RESUMEN
The under-performance of supply chains presents a significant hindrance to disease control in developing countries. Stock-outs of essential medicines lead to treatment interruption which can force changes in patient drug regimens, drive drug resistance and increase mortality. This study is one of few to quantitatively evaluate the effectiveness of supply chain policies in reducing shortages and costs. This study develops a systems dynamics simulation model of the downstream supply chain for amikacin, a second-line tuberculosis drug using 10 years of South African data. We evaluate current supply chain performance in terms of reliability, responsiveness and agility, following the widely-used Supply Chain Operation Reference framework. We simulate 141 scenarios that represent different combinations of supplier characteristics, inventory management strategies and demand forecasting methods to identify the Pareto optimal set of management policies that jointly minimize the number of shortages and total cost. Despite long supplier lead times and unpredictable demand, the amikacin supply chain is 98% reliable and agile enough to accommodate a 20% increase in demand without a shortage. However, this is accomplished by overstocking amikacin by 167%, which incurs high holding costs. The responsiveness of suppliers is low: only 57% of orders are delivered to the central provincial drug depot within one month. We identify three Pareto optimal safety stock management policies. Short supplier lead time can produce Pareto optimal outcomes even in the absence of other optimal policies. This study produces concrete, actionable guidelines to cost-effectively reduce stock-outs by implementing optimal supply chain policies. Preferentially selecting drug suppliers with short lead times accommodates unexpected changes in demand. Optimal supply chain management should be an essential component of national policy to reduce the mortality rate.
Asunto(s)
Amicacina/provisión & distribución , Antibacterianos/provisión & distribución , Medicamentos Esenciales/provisión & distribución , Tuberculosis/tratamiento farmacológico , Humanos , Asignación de Recursos , Sudáfrica , Análisis de SistemasRESUMEN
SETTING: In South Africa, tuberculosis (TB) has been the leading cause of death for over a decade. The TB incidence rate is the second highest in the world, and continues to rise. OBJECTIVE: To examine gender patterns in South Africa's TB epidemic. This is one of the first studies to use National Health Laboratory Service (NHLS) data to evaluate the epidemic at the national level. DESIGN: Observational study using NHLS retrospective data for every TB test performed in public health facilities between 2009 and 2011. RESULTS: Despite an increase in the number of TB tests performed, the number of TB cases remained relatively constant. Although prevalence rates differ between health districts, we find a similar female-to-male ratio (0.70) in each district. The age profile for TB resembles that of human immunodeficiency virus (HIV), with peak TB prevalence in women occurring 7 years earlier than in men. The female-to-male ratio of TB cases and 3+ positive (severe) cases decreases rapidly between ages 25 and 35 years. CONCLUSION: These age and gender patterns are driven by the HIV epidemic and risks associated with pregnancy and childbearing. Increasing the quality and quantity of active TB case finding at existing points of care would be a sustainable and cost-effective intervention for both treatment and prevention.