GeraClinic / NHS Agency Reliance Index / Methodology
How the Gera NHS Agency Reliance Index is calculated
The Gera NHS Agency Reliance Index is a reproducible base-100 index derived entirely from the real DHSC / NHS England agency-staff spend figures. This page sets out the exact formula, every spend input and where it comes from, a worked example, the provenance and the limitations — so anyone can reproduce or challenge the number.
What the index measures
The index answers one question: how heavily does the NHS in England rely on premium agency staffing, and is that reliance rising or falling? It expresses national NHS agency-staff spend as a base-100 index, where 100 is the 2023/24 level, above 100 means more agency reliance than 2023/24 and below 100 means less. Agency spend is money the NHS pays, at a premium, to fill shifts it cannot cover with its own permanent staff, so the index doubles as a read on the workforce gap.
The formula
Base-100 index
NARI(year) = spend(year) / spend(2023/24) × 100 (rounded to 1 dp)
This is a standard base-100 level index, exactly like a price index. The base year is 2023/24 (= 100). The only Gera choices are the base year and the rounding; every spend figure is a real published DHSC / NHS England number.
The spend inputs — and exactly where each comes from
| Financial year | Agency spend | Source | Index (2023/24 = 100) |
|---|---|---|---|
| 2023/24 | £3.0bn | Published (DHSC) | 100.0 |
| 2024/25 | £2.0bn | Derived (disclosed subtraction) | 66.7 |
The one disclosed derivation. DHSC published the 2023/24 total (around £3.0bn) and the size of the cut over 2024/25 (nearly £1 billion) rather than a headline 2024/25 total. The 2024/25 figure here is simply £3.0bn − ~£1bn ≈ £2.0bn. This is arithmetic on two published figures, not an estimate or a model, and it is the only derived number in the series.
Worked example — 2024/25
- Base (2023/24) agency spend: £3.0bn → index 100.0
- 2024/25 spend = £3.0bn − nearly £1bn ≈ £2.0bn
- NARI = 2.0 / 3.0 × 100 = 66.7
- That is a fall of 1.0bn (about 33%) from the base year.
Data provenance
The spend figures, vacancy count, per-shift premium and staff-bank figures come from the DHSC / NHS England announcement “Nearly £1 billion for NHS frontline after agency spend crackdown” (2 June 2025). The agency-reduction target and the agency-to-bank policy come from the NHS England letter “Further action to reduce NHS spending on temporary agency staffing” (2 June 2025). Both are public sector information under the Open Government Licence v3.0. No value is estimated or imputed beyond the single disclosed subtraction above.
Contains public sector information published by Department of Health & Social Care and licensed under the Open Government Licence v3.0. Source: DHSC / NHS England — "Nearly £1 billion for NHS frontline after agency spend crackdown" (2023/24 to 2024/25, published 2 June 2025).
Contains public sector information published by NHS England and licensed under the Open Government Licence v3.0. Source: NHS England — "Further action to reduce NHS spending on temporary agency staffing" (letter) (2025/26 planning, published 2 June 2025).
Contains public sector information published by Gera Systems and licensed under the Open Government Licence v3.0 (source data). Source: Gera NHS Agency Reliance Index — derived from DHSC / NHS England agency-spend figures (2023/24 to 2024/25, published 3 July 2026).
Per-trust and per-region layer (in progress)
A trust-level and NHS-region agency-spend breakdown is designed to load from NHS England’s published provider finance returns. Until each trust-level number can be traced to that real published file, no per-trust figure is shown: the national picture is the verified figure today.
What the index does NOT show
- It covers England only and measures agency spend — it does not add in the separate NHS bank pay bill, so it is not a total-temporary-staffing figure.
- It is a national figure, not a per-trust or per-region breakdown.
- A falling agency index reflects a genuinely healthier workforce only if shifts are covered by substantive and bank staff rather than left unfilled — the index tracks agency reliance, not whether the NHS has enough staff overall.
- It is a finance/workforce measure, not a clinical-quality or safety measure, and not medical advice. GeraClinic is a private service and is not affiliated with the NHS.
Update cadence
The index currently covers the two financial years for which DHSC published comparable national agency-spend totals. Gera extends the series when NHS England or DHSC publishes each subsequent year’s agency-spend total. The figures here were last compiled on 3 July 2026.