Abstract
Forty years ago, the 134 national government members of the WHO signed the Alma Ata Declaration. The Declaration made Primary Health Care (PHC) the official health policy of all members countries. Emerging from the conference was the consensus that health was a human right based on the principles of equity and community participation. Alma Ata broadened the perception of health beyond doctors and hospitals to social determinants and social justice. In the following years implementing this policy confronted many challenges. These included: (1) whether PHC should focus on vertical disease programmes where interventions had the most possibility of success or on comprehensive programmes that addressed social, economic and political factors that influenced health improvements; (2) whether primary care and PHC are interchangeable approaches to health improvements; (3) how equity and community participation for health improvements would be institutionalised; and (4) how financing for PHC would be possible. Experiences in implementation over the last 40 years provide evidence of how these challenges have been met and what succeeded and what had failed. Lessons from these experiences include the need to understand PHC as a process rather than a blueprint, to understand the process must consider context, culture, politics, economics and social concerns, and therefore, to recognise the process is complex. PHC needs to be examined within evaluation frameworks that address complexity. Recent developments in monitoring and evaluation have begun to respond to this need. They include realist evaluation and implementation research.