Racial disparities during admission to an academic psychiatric hospital in a large urban area

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ScienceDirect Comprehensive Psychiatry 63 (2015) 113 – 122 www.elsevier.com/locate/comppsych

Racial disparities during admission to an academic psychiatric hospital in a large urban area Jane E. Hamilton a, b,⁎, Angela M. Heads a , Raymond Y. Cho a , Scott D. Lane a, b , Jair C. Soares a, b a

Department of Psychiatry and Behavioral Sciences, The University of Texas Medical School at Houston, Houston, TX, USA b The University of Texas Harris County Psychiatric Center, Houston, TX, USA

Abstract Multiple studies confirm that African Americans are less likely than non-Hispanic whites to receive needed mental health services. Research has consistently shown that African Americans are under-represented in outpatient mental health treatment settings and are overrepresented in inpatient psychiatric settings. Further, African Americans are more likely to receive a diagnosis of schizophrenia and are less likely receive an affective disorder diagnosis during inpatient psychiatric hospitalization compared to non-Hispanic white patients, pointing to a need for examining factors contributing to mental health disparities. Using Andersen's Behavioral Model of Health Service Use, this study examined predisposing, enabling and need factors differentially associated with health service utilization among African American and non-Hispanic white patients (n = 5183) during psychiatric admission. We conducted univariate and multivariate logistic regression analyses to examine both main effects and interactions. In the multivariate model, African American race at admission was predicted by multiple factors including younger age, female gender, multiple psychiatric hospitalizations, elevated positive and negative symptoms of psychosis, a diagnosis of schizophrenia and substance use, as well as having housing and commercial insurance. Additionally, screening positive for cannabis use at intake was found to moderate the relationship between being female and African American. Our study findings highlight the importance of examining mental health disparities using a conceptual framework developed for vulnerable populations (such as racial minorities and patients with co-occurring substance use). © 2015 Elsevier Inc. All rights reserved.

1. Introduction Eliminating health disparities and achieving health equity among Americans is a major goal of Healthy People 2020 [1]. Yet health disparities remain a large and persistent problem. Health disparities occur when members of certain population groups do not benefit from the same health status as other groups, and among racial minorities, many complex factors contribute to disparities in health status [2,3]. A nationally representative study found African Americans were only 50–60% as likely to receive mental health services as were non-Hispanic whites [4]. Mental health disparities occur within multiple sectors of the health care system and are related to health care utilization, access and quality [5]. Research suggests African Americans in

⁎ Corresponding author at: 2800 S. MacGregor Way, HCP 3-E50, Houston, TX 77021, USA. Tel.: +1 713 741 8642. E-mail address: [email protected] (J.E. Hamilton). http://dx.doi.org/10.1016/j.comppsych.2015.08.010 0010-440X/© 2015 Elsevier Inc. All rights reserved.

particular are more likely to receive poorer quality mental health care, may be less satisfied with their care experience and may terminate care prematurely compared to nonHispanic whites [6–9]. While racial disparities in mental health care are not a new concern, this issue has not been adequately addressed in ways that decrease known disparities. In fact, two recent national studies indicate disparities in mental health care between African Americans and non-Hispanic whites worsened in the 2000–2001, 2001– 2003 and 2003–2004 year periods [10,11]. Prior research has shown that African Americans are under-represented in outpatient mental health treatment settings [12] and are over-represented in inpatient psychiatric settings [13–17]. Further, a relationship has been found between high rates of schizophrenia diagnoses and increased psychiatric hospitalizations in state and county psychiatric hospitals among African Americans [18,19]. These findings are consistent with prior research showing African Americans to be more likely to receive a diagnosis of schizophrenia and to be less likely receive an affective disorder diagnosis during

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inpatient psychiatric hospitalization compared to nonHispanic white patients [20–25]. This well-established pattern contrasts findings from national epidemiological studies showing no significant difference in rates of schizophrenia diagnoses between African Americans and non-Hispanic whites when controlling for socio-economic status [26,27], thus raising questions about the diagnostic process for persons with schizophrenia. Research suggests when diagnosing schizophrenia in African Americans, clinicians use different symptom criteria [28]. Clinicians have reported increased frequency and severity of hallucinations and paranoid ideation in African Americans compared to non-Hispanic whites according to studies conducted in the United States [21,29,30]. Research also points to inconsistencies in the diagnostic process based on clinician interpretation of symptoms of psychosis, with a greater likelihood of African Americans to be initially diagnosed with schizophrenia where an affective disorder may have been more appropriate [29,31]. Co-occurring substance use and mental health disorders are common and have been shown to increase the risk of inpatient psychiatric hospitalization [32,33]. The relationship between African American race, co-occurring substance use and the diagnosis of schizophrenia has been examined, but a clear relationship between these factors has not been established [22,25,34–37]. While two studies found African American psychiatric inpatients with a secondary diagnosis of a substance use disorder were more likely than non-Hispanic white patients to have a primary diagnosis of schizophrenia [34,35], research has also found the opposite to be true [35] or found no relationship at all [22,25,37]. Additionally, there is a dearth of information about potential mechanisms that might explain the relationship between substance abuse and the receipt of a diagnosis of schizophrenia among African Americans. Along with an elevated risk of psychiatric hospitalization, the misdiagnosis of schizophrenia among African Americans may result in errors in pharmacologic treatment related to treatment with antipsychotic medications rather than antidepressants, as well as increased exposure to severe medication side effects [22,37–42]. In spite of the interest in addressing mental health disparities related to the diagnosis of schizophrenia among African Americans [43,44], few recent studies have investigated the factors associated with this mental health disparity in a systematic way. The current study addresses a gap in the literature by utilizing Andersen's Behavioral Model of Health Service Use to systematically explore differential factors predicting psychiatric hospital admission for African American patients compared to non-Hispanic white patients. The Andersen model provides a conceptual framework for examining research questions related to disparities in health service use among disadvantaged populations—including racial minorities [45]. In our study, we used the Andersen model to examine racial disparities related to inpatient psychiatric hospital admissions among historically underserved patients

at a regional safety-net psychiatric hospital in Houston, Texas. We are aware of one prior study utilizing the Andersen model to examine the impact of need-related factors, such as a diagnosis of schizophrenia and substance use, on inpatient psychiatric hospital admissions in California [46]. However, we are not aware of any studies utilizing the Andersen model to examine racial disparities related to a diagnosis of schizophrenia and substance use during inpatient psychiatric hospital admission in our region or in other regions.

2. Methods The data for this retrospective study were obtained from an electronic medical records database in the hospital management information system at an academic psychiatric hospital serving as a regional safety-net provider. We gathered data on all African American and non-Hispanic white patients at least 18 years old admitted between January 1, 2010 and December 31, 2013. The Andersen conceptual framework enabled us to explore questions related to health disparities and differences in utilization patterns among African Americans as done in prior research [45]. In adapting the framework for our study, we grouped factors associated with health service utilization into three categories: predisposing (characteristics of the individual, i.e., age, gender, race, marital status), enabling (system or structural factors that make health service resources available to the individual) and need (clinical) factors [47,48]. Employing these methods, race at admission was selected as the outcome variable, with the need, predisposing and enabling factors added in blocks as predictors in the analysis. In the Andersen model, predisposing, enabling and need factors act independently or together to influence patterns of health care utilization or outcomes. Accordingly, the research questions for the study were: 1) Is a schizophrenia diagnosis predictive of race (African American vs nonHispanic white) at admission? 2) Does psychiatric symptomatology differentially predict race at admission? 3) Does substance use differentially predict race at admission? 4) What additional predisposing, enabling and need factors predict race at admission? We dichotomized race at admission into two categories: (a) African American and (b) non-Hispanic white. Predisposing factors included age at admission, gender and marital status. Enabling factors included insurance status (commercial insurance, Medicare, Medicaid, uninsured), homelessness (being homeless or residing in a homeless shelter versus living in a home/private residence or institution) and psychiatric services utilization (being involuntarily admitted or having a history of three or more previous psychiatric hospitalizations). Need factors included a schizophrenia diagnosis, elevated psychiatric symptoms, co-occurring substance use and a co-morbid personality disorder. The

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theoretical relationship between predisposing, enabling and need factors and racial disparities during inpatient psychiatric hospital admission is presented in Fig. 1. In adapting Andersen's conceptual model for our study, we examined predisposing factors from prior research associated with increased inpatient psychiatric utilization including younger age [49–51], male gender [49], racial minority status (outcome of interest) [49,52] and marital status [49]. The enabling factors associated with psychiatric hospital utilization we examined included insurance status [53], homelessness [54–57], prior psychiatric hospitalizations [50,51,55,58–60] and voluntary legal status [61,62]. The need factors we examined included a primary diagnosis of schizophrenia [49,50,54,58], co-morbid personality disorder [63], clinical symptom severity as indexed by the Brief Psychiatric Rating Scale (BPRS) during psychiatric admission [60,64] and substance use at admission as indicated by a positive urine drug screen for cannabis or opiates of cocaine [55,65,66]. During hospital admission, DSM-IV Axis I diagnoses were made by the attending psychiatrist responsible for the care of the patient using DSM IV diagnostic criteria. The attending psychiatrist administered the BPRS during admission to rate clinical symptom severity for the patient. The BPRS is an 18-item clinician-rated measure of positive, negative and affective symptoms of psychotic disorders [67] previously used to examine response to psychopharmacological treatment [68], psychiatric symptomatology associ-

ated with mental health disparities [14] and the link between psychiatric symptoms and psychiatric readmissions [60,69]. Specific BPRS items that have been previously defined in the research literature as positive or negative symptoms of psychosis or symptoms of depression and anxiety were included in the analysis. In our analyses, BPRS positive symptoms included conceptual disorganization, mannerisms and posturing, hostility, suspiciousness, hallucinatory behavior, unusual thought content, excitement [70] and grandiosity [71]; BPRS negative symptoms included emotional withdrawal, motor retardation and blunted affect [72–75] and BPRS depression and anxiety symptoms included depressive mood, guilt and anxiety [76]. We conducted univariate (unadjusted) logistic regression analyses to examine the relationship between each predictor variable and African American race during psychiatric hospital admission. We then conducted multivariate logistic regression analysis to examine the effect of each predictor variable after holding the other variables in the model constant. To conduct the multivariate statistical analysis, we used logistic regression analysis with block-wise entry and added predisposing, enabling and need variables separately as blocks into a hierarchical regression analysis to test whether each block significantly increased the pseudo R-squared (R 2), given the variables already entered into the regression equation. We tested both main effects and interactions and only retained significant variables in the final model. All analyses were conducted in SPSS for Windows version 2.1 (SPSS, Chicago, IL). This study was approved by the Institutional Review Board at UT Health Science Center at Houston.

Enabling Factors

Predisposing Factors Age

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Insurance Status

Gender

Multiple Psychiatric Hospitalizations

Marital Status

Racial Disparities during Psychiatric Hospital Admission

Schizophrenia Diagnosis Co-Occurring Substance Use

Elevated Psychiatric Symptoms

Co-Morbid Personality Disorders

Need Factors

Fig. 1. Conceptual model.

Housing Stability

Involuntary Admission

3. Results 3.1. Sample characteristics A total of 5183 patients met study inclusion criteria and were included in the sample. We calculated chi-square statistics to examine differences between African Americans and non-Hispanic whites and found significant differences for marital status, insurance status and patient diagnosis. The sample characteristics are summarized in Table 1. 3.2. Statistical analysis 3.2.1. Univariate analyses In the univariate (unadjusted) analyses, among predisposing factors, younger age (Odds Ratio [OR] = 0.993, 95% Confidence Interval [CI] = 0.989–0.998, p = 0.003) and being unmarried (OR = 0.657, 95% CI = 0.547–0.790, p b 0.001) predicted African American race at admission. Among enabling factors, having three or more previous psychiatric hospitalizations predicted African American race during admission (OR = 1.963, 95% CI =1.745–2.209, p b 0.001). Compared to non-Hispanic whites, African Americans were less likely to be uninsured and were more likely to have commercial insurance (OR =0.565, 95% CI =

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Table 1 Characteristics of the sample. Variable

Total sample (n = 5183)

African Americans Non-Hispanic (n = 2673) whites (n = 2510)

Age, mean (SD) Gender a (%) Female Marital status b (%) Never married Married Married but separated Divorced Widowed Living situation c (%) Home Homeless shelter Homeless Institution/jail Insurance status d (%) Commercial insurance Medicare Medicaid Uninsured Primary diagnosis e (%) Schizophrenia Bipolar disorder Depression Other

35.67 (11.82) 35.20 (11.83)

36.17 (11.83)

38.1

37.5

38.8

76.1 10.0 3.9 8.9 1.2

81.4 8.2 3.8 5.4 1.2

70.4 12.0 4.0 12.5 1.2

92.0 4.0 2.3 1.4

92.4 3.5 2.2 1.9

91.6 4.5 2.5 1.5

13.2 8.3 4.1 74.4

15.7 10.4 4.9 69.0

20.3 6.1 3.3 70.3

28.6 38.6 20.6 12.2

37.4 34.6 16.7 11.3

19.2 42.9 24.8 13.1

a

Non-significant difference between races: chi-square: 0.990; df: 1; p = 0.320. b Significant difference between races: chi-square: 113.514; df: 4; p b 0.001. c Non-significant difference between races: chi-square: 4.913; df: 3; p = 0.178. d Significant difference between races: chi-square: 52.447; df: 3 p b 0.001. e Significant difference between races: chi-square: 216.318; df: 3p b 0.001.

0. 477–0.669, p b 0.001). Among need factors, compared to non-Hispanic whites, African Americans were 2.5 times more likely to receive a diagnosis of schizophrenia (OR = 2.508, 95% CI = 2.211–2.847, p b 0.001) and were less likely to receive a co-morbid diagnosis of a personality disorder (OR = 0.606, 95% CI = 0.525–0.699, p b 0.001). African Americans were also more likely to screen positive for cannabis use (OR = 1.456, 95% CI = 1.274–1.663, p b 0.001) and to screen positive for cocaine use (OR = 1.796, 95% CI = 1.542–2.093, p b 0.001). Multiple BPRS positive symptom items predicted African American race at admission in the unadjusted analyses including conceptual disorganization (OR = 1.127, 95% CI = 1.089–1.168, p b 0.001), mannerisms and posturing (OR = 1.111, 95% CI = 1.017–1.213, p = 0.019), hostility (OR = 1.077, 95% CI = 1.045–1.109, p b 0.001), suspiciousness (OR = 1.133, 95% CI = 1.101–1.165, p b 0.001), hallucinatory behavior (OR = 1.143, 95% CI = 1.101–1.187, p b 0.001), unusual thought content (OR = 1.154, 95% CI = 1.121–1.188, p b 0.001) and grandiosity (OR = 1.055, 95% CI = 1.014–1.097, p = 0.008). All three negative symptom

items from the BPRS, emotional withdrawal (OR = 1.137, 95% CI = 1.097–1.179, p b 0.001), motor retardation (OR = 1.079, 95% CI = 1.030–1.130, p = 0.001) and blunted affect (OR = 1.121, 95% CI = 1.080–1.164, p b 0.001), predicted African American race at admission. In contrast, all three depression/anxiety BPRS items predicted non-Hispanic white race during admission including anxiety (OR = 0.849, 95% CI = 0.822–0.877, p b 0.001), guilt (OR = 0.841, 95% CI = 0.799–0.885, p b 0.001) and depression (OR = 0.855, 95% CI = 0.830–0.880, p b 0.001). 3.2.2. Multivariate analysis In the multivariate analysis (n = 5183), all predisposing, enabling and need factors were tested in the logistic regression model to study the association between these characteristics and African American versus non-Hispanic white race at admission. Significant predictors retained in the final multivariate model are summarized in Table 2. Among predisposing factors, compared to non-Hispanic whites, African Americans were more likely to be younger (OR = 0.989, 95% CI = 0.984–0.994, p b 0.001) but were less likely to be male (OR = 1.170, 95% CI = 1.010–1.356, p = Table 2 Predictors of African American race at admission (n = 5183). Variable

Odds ratio

95% C.I. for EXP(B)

Significance

Lower Upper 2

Block 1: predisposing factors** R = 0.007 Admit age .989 Female gender 1.170 Marital status .763 Block 2: enabling factors** R 2 = 0.057 Insurance status: commercial (ref) – Insurance status: Medicare .895 Insurance status: Medicaid .932 Insurance status: uninsured .650 Living in a home prior to admission 1.344 3 or more psychiatric hospitalizations 1.506 Involuntary status .853 Block 3: need factors** R 2 = 0.171 Schizophrenia diagnosis 1.634 Co-morbid personality disorder .657 Cannabis positive 1.371 Cocaine positive 2.559 BPRS: emotional withdrawal 1.053 BPRS: suspiciousness 1.045 BPRS: hallucinatory behavior 1.126 BPRS: motor retardation 1.073 BPRS: hostility 1.043 BPRS: anxiety .829 BPRS: depressive mood .921 Block 4: interaction term* R 2 = 0.173 Interaction of female gender and 1.468 cannabis use Block 5: interaction term* R 2 = 0.174 Interaction of female gender and .627 cocaine use Constant 1.273

.984 1.010 .626

.994 .000 1.356 .036 .929 .007

– .683 .665 .542 1.077 1.318 .747

– 1.173 1.306 .779 1.675 1.721 .975

.000 .421 .684 .000 .009 .000 .019

1.398 .560 1.144 2.083 1.008 1.003 1.083 1.014 1.005 .797 .887

1.910 .770 1.643 3.143 1.101 1.088 1.171 1.136 1.081 .862 .957

.000 .000 .001 .000 .022 .033 .000 .014 .024 .000 .000

1.086

1.984 .012

.444

.885 .008

–

–

Significance of block during entry: * p b .05; ** p b .01.

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0. 036) or married (OR = 0.763, 95% CI = 0.626–0.929, p = 0. 007) controlling for other factors in the model. Among enabling factors, compared to non-Hispanic whites, African Americans were less likely to be uninsured (OR = 0.650, 95% CI = 0.542–0.779, p b 0.001) and were less likely to be involuntarily admitted (OR = 0.853, 95% CI = 0.747–0.975, p = 0.019). In contrast, African Americans were more likely to live in a home (OR = 1.344, 95% CI = 1.077–1.675, p = 0. 009) and were also more likely to have three or more prior psychiatric hospitalizations (OR = 1.506, 95% CI = 1.318–1.721, p b 0.001) compared to nonHispanic whites. Among need factors, compared to non-Hispanic whites, African Americans were more likely to be diagnosed with schizophrenia (OR = 1.634, 95% CI = 1.398–1.910, p b 0.001), to screen positive for cannabis use (OR = 1.371, 95% CI = 1.144–1.643, p b 0.001) and to screen positive for cocaine use (OR = 2.559, 95% CI = 2.083– 3.143, p b 0.001). In contrast, African Americans were less likely to be diagnosed with a co-morbid personality disorder (OR = 0.657, 95% CI = 0.560–0.770, p b 0.001) compared to non-Hispanic whites. During admission, African Americans in the sample were more likely to be rated as having elevated BPRS positive symptoms of psychosis including hallucinatory behavior (OR = 1.126, 95% CI = 1.083– 1.171, p b 0.001), suspiciousness (OR = 1.045, 95% CI = 1.003–1.088, p = 0.033) and hostility (OR = 1.043, 95% CI = 1.005–1.081, p = 0.024). African Americans in the sample were more likely to be rated as having elevated BPRS negative symptoms of psychosis including emotional withdrawal (OR = 1.053, 95% CI = 1.008–1.101, p = 0.022) and motor retardation (OR = 1.073, 95% CI = 1.014–1.136, p = 0.014). African Americans were less likely to be rated as having BPRS symptoms of depression (OR = 0.921, 95% CI = 0.887–0.957, p b 0.001) or anxiety (OR = 0.829, 95% CI = 0.797–0.862, p b 0.001) compared to non-Hispanic whites when controlling for other factors in the model. Two interaction effects were found to predict African American race at admission, the interaction of female gender with cannabis use and the interaction of female gender with cocaine use. Cannabis use was found to moderate the effect of being female and being African American during admission (OR = 1.468, 95% CI = 1.086–1.984, p = 0.012). The moderating effect was indicated by an increase in the strength of the association between being female and being African American with the interaction of cannabis use. Cocaine use also moderated the effect of being female and being African American during admission (OR = 0.627, 95% CI = 0.444–0.885, p =0.008). In this case, the strength of the association between being female and being African American decreased with the interaction of cannabis use. The largest change in pseudo R-squared occurred with the addition of the third block of need factor variables that included a diagnosis of schizophrenia, a diagnosis of a co-morbid personality disorder, substance use positive

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screens and BPRS items (R increase = 0.114; p b 0.001). The second largest change in pseudo R-squared occurred with the addition of the second block of enabling factors that included insurance status, housing stability, prior hospitalizations and involuntary status (R 2 increase = 0.050; p b 0.001). Overall, the multivariate model showed a good fit to the data, with a Hosmer–Lemeshow goodness of fit statistic of 9.482 with 8 degrees of freedom (p = 0.303). In the final block containing all predictor variables, the Cox/ Snell and Nagelkerke pseudo R-squareds ranged from 0.131 to 0.174. The results of the final model are presented in Table 2. 2

4. Discussion Our study found that predisposing, enabling and need factors differed significantly among African Americans and non-Hispanic whites during psychiatric admission. Our finding that younger age predicted inpatient psychiatric admission among African Americans is consistent with previous research showing younger age to increase the risk of psychiatric hospitalization [49–51]. However, our finding from the multivariate analysis that female gender predicted African American race during psychiatric hospital admission contrasts with previous research findings of male gender predicting psychiatric hospital admission [49]. The lower inpatient utilization by African American males at our hospital may be related to sociocultural factors including a general mistrust [77,78] and the perceived stigma of mental health treatment [79]. Prior research has found African American males to be less likely to perceive a need for mental health treatment when compared to African American females and non-Hispanic white males and females [79], suggesting a need for additional outreach and intervention in this population. The lower utilization of inpatient psychiatric services by African American males at our hospital may also be related to the overrepresentation of African American males in the correctional system, often resulting from disparities in mental health diagnosis and treatment [80]. In the United States, research has shown that African American males suffering from substance abuse disorders and mental illness are incarcerated at much higher rates compared to non-Hispanic white males [81]. In our study, enabling factors predicting African American race during psychiatric admission included having commercial insurance, living in a home and having three or more prior psychiatric hospitalizations [50,51,53–60]. These findings may suggest that African Americans admitted to our hospital during the study period were less socio-economically disadvantaged compared to non-Hispanic white patients. Our findings are consistent with prior research showing a greater likelihood for African Americans to receive treatment with antipsychotic medications during outpatient visits with a psychiatrist or general practitioner compared to non-Hispanic whites while having commercial insurance increased the likelihood of psychiatric hospitalization following an outpatient visit [16].

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Nevertheless, the overall higher utilization of inpatient psychiatric services among African Americans despite the availability of health insurance and housing points to the possible existence of treatment disparities beyond the ability to pay. This finding suggests that further research is needed to determine if African Americans were encountering barriers accessing needed outpatient mental health services prior to inpatient psychiatric hospitalization for reasons other than a lack of insurance coverage or the cost of treatment. Among need factors, African Americans had a greater likelihood of being diagnosed with schizophrenia, a pattern which has been widely documented in prior research [20–25]. In contrast, African Americans were less likely to be diagnosed with a co-morbid personality disorder compared to non-Hispanic whites, which is also consistent with previous research [82]. In the multivariate model, African Americans were more likely to be rated as having elevated BPRS positive symptoms of psychosis including hallucinatory behavior, suspiciousness and hostility. The elevated ratings of hallucinatory behavior for African Americans found in our study is consistent with previous research comparing hallucinatory behavior among African Americans to nonHispanic whites in clinical settings [21,24,83]. Additionally, prior research conducted with mixed-diagnosis samples during psychiatric hospitalization has shown that clinicians conducting structured diagnostic interviews are more likely to attribute symptoms of hallucinations and suspiciousness to African Americans, but are less likely to attribute symptoms of elevated mood [23,84]. Prior research has also shown that hallucinatory behavior is more likely to be attributed to African American and non-African American patients at different rates that do not necessarily correspond to differences in diagnostic rates of schizophrenia [84]. A relationship between BPRS ratings of suspiciousness and hostility and patient perceptions of coercion, negative pressures and exclusion has also been found during psychiatric hospital admission [85]. In our study, African Americans were less likely to be involuntarily admitted compared to nonHispanic whites; however, the possibility of mistrust of the clinical process by African Americans during psychiatric admission should be considered with the occurrence of elevated symptoms of suspiciousness and hostility. While the African American sample showed elevated BPRS symptoms of grandiosity in the univariate analysis, this relationship did not remain significant in the multivariate model, which may be indicative of the complexity of symptom presentation with this population [83]. In the multivariate model, two negative BPRS symptoms of psychosis, emotional withdrawal and motor retardation, were predictive of African American race during admission. This finding is consistent with prior research with psychiatric inpatients that also found substantial differences in clinician attributions of negative symptoms of psychosis among African American and non-Hispanic white patients in relation to rates of schizophrenia diagnoses [84]. These

findings together may have important implications as the severity of negative symptoms during psychiatric hospital admission has been previously shown to predict poor outcomes across multiple domains including impairments in occupational, social and financial functioning [86]. Findings that elevated BPRS symptoms of depression were less likely to be rated in the African American sample may indicate that depressive symptoms among African Americans were unrecognized by rating clinicians or that African Americans in this sample were experiencing less severe depressive symptoms during admission. This finding is consistent with prior research on schizophrenia showing higher depression rates among non-Hispanic whites being treated for schizophrenia compared with African Americans [87,88]. Researchers have hypothesized that antipsychotic medications have greater antidepressant effects for African Americans compared to non-Hispanic whites such that prior pharmacological treatment for psychosis may have resulted in reductions in depressive symptoms [89]. While research has suggested that the misdiagnosis of schizophrenia in African Americans with affective disorders may not be attributable to differences in the presentation of positive symptoms of psychosis, research also suggests that clinicians perceive psychotic symptoms to be more chronic or persistent than affective symptoms among African Americans [90]. Because African Americans are less likely to receive appropriate depression treatment compared to non-Hispanic whites, improvements in both the diagnosis and treatment of affective disorders in African Americans have the potential to reduce mental health disparities [91]. Similarly, our findings that BPRS symptoms of anxiety were less likely to be rated in the African American sample are consistent with prior research suggesting that anxiety disorders in African Americans may be overlooked, undertreated or misdiagnosed as more serious forms of mental illness, thus contributing to considerable unmet mentalhealth needs [92]. Multiple additional BPRS items including conceptual disorganization, mannerisms and posturing, unusual thought content, blunted affect and guilt were significant in the univariate analyses but did not remain significant in the multivariate model when adjusting for multiple factors. In the present study, the diagnostic process may have been complicated by substance use in some cases, as our findings indicated a greater likelihood for African Americans to screen positive for cannabis and cocaine use at admission compared to non-Hispanic white patients. Prior research suggests that the diagnosis of psychiatric disorders among substance abusers is complicated by the resemblance of the effects of intoxication and withdrawal to the symptoms of psychiatric disorders [93,94]. In a study of 195 African American and non-Hispanic white psychiatric inpatients diagnosed with schizophrenia spectrum disorders, substance use was found to be associated with the presence of positive symptoms such as auditory hallucinations [90].

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The relationship between BPRS rated symptoms of hallucinatory behavior and cannabis use was examined in a population-based prospective study conducted in the Netherlands. The study found that a history of cannabis use increased the risk of psychosis for study participants without prior symptoms of psychosis, with a dose–response relationship between exposure and increased psychosis [95]. Additionally, a strong additive interaction was found between cannabis use and an established vulnerability to a psychotic disorder, and the difference in the risk of psychosis at follow-up between those who did and did not use cannabis was much higher for those with an established vulnerability to psychosis at baseline than for those without one [95]. The findings in the current study may be evidence of this vulnerability effect for psychosis given the tendency for African American patients in our study sample to be of a younger age and screen positive for cocaine or cannabis use. Our finding that cannabis use moderated the effect of being female and being African American during admission appears to be in line with previous research and provides further evidence of a possible link between cannabis use, and increased risk of psychosis. In our study, significantly more young African American females who were experiencing psychiatric impairment also screened positive for cannabis during psychiatric admission. The higher utilization of inpatient psychiatric services by younger African American females in the study sample may be related to findings from a recent study comprising socially disadvantaged, predominately African American, first-episode psychosis patients, in which daily cannabis use was found to result in a larger relative risk of the onset of psychosis for younger-age females compared to males [96]. A limitation of this study is the use of retrospective data, which limited our ability to examine the race of the psychiatrist diagnosing patients during admission. Prior research examining clinician race and diagnostic practices found a greater likelihood for African American clinicians to diagnose schizophrenia compared to non-African American clinicians when they believed hallucinations were present and to avoid the diagnosis when they considered substance abuse issues [31]. Non-African American clinicians were also found to relate the attribution of negative symptoms to the diagnosis of schizophrenia while African American clinicians did not make this linkage. To further elucidate these complex relationships, prospective, controlled studies are needed to examine the relationships between cannabis use, the risk of psychosis and the diagnosis of schizophrenia among African Americans in particular. While approximately 16% of the patients served within our hospital during the study period were Hispanic, we chose not to examine Hispanics as a third comparison group to avoid diluting the contrast and findings. The well-developed literature base from which we have compared our findings primarily contained comparisons of African American to non-Hispanic white patients and did not include Hispanics [14,21,37].

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Our study strengths include the large sample size, the collection of data over multiple years and the use of the BPRS to measure psychiatric symptoms. Past research supports the use of the BPRS to systematically screen patients during psychiatric admission in order to identify persons at risk for having a less favorable pattern of service use, including multiple hospitalizations [69,97]. The BPRS was developed and refined by faculty at our academic hospital [98], and the BPRS continues to be used at our hospital for training psychiatric residents in the full range of psychopathology likely to be encountered among our patients [99]. Therefore, we believe that continued use of the BPRS with the goal of improving the consistency of its administration is a best practice approach for monitoring and addressing trends related to mental health disparities. Our study findings also highlight the importance for psychiatrists and other clinicians at our hospital to obtain a detailed substance use history during psychiatric admission and to ensure that any relevant information is considered during the initial clinical assessment and treatment planning. 5. Conclusion Our study found that among a large sample of patients treated at an academic psychiatric hospital serving as a regional safety-net provider, compared to non-Hispanic whites, African Americans were more likely to have elevated positive and negative symptoms of psychosis and to receive a diagnosis of schizophrenia after controlling for other predisposing, enabling and need factors. African American patients were also more likely to be younger, female, screen positive for cocaine and cannabis use, be voluntarily admitted and have three or more previous psychiatric hospitalizations. These findings appear to be unrelated to financial barriers to care including housing instability and being uninsured. Our study findings highlight the importance of examining mental health disparities using a conceptual framework developed for vulnerable populations (such as racial minorities and patients with co-occurring substance use). References [1] U.S. Department of Health and Human Services. Office of Disease Prevention and Health Promotion, Healthy People, 2020. Washington, DC; 2014. Available at http://www.healthypeople.gov/2020/. Accessed 10/17/2014. [2] Nelson A. Unequal treatment: confronting racial and ethnic disparities in health care. J Natl Med Assoc 2002;94(8):666-8. [3] Cooper LA, Hill MN, Powe NR. Designing and evaluating interventions to eliminate racial and ethnic disparities in health care. J Gen Intern Med 2002;17(6):477-86. [4] Wang PS, Demler O, Kessler RC. Adequacy of treatment for serious mental illness in the United States. Am J Public Health 2002;92:92-8. [5] U.S. Department of Health and Human Services. Mental health: culture, race, and ethnicity—a supplement to mental health. A report of the surgeon general. Rockville, MD: U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Mental Health Services; 2001.

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