World Health Organization Collaborating Centre for Mental Health Policy, and Policy and Epidemiology Group, School of Psychiatry, University of New South Wales at St Vincents Hospital, Sydney
World Health Organization Collaborating Centre for Mental Health Policy, and Policy Epidemiology Group, School of Psychiatry, University of New South Wales at St Vincents Hospital, Sydney and Centre for Health Research, School of Public Health, Queensland University of Technology, Brisbane
World Health Organization Collaborating Centre for Mental Health Policy, and Policy and Epidemiology Group, School of Psychiatry, University of New South Wales at St Vincents Hospital, Sydney
World Health Organization Collaborating Centre for Mental Health Policy, and Policy and Epidemiology Group, School of Psychiatry, University of New South Wales at St Vincents Hospital, Sydney and Faculty of Health Sciences, University of Queensland, Brisbane, Australia
Correspondence: Professor Gavin Andrews, 299 Forbes Street, Darlinghurst, NSW 2010, Australia. Fax: +612 9332 4316; e-mail: gavina{at}unsw.edu.au
Funding detailed in Acknowledgements.
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ABSTRACT |
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Aims To study the cost-effectiveness of current and optimal treatments for mental disorders and the proportion of burden avertable by each.
Method Data for three affective, four anxiety and two alcohol use disorders and for schizophrenia were compared interms of cost, burden averted and efficiency of current and optimal treatment. We then calculated the burden unavertable given current knowledge. The unit of health gain was a reduction in the years lived with disability (YLDs).
Results Summing across all disorders, current treatment averted 13% of the burden, at an average cost of AUS$30 000 per YLD gained. Optimal treatment at current coverage could avert 20% of the burden, at an average cost of AUS$18 000 per YLD gained. Optimal treatment at optimal coverage could avert 28% of the burden, at AUS$16 000 per YLD gained. Sixty per cent of the burden of mental disorders was deemed to be unavertable.
Conclusions The efficiency of treatment varied more than tenfold across disorders. Although coverage of some of the more efficient treatments should be extended, other factors justify continued use of less-efficient treatments for some disorders.
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INTRODUCTION |
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METHOD |
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Estimating the prevalence and burden of mental disorders
Data on the 1-year ICD10 (World
Health Organization, 1992) prevalences of anxiety, affective and
alcohol use disorders as a principal complaint were obtained from the
Australian National Survey of Mental Health and Well-being (Andrews et
al, 2001,
2002), and data on the
prevalence of schizophrenia were obtained from a survey of low-prevalence
disorders (Jablensky et al,
2000). A 1-year time horizon (19971998) was used to
estimate the total burden, the burden averted with current and optimal
interventions and the costs. The burden of a disease can be estimated in
disability-adjusted life-years (DALYs) lost but because mortality data were
rarely attributed to the underlying mental disorders, and treatment
intervention studies never used death as an outcome, we present data in terms
of years lived with disability (YLDs). The YLDs account for 95% of the total
DALYs lost owing to mental disorders
(Mathers et al, 1999) and were calculated as the prevalence of the only or principal complaint
weighted by the disability weighting associated with that disorder. The
disability weighting is a health state preference value that reflects the
relative severity of a condition on a 01 continuum between perfect
health and death (Murray & Lopez,
1996). The YLDs were adjusted for time spent symptomatic using the
ratio between current and 12-month cases.
The true burden of a disorder, defined as the burden in the absence of treatment, is calculated from the burden observed in the population under study plus the burden presently averted by the current population coverage and mix of interventions. We identified the YLDs averted by the current mix of services from the prevalent cases (i.e. active in the past year) deemed to have received an effective treatment in that time, calculating their change in disability weighting from the effect sizes associated with the type of treatment they had received (Andrews et al, 2000; Sanderson et al, 2004). To enable us to do this, Sanderson et al had general practitioners provide health state preference values for vignettes of people with each mental disorder, with levels of severity set one standard deviation apart. This enabled a linear transfer factor to be computed for each disorder in order to convert the improvement due to treatment measured in standard deviation units (effect sizes) to the improvement measured in disability weighting change units. The YLDs averted by current treatment were added to the observed burden in order to give the burden that would exist in the absence of treatment. This provides the baseline from which the proportion of burden averted can be calculated.
Describing and costing current treatment for mental disorders
The respondents to the survey listed the services used and the treatments
received for a mental problem during the previous 12 months.
Coverage means the proportion of people reporting a consultation
for a mental disorder. When people met the criteria for two or more disorders,
they were asked to identify which set of symptoms troubled them the most
(Andrews et al, 2002). Costs and benefits were attributed to the principal complaint. Effective
treatment means that they saw the same type of clinician two or more times and
received medication or an efficacious psychological intervention such as
cognitivebehavioural therapy. Unit costs for direct health care
provided by the public or private sector were obtained from published sources,
converted to 1997 Australian dollars (AUS$). The cost of services and
treatments used was calculated for each person and attributed to a
persons only or principal complaint. The average 12-month cost of
treatment per case for each disorder was calculated and, when divided by the
number of YLDs averted, gave a cost-effectiveness ratio in dollars per YLD
averted for each disorder. The YLDs averted by current treatment were
estimated as described above.
Describing and costing optimal treatment for mental disorders
Next we calculated the proportion of burden that could be averted with
evidence-based medicine. We used a number of sources listed in the relevant
papers, but relied heavily on the Schizophrenia Patient Outcomes Research Team
(PORT) study recommendations to define optimal treatment for schizophrenia
(Lehman & Steinwachs,
1998); the clinical practice guidelines from the Royal Australian
and New Zealand College of Psychiatrists
(Andrews et al,
2003b; Ellis et
al, 2003), the Clinical Research Unit for Anxiety and
Depression (Andrews et al,
2003c) and the International Society for Traumatic Stress
Studies (Foa et al,
2000) to define optimal treatment for the anxiety and affective
disorders; and reviews by Moyer et al
(2002), Nathan & Gorman
(2002) and Proudfoot &
Teesson (2002) to define
optimal treatment in alcohol use disorders. Optimal treatment scenarios were
modelled for varying levels of severity for each mental disorder, the levels
based on epidemiological data as described in the relevant papers.
For the current analysis we modelled three optimal treatment scenarios for each disorder.
Sensitivity analyses
A sensitivity analysis conducted with @RISK version 4 software (Newfield,
NY: Palisade Corporation) for Microsoft Excel provided confidence intervals
around the YLDs averted, the total cost of treatment and the cost per YLD
averted for each disorder and disorder group at current coverage. Multivariate
stepwise linear regressions were conducted for each disorder to identify the
important contributors to variance around the cost-effectiveness ratios, and
univariate analyses assessed the impact of changing various
investigator-modelled parameters on the cost-effectiveness estimates.
Confidence intervals around the cost-effectiveness or efficiency estimates for
current and optimal treatment are presented in Tables
2 and
3. The results of univariate
modelling and regression analyses are reported in the disorder-specific
papers.
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RESULTS |
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The current mix of coverage and interventions was estimated to reach two-fifths of cases, although only one-fifth received a potentially effective treatment. The remaining cases were presumed to generate a treatment cost but no benefit. This mix of interventions was estimated to avert some 61 000 YLDs, which is one-eighth of the YLDs attributed to these mental disorders. About one-fifth of the burden of bipolar disorder was deemed to be averted by effective treatment, whereas only one-fiftieth of the burden of alcohol use disorders was averted, in part owing to the very low rate of effective coverage. The total cost of current interventions was AUS$1800 million, with the cost per case of schizophrenia being ten times the average.
In Table 3 we present data for optimal treatment, that is, patients are expected to receive optimal or evidence-based treatment, now defined and costed on the basis of established guidelines. Coverage and severity are held at the same level as in Table 2. Effective coverage is deemed to reach two-fifths of people with mental disorders and the replacement of ineffective with effective treatment results in an extra 30 000 YLDs being averted, so one-fifth of the YLDs attributed to these mental disorders could be averted. One-third of the burden of bipolar disorder was deemed to be averted by effective treatment, whereas only one-twentieth of the burden of alcohol use disorders was averted, again in part owing to the very low rate of effective coverage.
The total cost of an optimal treatment that included more therapies was AUS$1600 million, which is close to the cost of current treatment, principally because of a reduction in in-patient stays recommended by the clinical practice guidelines. Treatment of schizophrenia was still ten times the average cost per case. The average cost-effectiveness was AUS$18 000 per YLD gained. On average, the cost of providing evidence-based medicine to the people currently seeking treatment is within the present budget.
In Table 4 we present data for optimal treatment, but now coverage is increased to practical levels as defined in the method, and severity is assumed to reflect that among those in treatment as well as those who are not currently in contact with services. Coverage overall is now two-thirds, and in this situation 28% of the burden could be averted at a cost-effectiveness ratio of AUS$16 000 per YLD averted. The total cost rises by some AUS$300 million over the current level of expenditure on these disorders.
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In Table 5 we present data that presume the impossible situation of perfect coverage and complete evidence-based medicine, simply to show the proportion of mental disorder burden that could be averted and, as a corollary, the proportion that is unavertable given current knowledge. On average only two-fifths of the burden appears to be avertable within the limits of current best practices in mental health. The most optimistic finding is that two-thirds of the burden of generalised anxiety disorder is theoretically avertable; the most pessimistic finding is that only one-fifth of the burden of schizophrenia is avertable. Three-fifths of the burden of mental disorders therefore remains unavertable, which is a sobering fact about the limitations of current knowledge in psychiatry but one that is consistent with clinical practice.
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DISCUSSION |
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The present findings suggest that even if everyone was treated in the best possible fashion, about 60% of the burden of mental disorders appears to be unavertable in the light of current knowledge. Throughout all calculations about current, optimal or targeted optimal (Tables 2, 3, 4), the treatment of schizophrenia costs significantly more than the treatment of the other disorders. It is difficult to express the cost-effectiveness in other currencies simply because the unit costs are based on prices paid for services in Australia in 1997 and the prices in other countries can be markedly different. The strength of the present set of calculations is the ability to compare the cost of current and optimal treatment across the ten disorders, a relationship that may well apply in other countries. The cost of one unit of health gain in schizophrenia seems likely to be an order of magnitude greater than the cost of one unit of health gain in anxiety or depressive disorders, whatever the currency involved.
The limitations of this series of studies are many. Although the surveys from which the data are derived are good, it must be remembered that the data are based on self-reported symptoms to establish diagnosis and self-reported treatments to establish costs. The threshold for the proportion of people currently receiving evidence-based medicine in Table 2 is optimistic (two visits from the same professional and the receipt of medication or cognitivebehavioural therapy) and a stricter definition would have resulted in less efficiency and less burden averted. Nevertheless, few patients reported the minimum of two visits, with seven visits to a general practitioner being the mean and additional visits of the same frequency being reported to psychiatrists or psychologists. Optimal treatment, as costed in Tables 3, 4, 5, incorporated the recommendations of clinical practice guidelines and their operationalisation by the investigators, both of which may be imperfect. Adherence, calculated from the results of intention-to-treat analyses in randomised controlled trials, even compensated by our inclusion of treatment-resistant groups, may overestimate the real situation. The present data are therefore optimistic, but to correct for these biases would require data that do not exist.
A number of other diagnoses were identified in the surveys. Data on obsessivecompulsive disorder, drug use disorders and neurasthenia were not included because of the small numbers of people identifying these disorders as their principal complaint. Data on personality disorders were not included because of the lack of evidence-based guidelines for treatment. Nevertheless, the four disorder groups studied represent 80% of the identified costs of treatment for mental disorders. This study has a 1-year time horizon and there is evidence that a longer time horizon might have shown a greater proportion of burden able to be averted. But because the data for all disorders were only available for the 1-year period, and the evidence about burden averted in the longer term is only available for depression, this is a necessary limitation. The method to estimate YLDs averted from effect sizes is new, and although the magnitude of change is consistent with the few studies in mental health that have measured changes in symptoms and health state preference values (e.g. Hatziandreu et al, 1994; Lonnqvist et al, 1994), the method would benefit from replication. The confidence intervals are wide, reflecting uncertainty in some parts of the analysis, but even so the confidence intervals around some interventions, especially those for schizophrenia, indicate that differences in efficiency between some disorders are real.
The strength of the study is that it is based on two population surveys that have the capacity to provide a view of health service efficiency in Australia around 1997. Assumptions allow the cost and effectiveness of evidence-based medicine to be examined. Importantly, the method will allow replication in other data-sets as well as comparison with the cost-effectiveness of current and optimal treatment for a number of physical disorders. Current work is under way to compare these results with three physical disorders chosen to resemble mental disorders in prevalence, burden and natural history.
The results in Tables 2, 3, 4, 5 are displayed according to the burden presently averted, the burden averted by improvement in intervention and coverage and the burden unavertable in the light of existing knowledge. We would like to review these results, commenting on each of the disorders in turn.
It would be simple to look at these results and argue for a health system that would return the greatest health gain for the least money. Certainly we would recommend that the coverage of anxiety and depressive disorders be increased, given that treatment is so cost-effective. Given the affordability of evidence-based treatment we would recommend that clinicians be encouraged to practise evidence-based medicine, even if the budgetary and organisational requirements of implementation are considerable. However, setting priorities for service delivery is about equity, need and societal demand, as well as about efficiency (Calman, 1994; Callahan, 1995). Although there is extensive consideration of the tension between these elements in the literature, there is little consensus as to how they should be operationalised or whether such priority setting should be implicit or explicit (Musgrove, 1999; Rosenheck, 1999; Jack, 2000). Moreover, the existence of a hierarchical relationship among the grounds thought to justify public expenditure is also widely debated (Maynard, 1999; Musgrove, 1999; Rosenheck, 1999). A detailed analysis of these questions is warranted, but is best reserved until the present results have been discussed and the benefits and gains of each element in the treatment process carefully assessed (see Goldberg, 2003; Warner, 2003; Haby et al, 2004). In the meantime, the high cost of schizophrenia (AUS$200 000 per YLD) is a signal that cannot be ignored. We need to invest serious money into research on the mechanism behind this disease, exactly as we are doing for Alzheimers disease, and did for HIV/AIDS. Further, given that 60% of the burden of mental disorders appears to be unavertable with current knowledge, it would be reasonable to conclude that further research into both the prevention and the mechanisms of these diseases is required.
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Clinical Implications and Limitations |
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LIMITATIONS
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ACKNOWLEDGMENTS |
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REFERENCES |
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Andrews, G., Hall, W., Goldstein, G., et al (1985) The economic costs of schizophrenia. Archives of General Psychiatry, 42, 537 -543.[Abstract]
Andrews, G, Sanderson, K., Corry, J., et al (2000) Using epidemiological data to model efficiency in reducing the burden of depression. Journal of Mental Health Policy and Economics, 3, 175 -186.[CrossRef][Medline]
Andrews, G., Henderson, S. & Hall, W.
(2001) Prevalence, comorbidity, disability and service
utilisation. Overview of the Australian Mental Health Survey.
British Journal of Psychiatry,
178, 145
-153.
Andrews, G., Slade, T. & Issakidis, C.
(2002) Deconstructing current comorbidity: data from the
Australian National Survey of Mental Health and Well-Being. British
Journal of Psychiatry, 181, 306
-314.
Andrews, G., Sanderson, K., Corry, J., et al
(2003a) Cost-effectiveness of current and optimal
treatment for schizophrenia. British Journal of
Psychiatry, 183, 427
-435.
Andrews, G., Oakley-Browne, M., Castle, D., et al (2003b) Summary of guidelines for the treatment of panic disorder and agoraphobia. Australasian Psychiatry, 11, 29 -33.[CrossRef][Medline]
Andrews, G., Craemer, M., Crino, R., et al (2003c) The Treatment of Anxiety Disorders: Clinicians Guide and Patient Manuals (2nd edn). Cambridge: Cambridge University Press.
Callahan, D. (1995) Setting mental health priorities. In What Price Mental Health? (eds P. J. Boyle & D. Callahan), pp. 175-192. Washington, DC: Georgetown University Press.
Calman, K. C. (1994) The ethics of allocation of scarce health resources. Journal of Medical Ethics, 20, 71-74.[Abstract]
Corry, J., Sanderson, K., Issakidis, C., et al (2004) Evidence-based care for alcohol use disorders is affordable. Journal of Studies on Alcohol, in press.
Ellis, P. M., Hickie, I. H. & Smith, D. A. R. (2003) Summary of guidelines for the treatment of depression. Australasian Psychiatry, 11, 34-38.[CrossRef][Medline]
Foa, E. B., Keane, T. M. & Friedman, M. J. (2000) Effective Treatments for PTSD: Practice Guidelines from the International Society for Traumatic Stress Studies. New York: The Guilford Press.
Gold, M. R., Siegel, J. E., Russell, L. B., et al (1996) Cost-effectiveness in Health and Medicine. New York: Oxford University Press.
Goldberg, D. (2003) Invited commentary on:
Cost-effectiveness of current and optimal treatment for schizophrenia.
British Journal of Psychiatry,
183, 436.
Haby, M., Carter, R., Mihalopolous, C., et al (2004) Assessing cost effectiveness in mental health. Australian and New Zealand Journal of Psychiatry, in press.
Hatziandreu, E. J., Brown, R. E., Revicki, D. A., et al (1994) Cost utility of maintenance treatment of recurrent depression with sertraline versus episodic treatment with dothiepin. PharmacoEconomics, 5, 249 -268.[Medline]
Issakidis, C., Sanderson, K., Corry, J., et al (2004) Modelling the population cost-effectiveness of current and evidence based optimal treatment for anxiety disorders. Psychological Medicine, 34, 1-17.[CrossRef][Medline]
Jablensky, A., McGrath, J., Herrman, H., et al (2000) Psychotic disorders in urban areas: an overview of the study of low prevalence disorders. Australian and New Zealand Journal of Psychiatry, 34, 221 -236.[CrossRef][Medline]
Jack, W. (2000) Public spending on health care: how are different criteria related? A second opinion. Health Policy, 53, 61 -67.[CrossRef][Medline]
Kessler, R. C. (1999) The World Health Organization International Consortium in Psychiatric Epidemiology. Acta Psychiatrica Scandinavica, 99, 2-9.[Medline]
Lehman, A. F. & Steinwachs, D. M. (1998) Translating research into practice: the Schizophrenia Patient Outcomes Research Team (PORT) treatment recommendations. Schizophrenia Bulletin, 24, 1 -10.[Medline]
Lonnqvist, J., Sintonen, H., Syvalahti, E., et al (1994) Antidepressant efficacy and quality of life in depression: a double blind study with moclobemide and fluoxetine. Acta Psychiatrica Scandinavica, 89, 363 -369.[Medline]
Manderscheid, R.W., Rae, D. S., Narrow, W. E., et al (1993) Congruence of service utilisation estimates from the Epidemiologic Catchment Area Project and other sources. Archives of General Psychiatry, 50, 108 -114.[Abstract]
Mathers, C., Vos, T. & Stevenson, C. (1999) The Burden of Disease and Injury in Australia. AIHW cat. No. PHE17. Canberra: AIHW.
Maynard, A. (1999) Rationing health care: an exploration. Health Policy, 49, 5-11.[CrossRef][Medline]
Moyer, A., Finney, J. W., Swearingen, C. E., et al (2002) Brief interventions for alcohol problems. Addiction, 97, 279 -292.[CrossRef][Medline]
Murray, C. J. & Lopez, A. D. (1996) The Global Burden of Disease: a Comprehensive Assessment of Mortality and Disability from Disease, Injuries and Risk Factors in 1990 and Projected to 2020. Cambridge, MA: Harvard University Press.
Musgrove, P. (1999) Public spending on health care: how are different criteria related? Health Policy, 47, 207 -223.[CrossRef][Medline]
Nathan, P. E. & Gorman, J. N. (2002) A Guide to Treatments that Work. New York: Oxford University Press.
Ormel, J., Von Korff, M., Van den Brink, W., et al (1993) Depression, anxiety and social disability show synchrony of change in primary care patients. American Journal of Public Health, 83, 385 -390.[Abstract]
Proudfoot, H. & Teesson, M. (2002) Who seeks treatment for alcohol dependence? Social Psychiatry and Psychiatric Epidemiology, 37, 451 -456.[CrossRef][Medline]
Rosenheck, R. A. (1999) Principles for priority
setting in mental health services and their implications for the least well
off. Psychiatric Services,
50, 653
-658.
Sanderson, K., Andrews, G., Corry, J., et al (2003) Reducing the burden of affective disorders: is evidence based health care affordable? Journal of Affective Disorders, 77, 109 -125.[CrossRef][Medline]
Sanderson, K., Andrews, G., Corry, J., et al (2004) Using the effect size to model changes in preference values form descriptive health status. Quality of Life Research, in press.
Warner, R. (2003) How much of the burden of
schizophrenia is alleviated by treatment? British Journal of
Psychiatry, 183, 375
-376.
World Health Organization (1992) The ICD10 Classification of Mental and Behavioural Disorders. Geneva: WHO.
Received for publication August 26, 2003. Revision received January 7, 2004. Accepted for publication January 30, 2004.
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