Does the order you get sick matter more than how many diseases you have?

Doctors typically assess patient risk using comorbidity indices that tally diseases but ignore sequence and timing. By training a neural network on 13 years of Austrian hospital admission histories, researchers found that disease sequence improves predictions for 93 of 131 future conditions—especially mental and metabolic disorders. Among patients with identical age, sex, and standard risk scores, those flagged as high-risk by disease timing alone had 4–6 months fewer healthy years over five years of follow-up.