Non-communicable diseases account for a growing burden on the health systems of developing countries. The effective management of these diseases typically requires a collaborative effort across the health workforce as well as continuing care for months or even years. In resource-poor areas, a "task-shifting" strategy can be beneficial, in which community or lay health workers (with oversight from primary-health-care practitioners and specialists) provide "front-line" care, instead of physicians and trained nurses. (1) There is growing evidence of the effectiveness of such task-shifting in the management of some chronic conditions, including infection with the human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS), (2,3) diabetes (4) and some mental disorders. (5-9) Although the strategy appears particularly attractive in the many low-income countries with inadequate numbers of physicians and trained nurses, there is considerable institutional resistance to the widespread implementation of the strategy and also concern that the quality of care will deteriorate. (10) There is a clear need for more studies comparing the health outcomes of patients attended by lay health workers with those of patients attended by physicians and trained nurses. There is also a need for more studies in which the cost-effectiveness of the task-shifting strategy is evaluated. (10)
Depression and anxiety, two of the most prevalent non-communicable disorders, are often encountered in primary-care settings. (11) Depression is predicted to become the leading cause of disability-adjusted life years by the year 2030. (12) Depressive and anxiety disorders are classified separately in the tenth revision of the International statistical classification of diseases and related health problems (ICD-10). (13) In public-health interventions, however, they are often grouped together as "common mental disorders" because they show a high degree of comorbidity, have similar epidemiological profiles and respond to similar treatments. (11, 14-16)
In several studies, collaborative stepped care led by lay health workers has been found to be successful in the primary care of depression and/or anxiety in low- or middle-income countries. (17-19) This approach encourages the most effective sharing of tasks between medical, specialist and non-medical staff. There are various "steps" or levels of treatment, with the most intensive treatments reserved for the most severe cases. Used together, the collaborative-care and stepped-care components of this strategy can maximize the efficient use of scarce resources, especially in those public health facilities where case management has previously been relatively poor. (20) In the MANAS trial, the effectiveness of this approach in the primary care of patients with depression and/or anxiety was investigated in Goa, India. The design, implementation and general effectiveness of this cluster-randomized controlled trial have been described in detail elsewhere. (18, 19, 21) Both public and private facilities were included in the trial because in India's private facilities, the quality and costs of care are both generally higher than in public facilities: For example, private facilities offer repeated consultations with the same physician and are primarily financed with out-of-pocket payments from the patients. In contrast, many patients attending a public facility may see a different physician on each visit but will not pay for any of the consultations.
The present study evaluates the cost-effectiveness and cost-utility of the MANAS trial. We hoped that the additional resources needed to train, pay and supervise the lay health workers used in the "task-shifting" approach to the primary care of common mental disorders would promote recovery and reduced disability in a more cost-effective manner than more conventional care. In any particular country, the CHOICE programme of the World Health Organization (WHO) deems an intervention to be highly cost-effective if it generates an extra year of healthy life for an amount no greater than the country's per capita gross domestic product. …