Background: Cross-linkable register data enable reuse of healthcare data to assess and improve prescribing quality. A first step in the developing of quality indicators is summarising existing evidence.

Objectives: To identify prescribing quality indicators (PQIs) suitable for population-level assessment of outpatient prescribing across and within countries and regions, and applicable using the Nordic (Denmark, Iceland, Finland, Norway, Sweden) registers.

Design: Bibliographic databases were searched for original research articles published 2000-2023 in English or Nordic languages from high-income European, North American, East Asian and Pacific countries. Eligible studies included at least one explicit PQI for assessing outpatient prescribing or pharmacotherapy quality, calculable using aggregate- or individual-level structured data on sales, consumption, prescriptions or dispensings. Exploratory and snowballing strategies were used to complement searches.

Results: We identified 173 articles, of which 90% focused solely on pharmacotherapy and 10% had a broader service scope. Fifty-one percent focused on a specific disease or medication class (e.g., asthma, diabetes, opioids, antibiotics), 35% on a specific population subgroup (e.g. older adults, children), and 14% had a more general scope (e.g. general practitioner prescribing). We extracted 11 lists of potentially inappropriate medicines (PIM) for older adults validated for Nordic/European settings, and 915 PQIs. All PQIs adressed process dimension and 96% the effectiveness/safety aspects of quality; 50% required individual-level data on dispensings and diagnoses, 35% individual-level data on dispensings, and 16% were calculable using aggregate data.

Conclusion: Numerous register-applicable PQIs were identified, providing a basis for further quality framework development and validation across purposes and contexts.