Medicare caseloads per practice. Caseloads necessary to detect 10% relative differences in costs and quality were calculated using national mean ambulatory Medicare spending, rates of mammography for women 66 to 69 years, and hemoglobin A(1c) testing for 66- to 75-year-olds with diabetes, preventable hospitalization rate, and 30-day readmission rate after discharge for congestive heart failure (CHF). MAIN OUTCOME MEASURES: Percentage of primary care physician practices with a sufficient number of eligible patients to detect a 10% relative difference in each performance measure. RESULTS: Primary care physician practices had annual median caseloads of 260 Medicare patients (interquartile range [IQR], 135-500), 25 women eligible for mammography (IQR, 10-50), 30 patients with diabetes eligible for hemoglobin A(1c) testing (IQR, 15-55), and 0 patients hospitalized for CHF. For ambulatory costs, mammography rate, and hemoglobin A(1c) testing rate, the percentage of primary care physician practices with sufficient caseloads to detect 10% relative differences in performance ranged from less than 10% of practices with fewer than 11 primary care physicians to 100% of practices with more than 50 primary care physicians. None of the primary care physician practices had sufficient caseloads to detect 10% relative differences in preventable hospitalization or 30-day readmission after discharge for CHF. CONCLUSION: Relatively few primary care physician practices are large enough to reliably measure 10% relative differences in common measures of quality and cost performance among fee-for-service Medicare patients.

Comparison of Hospital Resource Use and Outcomes Among Hospitalists, Primary Care Physicians, and Other Generalists.

Importance: A physician's prior experience caring for a patient may be associated with patient outcomes and care patterns during and after hospitalization. Objective: To examine differences in the use of health care resources and outcomes among hospitalized patients cared for by hospitalists, their own primary care physicians (PCPs), or other generalists. Design, Setting, and participants: This retrospective study analyzed admissions for the 20 most common medical diagnoses among elderly fee-for-service Medicare patients from January 1 through December 31, 2013. Patients had at least 1 previous encounter with an outpatient clinician within the 365 days before admission, and diagnoses were restricted to the 20 most common diagnosis related groups. Data were collected from Medicare Parts A and B claims data, and outcomes were analyzed from January 1, 2013, through January 31, 2014. Exposures: Physician types included hospitalists, PCPs (ie, the physicians who provided a plurality of ambulatory visits in the year preceding admission), or generalists (not the patients' PCPs). Main Outcomes and Measures: Number of in-hospital specialist consultations, length of stay, discharge site, all-cause 7- and 30-day readmission rates, and 30-day mortality. Results: A total of 560 651 admissions were analyzed (41.9% men and 59.1% women; mean [SD] age, 80 [8] years). Patients' physicians were hospitalists in 59.7% of admissions; PCPs, in 14.2%; and other generalists, in 26.1%. Primary care physicians used consultations 3% more (relative risk, 1.03; 95% CI, 1.02-1.05) and other generalists used consultations 6% more (relative risk, 1.06; 95% CI, 1.05-1.07) than hospitalists. Lengths of stay were 12% longer among patients cared for by PCPs (adjusted incidence rate ratio, 1.12; 95% CI, 1.11-1.13) and 6% longer among those cared for by other generalists (adjusted incidence rate ratio, 1.06; 95% CI, 1.05-1.07) compared with patients cared for by hospitalists. However, PCPs were more likely to discharge patients home (adjusted odds ratio [AOR], 1.14; 95% CI, 1.11-1.17), whereas other generalists were less likely to do so (AOR, 0.94; 95% CI, 0.92-0.96). Relative to hospitalists, patients cared for by PCPs had similar readmission rates at 7 days (AOR, 0.98; 95% CI, 0.96-1.01) and 30 days (AOR, 1.02; 95% CI, 0.99-1.04), whereas other generalists' readmission rates were greater than hospitalists' rates at 7 (AOR, 1.05; 95% CI, 1.02-1.07) and 30 (AOR, 1.04; 95% CI, 1.03-1.06) days. Patients cared for by PCPs had lower 30-day mortality than patients of hospitalists (AOR, 0.94; 95% CI, 0.91-0.97), whereas the mortality rate of patients of other generalists was higher (AOR, 1.09; 95% CI, 1.07-1.12). Conclusions and Relevance: A PCP's prior experience with a patient may be associated with inpatient use of resources and patient outcomes. Patients cared for by their own PCP had slightly longer lengths of stay and were more likely to be discharged home but also were less likely to die within 30 days compared with those cared for by hospitalists or other generalists.

Concordance between continuity of care reported by patients and measured from administrative data.

Continuity of care can be measured using patient survey or administrative data, though the degree of concordance between continuity of care reported by patients and measured from their actual utilization is not well understood. A cross-sectional analysis of the 2010 Medicare Current Beneficiary Survey and linked 2009-2010 Medicare Carrier and outpatient claims data measured the concentration of ambulatory care visit patterns according to two commonly used metrics of continuity of care. Continuity of care measured from claims data did not align with patient reports of having a usual care provider. However, high levels of continuity for patients with a usual care provider were associated with a longer patient-provider relationship, greater patient-perceived provider knowledge of the patient's medical condition and history, and more confidence in the provider. Inferences about a patient's continuity of care must be placed in the context of the data source with which continuity is measured.

Continuity of care and the risk of preventable hospitalization in older adults.

IMPORTANCE: Preventable hospitalizations are common among older adults for reasons that are not well understood. OBJECTIVE: To determine whether Medicare patients with ambulatory visit patterns indicating higher continuity of care have a lower risk of preventable hospitalization. DESIGN: Retrospective cohort study. SETTING: Ambulatory visits and hospital admissions. PARTICIPANTS: Continuously enrolled fee-for-service Medicare beneficiaries older than 65 years with at least 4 ambulatory visits in 2008. EXPOSURES: The concentration of patient visits with physicians measured for up to 24 months using the continuity of care score and usual provider continuity score on a scale from 0 to 1. MAIN OUTCOMES AND MEASURES: Index occurrence of any 1 of 13 preventable hospital admissions, censoring patients at the end of their 24-month follow-up period if no preventable hospital admissions occurred, or if they died. RESULTS: Of the 3,276,635 eligible patients, 12.6% had a preventable hospitalization during their 2-year observation period, most commonly for congestive heart failure (25%), bacterial pneumonia (22.7%), urinary infection (14.9%), or chronic obstructive pulmonary disease (12.5%). After adjustment for patient baseline characteristics and market-level factors, a 0.1 increase in continuity of care according to either continuity metric was associated with about a 2% lower rate of preventable hospitalization (continuity of care score hazard ratio [HR], 0.98 [95% CI, 0.98-0.99; usual provider continuity score HR, 0.98 [95% CI, 0.98-0.98). Continuity of care was not related to mortality rates. CONCLUSIONS AND RELEVANCE: Among fee-for-service Medicare beneficiaries older than 65 years, higher continuity of ambulatory care is associated with a lower rate of preventable hospitalization.

Seniors' perceptions of health care not closely associated with physician supply.

We conducted a national random survey of Medicare beneficiaries to better understand the association between the supply of physicians and patients' perceptions of their health care. We found that patients living in areas with more physicians per capita had perceptions of their health care that were similar to those of patients in regions with fewer physicians. In addition, there were no significant differences between the groups of patients in terms of numbers of visits to their personal physician in the previous year; amount of time spent with a physician; or access to tests or specialists. Our results suggest that simply training more physicians is unlikely to lead to improved access to care. Instead, focusing health policy on improving the quality and organization of care may be more beneficial.