Background: Although IR may be conducted in only a limited geographical area or health facility for reasons of operational feasibility, human resources and funding, the implications of the IR might apply to a wider section of a given health system. The WHO has recommended use of a health systems 'building block' framework for comprehensively examining how interventions can operate more successfully and effectively in complex, real-world settings. This approach analyses the six WHO health systems building blocks, which define the essential components of a health system. This approach was used in the analysis of the barriers and motivators of voluntary medical male circumcision (VMMC) in 14 priority countries that were tasked with scaling-up VMMC services to 80% of HIV-negative men aged 15–49 years by 2016. Although the programme started in 2008, by July 2014 only two countries had achieved over 50% of the target, while the rest had <30%. This review used the WHO health systems building block framework to examine the factors influencing the scale-up of the VMMC programmes from 2008–2013 in 14 priority countries. The influence of each respective health system building block is summarized below.

(i) Leadership and governance: The success of the intervention was facilitated by sustained country ownership and political will. However continued commitment and engagement of the stakeholders is also key.

(ii) Health workforce: The activities of the proposed intervention should not compromise the already overstretched work force and the overall quality of health services provided. Thus, any innovations should ensure efficiencies to minimize human resource constraints. In VMMC, task shifting and task sharing appeared to facilitate scale up. Appropriate training of non-physician health workers was essential.

(iii) Health service delivery: Expanding access and improving demand for VMMC are essential to service utilization. Mobile or outreach services to expand access to VMMC were successful in countries such as Kenya. However, experience from Zimbabwe revealed understanding the barriers and motivating factors related to the uptake of VMMC was necessary to determine service demand.

(iv) Medical products, vaccines, and technologies: Availability of commodities and supplies in good quantities, on time and of acceptable quality is critical for the success of an intervention. Successful VMMC implementation requires coordinated partnerships that are effective and efficient in meeting commodity requirements. However, 10 of the 14 countries reported challenges related to inadequate supplies and delayed procurement. In addition, in most cases, VMMC waste management activities were not costed.

(v) Health system financing: In the scale-up of VMMC, availability of external funding was a major facilitator. However, reliance on donor funding for scale up proved to be a barrier in countries where achievements of VMMC targets had been low. To close such funding gaps, several countries are currently generating and directing national funds specifically to HIV programmes, including VMMC activities.

(vi) Health information: Quality information is needed to guide evidenced-based decisions on how to allocate limited resources for HIV prevention, including the VMMC programmes. Standardized sets of indicators agreed upon by technical and funding agencies was one factor that strengthened the monitoring and the evaluation of VMMC services. However, since ensuring that the data collected through the national health information systems are of sufficient quality for meaningful interpretation is a challenge, the VMMC monitoring systems in most of the countries are parallel to national health information systems.

Conclusion: Use of WHO health system building blocks to analyze implementation bottlenecks can explicitly identify barriers and facilitators to integrating IR into the health system.

Lessons: Understanding of contextual barriers and facilitators of demand for a given intervention are essential in enhancing integration and sustainability of IR into the health system.