The Impact of COVID-19 on Postdischarge Outcomes for Dialysis Patients in the United States: Evidence from Medicare Claims Data.

Background: Recent investigations have shown that, on average, patients hospitalized with coronavirus disease 2019 (COVID-19) have a poorer postdischarge prognosis than those hospitalized without COVID-19, but this effect remains unclear among patients with end-stage kidney disease (ESKD) who are on dialysis. Methods: Leveraging a national ESKD patient claims database administered by the US Centers for Medicare and Medicaid Services, we conducted a retrospective cohort study that characterized the effects of in-hospital COVID-19 on all-cause unplanned readmission and death within 30 days of discharge for patients on dialysis. Included in this study were 436,745 live acute-care hospital discharges of 222,154 Medicare beneficiaries on dialysis from 7871 Medicare-certified dialysis facilities between January 1 and October 31, 2020. Adjusting for patient demographics, clinical characteristics, and prevalent comorbidities, we fit facility-stratified Cox cause-specific hazard models with two interval-specific (1-7 and 8-30 days after hospital discharge) effects of in-hospital COVID-19 and effects of prehospitalization COVID-19. Results: The hazard ratios due to in-hospital COVID-19 over the first 7 days after discharge were 95% CI, 1.53 to 1.65 for readmission and 95% CI, 1.38 to 1.70 for death, both with P<0.001. For the remaining 23 days, the hazard ratios were 95% CI, 0.89 to 0.96 and 95% CI, 0.86 to 1.07, with P<0.001 and P=0.50, respectively. Effects of prehospitalization COVID-19 were mostly nonsignificant. Conclusions: In-hospital COVID-19 had an adverse effect on both postdischarge readmission and death over the first week. With the surviving patients having COVID-19 substantially selected from those hospitalized, in-hospital COVID-19 was associated with lower rates of readmission and death starting from the second week.

Association of the Comprehensive ESRD Care Model with Treatment Adherence.

Background: Poor adherence to scheduled dialysis treatments is common and can cause adverse clinical and economic outcomes. In 2015, the Centers for Medicare and Medicaid Innovation launched the Comprehensive ESRD Care (CEC) Model, a novel modification of the Accountable Care Organization framework. Many model participants reported efforts to increase dialysis adherence and promptly reschedule missed treatments. Methods: With Medicare databases covering 2014-2019, we used difference-in-differences models to compare treatment adherence among patients aligned to 1037 CEC facilities relative to those aligned to matched comparison facilities, while accounting for their differences at baseline. Using dates of service, we identified patients who typically received three weekly treatments and the days when treatments typically occurred. Skipped treatments were defined as days when the patient was not hospitalized but did not receive an expected treatment, and rescheduled treatments as days when a patient who had skipped their previous treatment received an additional treatment before their next expected treatment date. Results: Patients in the CEC Model had higher odds of attending as-scheduled sessions relative to the comparison group, although the effect was only marginally significant (OR, 1.02; 95% CI, 1.00 to 1.04, P=0.08). Effects were stronger among females (OR, 1.03; 95% CI, 1.00 to 1.06, P=0.06) than males (OR, 1.01; 95% CI, 0.98 to 1.04, P=0.49), and among those aged <70 years (OR, 1.02; 95% CI, 1.00 to 1.05, P=0.04) than those aged ≥70 years (OR, 1.00; 95% CI, 0.96 to 1.04, P=0.96). The CEC was associated with higher odds of rescheduled sessions (OR, 1.09; 95% CI, 1.05 to 1.14, P<0.001). Effects were significant for both sexes, but were larger among males (OR, 1.11; 95% CI, 1.05 to 1.18, P<0.001) than females (OR, 1.07; 95% CI, 1.02 to 1.13, P=0.01), and effects were significant among those <70 years (OR, 1.12; 95% CI, 1.07 to 1.17, P<0.001), but not those ≥70 years (OR, 0.99; 95% CI, 0.92 to 1.07, P=0.80). Conclusions: The CEC Model is intended to incentivize strategies to prevent costly interventions. Because poor dialysis adherence may precipitate hospitalizations or other adverse events, many CEC Model participants encouraged adherence and promptly rescheduled missed treatments as strategic priorities. This study suggests these efforts were a success, although the absolute magnitudes of the effects were modest.

COVID-19 Risk Factors and Mortality Outcomes Among Medicare Patients Receiving Long-term Dialysis.

Importance: There is a need for studies to evaluate the risk factors for COVID-19 and mortality among the entire Medicare long-term dialysis population using Medicare claims data. Objective: To identify risk factors associated with COVID-19 and mortality in Medicare patients undergoing long-term dialysis. Design, Setting, and Participants: This retrospective, claims-based cohort study compared mortality trends of patients receiving long-term dialysis in 2020 with previous years (2013-2019) and fit Cox regression models to identify risk factors for contracting COVID-19 and postdiagnosis mortality. The cohort included the national population of Medicare patients receiving long-term dialysis in 2020, derived from clinical and administrative databases. COVID-19 was identified through Medicare claims sources. Data were analyzed on May 17, 2021. Main Outcomes and Measures: The 2 main outcomes were COVID-19 and all-cause mortality. Associations of claims-based risk factors with COVID-19 and mortality were investigated prediagnosis and postdiagnosis. Results: Among a total of 498 169 Medicare patients undergoing dialysis (median [IQR] age, 66 [56-74] years; 215 935 [43.1%] women and 283 227 [56.9%] men), 60 090 (12.1%) had COVID-19, among whom 15 612 patients (26.0%) died. COVID-19 rates were significantly higher among Black (21 787 of 165 830 patients [13.1%]) and Hispanic (13 530 of 86 871 patients [15.6%]) patients compared with non-Black patients (38 303 of 332 339 [11.5%]), as well as patients with short (ie, 1-89 days; 7738 of 55 184 patients [14.0%]) and extended (ie, ≥90 days; 10 737 of 30 196 patients [35.6%]) nursing home stays in the prior year. Adjusting for all other risk factors, residing in a nursing home 1 to 89 days in the prior year was associated with a higher hazard for COVID-19 (hazard ratio [HR] vs 0 days, 1.60; 95% CI 1.56-1.65) and for postdiagnosis mortality (HR, 1.31; 95% CI, 1.25-1.37), as was residing in a nursing home for an extended stay (COVID-19: HR, 4.48; 95% CI, 4.37-4.59; mortality: HR, 1.12; 95% CI, 1.07-1.16). Black race (HR vs non-Black: HR, 1.25; 95% CI, 1.23-1.28) and Hispanic ethnicity (HR vs non-Hispanic: HR, 1.68; 95% CI, 1.64-1.72) were associated with significantly higher hazards of COVID-19. Although home dialysis was associated with lower COVID-19 rates (HR, 0.77; 95% CI, 0.75-0.80), it was associated with higher mortality (HR, 1.18; 95% CI, 1.11-1.25). Conclusions and Relevance: These results shed light on COVID-19 risk factors and outcomes among Medicare patients receiving long-term chronic dialysis and could inform policy decisions to mitigate the significant extra burden of COVID-19 and death in this population.

Persistent Variation in Medicare Payment Authorization for Home Hemodialysis Treatments.

OBJECTIVE: To analyze variation in medical care use attributable to Medicare's decentralized claims adjudication process as exemplified in home hemodialysis (HHD) therapy. DATA SOURCES/STUDY SETTING: Secondary data analysis using 2009-2012 paid Medicare claims for HHD and in-center hemodialysis (IHD). STUDY DESIGN: We compared variation across Medicare administrative contractors (MACs) in predicted paid treatments per standardized patient-month for HHD and IHD patients. We used ordinary least-squares regression to determine whether higher paid HHD treatment counts expanded HHD programs' presence among dialysis facilities. DATA COLLECTION: We identified HHD and IHD treatments using procedure, revenue center, and claim condition codes on type 72x claims. PRINCIPAL FINDINGS: MACs varied persistently in predicted HHD treatments per patient-month, ranging from 14.3 to 21.9 treatments versus 10.9 to 12.4 IHD treatments. The presence of facilities' HHD programs was uncorrelated with average HHD payment counts. CONCLUSIONS: Medicare's claims adjudication process promotes variation in medical care use, as we observe among HHD patients. MACs' discretionary decision making, while potentially facilitating innovation, may admit inefficiency in care practice as well as inequitable access to health care services. Regulators should weigh the benefits of flexibility in local coverage decisions against those of national standards for medical necessity.

Michigan's fee-for-value physician incentive program reduces spending and improves quality in primary care.

As policy makers and others seek to reduce health care cost growth while improving health care quality, one approach gaining momentum is fee-for-value reimbursement. This payment strategy maintains the traditional fee-for-service arrangement but includes quality and spending incentives. We examined Blue Cross Blue Shield of Michigan's Physician Group Incentive Program, which uses a fee-for-value approach focused on primary care physicians. We analyzed the program's impact on quality and spending from 2008 to 2011 for over three million beneficiaries in over 11,000 physician practices. Participation in the incentive program was associated with approximately 1.1 percent lower total spending for adults (5.1 percent lower for children) and the same or improved performance on eleven of fourteen quality measures over time. Our findings contribute to the growing body of evidence about the potential effectiveness of models that align payment with cost and quality performance, and they demonstrate that it is possible to transform reimbursement within a fee-for-service framework to encourage and incentivize physicians to provide high-quality care, while also reducing costs.

Blood transfusion practices in dialysis patients in a dynamic regulatory environment.

BACKGROUND: In 2011, Medicare implemented a prospective payment system (PPS) covering an expanded bundle of services that excluded blood transfusions. This led to concern about inappropriate substitution of transfusions for other anemia management methods. STUDY DESIGN: Medicare claims were used to calculate transfusion rates among dialysis patients pre- and post-PPS. Linear probability regressions adjusted transfusion trends for patient characteristics. SETTING & PARTICIPANTS: Dialysis patients for whom Medicare was the primary payer between 2008 and 2012. PREDICTOR: Pre-PPS (2008-2010) versus post-PPS (2011-2012). OUTCOMES & MEASUREMENTS: Monthly and annual probability of receiving one or more blood transfusions. RESULTS: Monthly rates of one or more transfusions varied from 3.8%-4.8% and tended to be lowest in 2010. Annual rates of transfusion events per patient were -10% higher in relative terms post-PPS, but the absolute magnitude of the increase was modest (-0.05 events/patient). A larger proportion received 4 or more transfusions (3.3% in 2011 and 2012 vs 2.7%-2.8% in prior years). Controlling for patient characteristics, the monthly probability of receiving a transfusion was significantly higher post-PPS (ß = 0.0034; P < 0.001), representing an -7% relative increase. Transfusions were more likely for females and patients with more comorbid conditions and less likely for blacks both pre- and post-PPS. LIMITATIONS: Possible underidentification of transfusions in the Medicare claims, particularly in the inpatient setting. Also, we do not observe which patients might be appropriate candidates for kidney transplantation. CONCLUSIONS: Transfusion rates increased post-PPS, but these increases were modest in both absolute and relative terms. The largest increase occurred for patients already receiving several transfusions. Although these findings may reduce concerns regarding the impact of Medicare's PPS on inappropriate transfusions that impair access to kidney transplantation or stress blood bank resources, transfusions should continue to be monitored.

The initial impact of Medicare's new prospective payment system for kidney dialysis.

BACKGROUND: Medicare implemented a new prospective payment system (PPS) on January 1, 2011. This PPS covers an expanded bundle of services, including services previously paid on a fee-for-service basis. The objectives of the new PPS include more efficient decisions about treatment service combinations and modality choice. METHODS: Primary data for this study are Medicare claims files for all dialysis patients for whom Medicare is the primary payer. We compare use of key injectable medications under the bundled PPS to use when those drugs were separately billable and examine variability across providers. We also compare each patient's dialysis modality before and after the PPS. RESULTS: Use of relatively expensive drugs, including erythropoiesis-stimulating agents, declined substantially after institution of the new PPS, whereas use of iron products, often therapeutic substitutes for erythropoiesis-stimulating agents, increased. Less expensive vitamin D products were substituted for more expensive types. Drug spending overall decreased by ∼$25 per session, or about 5 times the mandated reduction in the base payment rate of ∼$5. Use of peritoneal dialysis increased in 2011 after being nearly flat in the years prior to the PPS, with the increase concentrated in patients in their first or second year of dialysis. Home hemodialysis continued to increase as a percentage of total dialysis services, but at a rate similar to the pre-PPS trend. CONCLUSION: The expanded bundle dialysis PPS provided incentives for the use of lower cost therapies. These incentives seem to have motivated dialysis providers to move toward lower cost methods of care in both their use of drugs and choice of modalities.

Influence of ownership on access in outpatient substance abuse treatment.

Marked changes in ownership and control in substance abuse treatment delivery have garnered the attention of providers and policymakers alike. The proliferation of private for-profit providers and the shift to a delivery system that may be more explicitly influenced by financial incentives are of particular concern for this vulnerable population. This work empirically addresses how treatment unit ownership affected access and retention between 1995 and 2005 in the United States. Regressions show statistically significant associations between unit ownership and both restricted treatment access and shortening of treatment duration for financial reasons. In comparison to private nonprofit and public units, private for-profit units were less likely to provide initial treatment access and reported shortened treatment for a greater percentage of clients unable to pay. Other organization characteristics, such as methadone-maintenance programs and managed care participation, also were associated with limiting treatment accessibility. While this work does not determine the underlying motivation behind access limitations, continued shifts in ownership structure should heighten the attention of policymakers.

Tailored treatment in the outpatient substance abuse treatment sector: 1995-2005.

Interest in improving the quality of addiction treatment has led to the development of clinical paradigms that emphasize the principle of tailored care-matching treatments to the specific needs of each client or client subgroup. This work analyzes how trends in the provision of tailored treatment practices (TTPs) have changed between 1995 and 2005 across outpatient substance abuse treatment (OSAT) programs in the United States. Categories of interest include measures to capture needs assessment and treatment planning activities, treatment offerings for special populations, and case management activities. Results show that TTPs have diffused in an uneven fashion in the population of OSAT programs between 1995 and 2005. Specifically, needs assessment/treatment planning and case management remain a relatively common practice among OSAT programs, while treatment for special populations (especially same-race therapy) is less widely practiced and, indeed, experienced some decline over the study period. This trend is troublesome given that minority clients constitute a large proportion of those utilizing OSAT programs.

Tailoring of outpatient substance abuse treatment to women, 1995-2005.

BACKGROUND: Tailoring substance abuse treatment to women often leads to better outcomes. Previous evidence, however, suggests limited availability of such options. OBJECTIVES: This investigation sought to depict recent changes in outpatient substance abuse treatment (OSAT) tailoring to women and to identify unit and contextual factors associated with these practices. RESEARCH DESIGN: Data were from 2 waves of a national OSAT unit survey (N = 618 in 1995, N = 566 in 2005). Comparisons of weighted means between waves indicate which practices changed over time. Multiple logistic regressions with generalized estimating equations test associations between unit and contextual attributes and tailoring to women. MEASURES: Tailoring to women was measured as availability of prenatal care, child care, single sex therapy, and same sex therapists, and the percentage of staff trained to meet female clients' needs. RESULTS: Two measures of tailoring to women declined significantly between 1995 and 2005: availability of single sex therapy (from 66% to 44% of units) and percent of staff trained to work with women (from 42% to 32% of units). No aspect of tailoring to women became more common. Proportion of female clients, total number of clients, methadone status, and private and government managed care were associated with higher odds of tailoring to women. For-profit facilities, which became more prevalent during the study period, had lower odds than other units of tailoring treatment to women. CONCLUSIONS: Some key aspects of OSAT tailoring to women decreased significantly in the last decade. Managed care contracts may offer 1 mechanism for counteracting these trends.

Case management and client access to health and social services in outpatient substance abuse treatment.

A primary goal of case management is to coordinate services across treatment settings and to integrate substance abuse services with other types of services offered in the community, including housing, mental health, medical, and social services. However, case management is a global construct that consists of several key dimensions, which include extent of case management coverage, the degree of management of the referral process, and the location of case management activity (on-site, off-site, or both). This study examines the relationship between specific dimensions of case management and the utilization of health and ancillary social services in outpatient substance abuse treatment. In general, results suggest that more active case management during the referral process and providing case management both on-site and off-site are most consistent with our predictions of greater use of health and ancillary social services by substance abuse clients. However, these effects are specific to general health care and mental health services. Case management appears to have little effect on use of social services or aftercare plans.

Do licensing and accreditation matter in outpatient substance abuse treatment programs?

Licensing and accreditation are widely used to improve and convey organizational quality. The objective of this study was to provide substance abuse treatment stakeholders with better evidence about how well licensing and accreditation actually correlate with staffing and treatment practices. Regressions using data from national surveys of outpatient substance abuse treatment facilities indicated that no form of licensing or accreditation was associated with better staff-to-client ratios or with one important aspect of comprehensive treatment -- the percentage of clients receiving routine medical care. There were several positive associations between licensing/accreditation and other aspects of treatment comprehensiveness. Three categories of licensure/accreditation were also positively associated with use of after-treatment plans. Post hoc analyses revealed that accreditation was associated with units' organizational contexts and referral sources as well as the nature of the competitive environment. Licensing/accreditation may reveal as much about units' institutional environments as about the quality of treatment provided.

Is managed care closing substance abuse treatment units?

Despite high levels of unmet need for outpatient substance abuse treatment, a significant percentage of outpatient units have closed over the past several years. This study drew on 1999-2000 and 2005 national surveys to determine if managed care was associated with outpatient substance abuse treatment units' likelihood of surviving. Each substance abuse unit director was asked about the presence of any managed care contracts, percentage revenues from managed care, percentage of clients for whom prior authorization was required, and percentage of clients for whom concurrent review was required. A multiple logistic regression revealed that none of these factors was associated with substance abuse treatment unit survival. At this point, neither the presence nor the structure of managed care appears to affect the survival of outpatient substance abuse treatment units. Given the need for these facilities, however, and their vulnerability to closure, continued attention to managed care's potential influence is warranted.

Pay-for-performance as a method to establish the business case for quality.

One of the major reasons providers give for not implementing promising quality-enhancing interventions (QEI) is that no "business case" for quality has been made. This article clarifies the concepts of the business case for quality and the related economic case for quality and identifies the perspectives of the various actors in health care financing, production, and consumption decisions. A methodology to evaluate the business case for quality from the perspective of payers and providers is presented. The article then uses implemented QEIs to show how a pay-for-performance (P4P) program can alter the business cases for payers and providers. Specifically, the P4P programs described in this article allow a provider to implement a QEI with the financial alignment of the payer in order to achieve financial and non-financial benefits. In some cases, providers and payers may be able to establish P4P programs providing net benefits for both parties.

Duration of nonmethadone outpatient treatment: results from a national survey.

OBJECTIVES: This study examined organizational trends from 1990 to 2000 and unit characteristics associated with the duration of nonmethadone outpatient addiction treatment. METHODS: Program directors and clinical supervisors from a nationally representative panel of nonmethadone outpatient units in the United States were surveyed in 1990, 1995, and 2000. Treatment duration was measured from clinical supervisors' reports of the average length of stay. Negative binominal regression models controlled for multivariate effects. RESULTS: Treatment duration modestly declined between 1990 and 2000 while addiction severity increased. Affiliation with a mental health center, older program age, JCAHO accreditation-ostensibly a marker for structural quality-and serving more clients with prior authorization requirements- a measure of managed care stringency-were associated with shorter treatment durations. CONCLUSIONS: These findings suggest that treatment duration did not increase between 1990 and 2000 despite clients' worsening addiction severity and growing evidence that longer duration of formal treatment improves treatment outcome. In addition, programs with JCAHO accreditation and stronger managed care oversight appeared to seek efficiencies through reductions in treatment duration.

Counting physicians: inconsistencies in a commonly used source for workforce analysis.

PURPOSE: To assess the accuracy of the AMA Masterfile. METHOD: In 2002, the authors compared the listing in the Masterfile for pediatric cardiologists with a roster of all such physicians documented by the American Board of Pediatrics (ABP) to have completed pediatric cardiology training. Physicians listed on the Masterfile but without ABP records of training completion received a mail survey. For main outcome measures, the differences in state-level distribution of pediatric cardiologists were used, depending on whether data were from the ABP or the AMA Masterfile. Survey items included nature and duration of medical training, the amount of time caring for pediatric or adult cardiology patients, and whether the respondent conducted echocardiograms and/or cardiac catheterizations on children and/or adults. RESULTS: Of the 2,675 unique, individual physicians obtained from the queries of both lists, 58% (1,558) were listed by both the Masterfile and the ABP. Another 28% (738) were listed by the AMA Masterfile only, and 4% (108) were listed by the ABP only.Of those listed by the Masterfile only, 40% reported they provide no pediatric cardiology care. The amount of pediatric cardiology training was highly variable among the remainder of the respondents. CONCLUSIONS: There are large differences in the number and distribution of physicians identified as pediatric cardiologists between these two datasets. Also, many are potentially providing care for which they have little or no training. Use of such data has the potential to lead to policy options at odds with the actual needs of our nation as a whole or of specific geographic areas.

Cost-effectiveness of hospital pay-for-performance incentives.

One increasingly popular mechanism for stimulating quality improvements is pay-for-performance, or incentive, programs. This article examines the cost-effectiveness of a hospital incentive system for heart-related care, using a principal-agent model, where the insurer is the principal and hospitals are the agents. Four-year incentive system costsfor the payer were dollar 22,059,383, composed primarily of payments to the participating hospitals, with approximately 5 percent in administrative costs. Effectiveness is measured in stages, beginning with improvements in the processes of heart care. Care process improvements are converted into quality-adjusted life years (QALYs) gained, with reference to literatures on clinical effectiveness and survival. An estimated 24,418 patients received improved care, resulting in a range of QALYs from 733 to 1,701, depending on assumptions about clinical effectiveness. Cost per QALY was found to be between dollar 12,967 and dollar 30,081, a level well under consensus measures of the value of a QALY.

Hospital responses to pay-for-performance incentives.

Not-for-profit hospitals are complex organizations and, therefore, may face unique challenges in responding to financial incentives for quality. In this research, we explore the types of behavioural changes made by not-for-profit Michigan hospitals in response to a pay-for-performance system for quality. We also identify factors that motivate or facilitate changes in effort. We apply a conceptual framework based on agency theory to motivate our research questions. Using data derived from structured interviews and surveys administered to 86 hospitals participating in a pay-for-performance system, we compare hospitals reporting and not reporting behavioural changes. Separate analyses are performed for hospitals reporting structure-related changes and hospitals reporting process-related changes. Our findings confirm that hospitals respond to incentive payments; however, our findings also reveal that hospital responses are not universal. Rather, involvement by boards of trustees, willingness to exert leverage with physicians, and financial and competitive motivations are all associated with hospitals' behavioural responses to incentives. Results of this research will help inform payers and hospital managers considering the use of incentives about the nature of hospitals' responses.

Internal medicine-pediatrics physicians: their care of children versus care of adults.

Purpose To determine how practicing physicians who graduated from internal medicine-pediatrics residency programs allocate their practice time and professional activities between adult and child patients, and to investigate whether there are predictors of the extent to which a particular physician's practice is more or less focused on one or the other of these patient groups. Method In 2003, the authors mailed a questionnaire to the 1,300 generalists and 472 subspecialists who, as of 2003, had completed internal medicine-pediatrics training since the inception of the program in 1980. Results The response rate was 73% for the generalists and 65% for the subspecialists. The vast majority of the generalist physicians stated that they provide care to all ages of patients. However, the proportion of care they provided to different age groups was not uniformly distributed, with more care provided to adults than children. Both generalist and subspecialist respondents were more likely to feel better prepared by their residency training to care for adults than for children. Those who felt less well-prepared to care for children were less likely to do so in their practices (odds ratio, 0.68; 95% confidence interval, 0.48-0.96). Fifty-four percent of the subspecialists pursued subspecialty training in internal medicine only, while 38% completed a combined internal medicine-pediatrics subspecialty program. These respondents, like the generalist respondents, also were more likely to focus clinical efforts on adults than children. Fewer than half (43%) provided any care to children zero to one year of age, while 54% provided at least some care to children aged two to 11 years. Conclusions Internal medicine-pediatrics physicians are more likely to spend a majority of their clinical care focused on adults and to perceive that they stay more current in the care of adults than of children. Potential reasons for this disparity may include training issues, greater reimbursement for the care of adults, perceptions of the impact on the medical market of the demographic shifts to older adults, and employment opportunities following training. These results also demonstrate the need for a more detailed and comprehensive assessment of the adequacy of pediatrics training in these programs.

Changes in the proportion and volume of care provided to children by generalists and subspecialists.

OBJECTIVE: To assess whether primary care physicians, via referrals or other mechanisms, are now providing proportionally less care for children with specific common diagnoses, thus driving greater demand for specialist services. STUDY DESIGN: Secondary data analysis (1993-2001) from one of the largest commercial healthcare organizations in the United States. Evaluation and management (E/M) common procedural terminology (CPT) visit codes and International Classification of Diseases (ICD) codes pertaining to asthma, constipation, headache, and heart murmurs were selected. Visits were then assigned to the specialty of physician providing care. Significant differences between and among categories of physicians were tested using logistic regression. RESULTS: Overall, pediatrician generalists and specialists provided a greater proportion of E/M visits to children in 2001 than in 1993, compared with nonpediatrician providers. However, although the absolute increase in the proportion of all E/M visits by children <18 years of age to pediatrician generalists was greater than that of pediatrician subspecialists (4.77% vs 0.69%; P <.0001), the relative increase was much smaller for the generalists (8.9% vs 19.7%; P <.0001). Findings were consistent for most of the specific diagnoses examined. CONCLUSIONS: The increases in both the proportion and number of visits made to specialists has not been accompanied by a decrease in visits to generalists.