Factors Associated With Urgent Care Reliance and Outpatient Health Care Use Among Children Enrolled in Medicaid

Key Points Question Is high reliance on urgent care facilities by children associated with decreased use of other sites of outpatient health care? Findings In a cohort study of 4 133 238 children enrolled in Medicaid, 5% had high reliance on urgent care (defined as >33% of all outpatient visits). High reliance on urgent care was seen more often in healthy, nonminority, school-aged children and was associated with lower health care use across other outpatient settings. Meaning Although urgent care facilities may serve to increase access for acute care needs, in certain populations high reliance on urgent care was associated with lower use of other outpatient care sites.


Introduction
With increasing availability and ease of access, urgent care (UC) sites are a growing option for patients to address acute health care needs, including low-acuity illnesses or injuries. 1 As UC centers become a popular setting for acute care, there is a concern that this convenience may affect the patient's established relationship with their primary care provider (PCP; physician, advanced practice nurse, or physician assistant). If patients rely on UC for most of their health care needs, it may disrupt the continuity provided in the medical home model and lead to unanticipated changes in health. 2,3 The association of UC visits with patients' relationships with their PCP is especially pertinent in pediatrics, where routine well-child care (WCC) visits are paramount to ensuring children's optimal growth and development. The American Academy of Pediatrics recommends multiple WCC visits per year for children younger than 3 years and yearly WCC visits for those 3 to 21 years of age. 4 Children regularly seeking acute care outside the PCP's office may represent missed opportunities for preventive services or identification and management of chronic conditions, which in turn risks fragmenting continuity of care. 2,4 Previous studies exploring fragmentation of continuity of care evaluated the burden and risk factors of children who frequent the emergency department (ED) but did not evaluate children who frequently use UC. 3,[5][6][7][8][9][10] The literature on health care use makes an important distinction between those who frequently use the ED (high use) and those who rely on the ED for most of their health care needs (high reliance). 10 High ED reliance describes the proportion of ED visits in relation to all outpatient health care services and can be quantified as the percentage of all ambulatory services that occur in the ED. 10 The aims of this study were to identify factors associated with high UC reliance and to examine the association between high UC reliance and the use of other sites of outpatient health care. We hypothesized that high UC reliance may be associated with a disruption of the medical home model.

Population and Data Source
We conducted a retrospective cohort study of all children younger than 19 years in the 2017 Marketscan Medicaid multistate claims database (Truven Health Analytics). We included children who had continuous enrollment (defined as Ն11 months of coverage) and had at least 1 ED, UC, PCP, or specialist visit during the 2017 calendar year. In 2017, the Marketscan database contained all inpatient, outpatient, and retail pharmacy claims from 9 deidentified states, as well as enrollment information such as year of birth, sex, race/ethnicity, and the months of enrollment. 11 The study protocol was reviewed by the Children's Mercy Kansas City's institutional review board and deemed nonhuman participants research. This study adhered to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

Outcome Measure
The main outcome was UC reliance, adapted from the work of Kroner et al 10 on ED reliance, defined as the number of UC visits divided by the sum of UC, ED, PCP, and specialist visits. For each child, UC reliance could range from 0% (no reliance; no UC visits regardless of the number of ED, PCP, or specialty visits) to 100% (complete reliance; at least 1 UC visit and no ED, PCP, or specialty visits). Likewise, our definition of high UC reliance was also adapted from this prior work as well as work that a priori determined high ED reliance among young children based on an expert panel of pediatricians as reliance greater than 33%. 10,12 Reliance on other sources of care (eg, PCP reliance) was calculated similarly.

Covariates
We examined high and low UC reliance across demographic and clinical characteristics including age, sex, race/ethnicity, presence of a complex chronic condition (CCC), and number of chronic conditions. Children with CCCs 13 were identified using all diagnoses from all Medicaid claims in the  14 also using all diagnoses from all claims in the study period. To acknowledge the intersection of the CCC (CCCs such as muscular dystrophy) and

JAMA Network Open | Pediatrics
CCI categorization (potential non-CCCs such as asthma or allergic rhinitis), as well as the distinct information gained from each, we created a chronic condition profile categorizing into groups children with a CCC and for those without a CCC, the number of CCI conditions (0, 1, 2, or Ն3). 15 The setting in which the care was delivered (ED, UC, PCP, specialist, or inpatient) was classified based on the coded location of services provided in the claims data. 16  Multivariable logistic models were then used to provide estimated adjusted odds of high UC reliance.
Generalized linear models with an assumption of an underlying Poisson distribution were used to calculate adjusted use rates. Age, sex, race/ethnicity, chronic condition profile, and hospitalization in the study period were covariates in the models. We performed sensitivity analysis in the generalized linear models, removing ED visits from the determination of UC reliance to validate the association that UC visits had with nonemergency outpatient visits (PCP and specialist). All analyses were performed with SAS 9.4 (SAS Institute Inc). P values were from 2-sided tests and results were deemed statistically significant at P < .05.  (Figure 2). Although ED use remained steady across increasing UC use ( Figure 1), children in the high UC reliance group had a lower proportion using the ED and fewer ED visits compared with children in the low UC reliance group (Figure 2).

Discussion
Our study found that high UC reliance was associated with lower use of all other sites of outpatient care, including the PCP and ED. We also identified that increasing UC use was associated with declining reliance on other sources of care. Although high UC reliance represented a small percentage of the study population, its association was seen across the entire medical neighborhood. The number of UC centers increased from 6946 in 2015 to 9272 in 2019. 19 Urgent care sites as a setting for acute care are experiencing rapid growth, which may serve to magnify these findings. 20 Past work indicates that high UC use is associated with high use of all outpatient health care sites, including the PCP and ED 15 ; however, we found that those who rely on UC for more than 33% of their acute care needs have fewer visits to the PCP and ED. Urgent care sites may be filling a gap in access to care for certain populations. 15,21 We found that high UC reliance in the Medicaid population occurs more often in healthy, school-aged children. The potentially most vulnerable patientsyounger children, minority groups, and those with 3 or more CCIs or a CCC-had the least reliance on UC. Our findings on UC reliance were similar to findings by Kroner et al 10 on pediatric ED reliance, which indicated that younger children and those with a CCC have lower ED reliance. However, in that study, black children were found to have higher ED reliance, 10 which is different from our findings on UC reliance. 22,23 Additional investigation into the location of UC sites relative to minority populations may clarify the reasons for this difference. 24 Further study of factors associated with high UC reliance is needed to assess if and how reliance on UC may be associated with a child's relationship with the medical home. The data set used for this study does not capture nonbillable communication with the PCP, who may be counseling and coordinating where patients are seeking health care. A recent American Academy of Pediatrics policy statement endorses the "medical home as the best location for children to receive care for an acute nonemergent health concern" to achieve the "optimal clinical and long term health outcomes." 25 However, patients frequently seek care outside the traditional hours of operation of a primary care office, when they may receive acute care treatment at non-PCP sites. We found that patients who are younger or have complex medical problems rely more heavily on their medical home, regardless of whether they see a generalist or specialist, which may indicate that these patients are in closer

Limitations
There are several limitations that should be considered when interpreting these results. The type of UC center (independent or associated with the health care system of the patient's PCP) is not distinguished in the data set. Urgent care centers existing within a particular health care system may allow UC clinicians to access the patient's medical record and facilitate communication with the PCP.
Also, the database does not differentiate whether a patient had Medicaid managed care or Medicaid fee for service; therefore, we were unable to determine whether type of Medicaid coverage was associated with reliance. In addition, Medicaid makes up a small portion of overall UC visits, and analyzing data from a subset of a single public insurer may affect the generalizability of the results. 28 The data represent a 1-year period, which may not be long enough to fully account for patients' ongoing outpatient health care use patterns. Also, the inclusion criteria of 11 months of continuous enrollment in Medicaid limited our sample of infants. Finally, as the focus of our study was on patients seeking outpatient care, we can comment only on children with at least 1 outpatient visit. Reliance would be incalculable without any outpatient visits, as the denominator would be zero. 10

Conclusions
High UC reliance was associated with lower health care use across other outpatient care sites, including PCP and ED visits. High UC reliance was relatively uncommon in the Medicaid population but more common in healthy, nonminority, school-aged children. High UC reliance likely fills a need for children with acute care issues but has the potential to disrupt the medical home model. Further studies are needed to investigate the reasons that patients and families seek care at UC sites and evaluate the health and financial implications of this choice.