BackgroundThe Australian Orthotic Prosthetic Association (AOPA) regulates the profession of orthotist/prosthetists in Australia through the establishment, maintenance and application of professional standards, such as competency standards. While portfolios are commonly used to assess professional competency, little research has investigated how reliable these assessments are, or how reliability can be improved.AimTo evaluate how reliable AOPA's competency portfolio assessment is and examine causes of variation to improve reliability.MethodOverseas trained practitioners wishing to have their qualifications and experience recognised by AOPA submitted a portfolio for assessment. Portfolios were randomly assigned to two independent assessors who determined whether the applicant's portfolio demonstrates competency against each of the 68 AOPA Competency Standards (2014) and recorded their determination as “satisfied” or “not satisfied”. An administrator collated the independent evaluations and identified any points of disagreement for discussion at a consensus meeting. To quantify interassessor reliability, the Kappa statistic was used for each of the 68 competency standards. To better understand the reasons for disagreement, semi-structured interviews were conducted with each assessor.ResultsResults from this study show high rates of agreement between assessors upon independent assessment. Points of disagreement were commonly resolved during the consensus meeting between assessors, disagreement was rare. The standards which experienced the highest rates of disagreement were identified.Discussion and ConclusionEvidence based standards should be supported by evidence-based processes. Competency assessment via a portfolio of evidence can be conducted and assessed by two assessors with high levels of agreement. Factors that may increase the reliability of the assessment include; appropriate assessor training, the presence of a consensus meeting and clear standards. There are opportunities to further improve the clarity of standards identified as having the lowest level of agreement.