Key Points
Question
Are there disparities in emergency department clinicians’ consultation of ophthalmologists for management of eye problems?
Findings
In this study of medical and billing data from 13 361 eye-related emergency department encounters, approximately three-fifths were managed without consulting the ophthalmology service. Clinicians were significantly less likely to consult an ophthalmologist when patients were black or preferred a non-English language.
Meaning
The association of patient demographic factors with the decision to involve ophthalmologists in the care of eye problems in the emergency department should be explored in depth.
Abstract
Importance
Nearly 2 million patients visit emergency departments (EDs) because of eye concerns annually in the United States. How hospitals currently assign these patients to treatment is important for designing systems that equitably allocate resources for eye care in urgent settings.
Objective
To investigate factors associated with ophthalmology consultation for eye-related adult ED encounters to assess possible disparities by sex, race/ethnicity, language preference, or residential distance from the medical center.
Design, Setting, and Participants
Retrospective observational study of 13 361 adult ED encounters associated with an eye-related billing diagnosis between January 1, 2010, and September 30, 2015, at the University of Michigan Medical Center in Ann Arbor.
Exposures
Measures available from the University of Michigan clinical data warehouse included age, sex, race/ethnicity, preferred language, home distance from the ED, calendar year of encounter, and Charlson-Deyo Comorbidity Index score.
Main Outcomes and Measures
Association of the ED encounter with ophthalmology consultation. An ophthalmology consultation was identified by cross-referencing ophthalmology faculty and clinical instructors from 2010 to 2015 against billing providers for consultations using the Charlson-Deyo Comorbidity Index score and billing codes. Measures included patient age, sex, race/ethnicity, home address, preferred language (English vs non-English), and calendar year of encounter.
Results
Among the 13 361 encounters, 6840 (51.2%) involved a female patient. Mean (SD) age at encounter was 50.7 (19.3) years; 10 033 patients (75.1%) were of white and 1969 (14.7%) of black race/ethnicity. English was the preferred language for 13 022 patients (97.5%). The ophthalmology service was consulted in 5289 encounters (39.6%). Black patients had significantly lower odds of an ophthalmology consultation than white patients (odds ratio [OR], 0.85; 95% CI, 0.75-0.96). Patients who preferred a non-English language had significantly lower odds of receiving an ophthalmology consultation (OR, 0.73; 95% CI, 0.55-0.98).
Conclusions and Relevance
Many of the 13 361 eye-related ED encounters were managed by ED clinicians with no ophthalmology consultation. Patients who were black or who preferred a language other than English were less likely to have an ophthalmologist involved in their care. The associations found in this observational study do not imply causation but suggest disparities in care that should be further investigated.
This study uses emergency department electronic medical records and billing data to assess odds of receiving an ophthalmology consultation among patients presenting with eye problems.
Introduction
Almost 2 million people per year present to emergency departments (EDs) with eye problems, but many EDs do not have ophthalmologists available for consultation. In rural hospitals, nearly 60% of EDs report that ophthalmology consultation is unavailable. In community hospitals with patients who are predominantly uninsured and of ethnic/racial minorities, coverage by all specialties, including ophthalmology, declined from 2000 to 2006. Investigating the predictors of ophthalmology consultation in the ED is especially important as hospitals design systems to address the need for equitable access to eye health care in urgent settings with limited resource availability. Previous studies of eye problems in the ED used health care claims data or population-based national samples but did not have information on consultation with ophthalmologists. We obtained data from a clinical data warehouse with electronic medical record data on more than 13 000 eye-related adult ED visits at a tertiary care, university-based medical center. Our goal was to evaluate predictors of ophthalmology consultation and investigate whether disparities exist in ED eye care to inform and promote equity in future health system policies and practices.
Methods
Population
Through the clinical data warehouse for the University of Michigan, Ann Arbor, we identified all patient encounters between January 1, 2010, and September 30, 2015, in the adult ED that included an International Classification of Diseases, Ninth Revision (ICD-9) professional billing code related to eye diseases identified by ED or consulting physicians who billed for their services (eTable in the Supplement). This study was approved by the University of Michigan institutional review board, which also waived the need for informed patient consent because data were deidentified.
Measures
Measures included patient age, sex, race/ethnicity, home address, preferred language (English vs non-English), and calendar year of encounter. Charlson-Deyo Comorbidity Index scores based on ICD-9 codes were also included in the analysis. The Charlson-Deyo Comorbidity Index score is an indicator of overall patient health based on comorbid conditions. Possible scores range from 0 to 25, with higher scores representing more numerous or severe comorbidities. The main outcome measure, ophthalmology consultation, was identified by cross-referencing ophthalmology faculty and clinical instructors from 2010 to 2015 against clinicians who billed for their consultation services.
Statistical Analysis
Patient demographic data were summarized at the encounter level, calculating mean (SD) for continuous variables and proportion for categorical variables. Because the same patient could present multiple times for eye problems during this period, predictors of obtaining ophthalmology consultation were analyzed using multilevel mixed-effects logistic regression modeling, with random effects specified at the patient level and fixed-effects predictors of age at encounter, sex, race/ethnicity, preferred language, home address distance from the University of Michigan, calendar year of encounter, and the Charlson-Deyo Comorbidity Index score. All analyses were performed using Stata, version 12 (StataCorp).
Results
Characteristics of Population
Between January 1, 2010, and September 30, 2015, 13 361 ED encounters included eye-related diagnoses. Of the 13 361 encounters, mean (SD) patient age was 50.7 (19.3) years; 6840 patients (51.2%) were female; 10 033 patients (75.1%) were of white race/ethnicity and 1969 (14.7%) were of black race/ethnicity; and English was the preferred language in 13 022 encounters (97.5%). One thousand one hundred twelve encounters (8.3%) involved patients who traveled more than 160 km from their home addresses. The ophthalmology service was consulted in 5289 of the 13 361 encounters (39.6%). Characteristics of the population are summarized in Table 1. The 13 361 encounters comprised 10 333 distinct patients, of whom 8259 visited once and 2074 visited 2 or more times during the study period. Among the 10 333 patients, the mean (SD) age at first encounter was 50.1 (19.4) years, and 5338 (51.7%) were female; other demographic characteristics were likewise similar between the groups.
Table 1. Characteristics of Patients With Eye-Related ED Visits With and Without Ophthalmology Consultation.
| Characteristic | No Consultation (n = 8072) | Consultation (n = 5289) | Total (N = 13 361) |
|---|---|---|---|
| Age at encounter, mean (SD), y | 50.8 (19.5) | 50.7 (18.9) | 50.7 (19.3) |
| Female, No. (%) | 4354 (53.9) | 2486 (47.0) | 6840 (51.2) |
| Race, No. (%) | |||
| White | 6007 (74.4) | 4026 (76.1) | 10 033 (75.1) |
| Black | 1253 (15.5) | 716 (13.5) | 1969 (14.7) |
| Asian, Pacific Islander, Alaska Native, or Native American | 300 (3.7) | 182 (3.4) | 482 (3.6) |
| Other/unknown | 512 (6.3) | 365 (6.9) | 877 (6.6) |
| Preferred language, No. (%) | |||
| English | 7847 (97.2) | 5175 (97.8) | 13 022 (97.5) |
| Non-English | 225 (2.8) | 114 (2.2) | 339 (2.5) |
| Farther than 160 km from University of Michigan, No. (%) | 619 (7.7) | 493 (9.3) | 1112 (8.3) |
| Charlson-Deyo Comorbidity Index score, No. (%) of patientsa | |||
| 0 | 5449 (67.5) | 4162 (78.7) | 9611 (71.9) |
| 1 | 917 (11.4) | 471 (8.9) | 1388 (10.4) |
| 2-4 | 804 (10.0) | 381 (7.2) | 1185 (8.9) |
| ≥5 | 902 (11.2) | 275 (5.2) | 1177 (8.8) |
| Calendar year of encounter, No. (%) | |||
| 2010-2013 | 3994 (49.5) | 2268 (42.9) | 6262 (46.9) |
| 2014-2015 | 4078 (50.5) | 3021 (57.1) | 7099 (53.1) |
Abbreviation: ED, emergency department.
The Charlson-Deyo Comorbidity Index is an indicator of overall patient health calculated by totaling the number of points assigned to specific comorbid conditions. Possible scores range from 0 to 25, with 0 indicating a relatively healthy patient with no comorbidities and higher scores representing more numerous or severe comorbidities.
Predictors of Consultation
We sought to determine which population characteristics were associated with ED consultation of the ophthalmology service. Age, sex, race/ethnicity, preferred language, home distance from the University of Michigan, calendar year of encounter, and Charlson-Deyo comorbidity score were considered in univariable and multivariable models clustered by patient to account for those with multiple visits to the ED (Table 2). Male patients had a 42% greater adjusted odds of an ophthalmology consultation than female patients (odds ratio [OR], 1.42; 95% CI, 1.30-1.55). Black patients had significantly lower odds of an ophthalmology consult than white patients (OR, 0.85; 95% CI, 0.75-0.96). Those with a preferred language other than English also had a 27% lower odds of an ophthalmology consultation (OR, 0.73; 95% CI, 0.55-0.98). Patients who were more ill, as determined by the Charlson-Deyo comorbidity score, had lower odds of an ophthalmology consultation (OR, 0.36; 95% CI, 0.30-0.42, for score ≥5 compared with zero). Patients whose home address was more than 160 km from the University of Michigan Medical Center had a 35% higher odds of receiving an ophthalmology consultation (OR, 1.35; 95% CI, 1.16-1.58).
Table 2. Predictors of ED Consultation of Ophthalmology Service.
| Characteristic | OR (95% CI) | |
|---|---|---|
| Univariable | Multivariable | |
| Age at encounter, per 1-y increase | 1.00 (1.00-1.00) | 1.00 (1.00-1.01) |
| Malea | 1.39 (1.27-1.52) | 1.42 (1.30-1.55) |
| Race/ethnicityb | ||
| Black | 0.81 (0.72-0.93) | 0.85 (0.75-0.96) |
| Asian, Pacific Islander, Alaska Native, or Native American | 0.85 (0.66-1.08) | 0.86 (0.68-1.09) |
| Other/unknown | 1.06 (0.88-1.27) | 1.06 (0.89-1.27) |
| Non-English preferred language | 0.75 (0.56-1.00) | 0.73 (0.55-0.98) |
| Farther than 160 km from University of Michigan | 1.30 (1.10-1.52) | 1.35 (1.16-1.58) |
| Calendar year of encounter, 2014-2015 vs 2010-2013 | 1.33 (1.22-1.46) | 1.41 (1.30-1.54) |
| Charlson-Deyo Comorbidity Index scorec | ||
| 1 | 0.67 (0.58-0.77) | 0.63 (0.55-0.72) |
| 2-4 | 0.60 (0.51-0.70) | 0.55 (0.47-0.64) |
| ≥5 | 0.36 (0.30-0.42) | 0.32 (0.26-0.37) |
Abbreviations: ED, emergency department; OR, odds ratio.
Reference category is female.
Reference category is white.
Reference category is an index of zero. The Charlson-Deyo Comorbidity Index is an indicator of overall patient health calculated by totaling the number of points assigned to specific comorbid conditions. Possible scores range from 0 to 25, with 0 indicating a relatively healthy patient with no comorbidities and higher scores representing more numerous or severe comorbidities.
Discussion
This study of the electronic medical records of 13 361 ED encounters for ophthalmic problems enabled a previously unfeasible large-scale analysis of patterns and predictors of ophthalmology consultation in the ED. Even in a well-resourced, university-based medical center where a dedicated ophthalmology consultant is available 24 hours a day, ED clinicians managed 8072 eye-related encounters (60.4%) without consulting the ophthalmology service. Patients who were black had a 15% lower odds of being seen by an ophthalmologist; those whose preferred language was other than English had a 27% lower odds. These findings on disparities in ophthalmology consultation have not been widely reported in the ophthalmology literature, to our knowledge, and warrant further attention to address potential health care disparities. Studies of disparities in ED care in other specialties have reported that patients belonging to racial/ethnic minorities are less likely to receive thrombolytic treatment when presenting for emergency stroke care, less likely to receive testing in the diagnosis and management of acute chest pain, and less likely to be considered urgent at triage, leading to longer waiting times until being assigned to an ED treatment area. Systematic differences in the involvement of ophthalmologists in the care of eye problems in the ED may also lead to disparities in care provision.
Patients who were sicker (as measured by a higher Charlson-Deyo comorbidity score) had lower odds of receiving an ophthalmology consultation, potentially owing to prioritization of other health problems. Male patients had a 42% higher odds of ophthalmology consultation compared with female patients, which may occur because ocular trauma has been reported to be twice as common among male than female patients. Patients who lived more than 160 km from the University of Michigan were more likely to be referred for ophthalmology consultation. Many of these patients were likely transferred from a community hospital expressly for ophthalmology consultation, or their acute eye conditions may have worsened during transit.
Limitations
This study has several limitations. Encounters were limited to a single university-based medical center in the midwestern United States and may reflect regional variations in practice patterns, which may not generalize to different settings. Initial chief complaints and insurance status were not captured in the clinical warehouse; thus, differences in the severity or type of presenting symptoms and in insurance status could not be adjusted for when investigating patient factors that would predict ophthalmology consultation. Systematic differences in presenting chief complaint between different groups or by insurance status may partially mediate some of the associations found.
Despite these limitations, the large-scale availability of information on consultation status provides insight into how ophthalmologists are involved in the care of eye problems in the ED. With electronic medical records as a rich source of data, future directions for research may include text mining of clinical notes to determine and adjust for presenting chief complaints to further investigate causes of disparities in ophthalmic care in the ED.
Conclusions
More than 60% of ED encounters that included an eye diagnosis were managed without consulting the ophthalmology service. Emergency department management without ophthalmology consultation was more likely in black patients and those who preferred a non-English language. Although these associations do not prove a causative relationship, the disparities discovered in this work warrant further investigation.
eTable. Ranges of ICD-9 Codes Used to Identify Eye-Related Diagnoses
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
eTable. Ranges of ICD-9 Codes Used to Identify Eye-Related Diagnoses