Association between dental visits during pregnancy and setting for prenatal care.

OBJECTIVES: Federally Qualified Health Centers (FQHCs) may be well positioned to facilitate dental visits during pregnancy for low-income women. We sought to compare receipt of dental visits during pregnancy for women who received prenatal care at an FQHC versus a non-FQHC setting. METHODS: We analyzed Michigan Medicaid administrative data for all live birth deliveries between April 2018 and December 2020. We used billing data to categorize the predominant setting for prenatal care as occurring at a FQHC or a non-FQHC and claims data to identify dental visits during pregnancy (in the 9 months prior to delivery). We employed bivariate and multivariate analyses to explore the relationship between setting for prenatal care and dental visits during pregnancy. RESULTS: Women who received prenatal care at an FQHC versus non-FQHC had a higher proportion of dental visits during pregnancy (31.85% vs. 19.37%, p < 0.0001). In multivariate analyses, the strongest predictors of having a dental visit during pregnancy were FQHC prenatal care setting, having a dental emergency visit, having ≥3 prenatal visits, and having Medicaid coverage throughout pregnancy. Hispanic or Black race/ethnicity and 2020 delivery year were predictors of a lower likelihood of a dental visit. These predictors were consistent for the overall population and for the subset who had no dental visits pre-pregnancy. CONCLUSION: Medicaid-enrolled women who receive prenatal care at an FQHC are more likely to have a dental visit during pregnancy than their counterparts who receive prenatal care in a non-FQHC setting.

Missed Opportunities for Transcranial Doppler Screening Among Children With Sickle Cell Disease.

Transcranial Doppler (TCD) screening rates remain low among children with sickle cell disease (SCD). We assessed TCD screening rates and missed opportunities for TCD screening. Children 2 to 16 years old with SCD enrolled in Michigan Medicaid for ≥1 year (2007-2011) were identified through newborn screening. Receipt of TCD screening and presence of a missed opportunity (≥1 SCD-related outpatient visit, no TCD screening) were identified through administrative claims. Potential correlates of missed opportunities included SCD-related health services, comorbidities, and demographics. Logistic regression with generalized estimating equations modeled associations between a missed opportunity and correlates. Overall, 353 children contributed 1066 person-years. TCD screening was low yearly (10%-32%); missed opportunities occurred in 73% of the person-years. Increasing age (odds ratio [OR] = 1.11; confidence interval CI = 1.07, 1.15), previous TCD screening (OR = 0.26; CI = 0.16, 0.41), and 4 to 5 (OR = 0.48; CI = 0.26, 0.87) or ≥6 outpatient visits (OR = 0.26; CI = 0.14, 0.49) were associated with a missed opportunity. Reduction of missed opportunities is a potential strategy to increase TCD screening rates.

Trends in observation-prone emergency department visits among Michigan children, 2007-2011.

OBJECTIVES: To the best of the authors' knowledge, admission of children under observation status in community hospitals has not been examined. The hypothesis of this study was that there has been an increase in observation charge code use over time and variations in the application of observation charge codes across hospital types. METHODS: This was a cross-sectional analysis of 5 years (2007 through 2011) of administrative claims data from Michigan residents enrolled in Medicaid, Blue Cross/Blue Shield of Michigan preferred provider organization, and Blue Cross Network health maintenance organization compiled into a single data set. Emergency department (ED) visits to facilities in Michigan made by children (younger than 18 years) were selected. Observation-prone ED visits were identified based on the presence of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Counts of observation-prone ED visits were determined and descriptive statistics were calculated. Changes over time in the proportion of visits with observation charge codes by hospital type were assessed with chi-square analysis. RESULTS: The observation-prone ICD-9-CM codes were identified in 881,622 ED visits made by children to 142 Michigan facilities during the 5-year study period. Overall, the vast majority of visits (n = 646,499; 91.0%) with the selected ICD-9-CM codes resulted in discharge from the ED without associated observation or inpatient charge codes. Among the 64,288 visits that resulted in admission for observation or inpatient care, observation charge codes without inpatient charge codes were applied to 22,933 (35.7%) admissions, observation and inpatient charge codes were applied to 4,756 (7.4%) admissions, and inpatient charge codes without observation charge codes were applied to 36,599 (56.9%) admissions. Hospitals with pediatric ED and inpatient services (Type 1 and Type 2 hospitals) had higher proportions of ED visits that went on to admission for observation or inpatient care (15.9 and 10.7%) than hospitals without pediatric ED services (Type 3 and Type 4 hospitals; 7.2 and 3.7%). The proportion of admissions that had observation charge codes for all hospital types increased over time, most prominently among Type 1 and Type 2 hospitals. CONCLUSIONS: The application of observation charge codes to Michigan children with observation-prone conditions has increased over time across all hospital types. There is a need to evaluate pediatric observation care in diverse settings to compare the effectiveness of different models.

Prescription patterns for children with juvenile idiopathic arthritis in Michigan Medicaid: a comparison by prescriber type.

BACKGROUND: Due to a limited number and disparate distribution of pediatric rheumatologists in the US, a variety of physician types provide care to children with rheumatologic diseases. However, little is known about how that care may differ across prescribing physician groups. Our objective was to compare medication claims for children with juvenile idiopathic arthritis (JIA) by type of prescribing physician. METHODS: We performed a retrospective cohort study of children with JIA using Michigan Medicaid data for 7/1/2005-6/30/2007, employing descriptive and bivariate analyses by age, medication type, and prescriber type. RESULTS: Among 397 children, there was no difference in the frequency of medication claims for children with internist versus pediatric rheumatologist prescribers. Children with non-rheumatologist prescribers were less likely to have claims for disease modifying anti-rheumatic drugs (DMARDs) and biologic agents. CONCLUSION: Differential use of DMARDs and biologic agents by rheumatologists indicates the importance of referring children with JIA for specialty care.

Use of antihypertensive medications and diagnostic tests among privately insured adolescents and young adults with primary versus secondary hypertension.

PURPOSE: To compare the use of antihypertensive medications and diagnostic tests among adolescents and young adults with primary versus secondary hypertension. METHODS: We conducted retrospective cohort analysis of claims data for adolescents and young adults (12-21 years of age) with ≥3 years of insurance coverage (≥11 months/year) in a large private managed care plan during 2003-2009 with diagnosis of primary hypertension or secondary hypertension. We examined their use of antihypertensive medications and identified demographic characteristics and the presence of obesity-related comorbidities. For the subset receiving antihypertensive medications, we examined their diagnostic test use (echocardiograms, renal ultrasounds, and electrocardiograms). RESULTS: The study sample included 1,232 adolescents and young adults; 84% had primary hypertension and 16% had secondary hypertension. The overall prevalence rate of hypertension was 2.6%. One quarter (28%) with primary hypertension had one or more antihypertensive medications, whereas 65% with secondary hypertension had one or more antihypertensive medications. Leading prescribers of antihypertensives for subjects with primary hypertension were primary care physicians (80%), whereas antihypertensive medications were equally prescribed by primary care physicians (43%) and sub-specialists (37%) for subjects with secondary hypertension. CONCLUSIONS: The predominant hypertension diagnosis among adolescents and young adults is primary hypertension. Antihypertensive medication use was higher among those with secondary hypertension compared with those with primary hypertension. Further study is needed to determine treatment effectiveness and patient outcomes associated with differential treatment patterns used for adolescents and young adults with primary versus secondary hypertension.

Outpatient utilization by infants auto-assigned to Medicaid managed care plans.

To test the hypothesis that infants auto-assigned to a Medicaid managed care plan would have lower primary care and higher emergency department (ED) utilization compared to infants with a chosen plan. Retrospective cohort study. Medicaid administrative data were used to identify all children 0-3 months of age at enrollment in Michigan Medicaid managed care in 2005-2008 with 18-months of subsequent enrollment. Medicaid encounter and state immunization registry data were then acquired. Auto-assigned infants were compared versus chosen plan infants on: (1) well-child visits (WCVs); (2) immunizations; (3) acute office visits; and (4) ED visits. Chi squared and rank-sum tests and logistic and negative binomial regression were used in bivariate and multivariable analyses for dichotomous and count data, respectively. 18% of infants were auto-assigned. Auto-assigned infants were less likely to meet goal number of WCVs in 18-months of managed care enrollment (32 vs. 53%, p < 0.001) and to be up-to-date on immunizations at 12 months of age (75 vs. 85%, p < 0.001). Auto-assigned infants had fewer acute office visits (median: 4 vs. 5, p < 0.001) but were only slightly more likely to have 2 or more ED visits (51 vs. 46%, p < 0.001) in 18-months of enrollment. All results were significant in multivariable analyses. Auto-assigned infants were less likely to use preventive and acute primary care but only slightly more likely to use emergency care. Future work is needed to understand mechanisms of differences in utilization, but auto-assigned children may represent a target group for efforts to promote pediatric preventive care in Medicaid.

Use of diagnostic tests in adolescents with essential hypertension.

OBJECTIVE: To describe the use of diagnostic tests in adolescents with essential hypertension. DESIGN: Longitudinal analysis of administrative claims data. SETTING: Michigan Medicaid program during 2003 to 2008. PARTICIPANTS: Adolescents with 3 or more years of Medicaid eligibility (≥ 11 months/y) who had a diagnosis of essential hypertension and 1 or more antihypertensive medication pharmacy claims. MAIN OUTCOME MEASURES: We examined adolescents' echocardiogram use and compared it with electrocardiogram (EKG) and renal ultrasonography use. We examined timing of the 3 diagnostic tests in relation to the first pharmacy claim. We examined patient demographics and presence of obesity-related comorbidities. RESULTS: During 2003 to 2008, there were 951 adolescents with essential hypertension who had antihypertensive pharmacy claims; 24% (226) had echocardiograms; 22% (207) had renal ultrasonography; and 50% (478) had EKGs. Males (odds ratio [OR], 1.53; 95% CI, 1.06-2.21), younger adolescents (OR, 1.69; 95% CI, 1.17-2.44), those who had EKGs (OR, 5.79; 95% CI, 4.02-8.36), and those who had renal ultrasonography (OR, 2.22; 95% CI, 1.54-3.20) were more likely to obtain echocardiograms compared with females, older adolescents, and adolescents who did not have EKGs or renal ultrasonography. CONCLUSIONS: Guideline-recommended diagnostic tests-echocardiograms and renal ultrasonography-were equally poorly used by adolescents with essential hypertension. Sex and age differences exist in the use of echocardiograms by adolescents with essential hypertension. The decision and choice of diagnostic tests to evaluate adolescents with essential hypertension warrant further study to understand the underlying rationale for those decisions and to determine treatment effectiveness.

Clonidine utilization trends for Medicaid children.

OBJECTIVE: To characterize clonidine utilization trends among children. DESIGN/METHODS: Serial cross-sectional analysis of Michigan Medicaid claims data for children aged 6 to 18 years. The authors identified children with ≥1 clonidine prescription; the authors examined their ICD-9 diagnoses categorized as simple and complex attention deficit hyperactivity disorder (ADHD), non-ADHD mental health disorder, hypertension, or others. Also identified were child demographics and prescribing physician specialty. RESULTS: From 2003 to 2008, the proportion of children receiving clonidine prescription nearly doubled in all demographics. Across years, the majority of clonidine prescription was for simple and complex ADHD and other mental health disorders. Leading prescribers were psychiatrists followed by general pediatricians and adult primary care physicians. CONCLUSIONS: Clonidine was used extensively to treat simple and complex ADHD in children although FDA approval for this indication did not occur until 2010. Further study is warranted to better understand clinical outcomes and costs associated with clonidine use for the treatment of children with ADHD.

Follow-up analysis of adolescents partially vaccinated against human papillomavirus.

PURPOSE: To evaluate factors associated with human papillomavirus vaccination among a cohort of female adolescents previously identified as receiving only one or two doses of vaccine. METHODS: This was a 15-month follow-up analysis of a previously identified cohort of 9-18-year-old female adolescents seen in primary clinics within a university-based health system. Vaccine receipt and associated factors were identified by review of administrative records. RESULTS: Among the 1,714 partially vaccinated female adolescents, 53% eventually completed the vaccination series. There was a wide range of dosing intervals ranging from 31 to 840 days between first and second doses and from 85 to 666 days between second and third doses. Race and insurance type were associated with lower rates of series completion, but not with receiving second doses. CONCLUSIONS: Approximately half of the partially vaccinated girls in our cohort eventually completed the series, albeit often over a longer than recommended interval. There were important disparities in human papillomavirus vaccination.

Antihypertensive prescribing patterns for adolescents with primary hypertension.

BACKGROUND: Hypertension is an increasingly common problem in adolescents yet current medical management of primary hypertension in adolescents has not been well-described. METHODS: We identified adolescents with primary hypertension by International Classification of Diseases, Ninth Revision codes and looked at prescription patterns chronologically for antihypertensive drug class prescribed and the specialty of prescribing physician. We also examined patient demographics and presence of obesity-related comorbidities. RESULTS: During 2003-2008, there were 4296 adolescents with primary hypertension (HTN); 66% were boys; 73% were aged 11 to 14 years; 53% were black, 41% white, and 4% Hispanic; and 48% had obesity-related comorbidity. Twenty-three percent (977) received antihypertensive prescription. White subjects (odds ratio [OR]: 1.61; confidence interval [CI]: 1.39-1.88), older adolescents (≥15 years, OR: 2.11; CI: 1.79-2.48), and those with comorbidity (OR: 1.57; CI: 1.36-1.82) were more likely to receive antihypertensive prescriptions controlling for gender and years of Medicaid eligibility in logistic regression. Angiotensin converting enzyme inhibitors were the most frequently prescribed monotherapy. Nearly two-thirds of adolescents received prescriptions from adult primary care physicians (PCPs) only. More than one-quarter of adolescents who received a prescription received combination therapy, which was most often prescribed by adult PCPs. CONCLUSIONS: Adult PCPs were the leading prescribers of antihypertensives for adolescents with primary HTN. Race differences exist in physicians' prescribing of antihypertensives to adolescents with primary HTN. The choice of antihypertensives by physicians of different specialties warrants additional study to understand the underlying rationale for treatment decisions and to determine treatment effectiveness.

Long-acting ß-agonist monotherapy among children and adults with asthma.

OBJECTIVES: To determine the prevalence of long-acting ß-agonist (LABA) monotherapy among a Medicaid-enrolled population with asthma and to describe continued LABA monotherapy use. STUDY DESIGN: Retrospective cohort. METHODS: Administrative Medicaid claims data for Michigan were used to identify children and adults with asthma, defined as having 4 or more asthma medication­dispensing events during a calendar year between 2006 and 2008. We determined the annual prevalence of LABA monotherapy, defined as having at least 1 dispensing event for a LABA medication in the absence of any other maintenance therapy. The cohort using LABA monotherapy was followed up for 12 months after the identification year to assess continued LABA monotherapy and the frequency of missed opportunities for changes in therapy. Analyses included prevalence proportions, median numbers of office visits, and χ(2) tests to test for significant differences between subgroups. RESULTS: LABA monotherapy among persons with asthma was uncommon (<1%) and decreased over time. LABA monotherapy was more prevalent among female subjects, persons of white race, and older age groups. The prevalence of continued LABA monotherapy during the followup year was 41.2% among the cohort of LABA monotherapy users. Most users of continued LABA monotherapy (92.9%) had at least 1 missed opportunity for therapy change or patient education during the follow-up period. CONCLUSION: Although our results indicate that LABA monotherapy was rare, this study provides further evidence supporting enhanced information sharing between points of service about medication utilization that is inconsistent with accepted guidelines.

Worsening disparities in HPV vaccine utilization among 19-26 year old women.

We evaluated the characteristics associated with uptake of HPV vaccine by 19-26 year old women seen in primary care university-based clinics. Of the 11,545 women analyzed only 18% had initiated the 3-dose vaccine series. Series completion among the sample overall was only 10% in the 30 month study period. Decreased series initiation was associated with older age, public insurance, white race and non-family medicine specialty. Decreased series completion was associated with public insurance and African American race. Utilization disparities by race and insurance worsened over time suggesting that the highest risk populations of women were not getting vaccinated.

Patient and clinic factors associated with adolescent human papillomavirus vaccine utilization within a university-based health system.

We reviewed clinical and billing data from a university-based health system to assess HPV vaccine utilization among 9-18-year-old girls by individual, visit and medical specialty characteristics. Our sample included 10,082 adolescent patients with 27,928 visits to outpatient family medicine (FM), pediatric and gynecology clinics between January 2007 and March 2008. Vaccine series completion was low among eligible adolescents (15%), with important disparities in vaccine utilization by medical specialty, age, race and insurance status. Missed opportunities for vaccination were common. Our findings may help to target future interventions aimed at increasing adolescent HPV vaccine utilization.

Continuity of prescribers of short-acting beta agonists among children with asthma.

OBJECTIVE: To determine whether short-acting beta-agonist (SABA) prescriber continuity was associated with emergency department visits among children with asthma. STUDY DESIGN: An analysis of Michigan Medicaid administrative claims (2004-2005) for children ages 5 to 18 with asthma. Logistic regression models assessed the effect of SABA prescriber continuity (the number and site of prescribers) on emergency department visits, controlling for demographics, historical (2004) asthma use and SABA prescription frequency (2-5 low; > or = 6 high). RESULTS: Most children had one SABA prescriber (62%); 13% had multiple prescribers in the same practice as the primary care provider and 25% had multiple prescribers in different practices. Children with multiple prescribers in different practices had increased odds of an emergency department visit compared with those with 1 prescriber, among those with high SABA prescription frequency (AOR: 2.7, 95% CI: 1.9, 3.9), as well as those with low prescription frequency (AOR: 1.7, 95% CI: 1.3, 2.2). CONCLUSIONS: Children with discontinuity of SABA prescribers have an increased risk of asthma emergency department visits, irrespective of their SABA prescription frequency. Primary care providers may have difficulty identifying patients at high risk with asthma solely on the basis of SABAs prescribed within their own practices.

Treatment patterns for early pregnancy failure in Michigan.

AIMS: We describe current treatment patterns for early pregnancy failure (EPF) among women enrolled in two Michigan health plans. METHODS: We conducted a retrospective review of EPF treatment among Michigan Medicaid enrollees between January 1, 2001, and December 31, 2004, and enrollees of a university-affiliated health plan between January 1, 2001, and December 31, 2005. Episodes were identified by the presence of a diagnostic code for EPF. Surgical treatment was distinguished from nonsurgical management using procedure codes. Facility charges, procedure, and place of service codes were used to determine whether a procedure was done in an office as opposed to an operating room. Cases without a claim for surgical uterine evacuation were examined for a misoprostol pharmacy claim and, if present, were classified as medical management. Cases without a procedure or pharmacy claim were classified as expectant management. RESULTS: Respectively, we identified 21,311 and 1,493 episodes of EPF in the Medicaid and university-affiliated health plan databases, respectively. Women enrolled in Medicaid were more likely to be treated with surgery than were enrollees of the university-affiliated health plan (35.3 vs. 18.0%, respectively, p < 0.000). Among Medicaid enrollees, only 0.5% of surgical evacuations occurred in the office, but office procedures were common among enrollees of the university-affiliated health plan (30.5%, p < 0.000). The proportion of cases managed with misoprostol was <1% in both groups. Caucasian race and age were both associated with having a surgical uterine evacuation (p < 0.001). CONCLUSIONS: EPF is primarily being treated with expectant management or surgical evacuation in an operating room and may not reflect evidence-based practices or patient preferences.

Interhospital transfer of critically ill and injured children: an evaluation of transfer patterns, resource utilization, and clinical outcomes.

OBJECTIVE: To describe patterns of transfer, resource utilization, and clinical outcomes associated with interhospital transfer of critically ill and injured children. DESIGN: Secondary analysis of administrative claims data. PARTICIPANTS: Children 0 to 18 years in the Michigan Medicaid program who underwent interhospital transfer for intensive care from January 1, 2002 to December 31, 2004. The 3 sources of transfer from referring hospitals were: emergency department (ED), ward, or intensive care unit (ICU). MEASUREMENTS: Mortality and duration of hospital stay at the receiving hospitals. RESULTS: Of 1643 interhospital transfer admissions to intensive care at receiving hospitals, 62%, 31%, and 7% were from the ED, ward, and ICU of referring hospitals, respectively. Nineteen percent had comorbid illness, while 11% had organ dysfunction at the referring hospital. After controlling for comorbid illness, patient age, and pretransfer organ dysfunction; compared with ED transfers, mortality in the receiving hospital was higher for ward transfers (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.02-3.03) but not for ICU transfers. Also, compared with ED transfers, hospital stay was longer by 1.5 days for ward transfers and by 13.5 days for ICU transfers. CONCLUSION: In this multiyear, statewide sample, mortality and resource utilization were higher among children who underwent interhospital transfer to intensive care after initial hospitalization, compared with those transferred directly from emergency to intensive care. Decision-making underlying initial triage and subsequent interhospital transfer of critically ill children warrants further study.

Effect of missed opportunities on influenza vaccination rates among children with asthma.

OBJECTIVES: To assess rates of influenza vaccination among children with asthma; document the frequency, timing, and patterns of missed opportunities to vaccinate during successive influenza seasons; and project potential influenza vaccination rates that could be achieved by reducing or eliminating missed opportunities. SETTING: Michigan Medicaid program during the 2001-2002 and 2002-2003 influenza seasons. DESIGN: Retrospective cohort analysis of administrative claims. PARTICIPANTS: We evaluated the claims of 4358 children aged 5 to 18 years with persistent asthma who were continuously enrolled in Medicaid. MAIN OUTCOME MEASURES: Influenza vaccinations and missed opportunities assessed using procedure and diagnosis codes. RESULTS: During the 2001-2002 season, 16.7% of children with asthma received an influenza vaccination; during 2002-2003, 21.8% received the vaccine (9.5% vaccinated in both seasons). However, 76.5% of children had at least 1 office visit during the 2001-2002 influenza season (75.3% during 2002-2003). Among children without influenza vaccination, 72.9% had at least 1 missed opportunity for vaccination during the 2001-2002 season and 69.3% during 2002-2003. The most common outcome was having at least 1 missed opportunity (39.6%) in each of 2 successive influenza seasons. Eliminating missed opportunities prior to the historical peak of influenza season would have increased the influenza vaccination rate among this population of children to 76%. CONCLUSIONS: Missed opportunities for influenza vaccination among children with asthma are common and are often repeated from one influenza season to the next. Future studies should assess how interventions could be aimed at patients and health care professionals to improve awareness of the need for annual influenza vaccination.

Geographic variation of asthma quality measures within and between health plans.

OBJECTIVE: To contrast health plan performance in treating pediatric asthma within and between different geographic regions. STUDY DESIGN: Retrospective analysis of administrative claims data for 18 health plans serving Medicaid enrollees. METHODS: The study population was 3970 children 5-18 years old with persistent asthma who were continuously enrolled in the same Michigan Medicaid health plan for 2002 and 2003, with no other source of health insurance. Outcome measures were assessed based on national guidelines for asthma management: at least 1 asthma controller medication prescription, at least 1 outpatient visit, 1 or more asthma emergency department visits, and an annual influenza vaccination. RESULTS: Adherence to national guidelines varied significantly (P

Blood lead testing among Medicaid-enrolled children in Michigan.

BACKGROUND: Federal regulations mandate that Medicaid-enrolled children be tested for lead poisoning at the age of 1 and 2 years or 3 through 5 years if not previously tested. OBJECTIVES: To measure the rate of blood lead testing among Medicaid-enrolled children in Michigan and the subsequent proportion of children with elevated lead levels and to determine factors associated with testing and elevated lead levels. METHODS: We performed a retrospective analysis of children aged 5 years or younger continuously enrolled in Michigan Medicaid during 2002. RESULTS: There were 216,578 children included in the analysis. The overall rate of blood lead testing was 19.6% (95% confidence interval [CI], 19.4-19.8) of which 8.3% (95% CI, 8.0-8.5) had a level of 10 microg/dL [0.48 micromol/L] or higher. Hispanic or nonwhite children or those living in high-risk areas for lead exposure were more likely to be tested and more likely to have an elevated blood lead level. However, 1.2% of tested children without these additional risk factors had a level of 10 microg/dL or higher. Enrollment in Medicaid managed care was associated with an increased likelihood of blood lead testing. After adjusting for other factors, those in managed care for 75% or more of their enrollment in 2002 had 1.98 (95% CI, 1.46-2.68) greater odds of being tested than those in fee-for-service for 75% or more of their enrollment. CONCLUSIONS: The rate of blood lead testing was low. Patterns suggest testing was targeted to those at highest risk, potentially leading some children with elevated blood lead levels to be missed.

Follow-up testing among children with elevated screening blood lead levels.

CONTEXT: Follow-up testing after an abnormal screening blood lead level is a key component of lead poisoning prevention. OBJECTIVES: To measure the proportion of children with elevated screening lead levels who have follow-up testing and to determine factors associated with such care. DESIGN, SETTING, AND PARTICIPANTS: Retrospective, observational cohort study of 3682 Michigan Medicaid-enrolled children aged 6 years or younger who had a screening blood lead level of at least 10 microg/dL (0.48 micromol/L) between January 1, 2002, and June 30, 2003. MAIN OUTCOME MEASURE: Testing within 180 days of an elevated screening lead level. RESULTS: Follow-up testing was received by 53.9% (95% confidence interval [CI], 52.2%-55.5%) of the children. In multivariate analysis adjusting for age, screening blood lead level results, and local health department catchment area, the relative risk of follow-up testing was lower for Hispanic or nonwhite children than for white children (0.91; 95% CI, 0.87-0.94), for children living in urban compared with rural areas (0.92; 95% CI, 0.89-0.96), and for children living in high- compared with low-risk lead areas (0.94; 95% CI, 0.92-0.96). Among children who did not have follow-up testing, 58.6% (95% CI, 56.3%-61.0%) had at least 1 medical encounter in the 6-month period after the elevated screening blood lead level, including encounters for evaluation and management (39.3%; 95% CI, 36.9%-41.6%) or preventive care (13.2%; 95% CI, 11.6%-14.8%). CONCLUSIONS: The rate of follow-up testing after an abnormal screening blood lead level was low, and children with increased likelihood of lead poisoning were less likely to receive follow-up testing. At least half of the children had a missed opportunity for follow-up testing. The observed disparities of care may increase the burden of cognitive impairment among at-risk children.