Quality Assurance (QA) methods in developing countries at various health system levels, from national to community. The series focuses on QA applications in child survival, maternal and reproductive health, and infectious diseases. Each case study focuses on a major QA activity area, such as quality design, quality improvement, the development and communication of standards, cost and quality, or quality assessment. In some cases, more than one QA activity is presented. Analyzing cost and quality seeks to shed light on the costs and cost savings that are associated with implementing quality improvement and other quality assurance interventions. Cost and quality analyses are used to examine the cost-effectiveness of alternative quality improvement interventions, quantify the costs of quality failures and inefficiency, project cost savings that may be derived from improving healthcare quality, and/or estimate the costs of either individual interventions or comprehensive quality assurance programs. This case study illustrates how an analysis of cost effectiveness and marginal costs and benefits demonstrated the desirability and affordability of investing in reinforcement interventions to enhance providers' skills following training. (author's)