Inauguration prof. Jochen Cals

Prof. Jochen Cals is a versatile man; general practitioner (GP) in Sittard and researcher at the Department of Family Medicine. He initiated the webpage Usable science, to put research from Maastricht on the map and offer fellow GPs accessible insight into the latest developments in the field. Besides, Jochen is columnist for the Observant and section editor of the Dutch Journal of Medicine. Last year he was appointed professor of "Effective Diagnostics in General Practice". He gave his inaugural lecture on 28 June.

As a little boy, Jochen Cals did not dream of a career as a doctor. He didn't know exactly what he wanted. It was only when he visited the Skillslab, during an open day at Maastricht University, that he thougt: "I want to study here". Studying Medicine met his expectations. “In my third year I knew that I wanted to become a GP. Why? Well, I am not a type for the hospital. I had a good time there during my studies, but I didn't want that for the rest of my life. The great thing about the GP's profession is that you see people from the cradle to the grave. You have a lot of independence in your work and in the decisions you make. The general practitioner has clinical skills, but social communication skills are just as important. You oversee all kinds of (family) relationships and that gives you the opportunity to see the patient in his context. That can be very important in making certain decisions."

General practitioner and researcher

Jochen combines his job as a GP with that of a researcher. “During my medicine studies I already worked as a PhD candidate at the Department of Family Medicine. During my PhD research, I enrolled into the GP Training Programme. The combination was already there from the very beginning. For me, this combination definitely has an added value. It gives me a lot of satisfaction. As a GP I can mean something for the individual patient during the consultation, but as a researcher I can possibly make a difference in 8,000 consultation rooms in the Netherlands. I don't dare to say if it makes me a better GP or researcher. It is of course true that being a GP provides a basis for doing research and understanding why certain things do or do not work. As a researcher you can find and discover all kinds of things, but why doctors do what they do is sometimes very subtle.”

Effective diagnostics

Jochen’s chair is called "Effective Diagnostics in General Practice.” What are Effective Diagnostics? "Ha ha", Jochen laughs. “That's the nice thing about this title, it evokes discussion. Everyone you ask, gives it a different meaning. The health economist takes out "affordable and good diagnostics", the clinical chemist "diagnostics that measure what they have to measure", the GP "diagnostics that are is really useful in my practice". To me, it means diagnostics that benefit the patient, which bring about a change in a positive sense. Such a change can be anything: better treatment, more compliance, or better medication. But also: patient acceptance and understanding. To measure whether diagnostics are effective, you must therefore look beyond the validity of the test, but also include the entire treatment strategy in the evaluation.”

A patient is not a car

“Diagnostics are booming," Jochen concludes. “That is quite understandable, because it gives a sense of manufacturability. The general opinion is that diagnostics show what someone has or does not have. If only it were that simple. The patient is not a car that you measure, lubricate and give new parts. The results of a test are not always black or white, but often gray. Moreover, all too often unexpected findings occur, which you consequently have to deal with, although you actually know it is not necessary. That is what I call cascade diagnostics; one follows from the other. During a lecture I sometimes give the example that if you make an MRI of the shoulder or knee of all the people in the room, something comes to light in 50% of the cases. Even though nobody has complaints."

The doctor is the best test himself

The best diagnostic is the doctor himself," is Jochen's firm conviction. “There are all kinds of studies that confirm that. 80% of the diagnoses come from the anamnesis, 10% from physical examination and only 10% from additional diagnostics. I think it's a big compliment to the profession; the diagnosis is made on the basis of the conversation, experiences, pattern recognition and the context. Only in 10% of the cases additional diagnostics are required, regularly only because of expectation management. Then you already know that nothing will come out, but you need the result for another purpose." He explains: “A doctor is a merchant in expectations, I sometimes jokingly say. Sometimes you have to explain to patients that recovery takes a few weeks. But if a freelance construction worker is sitting in front of me, who is disappointed that he cannot work, then a scan or MRI can help to strengthen my story. I can show that nothing serious is going on, but something that just needs time. The scan or MRI does not help against the pain, but it does help with acceptance. As a GP, you must always realize for which purpose you use diagnostics.”

Everyone satisfied with an imperfect test

Jochen mentions the example of the PSA (prostate-specific-antigen)-test. “It is generally known that this is an imperfect test that is nevertheless often done. The test provides very limited certainty about prostate cancer. Yet almost every man is satisfied after performing it. If the outcome does not show increased values, the patient is reassured. If the values are increased, annoying invasive examinations by the urologist follow. If it turns out that there is no cancer, the patient is satisfied after all. If there is prostate cancer, the patient is also satisfied because it was discovered "in time." That speaks out. However, most men do not die because of, but with prostate cancer."

“Komt een test bij de dokter”

On 28 June Jochen will give his inaugural lecture titled "Komt een test bij de dokter". What is the most important message in your speech? "There are a few. The first is that diagnostics should not be evaluated isolated, but should be evaluated in healthcare. It sounds like an open door, but strangely enough there are plenty of studies that measure the validity of diagnostic tests, but few studies that evaluate diagnostics based on outcomes that are relevant to the patient. Ultimately, that is what matters most.

A second message is that the best diagnostics still comes from the GP himself, I think it's important that we realize that. There have been nice studies showing that the clinical assessment of the doctor was just as good as the best computer model. Kudos to the medical profession!

A third message is that GPs are just like people. By that I mean that their behavior that does not always seem logical. Because why do we prescribe testing or imaging, take the PSA-test, that we know doesn't add anything? That is because it is not always simple in the doctor’s office. The patient's context means that the doctor makes certain decisions. Other choices may follow from two exactly the same anamneses. Then I come back to expectation management. Our specialty is that we have to puzzle based on a lot of information. That is what makes the profession of GP so enjoyable.”

Scientific research at the service of the doctor’s office

In his spare time Jochen is committed to sharing research results from Maastricht with the outside world. Laughing: “No, this is not in my job description, but I like doing it and I learn a lot from it. CAPHRI is a research institute, our primary mandate is outside the university and hospital. I think it is our duty to make visible what we are doing. Via the webpage Usable Science, LinkedIn and Twitter, I share relevant research results from CAPHRI, the department and MUMC + with colleagues in the country in an accessible way. I get a lot of positive responses and I see my posts being actively shared. The active sharing of research results helps with starting new collaborations and attracting new employees. But above all it brings usable science into the doctor’s office. This allows GPs to benefit from it and to better serve their patients. And we ultimately do it all for that.”

Text: Margo van Vlierden
Translation: Hanneke Trines 

Also read

  • For 40 years already, Annemie Mordant has been convinced that academic and support staff are stronger together. Until her retirement, as the head of MEMIC (the centre for research data management), she dedicated herself to optimally facilitating collaboration between academic and support staff. “We...

  • Annually, the European Respiratory Society (ERS) honors highly regarded senior scientists who have made significant contributions to the respiratory field. During the 2023 ERS International Congress in Milan (Italy), the ERS presented the ERS Lifetime Achievement Award 2023 to Martijn Spruit.

  • The bachelor’s programme in Medicine at Maastricht University is undergoing a major overhaul. Not only will its curriculum be brought into line with the latest societal and medical developments, but its teaching method will also change. The students who started the English track of the Bachelor of...