A health workforce forecasting model projects how many providers of each type a health system will have, and how many it will need, over a planning horizon of typically three to ten years. It does this by modeling the workforce as a moving system: a current stock of providers, inflows that add to it (graduates, recruitment, migration, return from leave), outflows that reduce it (retirement, attrition, emigration, reduced hours), and a demand side driven by the population and the services it uses. The output is a gap, by role, place, and year, with the assumptions that produced it.
Most health systems in Canada and the United States do not have one. Health Workforce Canada's 2024 review of provincial modelling and forecasting found capacity uneven and, in many jurisdictions, immature: models built for a single policy question, maintained by one analyst, or commissioned once and never refreshed. The consequence is visible in the news cycle: ratio mandates, agency-nursing audits, and restructurings that all arrive as surprises to systems that had the data to see them coming.
A forecast is not a prediction of one number. It is a documented argument about direction, magnitude, and which decisions change the outcome.
The three model families
Supply models (stock-flow)
The workhorse. Start with the current headcount or FTE by provider type, age band, location, and employment status. Apply annual inflow and outflow rates by cohort. Project forward. Because the rates are applied by cohort, an aging workforce produces a retirement wave the model can see years out. The method is transparent, auditable, and buildable in a spreadsheet for a first version, which is why it is where most systems should start.
Demand models: utilization-based and needs-based
Utilization-based demand projects forward the services a population currently uses, adjusted for demographic change. It is simple and defensible but bakes in today's access problems. Needs-based demand estimates the services a population should receive given its health status and evidence-based levels of care, then derives the workforce required to deliver them. It is harder, requires clinical input on productivity and models of care, and is the approach recommended in the Canadian literature. The two are compared in detail in Needs-Based vs. Utilization-Based Planning.
Gap and scenario models
Supply minus demand, by year, under alternative futures. Scenarios are where the model earns its keep: what happens to the nursing gap if a ratio mandate lands in 2027, if retirement accelerates by two years, if a new tower opens, if international recruitment halves? Each scenario is a changed assumption with a traceable effect, which is what a board or a ministry needs in order to choose.
What goes into a credible model
- Provider taxonomy that matches how the organization actually manages people, not just the regulatory categories. Nurse practitioner and RN are different lines; casual and full-time are different lines.
- Cohort structure by age or tenure, because attrition and retirement are not uniform.
- Flow rates from the organization's own history, validated by clinical and HR leads. National averages are a placeholder, not a basis.
- Geographic resolution sufficient to see where the gap is, since a provincial surplus and a regional shortage can coexist.
- Explicit assumptions, each in its own cell or parameter, dated, sourced, and owned.
- A refresh cadence and a process for comparing last year's forecast with what actually happened.
How we build one
Frame the decisions
Establish the data foundation
Build the supply baseline and flows
Build demand
Run the base case and scenarios
Operationalize
Reading the output
A useful forecast answers four questions for each provider group: in which year does the gap open or close; how large is it relative to the workforce (a 4 percent gap is a recruitment problem, a 20 percent gap is a model-of-care problem); which assumptions is the result most sensitive to; and which decisions available now change the trajectory. A forecast that produces a single number without those four answers will be argued with, and should be.
Sources
- Health Workforce Canada. State of Health Workforce Modelling and Forecasting in Canada. 2024. healthworkforce.ca
- Methods for health workforce projection model: systematic review and recommended good practice reporting guideline. Human Resources for Health, 2024. biomedcentral.com
- McMaster Health Forum. Rapid Synthesis: Exploring Models for Health Workforce Planning. 2019. mcmasterforum.org
- Canadian Health Workforce Network. Health Workforce Planning. hhr-rhs.ca