My Public Health final experience

Had public health final this morning. At around 09:00 Prof. István Kiss called me on teams, after having examined a few other students. In the voice call were me, Kiss, and a co-examiner I didn’t know.

He is sitting outside on his terrace, and as the exam starts he says that it starts to rain. After moving under the roof, the co-examiner asks me to show ID.

Kiss says that he has three envelopes, and that he will draw topics from me. He showed me as he reached into the envelope and drew a topic. My first topic was

21. Ecological studies. Immigrant studies

He wants me to start to talk about the topic. I begin by explaining that ecological studies are studies where we look at ecological factors like geographic and demographic factors and try to relate them to risk factors and disease. I give him the example of John Snow and the water pump contaminated with cholera, and how he used the geographical information of the cholera-infected people to determine that the water pump was the source.

Prof. Kiss responded by saying that my description of ecological studies was not correct, and that John Snow’s study is not an example of an ecological study. I immediately panic a little inside. It was the first question of my exam and I had already answered wrong. Searching my thought for alternative explanations of ecological studies yields no results.

I stay quiet for a while, trying to think of something. After a few minutes of silence I seem to recall that ecological studies are on the populational level while other studies are on the individual level. He tells me that it’s correct, and wants me to once again try to explain, from the beginning, what ecological studies are. I try, but can’t really find an explanation he is satisfied with.

Eventually he asks me about the strength and weaknesses of ecological studies. I say that conclusions drawn on the populational level can’t always be applied on the individual level, which is the ecological fallacy. He asks me for an example of this fallacy. I don’t know any, and can’t think of any.

He tells me that he will give me a research question which can be solved by an ecological study or by an individual-level study, and asks how I would conduct the studies. The question is “how would you determine whether fluoride intake protects against dental caries?”

I tell him that it could be determined with a field trial, where you have two groups and give one group extra fluoride intake and measure the differences in caries incidence between the group. With an ecological trial, it could be determined by looking at the difference in incidence of dental caries in two populations, where one has higher fluoride intake than the other. He asks how I would measure the difference in fluoride intake between the populations. I say that a major source of fluoride is in drinking water, so we could measure the differences in fluoride in the drinking water of the two populations.

We finally move on to immigrant studies. I explain how they allow to compare how genetic and environmental factors influence the incidence of a disease by comparing immigrants and their descendants to the general population.

He asks the co-examiner whether he has any questions, which he doesn’t. Prof. Kiss reaches into envelope number 2, and picks out my second topic:

57. Epidemiology and prevention of airborne bacterial infections

I begin by listing airborne bacterial infective agents, diphtheria, haemofilus influenzae, pertussis, meningococcus, tuberculosis, pneumococcus, legionella, etc. He asks me about prevention of these agents. I say that many of them have vaccines, but general hygiene is important, like hand washing, staying away from symptomatic people, staying at home if you have symptoms, etc.

He says that he will asks more specifically about some of them. First he asks about TB and it’s prevention. I say that it’s a prevalent disease in developing countries, and the BCG vaccine is the most important preventative measure. He asks me what type of vaccine it is, and I say live attenuated.

He asks me about pertussis, and what the causative agent is and the symptoms. I say bordetella pertussis, and that it causes whooping cough. I asks about prevention, and I say the acellular pertussis vaccine. He asks me why it’s lethal, and this is where I get stuck. I try to guess some causes, and I did say respiratory failure and breathing problems, but I never said apnea, which I think is what he wanted to know?

We move on to diphtheria. He asks me about the causative agent and the symptoms. I say corynebacterium diphtheriae, and that it causes pseudomembranes in the pharynx, with fever and pain. He asks about why it’s lethal. Once again I’m stuck, and after some poor guessing he tells me that he has to stop the exam here. He tells me about the diphtheria toxin, and how it causes kidney problems, myocarditis, etc. I knew of the toxin of course, but I couldn’t recall it. The vaccine is even against the toxin, which should’ve reminded me of its existence. Oh well.

So I failed ph final. Didn’t even get to draw the third topic. Shit happens.

I’ll update my notes to correct the part about ecological studies and add more about the symptoms of the infectious diseases. I’ll also look at other students’ exam experiences and try to make sure all questions are answered in the notes. I’ll do that on Monday probably, as I have surgery tomorrow and trauma on Monday, and I’ll probably retake ph on Wednesday.

Is Greek Doctor on an oral exam failing spree? Stay tuned to find out!