Emergency Department Visits and Use of Outpatient Physician Services by Adults With Developmental Disability and Psychiatric Disorder

Transcription

1 CanJPsychiatry 2012;57(10): Original Research Emergency Department Visits and Use of Outpatient Physician Services by Adults With Developmental Disability and Psychiatric Disorder Yona Lunsky, PhD 1,2 ; Elizabeth Lin, PhD 2,3 ; Rob Balogh, PhD 4 ; Julie Klein-Geltink, MHSc 5 ; Andrew S Wilton, MSc 6 ; Paul Kurdyak, MD, PhD 2,7 1 Clinician Scientist, Centre for Addiction and Mental Health, Toronto, Ontario. Correspondence: Centre for Addiction and Mental Health, 501 Queen Street West, Toronto, ON M5V 2B4; yona.lunsky@camh.ca. 2 Adjunct Scientist, Institute for Clinical Evaluative Sciences, Toronto, Ontario. 3 Independent Scientist, Centre for Addiction and Mental Health, Toronto, Ontario. 4 Postdoctoral Fellow, Centre for Addiction and Mental Health, Toronto, Ontario. 5 Epidemiologist, Institute for Clinical Evaluative Sciences, Toronto, Ontario. 6 Data Analyst, Institute for Clinical Evaluative Sciences, Toronto, Ontario. 7 Staff Psychiatrist, Centre for Addiction and Mental Health, Toronto, Ontario. Key Words: developmental disability, serious mental illness, primary care, mental health services, emergency departments Received October 2011, revised, and accepted March Objective: To compare the emergency department (ED), primary, and psychiatric care visit rates associated with the presence and absence of a developmental disability (DD) and a mental illness. Method: This is a population-based study comparing Ontario adults, with and without DDs and mental illnesses, in terms of rates of primary, psychiatric, and ED care, from April 2007 to March Results: In Ontario, 45% of adults with a DD received a psychiatric diagnosis during a 2-year period, and 26% of those with a psychiatric diagnosis were classified as having a serious mental illness (SMI), compared with 8% of those with a psychiatric diagnosis but no DD. People with DDs had an increased likelihood of psychiatric and ED visits. Patients with SMIs and DDs had the highest rates of such visits. Conclusions: People with more severe impairments had the greatest likelihood of ED visits, despite access to outpatient services, suggesting that outpatient care (primary and psychiatric), as currently delivered, may not be adequate to meet their complex needs. W W W Objectif : Comparer les taux de visites du service d urgence (SU), des soins de première ligne, et des soins psychiatriques associés à la présence et à l absence d une déficience développementale (DD) et d une maladie mentale. Méthode : Il s agit d une étude dans la population qui compare les adultes ontariens, avec et sans DD et maladies mentales, en ce qui concerne les taux des soins de première ligne, des soins psychiatriques, et des soins du SU, d avril 2007 à mars Résultats : En Ontario, 45 % des adultes souffrant de DD ont reçu un diagnostic psychiatrique durant une période de 2 ans, et 26 % de ceux ayant reçu un diagnostic psychiatrique ont été classés comme ayant une maladie mentale grave (MMG), comparativement à 8 % de ceux ayant reçu un diagnostic psychiatrique mais sans DD. Les personnes souffrant de DD avaient une plus grande probabilité de visites psychiatriques et au SU. Les patients souffrant de MMG et de DD avaient les taux les plus élevés de ces visites. Conclusions : Les personnes souffrant de déficiences plus graves avaient la plus grande probabilité de visites au SU, malgré l accès à des services ambulatoires, ce qui suggère que les soins ambulatoires (de première ligne et psychiatriques), tels qu ils sont dispensés actuellement, ne sont peut-être pas adéquats pour répondre à leurs besoins complexes. The Canadian Journal of Psychiatry, Vol 57, No 10, October 2012 W 601

2 Original Research People with a DD have higher rates of chronic medical and psychiatric conditions than the general population. 1 People with a concurrent psychiatric illness comprise a significant proportion of the DD population (41%) 2 and have even greater health care needs and potentially larger gaps in care, than those with DD-only. 3 These people access mental health services younger and more frequently than people with psychiatric disorders but no DD 4,5 and are frequent users of EDs. 6 It has been suggested that ED visits by people with psychiatric disorders with DD occur, in part, because other resources are inadequate 7,8 and thus serve as a barometer of the adequacy of primary and specialty outpatient care. A recent study found that lack of primary care predicted ED use in a sample of adults with DD experiencing psychiatric crisis, when adjusting for age, sex, residential setting, and disability severity. 9 Only one population-based study from the United States has examined the relation in people with DD between the adequacy of primary care and ED use 10 but it did not look specifically at health service patterns for those with both DD and psychiatric disorder. This raises the question of whether the relation holds for people with the most complex needs. Research in the general population has suggested that it does not, reporting that frequent users of ED services are also frequent users of outpatient care. 11,12 Our study s first goal is to present the demographic profile of Ontario adults with DD, with and without mental illness of varying degrees of severity, relative to Ontarians without DD. Our second goal is to describe the ED, primary, and psychiatric care visit rates associated with the presence and absence of DD and mental illness. We speculated that primary and psychiatric care visit rates, along with ED use, would be higher in people with DD than those without. Across the psychiatric disorder categories, we hypothesized that the SMI category would be associated with the highest rates of ED, primary, and psychiatric care visits. Finally, when DD and mental illness co-occur, people with SMI-DD would have the highest likelihood of ED use despite high rates of outpatient services. Abbreviations BD DD DD-only ED NACRS OHIP OMHRS OthMI OthMI-DD bipolar disorder developmental disability DD only (no mental illness) emergency department National Ambulatory Care Reporting System Ontario Health Insurance Program Ontario Mental Health Reporting System other mental illness OthMI with DD OthMI-only OthMI only (no DD) SMI SMI-DD SMI-only serious mental illness SMI with DD SMI without DD 602 W La Revue canadienne de psychiatrie, vol 57, no 10, octobre 2012 Clinical Implications Given that a significant proportion of adults with DDs develop psychiatric disorders and rates of SMIs in particular are significantly higher than those of the general population, provision of psychiatric care is crucial. Patients with DDs and psychiatric disorders are likely to require more than simple access to psychiatry and primary care to prevent ED visits. Limitations Research findings were based on administrative data, thus diagnoses cannot be validated. Our study provides information at the population level but cannot speak to the relation between outpatient care and ED care at the individual level. Method Our study was completed using several linked administrative health datasets held at the Institute for Clinical Evaluative Sciences. Together, these datasets contain information on all in- and outpatient physician visits made by the Ontario population. Diagnostic data contained in these datasets before April 1, 2007, were used to identify 6 groups of people (described in further detail below, in the Group Assignment Data Sources and Definitions section): 1. SMI-DD 2. OthMI-DD 3. DD-only 4. SMI-only (for example, schizophrenia or delusional disorders, and BD) 5. OthMI-only 6. the general population (no DD and no mental illness) Health service use for these 6 groups was described for the period between April 1, 2007, and March 31, Any contact (yes or no) and the number of visits to each of 3 types of providers (ED, general practitioner, and psychiatrist) were tracked. Data were accessed through a comprehensive research agreement with the Ontario Ministry of Health and Long-Term Care. Before data analysis, all patient and provider identifiers were removed and replaced with unique encrypted numbers that allowed for data linkage. Our study was approved by the Research Ethics Board of the Sunnybrook Health Sciences Centre in Toronto, Ontario. Group Assignment Data Sources and Definitions Group assignment was performed using data from 4 sources: the OMHRS, which collects data on clients in adultdesignated mental health hospital beds, including beds in general, provincial psychiatric, and specialty psychiatric facilities since 2006; the Discharge Abstract Database from the Canadian Institute for Health Information, which contains data on all inpatient admissions other than those recorded in OMHRS; the OHIP database, which contains

3 Emergency Department Visits and Use of Outpatient Physician Services by Adults With Developmental Disability and Psychiatric Disorder physician billing claims for all eligible services dating back to 1991; and, the NACRS, which contains data on all ED visits to Ontario hospitals. All records from these 4 data sources were examined for the relevant diagnostic codes. For the DD diagnoses, the time period examined was from the inception of the data source up to and including March 31, This method was adopted because the onset of DD is before age 18 years, and a diagnosis is typically obtained in childhood; after this period, they are frequently not identified in the health administrative data. 13 DD and related developmental disorders included mental retardation, Down syndrome, and fragile X syndrome, fetal alcohol syndrome, and autism. For mental health diagnoses, the time period examined was from April 1, 2005, to March 31, SMI included schizophrenia or delusional disorders, BD, or depressive psychosis 14 (for more details, see online eappendix 1). OthMI included depressive disorders (except those included as SMI), anxiety disorders, and other psychiatric disorders. Because the administrative datasets used different coding systems (for example, the International Classification of Diseases, 9th Edition, before 2002, and 10th Edition, 2002 onward, and the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision), diagnostically equivalent categories were defined for the DDs, SMIs, and the OthMIs. For full details, see online eappendix 1. People were categorized into 1 of 6 mutually exclusive groups in a hierarchical fashion. People were first divided into those who received a DD diagnosis in the absence of, or before, a psychiatric disorder diagnosis and those who had not. Next, both groups were subdivided into those who had received a psychiatric diagnosis between 2005 and 2007 and those who had not. Next, people with a psychiatric diagnosis were subdivided into those with an SMI and those with an OthMI. Given their size relative to the other 5 groups, only a random subset (20%) of people who had neither a psychiatric diagnosis nor a DD diagnosis were used to comprise our general population group. All people were required to have had contact with the health care system in the 5 years before April 1, While our focus was the group hypothesized to have the most complex needs (SMI-DD), the creation of these 6 groups also allowed us to compare people with DD, SMI, OthMI, and no mental illness singly and in combination. Demographics Statistics Canada s Postal Code Conversion File was used to assign postal codes of residence to the 2006 Census subdivisions. From these subdivisions, we determined the urban or rural status of patients, using the Statistical Area Classification of Statistics Canada. 15 Rural represents the areas that are outside of the commuting zones of larger urban centres, with a core population of or more. Neighbourhood income quintile was also derived using the Statistics Canada s Postal Code Conversion File, using 2006 Census dissemination areas for household size and community of residence. Ontario s Registered Persons Database is the province s health care registry and was accessed for patient demographic information, including age, sex, and place of residence for all people covered by OHIP. Health Service Use Health service use was based on data for the period between April 1, 2007, and March 31, For each person in our 6 groups, we ascertained whether he or she had visited a primary care physician, a psychiatrist, or an ED during those 2 years, as well as the number of visits he or she made. For ED visits, additional information on type of visit, triage level, and time of visit was also captured as indirect measures of the accessibility or adequacy of primary care. Visit type was grouped as either psychiatric or nonpsychiatric, based on the primary discharge diagnosis coded in the NACRS record (F code, or not F code). The triage categories of 4 and 5 (semiurgent and nonurgent, respectively) were used to identify ED visits with less urgency, compared with those with greater urgency (categories 1, 2, and 3; resuscitation, emergent, and urgent, respectively). We also examined the proportion of after-hours ED visits, compared with those occurring within 9-to-5, Monday-to-Friday hours, based on the registration time listed in the NACRS record. Descriptive statistics were used to describe the sociodemographic characteristics and service use of our 6 groups. Because our 5 groups with illness were populationbased rather than samples, we did not compute statistics for this part of the analysis. To compare the combined use of primary and psychiatric outpatient care to ED care, we calculated age and sex risk-adjusted rates and 95% confidence intervals using logistic regression models. All analyses were conducted using SAS, version Results Demographics The total number of adults with DD in our study was Among these, (45%) had a concurrent psychiatric disorder. For 5220 people (26.4% of the total with DD and psychiatric disorder), the specific concurrent disorder was categorized as SMI-DD. In contrast, among those with a psychiatric disorder but no DD (n = ), only 8% were categorized as SMI-only. On average, the DD groups were younger than either the SMI-only or the OthMI-only groups and had a greater proportion falling in the young adult age range of 18 to 24 years (Table 1). Among people with DD, those with SMI-DD appeared to have a similar age profile as those with either OthMI-DD or DD-only, with the exception of fewer young people in the SMI group. All 3 DD groups were more likely, compared with those without DD, to live in the poorest neighborhoods. However, there was a gradient, with people with DD-only having the lowest percentage of residents from the lowest quintile (26.9%) and those with SMI-DD having the highest (34.8%). The Canadian Journal of Psychiatry, Vol 57, No 10, October 2012 W 603

4 Original Research Table 1 Patient demographics and physical health status of Ontarians by DD and mental health status as of April 1, 2005 Demographic SMI-DD n = 5220 DD OthMI-DD n = DD-only n = SMI-only n = No DD OthMI-only n = General population sample n = Age, mean (SD) (12.22) (12.93) (12.93) (11.81) (12.41) (12.70) Age, years, n (%) (14.2) 2985 (20.5) 5393 (22.7) (9.6) (11.8) (14.9) (21.3) 3096 (21.3) 5309 (22.3) (18.3) (19.5) (21.5) (27.7) 3543 (24.4) 5526 (23.2) (27.5) (26.1) (25.3) (23.0) 3092 (21.3) 4853 (20.4) (27.9) (24.9) (22.4) (13.9) 1823 (12.5) 2709 (11.4) (16.7) (17.6) (16.0) Male, n (%) 2859 (54.8) 7686 (52.9) (57.5) (40.9) (39.5) (52.8) Rurality, n (%) 610 (11.7) 2176 (15.0) 4242 (17.8) (9.7) (10.5) (12.2) Income quintile, n (%) Missing , low 1803 (34.8) 4111 (28.5) 6319 (26.9) (25.6) (21.0) (19.6) (22.9) 3094 (21.4) 4968 (21.1) (21.0) (20.3) (20.0) (16.5) 2591 (17.9) 4409 (18.7) (18.5) (19.7) (19.9) (13.9) 2461 (17.0) 4265 (18.1) (17.9) (19.7) (20.2) 5, high 621 (12.0) 2186 (15.1) 3569 (15.2) (17.1) (19.5) (20.4) Table 2 Percentage of primary, psychiatric, and ED visits among Ontarians from April 1, 2007, to March 31, 2009, by DD and mental health status DD No DD Source of care SMI-DD OthMI-DD DD-only SMI-only OthMI-only General population sample Any primary or psychiatry care Any primary care visits during 2 years Any psychiatry care visits during 2 years Any ED care visits during 2 years Unplanned mental health visits Unplanned visits, mean (SD) 4.9 (13.4) 2.1 (5.9) 1.3 (3.1) 1.7 (4.4) 0.91 (2.3) 0.49 (1.2) Low-triage visits, mean (SD) 2.8 (8.0) 1.1 (3.0) 0.8 (2.1) 1.0 (2.8) 0.53 (1.6) 0.26 (0.8) After-hours ED visits, mean (SD) 3.3 (10.2) 0.9 (2.2) 0.6 (1.8) 1.4 (4.6) 1.2 (3.4) 0.4 (1.0) Patterns of Health Care Use As shown in Table 2, most people in all 6 groups had visited a primary care provider at least once in the 2-year period. The 2 groups with no mental illness had the lowest percentages of visiting any primary care (DD-only, 81.1%; general population sample, 78.5%). Among the remaining groups, people with a DD were less likely to visit any primary care than those without (SMI-DD, 89.5 % and SMI-only, 93.2%; OthMI-DD, 89.3% and OthMI-only, 93.8%) and were also less likely to make frequent ( 10) visits when they did. In contrast, the presence of DD was associated with an increased 604 W La Revue canadienne de psychiatrie, vol 57, no 10, octobre 2012 likelihood of psychiatric visits and an increased likelihood of frequent visits during the 2-year period. The patterns for ED visits were similar to those found for psychiatric visits. The presence of DD was associated with an increased likelihood of ED visits during the 2-year period, as was the presence of SMI. People with SMI-DD were more likely to visit an ED than their counterparts (62.6%, compared with 51.0% for SMI-only), as were those with OthMI-DD (52.9%, compared with 40.2% for OthMI-only) and DD-only (44.1%, compared with 28.2% for the general population sample). The same pattern was

5 Emergency Department Visits and Use of Outpatient Physician Services by Adults With Developmental Disability and Psychiatric Disorder Figure 1 Rates of any primary or psychiatric care (age- and sex-adjusted) and any ED care (age- and sex-adjusted) among Ontarians from April 1, 2007, to March 31, 2009, by DD and mental health status Primary or psychiatric care ED care Rate, % SMI-DD OthMI-DD DD-only SMI-only OthMI-only General population sample observed when only ED visits for mental health issues were analyzed. For example, 28.1% of the SMI-DD group had an unplanned mental health related ED visit, compared with 19.2% of the SMI-only group. This translates into 44.8% of total ED visits for SMI-DD and 37.6% for SMI-only. Similar patterns were observed for all the groups. The same pattern held for frequent ED visits ( 10) and mean number of unplanned and low-triage visits. This pattern deviated for after-hours visits in that the OthMI-only group averaged more visits than their counterparts (1.4, compared with 0.9 for OthMI-DD). To compare primary and psychiatric outpatient care to ED care between the 6 groups, we adjusted for age and sex and calculated the 95% confidence intervals around the riskadjusted rates (Figure 1). The clear gradients shown in Table 2 persist (indeed, the adjusted and unadjusted rates were quite close). For primary and psychiatric care, the 2 SMI groups were statistically similar and had the highest riskadjusted rates (94.8% and 95.0%, respectively), while the general population sample had the lowest (79.3%). Rates for the other 3 groups were statistically distinct, both from the highest and lowest rates, as well as from each other. For ED care, the 6 groups were all statistically distinct from each other, owing to the very narrow confidence intervals. The group with the highest risk-adjusted rate of any ED visit was the SMI-DD (62.9%), followed by the OthMI-DD and SMI-only groups, the DD-only group, and the OthMI-only group. The general population sample had the lowest riskadjusted rate of ED care (28.2%). To compare the relation between primary and psychiatric outpatient care to ED care, we calculated the ratio of these risk-adjusted rates. The ratio was lowest for the most severe group (SMI-DD, 1.5), followed by ratios ranging from 1.8 to 1.9 for the OthMI-DD, DD-only, and SMI-only groups, and ratios of 2.3 to 2.8 for the OthMI-only and general population groups, respectively. Discussion Our study describes the demographics and service use patterns of the adult population with DD, with varying degrees of psychiatric disorder, demonstrating high use of ED services in those with complex needs, despite access to outpatient care. Our study is unique in several ways. Internationally, this is the first population-based study that examines the dual diagnosis group in terms of severe and less severe psychiatric disorder. It is the first to compare different DD psychiatric subgroups with parallel subgroups that do not have DD and to report prevalence rates based on Canadian data. Finally, no other studies have considered The Canadian Journal of Psychiatry, Vol 57, No 10, October 2012 W 605

6 Original Research 3 types of health care use (that is, primary care, outpatient psychiatric care, and ED care) as they relate to DD, with and without psychiatric disorder. The number of adults we identified as having DD is equivalent to a prevalence rate of 5.4 per 1000, which is comparable to what was recently found in another Canadian province using administrative health data. 17 Our study found that 45% of adults with DD also had a psychiatric diagnosis, similar to the 40.9 rate reported in a recent epidemiologic study in Scotland. 2 Among people with DD and psychiatric disorder, the proportion of adults with SMI was much higher than was found in those without DD, a finding similar to what was reported in Australia. 5 The association we found between psychiatric disorder, DD, and living in the poorest neighbourhoods is consistent with what has been reported in the United Kingdom, in children and adolescents, 18 but different from what has been reported in Scotland, where no association was found for adults with DD. 2 Differences again may be due to differences in methodology between studies. Our study, based on administrative data, may have included more people with mild DD living in poverty but not known to community disability providers than the Scottish study. Our study found that most people had access to at least some primary care, and people with psychiatric issues were more likely to access psychiatric and ED services than those without. Access to primary care may be better among Canadians with DD, compared with a US-based population with DD supported by Medicaid. For example, the study by Wood et al 10 found that most people had less than one primary care visit in a year. The proportion of people in the 3 DD groups who visited EDs in our study (44% to 63%) were considerably higher than the proportions reported in the US study (18%) 10 and the Taiwan study (18.4%). 8 This difference in findings is likely due, in part, to the different observation periods (2 years, 1 year, and 7 months, respectively) used to calculate the ED visit frequency. High rates of ED visits reported here cannot be attributed to a general inability to access primary care because most patients had at least one primary care visit during the study period. We found a gradient for psychiatric and ED use by mental illness severity whereby the most severely impaired group (those with SMI-DD) had the greatest likelihood of ED and psychiatric visits. These findings suggest that ED use as a barometer for inadequate outpatient care may be applicable primarily for groups that have conditions of mild or moderate severity. This interpretation is supported by other studies in Canada, 11 the United States, 19 and Sweden, 12 which have also demonstrated that high users of ED services also frequently use primary and specialty outpatient services (albeit not for a DD population). As would be expected, groups with mental health or DD concerns had higher percentages of ED visits for mental health reasons. However, note that even for the group with the highest proportion of mental health related ED visits, most visits were still for medical reasons, reflecting that 606 W La Revue canadienne de psychiatrie, vol 57, no 10, octobre 2012 people with DD have multiple physical and mental health needs. Rather than strictly consider whether the frequency of outpatient visits should be increased for people with the most severe and complex mental health needs, the quality of care provided during each visit should also be examined. In Canada, family physicians and psychiatrists receive very limited training on treating patients with DD, 20,21 and physicians may be unable to address all presenting issues proactively, particularly for people with complex conditions. Another critical factor, in addition to frequency and quality of visits, may be continuity of care between visits. Wood et al 10 found that ED use was highest for people with DD who had low continuity of primary and specialist care. Even if the quantity, quality, and continuity of medical care could be improved, coordination of care between health care providers and other sectors (particularly the social services sector) remains an issue. These other services and supports are particularly important for people with dual diagnosis who require mental health services as well as residential, vocational, and family supports. The challenges for providers to coordinate care and for people with DD to navigate across multiple sectors are considerable but important, as the consequence of poor coordination may be increased risk of crisis. 22 Limitations These analyses are subject to several limitations. Our study used only administrative data that are collected for purposes other than research. Consequently, important issues (most notably, quality of care) could not be addressed. Inaccuracy in postal codes (in this case, owing to lack of routine updating of Ontario s Registered Persons Database addresses), inaccurate diagnoses, and use of area-level socioeconomic information are among the limitations of administrative data. 23 However, prior investigation into these limitations has shown that they are unlikely to have had an important impact on our main findings. 24 DD diagnosis was ascertained through administrative data, as opposed to clinical diagnosis 2 or a DD registry, 5 and has not been validated. Inclusion of syndromes and related developmental disorders may have allowed for the inclusion of some people who have significant cognitive impairments and adaptive behaviour deficits but IQ scores of 70 or more. Such categorizing is consistent with how DD is defined in Ontario but may not match diagnostic categories adopted in other studies or jurisdictions. Categorization of health services in our study was quite general and does not reflect the nature of each type of service provided or potential overlap among services. The descriptive analyses do not speak directly to clinical significance, which requires other information (for example, specific type and severity of illness, individual preferences, and response to services). Consequently, our report should lead to other studies that examine the clinical impact of differences in the service use patterns we have reported. Finally, because our study only provides population rates,

7 Emergency Department Visits and Use of Outpatient Physician Services by Adults With Developmental Disability and Psychiatric Disorder we cannot comment on how the services provided by general and specialty outpatient care interact with ED care at the individual level. Getting more information about this interaction will be important to help us develop better interventions, outreach, and organization of health services. Conclusions People with DD and psychiatric disorder have complex needs. They visit hospital EDs frequently, even though the ED is not an ideal environment for them. 7,25,26 As severity of psychiatric comorbidity increases, ED use cannot simply be attributed to poor access to either primary or psychiatric care. Rather, increased ED use among people with DD and concurrent psychiatric illness occurs despite reasonable access to primary care and specialty services, compared with access by people without DD. The needs of people with DD and concurrent psychiatric illnesses need to be measured carefully and responded to proactively and comprehensively so that inappropriate ED use can be reduced. Large-scale studies, such as this one, should be followed up with more in-depth quantitative and qualitative research into determinants of ED use, and mechanisms to decrease such use in people with complex needs. Acknowledgements This study was supported by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). Additional support was from annual MOHLTC funding to the Centre for Addiction and Mental Health. The opinions, results, and conclusions reported here are those of the authors. Endorsement by the ICES or the Ontario MOHLTC is neither intended nor to be inferred. References 1. Satcher D. Closing the gap: a national blueprint for improving the health of individuals with mental retardation. Report of the surgeon general s conference on health disparities and mental retardation [Internet]. Rockville (MD): US Public Health Service; 2001 [cited 2011 Aug 22]. Available from: topics/mentalretardation/retardation.pdf. 2. Cooper S, Smiley E, Morrison J, et al. Mental ill-health in adults with intellectual disabilities: prevalence and associated factors. Br J Psychiatry. 2007;190(1): Ouellette-Kuntz H, Garcin N, Lewis MES, et al. Addressing health disparities through promoting equity for individuals with intellectual disability. Can J Public Health. 2005;96(Suppl 2):S8 S Lunsky Y, Balogh R. Dual diagnosis: a national study of psychiatric hospitalization patterns of people with developmental disability. Can J Psychiatry. 2010;55(11): Morgan VA, Leonard H, Bourke J, et al. Intellectual disability co-occurring with schizophrenia and other psychiatric illness: population-based study. Br J Psychiatry. 2008;193(5): Pasic J, Russo J, Roy-Byrne P. High utilizers of psychiatric emergency services. Psychiatr Serv. 2005;56(6): Bradley E, Lofchy J. Learning disability in the accident and emergency department. Adv Psychiatr Treat. 2005;11: Lin J, Yen C, Loh C, et al. A cross-sectional study of the characteristics and determinants of emergency care utilization among people with intellectual disabilities in Taiwan. Res Dev Disabil. 2006;27(6): Lunsky Y, Balogh R, Cairney J. Predictors of emergency department visits by persons with intellectual disability experiencing a psychiatric crisis. Psychiatr Serv. 2012;63(3): Wood D, Hall A, Hou T, et al. Continuity of care to prevent emergency room use among persons with intellectual and developmental disabilities. J Policy Pract Intellect Disabil. 2007;4(4): Ovens HJ, Chan BT. Heavy users of emergency services: a population-based review. CMAJ. 2001;165(8): Hansagi H, Olsson M, Sjöberg S, et al. Frequent use of the hospital emergency department is indicative of high use of other health care services. Ann Emerg Med. 2001;37(6): Balogh R, Brownell M, Ouellette-Kuntz H, et al. Hospitalisation rates for ambulatory care sensitive conditions for persons with and without an intellectual disability a population perspective. JIDR. 2010;54(9): Durbin J, Lin E, Rush B, et al. A study of hospital emergency service use, crisis service delivery and police response after mental health system enhancements [Internet]. Toronto (ON): Centre for Addiction and Mental Health; 2010 [cited 2011 Aug 22]. Available from: Statistics Canada. Standard geographical classification. Volume I. The classification [Internet]. Ottawa (ON): Statistics Canada; 2007 [cited 2011 Aug 22]. Available from: Collection/Statcan/ XIB/ XIE pdf. 16. SAS Institute Inc. SAS version 9.2 [software]. Cary (NC): SAS Institute Inc; Ouellette-Kuntz H, Shooshtari S, Temple B, et al. Estimating administrative prevalence of intellectual disabilities in Manitoba. J Dev Disabil. 2009;15(3): Emerson E, Hatton C. Mental health of children and adolescents with intellectual disabilities in Britain. Br J Psychiatry. 2007;191(6): Sun BC, Burstin HR, Brennan TA. Predictors and outcomes of frequent emergency department users. Acad Emerg Med. 2003;10(4): Burge P, Ouellette-Kuntz H, Isaacs B, et al. Medical students views on training in intellectual disabilities. Can Fam Physician. 2008;54(4): Lunsky Y, Bradley E. Developmental disability training in Canadian psychiatry residency programs. Can J Psychiatry. 2001;46(2): Lunsky Y, Garcin N, Morin D, et al. Mental health services for individuals with intellectual disabilities in Canada: findings from a national survey. J Appl Res Intellect Disabil. 2007;20(5): Iron K, Zagorski BM, Sykora K, et al. Living and dying in Ontario: an opportunity for improved health information. ICES investigative report [Internet]. Toronto (ON): Institute for Clinical Evaluative Sciences; 2008 Mar. Available from: Living_and_dying_in_Ontario_March19-08.pdf. 24. Glazier RH, Creatore MI, Agha MM, et al. Socioeconomic misclassification in Ontario s health care registry. Can J Public Health. 2003;94(2): Lunsky Y, Gracey C, Gelfand S. Emergency psychiatric services for individuals with intellectual disabilities: perspectives of hospital staff. Intellect Dev Disabil. 2008;46(6): Weiss JA, Lunsky Y, Gracey C, et al. Emergency psychiatric services for individuals with intellectual disabilities: caregivers perspectives. J Appl Res Intellect Disabil. 2009;22(4): The Canadian Journal of Psychiatry, Vol 57, No 10, October 2012 W 607