摘要：Summary Background Four initiatives have estimated the value of aid for reproductive, maternal, newborn, and child health (RMNCH): Countdown to 2015, the Institute for Health Metrics and Evaluation (IHME), the Muskoka Initiative, and the Organisation for Economic Co-operation and Development (OECD) policy marker. We aimed to compare the estimates, trends, and methodologies of these initiatives and make recommendations for future aid tracking. Methods We compared estimates of aid for RMNCH from the four initiatives for all years available at the time of our analysis (1990–2016). We used publicly available datasets for IHME and Countdown. We produced estimates for Muskoka and the OECD policy marker using data in the OECD Creditor Reporting System. We sought to explain differences in estimates by critically comparing the methods used by each approach to identify and analyse aid, and quantifying the effects of these choices on estimates. Findings All four approaches indicated substantial increases over time in global aid for RMNCH, but estimates of aid amounts and year-on-year trends differed substantially, especially for individual donors and recipient countries. Muskoka (US$ 13·0 billion in 2013, constant 2015 US$) and Countdown's RMNCH estimates ($13·1 billion in 2013) tended to be the highest and most similar, although they often indicated different year-on-year trends. IHME produced lower estimates ($10·8 billion in 2013), which often indicated different trends from the other approaches. The OECD policy marker produced by far the lowest estimates ($2·0 billion in 2013) because half of bilateral donors did not report on it consistently and those who did tended to apply it narrowly. Estimates differed across approaches primarily because of differences in methods for distinguishing aid for RMNCH from aid for other purposes; adjustments for inflation, exchange rates, and under-reporting; whether donors were credited for their support to multilateral institutions; and the handling of aid to unspecified recipients. Interpretation The four approaches are likely to lead to different conclusions about whether individual donors and recipient countries have fulfilled their obligations and commitments and whether aid was sufficient, targeted to countries with greater need, or effective. We recommend that efforts to track aid for the Sustainable Development Goals reflect their multisectoral and interconnected nature and make analytical choices that are appropriate to their objectives, recognising the trade-offs between simplicity, timeliness, precision, accuracy, efficiency, flexibility, replicability, and the incentives that different metrics create for donors. Funding Subgrant OPP1058954 from the US Fund for UNICEF under their Countdown to 2015 for Maternal, Newborn and Child Survival Grant from the Bill & Melinda Gates Foundation.
