Nobody knows how big the medical tourism industry is but it might be shrinking, says publisher Keith Pollard who runs The International Medical Travel Journal (IMTJ).

The problem with the medical tourism industry is that no one really knows what it looks like. Data is scarce and unreliable. There isn’t even a universal definition of a medical tourist – or should that be medical traveller? Does it include tourists who fall ill on holiday or folk who travel primarily for a procedure? And what about spas and wellness: if I visit a hotel with a sauna do I get counted as a healthcare tourist?

It’s not surprising then that some in the industry are known for their liberal approach to the truth. Take the example of the $439bn figure the US-based Medical Travel Association put the size of the industry at last year. This sizes the industry at about 35% of all tourism revenues!

Keith Pollard from the IMTJ, which hosted its annual – and fake-news free! –conference in Croatia last month, revealed some more realistic but disappointing growth figures.

Look at Google Trends, he says, and you’ll see searches for “medical tourism” peaked around 2008 before starting a gradual decline. Yes, patients use this search term less often than providers, but it’s still a useful measure and he says that other terms paint a similar picture.

Around the world, we think there’s plausible evidence for this stagnation or even decline. The oil crisis is now feeding through to the Gulf’s health systems, for example, meaning the major source of patients has tighter budgets and spare capacity in its own health systems. Where the outflow persists it’s harder to tap into. Qatar has cut the number of foreign hospitals it uses from 300 in 2013 to just 50 now. Currency falls in Nigeria and Russia and Obamacare in the US are also likely to have led to more patients staying at home.

Hospital groups rarely see medical tourism as anything more than a supplement to their core business. The stream of patients is too unstable. Cosmetic procedures aside, most would prefer to be treated at home and, if a nation has the cash to seek care abroad, it’s not long before someone offers it at home. Telemedicine in all its forms from digitalised tests to the second opinion industry is also likely to cut the need for travel.

Fertility is an interesting case study. Restrictions on IVF means that many would-be mothers have to seek treatment abroad creating fertility tourists. But the biggest players in this industry are now in ten or more countries – they’ve built international businesses rather than relying on medical tourism. The future of healthcare lies with multinational groups that bring affordable care to the patients rather than the other way around.

Still, professionalism was being built at the IMTJ, with people were getting to grips with the marketing, analytics and quality needed to build trusted providers. There were around 250 delegates including a lot of operators from around the world. But what’s distinctive about the medical tourism industry, Pollard says, is the churn rate. He said that people run an agency one week and a jewellery site the next. That does not give a good picture of an industry that asks patients to trust it with their health and wellbeing.