Delphi-based validation and prioritisation of a national refractive error and optical service delivery model for Bhutan

Abstract

<title>Abstract</title> Aim The World Health Organisation Refractive Error Situation Analysis Tool (RESAT) was recently implemented in Bhutan. Building on the findings of this assessment, the present study aimed to develop and validate a context-specific, evidence-based refractive error and optical service delivery model for Bhutan through a structured expert consensus process. Methods A two-round, online Delphi technique was employed to refine a 37-component model derived from a nationwide application of the RESAT. A purposive panel of national experts in Bhutan, each with a minimum of three years’ experience in eye care delivery, health systems, policy development, or programme implementation, evaluated each component for relevance, feasibility, and expected impact using a 5-point Likert scale. Consensus was defined a priori as at least 70% of respondents rating a component as 4 or 5 in Round 2. Descriptive statistics including proportions, medians, and interquartile ranges, were used to assess levels of consensus and changes in ratings across rounds. Qualitative data from open-ended responses were subjected to thematic analysis to inform iterative refinement of the model. Results Forty-six experts participated in Round 1 (response rate = 83.6%), with 33 retained in Round 2 (retention rate = 71.7%), representing a broad range of professional cadres and geographic regions. The median participant age remained 41 years across both rounds, while median professional experience increased from 14 to 15 years. The draft model comprised 37 components. In Round 2, consensus was reached for 30 components (81.1%) regarding relevance, 16 components (43.2%) regarding feasibility, and 32 components (86.5%) regarding expected impact. Components demonstrating consistently high consensus across all three dimensions included facility-based refraction services, optical dispensing, school-based vision screening, outreach services, supply-chain strengthening, regulation of optical services, and monitoring of effective refractive error coverage (eREC). Components identified as highly relevant and potentially impactful, yet constrained by lower feasibility such as workforce expansion, sustainable financing mechanisms, and digital innovations, were retained as medium-term or enabling elements. Feasibility ratings increased across successive rounds, resulting in a reduced divergence between relevance and feasibility assessments. Expert consensus highlighted workforce capacity, affordability of spectacles, quality assurance, and strong governance as key priority areas. Conclusions This Delphi study developed an expert-validated, evidence-based model for the delivery of refractive error services in Bhutan. Beyond its national application, the study demonstrates the utility of a structured expert-consensus methodology as a reproducible approach for translating health-system assessments into a validated, prioritised service-delivery framework. This approach is particularly relevant for informing policy, planning, and implementation in resource-constrained settings. The resulting model provides a structured framework to support strategic planning, resource allocation, and monitoring of refractive services in Bhutan and comparable health systems.