This annex outlines the data sources underpinning the project’s analysis of the independence of SAIs. As illustrated in Figure A A.1, four main data sources were designed to ensure comprehensive coverage across three key variables: the relevant INTOSAI regional group to which each SAI belongs (see Annex C); the institutional model of the SAI (see Annex B); and the stakeholder category of each interviewee, including SAIs, the executive, legislature, judiciary, media, academia, donors, other oversight institutions, and civil society organisations. In total, data were gathered from 95 countries, spanning all INTOSAI regions and SAI models. This breadth of coverage enabled the project to reflect a wide range of institutional contexts and governance dynamics, thereby strengthening its capacity to identify patterns and variations in the de facto independence of SAIs worldwide.
Strengthening the Independence of Supreme Audit Institutions
Source: OECD-IDI elaboration.
Source: OECD-IDI elaboration.
Source: Based on data collection.
Country visits were central to the project’s methodology, designed to uncover non-documented institutional practices and power dynamics that influence SAI independence. These visits employed semi-structured interviews, both group and individual, guided by open-ended questions. This approach encouraged reflection and allowed consulted stakeholders to share insights in their own terms, fostering the collection of rich testimonial evidence.
The countries were selected with the aim of covering different regions and models in order to be able to capture different nuances of informal factors and be able to suggest potential patterns across countries.
The country visits encompassed 91 interviews across countries from all INTOSAI regions. These interviews engaged a diverse array of actors, including SAI officials, government representatives, parliamentarians, civil society members, academia, media and donors.
Source: Based on fact-finding missions that took place.
In addition to country-specific insights, the project conducted regional workshops to capture broader patterns and validate preliminary findings. Four regional workshops took place: CREFIAF (Djibouti, April 2025), ARABOSAI (Jordan, May 2025), PASAI (New Caledonia, August 2025), and ASOSAI (Philippines, September 2025) involving participation from 30 SAIs. These events combined expert presentations, small group discussions, and participant interviews to solicit regional interpretations of independence challenges and informal influences. By facilitating peer-to-peer exchanges, these workshops helped identify common experiences and region-specific nuances, contributing to a more layered and comparative understanding of informal factors.
A structured questionnaire was designed to gather insights from SAIs themselves. 50 SAIs (both OECD and non-OECD) from all regions responded to the questionnaire. The questionnaires from non-OECD SAIs were developed by the US Government Accountability Office and deployed through their survey platform, the instrument explored four key areas: (1) legal protections and constraints from different branches of government; (2) perceived interferences; (3) positive enabling factors for independence; and (4) areas requiring improvement. The questionnaires to OECD SAIs were deployed by the OECD through Lime Survey. While capturing information on formal frameworks, the questionnaires also included perceptual data, allowing SAIs to report on informal constraints and enabling conditions.
To complement SAI perspectives, the project launched stakeholder surveys targeting external actors with insight into SAI operations. This included the OECD Parliamentary Network, the OECD Internal Auditor Network, and CSOs. For CSO engagement, IDI partnered with the World Justice Project (WJP), leveraging its global network to distribute the survey. The WJP database yielded 1 700 responses from 80 countries, covering all INTOSAI regions.
Respondents from the WJP network, legal experts in their respective countries who do not belong to the public sector, express strong concerns about SAI independence. 90% agree or strongly agree that the political context, driven by informal factors, influences the level of independence of the SAI. Additionally, 30% agree or strongly agree that the judiciary poses threats to SAI independence, with Latin America showing the highest share at 52%.