Differential diagnosis procedures are hard and painful. As someone who has been through them I would say that the show “House, MD” is the most accurate from the patient’s point of view.

On the doctor side, the show is, as all shows concerning tv-doctors are, over the top. But that is what keeps us watching.

I have for a long time now had a love for diagnostics; the challenge the grey zones, the chase, the prize. I’ve studied the ICD10 as if it was a beautiful song. And trust me, it is far from logic in many respects, but my obsessive thoughts and acts (code F42.2) finds the non-logical logic and the universal medical language that the ICD10 is, intriguing. So when Dr House, MD comes on I watch with excitement (ignoring the obvious clinical fallacies) and I compete with Gregory for the final diagnosis. And I almost always beat him, which has made my husband stop watching the show. I’ve annoyed him with my constant spoilers. So I shared a formula on twitter, as I perceived it.

But being a scientist, and a lover of the ICD10 (however incomplete or overwhelming it may feel at times) I had to test my theory. And as my friends on twitter pointed out, some diseases I had not accounted for, and even worse, after some research I found out that nobody had done a compilation of frequency of diagnosis. So I took on the task.

Method:

I found a site disclosing all diagnosis featured in the show, episode by episode here. I printed the results and made my own evaluation of category by heart, to train my own ability. Then I went to ICD10 online and noted of the category A-Z the disease belonged to.

Then I placed all the categories in X-Cell (STATA, R, SPSS felt a bit redundant). I used the features of X-Cell to count the prevalence and make the table.

Non-specific diagnosis e.g. ectopy, without specification of organ affected were removed from analyses (n = 48)

ICD10 codes C00-D99 were merged together, however all diagnostic labels were kept in chart text.

Approximated total number of diagnosis accounted in the document (n = 284)

Result: I have to reject my hypothesis. Neurology was not favored but parasites were…

Neurological diseases were only accountable for 9% of the diagnosis

Oncology for 8,5%,

Endocrine 7,6%,

Parasitic viral 29,6%

Genetic 1,2%

The results show that the show writers are particularly interested in parasitic and viral diseases. My own by hand diagnostic accuracy was almost 90% in correspondence with the actual ICD10 (it’s besides the point, but since it is my only party trick I have to at least mention it).

Click on the picture for enlargement.

Chart 1: Prevalence (%) of diagnosis throughout the show. Diagnosis (N = 236)

Discussion

The reliability of the original data may not cover all of the diseases but does provide a solid source and at least points to a trend in the diagnostics. Though Dr House is an American, and hence the ICD9 would be used at his office, due to convenience I have chosen to classify the diagnosis according to the ICD10, which may enhance and attenuate the prevalence of certain diseases. The diagnosis removed were predominantly associated with either infectious, dermatological or respiratory codes, hence if included these might find more statistical power.

So in light of the findings, the prevalence of the diagnosis tells us that parasites and viruses are things that interest us most, or are easiest to make scripts out of.

Conclusion

Scientist with obsessive thoughts, too much time spent on watching House, MD and working with ICD10 criteria, are bound to make statistics out of any data available.

Future directions

Next step is to evaluate to what extent the prevalence of Dr House’s diagnosis correspond with real life ones.

Author: Almira Osmanovic Thunström almira@almiraosmanovicthunstrom.com

ICD10 Diagnosis (The entire F-section, minus non-organic psychosis)

Appendix: Yes I did it by hand.