A credible clinical-learning market model counts distinct purchasing opportunities before adding revenue. Examination preparation, simulation, reference and CPD may be separate use cases for the same person, not four independent customers. Define the buyer, product and period first, then show how overlapping needs translate into spending that could actually occur.
A large audience is not a market estimate
A slide listing every doctor, student, pharmacist and advanced practitioner may describe people who could find a product relevant. It does not establish how many can be reached, who pays or what proportion needs the particular offering during the period modelled.
Start with a bounded definition. For example: "Annual spending on individually purchased digital preparation for a specified set of professional examinations in a defined geography." A separate model might concern institutional simulation licences or clinical-reference subscriptions. They can later be connected, but they should not begin as interchangeable rows.
This article provides an original analytical framework and hypothetical arithmetic, not an independently measured market size or an investment recommendation.
Build the person-year before the product stack
All figures in the following example are invented for modelling on 19 September 2026. They are not estimates of the medical workforce, examination candidature or iatroX's addressable population.
Suppose a defined population contains 10,000 unique people during a year. Of these, 4,000 have an examination-preparation need, 3,000 have a simulation-related need and 6,000 have a continuing-learning need. Adding the category counts produces 13,000 need instances, not 13,000 people.
The overlap is not necessarily a problem. One person may buy more than one product. The error is failing to state whether the model counts people, use cases, subscriptions or spending events.
Create a person-year or segment-year view first. Then describe which purchases could occur together, which replace one another and which are already funded by an institution.
A worked revenue model
Continue the hypothetical example with deliberately simple, non-overlapping purchase segments. Assume 2,000 people buy an examination-only product at £100 for the year, 1,000 buy a combined product at £150, and 1,500 buy a continuing-learning-only product at £60. The remaining people make no individual purchase in this scenario.
The modelled annual spending is £200,000 plus £150,000 plus £90,000, totalling £440,000. There are 4,500 distinct purchasers under these assumptions.
Those amounts are hypothetical prices, not advertised offers. The combined-product buyers must not also be counted as buying each included component unless there is evidence that they actually make those additional purchases.
Now consider an alternative assumption: some combined-product purchasers also buy a specialist course. That can be added as separate spending, but it belongs in a clearly labelled complementary category. It should not silently increase revenue attributed to the combined subscription.
Treat institutional access as a different purchasing route
An institution buying access for 1,000 learners does not necessarily create 1,000 new individual subscriptions. Some users may stop buying personally, some may never have purchased, and some may continue paying for a different specialist resource.
Model the contract as a contract, with its price basis, access population, implementation costs and renewal assumptions. Separately model any incremental individual spending. This prevents an institutional seat and a personal account belonging to the same person being counted as two independent customers without justification.
The economic unit may also change. An individual buys convenience or a specific preparation goal. An institution may buy a teaching capability, a library service or access across a programme. The same product description does not imply the same willingness to pay.
Separate total, serviceable and obtainable markets
The total addressable market describes the defined opportunity under broad assumptions. The serviceable market reflects the parts the product can actually support, including geography, professional scope, content and delivery requirements. The obtainable market adds a credible route to reaching and converting buyers.
Do not use a fixed percentage of a large total as a substitute for that route. Explain the acquisition channel, sales cycle, access constraints and existing alternatives. A product available online worldwide is not automatically serviceable for every country's clinical or educational requirements.
Use conservative and expansive scenarios by changing explicit assumptions. A conservative case might restrict the model to verified examination pathways and current languages. An expansive case might include future content or institutional sales, clearly identified as contingent rather than already available.
Make the model falsifiable
For each assumption, record what evidence would change it. Candidate counts might come from examination bodies; workforce figures from professional registers or official statistics; spending assumptions from observed purchases, contracts or structured customer research.
Keep the time period consistent. Annual examination entrants, cumulative registered professionals and monthly active subscribers cannot be added without conversion into a coherent model. Do not treat a historical user milestone as current paying demand.
Sensitivity analysis should identify the assumptions that dominate the result. If changing uptake modestly overwhelms every other input, more precise formatting of the workforce count will not make the forecast robust. Focus the next research effort on the uncertain variable that matters most.
What the iatroX bundle illustrates
This analysis is published by iatroX and uses its own product as an example, not as evidence that the hypothetical market has been measured. The published UK subscription on 19 September 2026 is £99 paid annually, equivalent to £8.25 per month, or £29 monthly. The learning offer combines question banks, Tutor, planning, simulations and CPD rather than pricing each as an obligatory separate purchase. Source: iatroX pricing and product information.
That structure illustrates why adding several category markets can exaggerate spending available to one platform. A candidate's willingness to pay may concern one examination goal supported by several methods. Access to unrelated examinations does not multiply that individual's budget.
The model should therefore show the value of the relevant learning journey and the evidence for purchasing it. Broad product coverage expands possible audiences; it does not remove overlap between them.
Frequently asked questions
Can I add the question-bank, simulation and CPD markets together?
Only after addressing overlapping buyers and spending. Separate category totals may include the same person and subscription more than once.
Does institutional access create an additional market on top of individual sales?
It may create incremental spending, replace individual purchases or do both. Model the purchasing routes and overlap rather than assuming all contract revenue is additional.
Are the numbers in this article a forecast for iatroX?
No: they are explicitly hypothetical inputs used to demonstrate a modelling method. An actual forecast requires defined, dated source data and commercial evidence.
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