Blood pressure states transitions among bus drivers: the application of multi-state Markov model

To explore the transition patterns among different levels of blood pressure for bus drivers.

A follow-up study was conducted to investigate the transition probabilities of three blood pressure states, the sojourn time in each state, the survival probabilities, and the risk factors affecting hypertension progression. Based on 5618 blood pressure measurements of 1883 Chinese bus drivers from 2017 to 2021, a multi-state Markov model was established.

The mean age of participants was 41.43 ± 6.71 years, and 82.37% were male. The probabilities from normal state to hypertension within 1-year follow-up were 4.60% (male) and 2.13% (female); however, the corresponding changes over a 3-year follow-up had a significant increase to 20.27% (male) and 7.98% (female). The sojourn time of normal state and elevated state was 1.82 ± 0.09 years and 1.98 ± 0.08 years, respectively. The male participants, the increasing age, BMI, CHOL and TG were risk factors for progression from normal state to elevated state, and/or from elevated state to hypertensive state (HR: 1.04-2.53).

Early preventive measures on the progression of hypertension should be taken for Chinese bus drivers, and at least one physical examination per year is strongly recommended. The government and bus companies should pay more attention to these kinds of bus drivers with high probabilities of hypertension: male, older than 40 years, with the higher values of BMI and blood lipid. The derived findings of sojourn time, transition probabilities and survival probabilities can provide reference for health professionals to make targeted intervention to reduce bus drivers' hypertension occurrence.