Use of Health Care Services by People With Mental Illness
Secondary Data From Three Statutory Health Insurers and the German Statutory Pension Insurance Scheme
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Background: A discipline- and sector-specific analysis of health-care utilization by persons with mental illness in Germany is an indispensable aid to planning for the provision of adequate basic care.
Methods: Secondary data from three statutory health insurers and the German Statutory Pension Insurance Scheme for the period 2005–2007 were evaluated to identify insurees with mental illness (ICD-10 diagnosis groups F0–F5).
Results: In the period 2005–2007, 3.28 million (33%) of 9.92 million insurees had at least one contact with the health-care system in which a mental disorder was diagnosed. 50.4% (1 651 367) of these insurees had at least two mental disorders. Nearly all (98.8%) of the insurees with a psychiatric index diagnosis had at least one somatic diagnosis coded as well. 95.7% of treatments were provided in the outpatient setting. Somatic medical specialties provided the majority of treatments both in ambulatory care and in the hospital. For example, 77.5% of persons with severe depression were treated with five kinds of treatment that were provided exclusively by primary care physicians and other specialists in somatic medicine in private practice, sometimes in combination with psychiatric treatment or psychotherapy.
Conclusion: There was a high degree of comorbidity of mental and somatic illness. The fact that the vast majority of treatment was provided in the outpatient setting implies that cooperation across health-care sectors and disciplines should be reinforced, and that measures should be taken to ensure the adequate delivery of basic psychiatric care by primary care physicians.
Facing the current challenges in the care of patients with mental illness requires reliable data on their health care. The problems to be addressed include not only increased use of health care services, incapacity for work, and early retirement due to mental disorders (1, 2), but also the lack of specialized physicians with associated long waiting times, the further development required in intersectoral and interdisciplinary care, and the implementation of new care structures and new compensation systems. Germany’s health care system is very complex. Studies of care provided often include only individual sectors such as outpatient care (3). There are essentially two representative research works available on the prevalence and care of mental illness in Germany: the 1998 German National Health Interview and Examination Survey (4) and a European study (5).
The research presented here was the first to bring together secondary data from three insurers (DAK-Gesundheit, KKH-Kaufmännische Krankenkasse [formerly KKH-Allianz], and hkk-erste Gesundheit) and the German statutory pension insurance scheme over a three-year study period (2005 to 2007), forming a dataset that includes almost 3.3 million insurance holders with mental illness. This dataset differs from the German National Health Interview and Examination Survey (1998) in its use of routine data, sample size, and longitudinal design. This makes it possible to assess health care service use objectively and representatively on the basis of rehabilitation and benefit payments.
This article presents the prevalence of use of outpatient, inpatient, and rehabilitational care services by those with mental illnesses (ICD-10, F0 to F5) during the study period of 2005 to 2007. For example, for serious depressive illnesses analysis examined the specialties and sectors of care used.
This study aims to identify any shortcomings, such as problems at the interface of different sectors of care, and areas in which the care of mental illness might be optimized, through interdisciplinary and intersectoral analyses of the care pathway.
The project involved secondary, mainly descriptive analysis of the care of patients with mental illness. The study was financed by the German Medical Association (Bundesärztekammer) and funds provided by the German Association of Psychiatry, Psychotherapy and Psychosomatics (DGPPN, Deutsche Gesellschaft für Psychiatrie und Psychotherapie, Psychosomatik und Nervenheilkunde) and the LVR-Klinikum Düsseldorf. The involved insurers searched the secondary data (6) of a total of 9 921 363 insurance holders for coding of a mental illness in ICD-10-GM groups F0 to F5 (Figure 1) between 2005 and 2007 and made available for analysis the datasets for the insurance holders who met this selection criterion (according to the standard in use for secondary data analysis, cf. ).
The Institute for Health and Social Research (IGES Institut, Institut für Gesundheits- und Sozialforschung) assumed trusteeship of the data and performed data analysis. See the eBox for a detailed description of the methods used.
The limitations associated with secondary data analysis are described in detail in the Discussion section and the further description of the methods used (eBox).
Distribution of coded diagnoses
3 275 399 people insured with the insurers involved in this study met the criterion of an index diagnosis F0 to F5 during the study period (1 January 2005 to 31 December 2007). Figure 1 shows the distribution of diagnoses. Of the insurance holders with an index diagnosis, 50.4% presented mental comorbidity in the form of multiple diagnoses from different mental illness diagnosis groups, either simultaneously or longitudinally. The distribution of diagnoses has already been presented elsewhere (8). The differences between the distribution of diagnoses recorded here and that reported previously are the result of different groupings of the people in question: in the findings presented here all insurance holders with more than one diagnosis of mental illness were placed in the group “mental comorbidity” (Figure 1), while in the previous analysis they were counted multiple times.
For patients with mental comorbidity, the most common diagnosis combinations came from groups F3 (affective disorders) and F4 (neurotic, stress, and somatoform disorders). A code for at least one additional somatic diagnosis had also been recorded for nearly all insurance holders with a diagnosis of mental illness (inpatient or outpatient) (F0: 96.4%, F1: 96.5%, F2: 88.3%, F3: 98.2%, F4: 99%, F5: 99.1%; total for somatic comorbidity: 98.8%). In order to obtain the most comprehensive overview possible, analysis included all somatic diagnoses (at least one coded outpatient diagnosis or main/secondary inpatient diagnosis according to ICD-10, Chapter A to E, G to T [except G30]) during the study period.
Use of the health care system
Case-based analysis (eBox) for the three-year study period yielded almost 22 million cases treated for a diagnosis of mental illness (multiple cases for a single individual were possible. Of all treatments, 95.7% were provided on an outpatient basis, 4.2% on an inpatient basis, and 0.1% on a day-patient basis.
Of the insurance holders with an index diagnosis, 98% had received at least one outpatient treatment, 6% one inpatient treatment, and 0.2% one day-patient treatment (multiple treatments for a single individual permitted). Outpatient or inpatient rehabilitation care with a main diagnosis of a mental disorder was received by 2.6% of those insured.
Almost three-quarters of insurance holders who received outpatient treatment for a psychiatric diagnosis were cared for only by primary care physicians or other specialists in somatic medicine (Figure 2).
In inpatient care too, a relatively high percentage (27% to 64%) of patients with a psychiatric main diagnosis received care in departments specializing in somatic medicine (Figure 3).
The greatest amount of outpatient rehabilitation care for treatment cases with a psychiatric main diagnosis was provided by departments specializing in psychosomatic care (n = 25 136, approximately 67% of all cases of rehabilitation treatment in 2005 to 2007). This was followed by departments specializing in addiction medicine (n = 5674, 15%), and general psychiatric departments (n = 3509, 9%). In 6% (n = 2392) of cases of rehabilitation with a psychiatric main diagnosis, patients were treated in departments specializing in somatic medicine, 0.1% (n = 3077) on an outpatient basis.
Care for severe depression
During the observation period, 110 462 insurance holders were diagnosed with severe depression (ICD-10-GM: F32.2, F32.3, F33.2, F33.3). In 23.9% of these cases (n = 26 412) the patient was diagnosed with severe depression as early as the first quarter of 2005. These individuals formed the index population for sample analysis of the care pathway. Sociodemographically, this core group differed little from the total population of all insurance holders diagnosed with severe depression (Table 1). A total of 524 different care pathways were found; they differed in terms of the type, number, or chronological sequence of the sectors of care or specialties. The most common pathways were those involving primary care and specialties within somatic medicine, and physicians specializing in psychiatry and psychotherapy (eTable 1).
Most (74%) of the initial care provided at the beginning of the observation period (index care) was provided on an outpatient basis by a primary care physician or an other specialist in somatic medicine. In these cases, the probability of not being referred to another sector of care or another specialty during the time period studied was 53%. The probability of being referred on to another physician specializing in psychiatry and psychotherapy was 36%; and the probability of being transferred to another sector of care or another specialty was 11%.
For index care provided on an outpatient basis by a physician specializing in psychiatry and psychotherapy or neurology, which accounted for 20% of all index cases, the probability of not being referred to another sector of care or another specialty was 26%. The probability of being referred to a primary care physician or an other specialist in somatic medicine was 63%; the probability of being referred to another sector of care or another specialty was 11%.
For 2.5% of the index population, outpatient treatment was initially provided by a physician specializing in psychosomatic medicine and psychotherapy; for 0.7% it was initially provided by a psychotherapist (Psychologischer Psychotherapeut). Inpatient index care was very rare (department of somatic medicine: 0.1%; psychiatric department: 2.2%; department of psychosomatic medicine: 0.2%; rehabilitation: 0.2%). For these rarer types of index care, the probability of not being referred on to another sector of care was lower than for primary or psychiatric index care (primary care physician/other specialist in somatic medicine: 53%; physician specializing in psychiatry and psychotherapy/neurology: 26%; physician specializing in psychosomatic medicine and psychotherapy: 14%; psychotherapist: 13%; department of somatic medicine: 12%; psychiatric department: 12%; psychosomatic department: 4%; rehabilitation: 0.4%).
The five most common care pathways in this research, which together accounted for more than three-quarters (77.5%) of the index population, are shown in Figure 4.
The study investigated significant events during these five most common care pathways (Table 2). The rates of incapacity for work and retirement were significantly lower for the two care pathways that included no referral to another sector of care than for any others. These care pathways also had the highest mortality rates.
In addition, persons with an index diagnosis of severe depression in the first quarter of 2006 who had not used the health care system for a depressive or other psychiatric disorder in 2005 (n = 1149) were analyzed separately, in order to rule out incomplete presentation of these care pathways due to left-censoring of the data resulting from the lack of a preobservation period. These analyses showed certain shifts in order; the most common of these in this analysis too was “primary care physician/other specialist in somatic medicine, no onward referral” (eFigure, eTables 2 and 3).
Approximately 70 million people in Germany hold statuary health insurance (as of 2012, National Association of Statutory Health Insurance Funds [GKV Spitzenverband]). The number insured with the insurers involved in this study is 9 921 396, approximately one in seven holders of statutory health insurance.
Of all insurance holders, 33% had contact with the health care system during the three-year study period as a result of diagnosis of a mental illness. The most common types of service use resulted from mental comorbidity, followed by neurotic, stress, and somatoform disorders (F4), affective disorders (F3), and addictions (F1). In terms of their relative ranking, the service use prevalence rates shown here essentially reflect the prevalence rates already reported in the German National Health Interview and Examination Survey (4). These figures show the high demand for psychiatric/psychosomatic/psychotherapeutic care. This may pose a challenge for care planning in line with demand, as there is currently a lack of specialized physicians (9).
All those with mental illness showed high rates of mental and somatic comorbidity during the study period. The high rate of mental comorbidity (50.4%) is comparable with the rate reported in the 1998 German National Health Interview and Examination Survey (48% ). In addition to their psychiatric diagnosis, more than 90% of those insured were also diagnosed with a somatic disorder (excluding the group F2: 88.3%) during their care. The comparatively low somatic comorbidity rate in those with schizophrenia and other psychotic disorders (F2) may be evidence of underdiagnosis of somatic illnesses in this group of patients, as this is precisely where one would expect a comparatively high percentage of somatic comorbidity (10). Overall, our findings highlight the high rates of mental and somatic comorbidity in those with mental illness (11), just as those with somatic illness have an increased risk of somatic and mental comorbidity (12–15). This means interdisciplinary care including psychiatric/psychosomatic/psychotherapeutic disciplines and primary care or other somatic specialties must be developed. Ungewitter et al. (16) found that treating physicians rarely collaborate in care of the mentally ill, and when they do this is usually only through flexible networks, not explicit collaboration.
Most care services were used by those with mental illness on an outpatient basis, as already shown in the 1998 German National Health Interview and Examination Survey (17). The current compensation structures mean that securing specialist care on an outpatient basis will become a particular challenge, as the funding structure does not provide a sufficient guarantee that guideline-compliant care or compensation for the necessary scope of treatment will be provided (9).
For both inpatients and outpatients, a considerable proportion of care for mental illnesses was provided by primary care physicians/other specialists in somatic medicine (18). Studies of the prevalence of the use of care by those with mental illness in Europe show that only 30% to 50% of the mentally ill have been treated by psychiatrists and psychotherapists (19). The relatively low proportion of psychiatric/psychosomatic/psychotherapeutic care may result from a lack of specialized physicians, together with barriers to access to specialized care. The German Federal Chamber of Psychotherapists reported very long waiting times for psychotherapy (20). Individual patients’ behavior when seeking help and their treatment preferences may also play a role. Primary care physicians remain the gateway for patients with mental complaints, and primary care carries little stigma (21). An insufficient rate of referral to specialized care may also be a possible cause. The reasons for there being less use of specialized psychiatric/psychosomatic/psychotherapeutic care than of primary care should be evaluated in the future.
Sample analyses of cases of severe depression reveal the low levels of collaboration between primary and specialized care. The results shown here for severe depression are taken from care analyses that bring together various disciplines and sectors of care for the first time; until now only individual aspects have been investigated, at the most (22, 23). The authors’ own cross-section analyses had already shown the high percentage of care provided by disciplines within primary care and somatic medicine (24).
There was a high number of care pathways (n = 524); the most common type of pathway was care by primary care physicians or other specialists in somatic medicine in private practice, sometimes in combination with psychiatric or neurological care. As shown by studies of the diagnosis of depression in primary care, depression in primary care practice is very common according to expert opinion, but only some are diagnosed as such (26–28). In general, there are low rates of care for mental illnesses (19). Furthermore, Schneider et al. (25) found a higher rate of non-guideline-compliant treatment for depression in primary care compared to specialized psychiatric care. However, there are no systematic studies on the quality of outpatient care for depression in either primary or specialized care. In view of this situation, greater emphasis should be placed on measures to optimize the quality of outpatient care for depression (and other mental illnesses).
International studies show that depression is associated with an extremely heavy personal and societal burden, even more so than other widespread diseases such as diabetes and coronary heart disease (29, 30). The extent to which the care pathway is associated with unfavorable outcomes such as incapacity for work, early retirement, and mortality is not yet clear. Such questions take on particular significance given that, as discussed, there is room for improvement in the diagnosis and treatment of depression.
The analyses presented here do not show a systematic relationship between care pathways and these illness-associated events. The lowest rates of incapacity for work and early retirement as a result of depression occurred in the two care pathways without onward referral from the initial sector of care. This may indicate that cases of depressive disorders with more favorable prognoses are found with this type of care; this is also suggested by the fact that these cases show the significantly lowest rates of mental comorbidity. An argument against this idea is provided by the comparatively high mortality rate. The mortality rate cannot be interpreted as an age-related artefact, because the average age was almost identical for all care pathways. This may indicate that comprehensive, interdisciplinary care, possibly including inpatient care, has an effect in preventing mortality/suicide.
The predictive power of the care analyses performed here was limited first of all by the fact that for index diagnoses made in the first quarter of 2005 no distinction could be made between insurance holders with and without a preexisting depressive or other mental illness, as there was no preobservation period. Additional analyses were therefore performed, including only insurance holders who had not had any contact with the health care system for a depressive or other preexisting mental illness for a one-year preobservation period. This essentially confirmed the results of the first analyses.
Because these analyses found no evidence of a systematic relationship between the characteristics of care pathways and illness-related events during care, detailed analysis should clarify whether other predicting factors, such as frequency of service use or length of treatments, have any influence. These analyses were not included in the evaluations presented here.
Further factors limiting the analyses of pathways of care are, on the one hand, lack of information on initial diagnoses, and, on the other hand, the fact that it was not possible to include contact with the health care system before and after the beginning of the observation period; this means the whole care pathway may not have been covered.
A further limitation to be taken into account when interpreting somatic comorbidity is the fact that the analysis included all somatic diagnoses, in order to provide as complete as possible a picture of health care service use for somatic illnesses. No distinction was made here between milder, short-term and severe, chronic illnesses.
One major methodological limitation in the analysis of secondary data is the unknown validity and reliability of the underlying information (31). The data used for this study were examined for plausibility and completeness at the IGES Institut. No external data validation such as checking against medical records was possible; as a result, the influence of mistaken diagnoses cannot be completely ruled out. For primary care, analysis did show that for various reasons primary care physicians often do not provide a psychiatric diagnosis of depression, although they are aware of the mental burden on those affected and take it into account in consultation (28). Further limitations of the evaluation of secondary data analyses are shown in detail in the eBox.
This project accomodates demands to use routine data for purposes of research into health care processes and for purposes of quality assurance (32). The results of the analysis show, on the one hand, an imbalance between health service use for mental illnesses and, on the other, the high levels of somatic and mental comorbidity in those with mental illness. In addition, we analyzed some of the more common care pathways for those with severe depression for the German health care system as an example; this yielded a high proportion of nonspecific psychiatric/psychosomatic/psychotherapeutic care.
Setting aside boundaries between different disciplines and sectors, the use of secondary data can, despite all its limitations, contribute to the detection of underdiagnosis, overdiagnosis, mistaken allocation, and intersectoral interface problems. This is revealed in the findings of this study, such as the detection of a high proportion of care provided by disciplines specializing in somatic medicine and somewhat low levels of interdisciplinary and intersectoral care. More importance should therefore be attached to secondary data as a routinely available source of data for further planning of care for mental illness.
Conflict of interest statement
Prof. Gaebel is a faculty member of the Lundbeck International Neuroscience Foundation (Scientific Advisory Board). He has received reimbursement of travel expenses from the DGPPN, the AQUA-Institut, and the Federal Working Group of Psychiatric Hospital Operators (Bundesarbeitsgemeinschaft der Träger psychiatrischer Krankenhäuser). He has received event sponsorship (symposium support) from Lilly, Servier, and Janssen Cilag.
M.A. Kowitz has received reimbursement of travel expenses from the DGPPN.
Prof. Fritze has received consultancy fees (Scientific Advisory Board) from Janssen Lundbeck, Lilly, Pfizer, Roche, Novartis, 3M, Eisai, AstraZeneca, the Private Health Insurance Association (Verband der Privaten Krankenversicherung), and the DGPPN.
PD Dr. Zielasek has received reimbursement of conference fees and travel expenses from the DGPPN.
Manuscript received on 26 November 2012, revised version accepted on 22 August 2013.
Translated from the original German by Caroline Devitt, M.A.
Prof. Dr. med. Wolfgang Gaebel
Klinik und Poliklinik für Psychiatrie und Psychotherapie
Kliniken der Heinrich-Heine-Universität Düsseldorf
Bergische Landstr, 2
@For eReferences please refer to:
eFigure, eTables and eBox:
Prof. Dr. med. Gaebel, Kowitz, M.A., PD Dr. med. Zielasek
Pulheim: Prof. Dr. med. Fritze
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