The Measuring Advanced Practitioner Presence, Patterns, and Evolving Distribution (MAPPED) study: Protocol for secondary data analysis

Background Advanced Practitioners (APs) are a growing multi-professional workforce within the National Health Service (NHS) in England, spanning nursing, pharmacy, allied health, and healthcare science disciplines. Despite their policy prominence, no national quantification of this workforce using routinely collected administrative data has been published. Existing intelligence relies on regional surveys, employer self-reports, and bespoke data requests, each limited in coverage and comparability. This protocol describes a secondary analysis of NHS Workforce Statistics to address this gap, to support national workforce planning and service redesign. Methods The Measuring Advanced Practitioner Presence, Patterns, and Evolving Distribution (MAPPED) study is a secondary analysis of NHS Workforce Statistics derived from the Electronic Staff Record (ESR), examining the AP workforce in Hospital and Community Health Services (HCHS) in England. The study combines longitudinal analysis of national trends from September 2014 to April 2026 (13 time points) with cross-sectional geographic analysis at NHS England region and Integrated Care System (ICS) levels in April 2026. APs are identified using National Workforce Dataset Job Role codes. The analytical framework comprises descriptive statistics, Mann-Kendall trend tests, Kruskal-Wallis tests, Gini coefficients, and Wilson score confidence intervals; trainee Advanced Practitioners are analysed separately. Reporting follows the REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement and the STandardisierte BerichtsROutine fur SekundardatenAnalysen 2 (STROSA-2) checklist for secondary data analyses. Results and analysis This paper presents the study protocol; no results are reported. Planned outputs include national trend figures, distribution tables by staff group and Area of Work, geographic inequality measures using Lorenz curves, and sensitivity analyses addressing classification-version effects and generic code persistence. Discussion This study will provide the first national, longitudinal quantification of the AP workforce from routinely collected administrative data. The principal limitation is that Job Role coding accuracy varies across trusts, and the transition to profession-specific codes from the year 2022 creates a measurement discontinuity that sensitivity analyses address but cannot fully eliminate.