versión impresa ISSN 0185-3325
LARA-MUNOZ, María del Carmen et al. Cost effectiveness study of schizophrenia a management in Mexico. Salud Ment [online]. 2010, vol.33, n.3, pp. 211-218. ISSN 0185-3325.
Introduction Schizophrenia is a disorder that causes significant disability. In addition, its treatment is expensive because the increased prescription of atypical antipsychotics with associated high costs. In a recent 14-country study on disability associated with physical and mental conditions, active psychosis was ranked the third most disabling condition in general population, more than paraplegia and blindness. In the global burden of disease study, schizophrenia accounted for 1.1% of the total Disability-adjusted life years (DALYs) and 2.8% of Years of lived with disability (YLDs). The economic cost of schizophrenia for society is also high. The study of the burden of schizophrenia for society, whether expressed in epidemiological or costs terms, is an insufficient basis for setting priorities for resources allocation. Thus, increasingly sophisticated economic models have been developed. Such is the case of cost-effectiveness studies, which show the relationship between resources used (costs) and benefit achieved (effectiveness) of an intervention compared with others. In Mexico, there is only one study that evaluated the cost-effectiveness of different antipsychotics to treat schizophrenia, but it was a specific approach (not generalized), and did not include psychological interventions. The present study is part of a World Health Organization's initiative labeled WHO-CHOICE: CHOosing Interventions that are Cost-Effective. WHO-CHOICE methodology involves the evaluation of interventions based on a generalized measure: DALYs, which allows carrying out several and important comparisons. The main objective was to determine the cost-effectiveness of different interventions for the treatment of schizophrenia in Mexican communitarian settings. Method Schizophrenia was modeled as a serious chronic disorder with a high level of disability, excess mortality from natural and unnatural causes, and a low rate of remission. The incidence, prevalence, and the fatality rate were estimated based on the study of the Global Burden of Disease and a review of the epidemiological literature. As the first episode of schizophrenia is currently not preventable, the occurrence represents how the epidemiological situation would be without intervention. In relation to the referral and the fatality, we did not found evidence that these rates change by a specific effect of the treatment; thus, they were kept as constants for the scenarios with or without treatment. Community-level interventions assessed were: 1. typical traditional antipsychotics (haloperidol), 2. new atypical antipsychotics (risperidone), 3. traditional antipsychotics + psychosocial treatment (family therapy, social skills training and cognitive behavioral therapy), 4. new antipsychotics + psychosocial treatment, 5. traditional antipsychotics + psychosocial treatment + case management, and 6. new antipsychotics + psychosocial treatment + case management. The effectiveness of the treatments referred to the control of positive and negative symptoms and associated levels of disability. To calculate the improvement in disability compared with natural history (when the disease is not treated), the effect sizes reported in controlled clinical trials were converted to a weight change of disability. Efficacy and extrapyramidal effects of typical and atypical antipsychotics compared to placebo were estimated from the meta-analysis of controlled clinical trials, with the score of the BPRS severity scale and the need anti-Parkinson drugs as efficacy measures. From another meta-analysis we obtained an estimate of the magnitude of the effect by adding psychosocial interventions. As an ad hoc Cochrane systematic review that found case management did not had a significant impact on clinical or psychosocial outcomes, only a minimal addition effect size when added to the combination of pharmacologic-psychosocial treatment was observed. Costs included those of the patient, the program and the training required to implement the intervention. The provision of community-based services, daily administration of antipsychotics and anticholinergics, and laboratory tests were taken into account. For psychological interventions were envisaged from 6 to 12 sessions: in primary care from 6 to 12 visits, in outpatients services a visit per month for 20-50% of cases, and in day care communitarian attention from 1-2 times a week for 20-50% of cases. A 3% discount by the process of converting future values to present ones and an age adjustment giving less weight to year lived by young were included. Finally, the cost of DALYs averted for each intervention was estimated to determine their cost-effectiveness. Results The main findings of the study are, in relation to the costs of interventions: 1. the largest share corresponds to those generated by medication, 2. the current intervention is the cheapest, and 3. the combination of new atypical antipsychotics, psychological treatment and proactive case management is the most expensive intervention. Concerning the effectiveness of interventions, the one available today, with a coverage of 50%, prevents 68 222 DALYs. Increasing coverage to 80%, the number of DALYs averted is almost doubled with the use of typical antipsychotics. The effect of psychological interventions makes the number of DALYs averted three to four times higher. Finally, in regard to cost effectiveness, the combination of typical antipsychotics, psychosocial intervention and proactive case management was the treatment with the best relation. The cost per DALY averted was $390,892 Mexican pesos, which corresponds to one third of the cost of DALY averted in the current scenario ($1,313,120 Mexican pesos). Conclusions The resources for the attention of a public health issue involve a social investment rather than an expense budget, but they are also finite and must be chosen properly to be allocated. Cost-effectiveness studies of available interventions are an essential tool for making such important decisions. Our Mexican study of cost-effectiveness of interventions to treat schizophrenia in communitarian settings suggests, in general terms: 1. That while the current situation is the one with the lowest cost, it is the least efficient, 2. all alternatives involve an additional cost to the current situation because they assume an expansion of coverage; however, the extra cost in not excessive, and 3) that within a model of community-based care, the least expensive option is treatment with typical antipsychotics combined with psychological intervention. Thus, for a modest extra cost it is possible to yield a major impact on disability. Recently, the Mexican Federal Government has included schizophrenia in the catalog of diseases covered by the program called <<Seguro Popular>>, that provides a health insurance to general population, especially to the poorest and unemployed ones. The planned actions include four specialty consultations in an interval of two months and annual psychopharmacological treatment. Clearly the addition of haloperidol, trifluoperazine and risperidone to the list of available medications should be considered a success. However, schizophrenia also requires a proactive case monitoring of long-term for best control of symptoms and a successful rehabilitation. Moreover, consistent with our findings, case management has proven to be cost-effective when compared with routine care in the community. Among the limitations of the study it is important to note that it was based on modeled parameters obtained from the international literature. In this sense, the challenge is the data generation directly from studies in Mexico.
Palabras llave : Schizophrenia; treatment; cost-effectiveness.