Abstract

Online doctoral programs have expanded across disciplines and institutional settings, yet the literature on completion, attrition, persistence, and extended time-to-degree remains fragmented. This scoping review mapped peer-reviewed, open-access empirical studies on factors associated with these outcomes in online doctoral programs. The review followed PRISMA-ScR reporting principles and JBI methodological guidance. The search targeted open-access articles that are also discoverable through major scholarly indexing systems, even when accessed directly via open interfaces or publisher sites. Across ERIC, DOAJ, targeted journal sites, DOI-based discovery, and backward and forward citation chasing, 66 records were identified. After removal of 15 duplicates, 51 titles and abstracts were screened, 36 full texts were assessed for eligibility, and 22 studies were included. The studies were published between 2007 and 2025 and were concentrated in U.S.-based contexts in education, leadership, and psychology, with smaller contributions from Canada, Spain, and Australia. Seven studies examined direct outcomes or explicit persistence-group membership, whereas 15 examined persistence-related proxy constructs. Across the sample, the most frequently studied domains were supervision, advising, mentoring, dissertation-stage structure, peer and cohort interaction, and program integration. The clearest direct evidence concerned dissertation-stage architecture and time to completion. Overall, the field is conceptually rich but methodologically uneven. This review offers a transparent evidence map of an open-access study sample and clarifies where direct evidence on completion and attrition remains limited.

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