To address inequitable access to health services of indigenous communities in the Bolivian highlands, the Bolivian Ministry of Health, with the support of Save the Children-Saving Newborn Lives, conducted operational research to identify, implement and test a package of maternal and newborn interventions using locally recruited, volunteer Community Health Workers (vCHW) between 2008 and 2010. The additional annual economic and financial costs of the intervention were estimated from the perspective of the Bolivian Ministry of Health in two municipalities. The cost of intervention-stimulated increases in facility attendance was estimated with national surveillance data using a pre-post comparison, adjusted for secular trends in facility attendance. Three scale-up scenarios were modelled by varying the levels of coverage and the number (per mother and child pair) and frequency of home visits. Average cost per mother and average cost per home visit are presented in constant 2015 US$. Eighteen per cent of expectant mothers in the catchment area were visited at least once. The annualized additional financial cost of the community-based intervention across both municipalities was $43 449 of which 3% ($1324) was intervention design, 20% ($8474) set-up and 77% ($33 651) implementation. Drivers of additional costs were additional paid staff (68%), 81% of which was for management and support by local implementing partner and 19% of which was for vCHW supervision. The annual financial cost per vCHW was $595. Modelled scale-up scenarios highlight potential efficiency gains. Recognizing local imperatives to reduce inequalities by targeting underserved populations, the observed low coverage by vCHWs resulted in a high cost per mother and child pair ($296). This evaluation raises important questions about this model's ability to achieve its ultimate goals of reducing neonatal mortality and inequalities through behaviour change and increased care seeking and has served to inform innovative alternative models, better equipped to tackle stagnant inequitable access to care.
